Info about Brian's fantastic original:
Zeke Clark, Edward Van Halen's longtime renowned guitar tech played through a pinnacle and this is what he had to say:
“I've played tons of pedals that promised that “Brown Sound”... this pedal NAILS it better than anything I've ever heard or played.” - Zeke Clark, former tech for Eddie Van Halen
Sometimes you need extreme gain, sometimes you need mild overdrive...this pedal does that with an awesome “Brown Sound”! It has an extremely tweakable EQ - from scooped mids to tons of warm mids, all with the turn of 2 knobs.
This pedal has 4 knobs -- two separate tone controls that act as a sort of parametric EQ, gain and volume. It also has a 'bright' switch that adds a ton of variety and is very handy when playing a dark sounding amp, as well as another toggle switch that will give you high gain “Brown Sound” tones.
“I've played tons of pedals that promised that “Brown Sound”... this pedal NAILS it better than anything I've ever heard or played.” - Zeke Clark, former tech for Eddie Van Halen
Sometimes you need extreme gain, sometimes you need mild overdrive...this pedal does that with an awesome “Brown Sound”! It has an extremely tweakable EQ - from scooped mids to tons of warm mids, all with the turn of 2 knobs.
This pedal has 4 knobs -- two separate tone controls that act as a sort of parametric EQ, gain and volume. It also has a 'bright' switch that adds a ton of variety and is very handy when playing a dark sounding amp, as well as another toggle switch that will give you high gain “Brown Sound” tones.
Untrimmable J201s... Have fun guys, i'm not going to touch this :)
ReplyDeleteTo tell the truth, i nowadays hate PT2399s more than JFETs, since with JFETs there's some remote possibility to get them working/biased like they should... :D
+m
Aaah but these are Mu-amps! Did you ever make a Formula No.5 or DLS?
ReplyDeleteI didn't... J201s were the reason i skipped them. But i am a bit low on overdrives (only like 12 different, good ones)...
DeleteMu-amps you say? http://www.geofex.com/article_folders/foolwfets/foolwfets.htm
Haven't heard about that earlier.
And you say that they get biased just like that? Without swapping my whole batch back and forth or measuring for matched set to get working sextet?
:)
+m
I still think Brian must select them if you look at the readings from the FETs on FSB.
DeleteWhat are you guys on about? I love J201's and pretty much anything I make with them sounds amazing. Do they usually vary a lot?
ReplyDeleteI'll have to agree, I've never noticed any issues with J201's...Biasing was a pain for the Dr Boogie but got there in the end. I might have a crack at this at some point as I've just received an order of 500 of the buggers...:)
DeleteI think JFET dirt pedals are some of the best sounding out there and definitely worth the trouble. They are a pain to bias properly sometimes though. And lol @500 Vince! I know where to come when I run out! :o)
DeleteHaha, It was some auction on eBay I had no thought about winning..seems I did.. I've yet to try them so half may be duff.
DeleteWell here ya go, give them a test! :o)
DeleteHow much did you pay for 500 J201's?
DeleteI would Mark but I don't have any C50k's, I'll have to wait til I build up an order with Tayda and throw a few in.
DeleteGeiri, I think it was about £10.. They usually sell 200 for £20 but this was a one off auction :)
http://www.ebay.co.uk/itm/Free-Shipping-New-200-pcs-x-J201-JFET-N-Channel-Amplifier-Transistor-/160784898122?pt=LH_DefaultDomain_0&hash=item256f86d84a#ht_2244wt_1037
I bought a bunch from ebay and got some more from tayda. These are relatively expensive JFETs (at lower quantities at least) and if they don't get biased just right, they either A) sound like crap or B) don't work at all. None of my J201 builds (ones without trimmers) have ever worked by just grabbing some from the bag. First horrible encouter was with Plexi-Drive. I just couldn't get it to work. After measuring and swapping J201s for some six hours, it lighted up. I admit that they sound really good - if they work. But with your comments, it seems that someone sold me 50 J201s that he or she carefully measured to be literally batch of shit. From the experience, i can't even remember when a board didn't work right off. Except all the JFET builds...
DeleteSo that's what i'm talking about. Even if something is meant to sound real good, i don't want to frustrate myself for hours with trial and error - mostly error - on swapping them back and forth.
If you have a circuit that is fool proof and you can guarantee that it works with any J201 from the bag, i'll build it..
+m
yeah, but if it was easy any fool could do it ;o)
DeleteWell, the BSIAB looks pretty similar, and sounded great on the first run with it's non trimmed J201s
DeleteMust depend on the circuit...i'm no specialist though
BSIAB was mu-amps as well so yes I think that's what a lot of these pedals are based on.
DeleteAny fool, including me, could still do it right now. Patience and measuring. Anything can be done. I just don't like to intentionally frustrate myself :) And there are other projects always going on, so i don't think i'm missing out on anything by being so comfort-loving.. :D
Delete+m
I was so excited to see this layout, but now I'm very confused. I'd love to build this eventually, but I don't know the first thing about biasing the J201s. I've been doing research, so I know what biasing is, but I have yet to find a good explanation as to how to do it and when you need to do it. Do all transistors and their like need to be biased? Any help would be appreciated. Thanks. And thanks, Mark, for the layout!
ReplyDeleteThe JFETs are biased by the gate, drain and source resistors and so unless there is a trimmer the bias is fixed. The problem is that some JFETs are more difficult to bias correctly because of variations in its own specification, and so sometimes the fixed resistors need swapping to get things working correctly (usually with a trimmer to make it easier - you'll have heard people mention that you need to adjust the trimmer until you get between 5V and 5.5V on the drain). But this uses JFET combinations known as a mu-amp and it should bias more easily and so hopefully everything will be ok with the default values.
DeleteSo, ideally, I won't have to worry about messing with the JFETs. They should work as-is?
DeleteOkay. Here are a few more questions:
1) Is using a trimmer the only way to change the bias?
2) How do you know that you have to bias a transistor?
3) If I'm understanding all of this properly, there is anything inherently scary about this build--it's just a matter of putting it all together properly?
Again, thanks for your time. I'm still learning the ropes.
Like Mark said, biasing happens through the resistors, so changing resistor values would be the same as having a trimmer there. As mu-amps and all trimmerless JFET designs go, they all *should* work with any JFET right away.
DeleteAll transistors need to be biased to work properly. That means the current and voltage has to be right at the right pins. Nothing more to it. Some transistors like NPN bipolar juntion transistors work with pretty wide range on current/voltage, but for example, JFETs are much more picky about their currents and voltages.
Don't be scared 'bout me being a downer. It's really just possible that all of my 60 J201s are/were more or less bad.. :) And you would probably get yours to work on the first try. That is definitely a possibility.
+m
Okay, it's starting to come together.
DeleteWhere/How do you read a JFET to see if it needs "help" with the biasing (i.e. trimmer, change in resistor, etc)?
How do you know if a JFET/Transistor is trimmerless or a mu-amp?
So, there really isn't anything to stress out about over this build?
Have a read of the page Miro linked before:
Deletehttp://www.geofex.com/article_folders/foolwfets/foolwfets.htm
That describes a usual JFET gain stage and a mu-amp stage if you want a bit of light reading material.
JFETs can be matched using this method:
http://www.geofex.com/article_folders/fetmatch/fetmatch.htm
Which allows you to select examples which have close measuring attributes. But looking at the figures Equinox came up with for the JFETs used in the original pedal, it doesn't look like they have been specifically matched to me. The Gate Source voltage (Vgs) is similar (but that figure should be close anyway), but looking at the Zero Gate Voltage Drain Current (Idss) they are all over the place, not closely matched and not in any sort of order which would suggested they'd been hand selected. Here are the figures:
______Vgs____ Idss____Vp
Q1 - -2.03V, .65mA, .798V
Q2 - -2.04V, .59mA, .768V
Q3 - -2.20V, .59mA, .784V
Q4 - -2.20V, .64mA, .793V
Q5 - -2.20V, .46mA, .679V
Q6 - -2.20V, .45mA, .681V
So if they have just been picked out of a bag and soldered in it suggests that this circuit is quite tolerant of variation in spec.
These are the measured voltages of the original pedal which should give you a good point of reference if you think something is amiss:
Drain / Gate
Q1 4.72 / 0
Q2 8.98 / 2.99
Q3 4.78 / 0
Q4 8.98 / 2.99
Q5 3.59 / -1.68
Q6 3.86 / 0
@9VDC input regulated all switches up and all pots full "10"
Drain / Gate
Q1 5.01 / 0
Q2 8.98 / 2.99
Q3 5.05 / 0
Q4 8.98 / 2.99
Q5 4.18 / 0
Q6 4.19 / 0
@9VDC input regulated all switches down and all pots off "0"
First, I want to thank both of you for answering my questions and being patient with me. I appreciate it. Second, I think I can more or less take it from here so long as nothing goes terribly wrong.
DeleteThanks to both of you.
Most of these values sort of match what I am getting . . but I am only getting 0.7-0.9 volts on Drain on Q5 & Q6 . . I haven't boxed it or wired up the switches yet but that shouldn't matter right ? . . any ideas ?
DeleteHi Gauti,
DeleteI am also seeing only 0.8 - 0.9 Volts on Drain of Q5 & Q6. But I got it wired up and it doesn't sound right at all. It is not nearly as loud as it should be and unpleasantly distorted.
So after wiring it up, did yours sound right?
To answer my own question:
DeleteI lowered R15 and R25 to 10k as I had some laying around. Voltage increased and now it's usable at least. The Voltage is now higher than the original tho. Going to get 20k trim pots next time I order parts and put them there.
I also got Low Voltage at Drain on Q5 and Q6 and the Pedal was terrible, Farty in and out also in amplification. Voltages at Drain were on Q1 5.7v , Q2 9.3v, Q3 5.5v, Q4 9.3v , Q5 0.8v (Problem) Q6 0.7v (Problem). On others advice I too change the 22K Resistors to Drain Q5 & Q6 to 10K and got the Following:Voltages at Drain were Q1 5.7v , Q2 9.3v, Q3 5.5v, Q4 9.3v , Q5 4.55v , Q6 3.56v. The Pedal now sounds Fantastic and most definitely a worthwhile Build. Thanks everyone for Comments as these comments help New Builders.
DeleteThanks for the kudos and everyone's help!
ReplyDeleteI personally have not had any issue with any JFET builds, though most did include trimmers to establish bias. I think Brian might have gone away from the MFP... transistors and just went with the J201's because they are very close. I purchased like 100-200 of them a while back. They are Fairchild and from Mouser or some other major distributor. All seem to be the same. Between that and the circuit, I don't think anyone will have any problems, but we'll find out.
The voltages were taken before anything was taken apart, but Vgs/Idss/Vp were after desoldering and testing circuits, so who knows if that was before depopulating....but I personally am very good at it!
There are two test points on the original PCB to test drain at Q5 and Q6 for 4.5V. Being that the above settings are shy of that in the 3.86 to 4.19 range and before depopulating, that would indicate even thou the sound is great...it could be better!
I'm personally going to build this, but it won't be complete as I do not have the 50k-C pot, etc. I'm going to run this in a larger box (1590) and dual footswitches, one for the extra gain. I'll probably put in some sockets so that I can tune eat JFET (R15 and R25 - 22k resistors).
Can't wait to build this, tweak, and get this "verified"!
Enjoy!
Equinox
I like the idea of the extra footswitch for the boost. Would you just use a standard DPDT footswitch and wire it as the toggle would have been wired?
DeleteYes
DeleteCool. Thanks
ReplyDeletehello. ive built 2 pedals in the last year from madbeanpedals.com...and i have to say..i think ive found a new favorite web site. holeee crap. this place is awesome. i think i love you. cant wait to build many of these.
ReplyDeletewoot.
the new guy
man that's the first demo i've heard of this circuit, I hated brian's diyguitarist site, but man that's a great sounding bsiab!
ReplyDeletei built one of these today and got all of my J201's to hit all of the drain voltage numbers by juggling a few around. all of the controls are functioning properly, but i can't believe that a genuine pinnacle would be this bright and upper mid heavy. for me, this pedal is just way too bright (i thought the 'brown sound' was supposed to be slightly dark?!) and if you use the contour and tone knobs to darken it it can get dull and lifeless.. there is some (attenutated) bass but nothing like the ecstasy which i find to be an awesome pedal. after building the ecstasy, and loving it, was the reason i decided to build another one of Brain's pedals. i think i'm going to try and see if i can raise the value of the input cap to allow more low end to pass thru the cicuit in the first place.
ReplyDeletewell, i feel like a complete buffoon! while looking at the tone stack, i realized that i forgot to add the 10n cap that goes to ground (the top right one on the vero). i installed a socket for both of the 10n's in the tone stack circuit so i could play around with slightly different values and went with a 22n for the one that goes to ground to slightly scoop the mid bass for use with a bass. the pedal sounds absolutely awesome now, with the stock caps, or the scooped one. props to Mark for posting the vero for it!
Deletehere's two pics of the build (i still need to label it):
http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/Pinnacle-Clone/Pinnacleclone-01.jpg
http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/Pinnacle-Clone/Pinnacleclone-02.jpg
That is great news, John. I was halfway through this build and was looking forward to the end result until your previous comment about it being too bright. Now I'm stoked to get it finished! Those Marshall style knobs look top notch with that enclosure finish!
ReplyDeleteEctasy is next on the list....
...built a second one and it sounds killer! I used all 6 matched JFETs...why not. It's for ME!
ReplyDeleteWell...it's almost a success. It works, but the distortion doesn't sound good above a certain level. I checked my drain voltages, All normal except q2 and q4. Tried 20 different transistors in both sockets - all measure 9.2 V from drain to ground no matter which one I put in. Looks like all the components are there and in the correct places.
ReplyDeleteGoing to tear it down and start looking for solder bridges. Does anything jump out at you as obvious from that info?
Thanks
Q2 and Q4 should be 9V(ish). Their drains are sat on the 9V rail so that isn't going to change. As a mu-amp circuit Q1 and Q2 work in conjunction, as do Q3 and Q4 and it's only Q1 and Q3 which need biasing because they're the JFETs providing the gain.
DeleteOk. I'm not as bad off as I thought then. The main thing I am noticing is a kind of squeal when I have the boost on and the gain maxed ( I had thought maybe that was from the voltage being too high on q2 and q4 ). I think that the optimal voltage on q1 and q3 is supposed to be in that 4.5 - 5 spot and I think they were both to the lower side of that. I'll get those in the correct place.
ReplyDeleteKnowing that the q2 and q4 voltage are correct then, I also may just have a wire or two too close to one another. There was a lot going on in this build and it wasn't as neat as I usually like it. Still much better than my builds from a year ago. I look at a couple of those now and its almost embarrassing...
Thanks for the wisdom and expertise, Mark
Have you boxed it yet? With higher gain circuits I often get squeaks and squeals when I'm testing before boxing, particularly using a breadboard for connections for pots etc.
DeleteIt's boxed. I'll send you a pic to your email to see if you see anything that shouldn't be close to something else. I really pay attention to input and output wires but may have missed something else. thx
ReplyDeleteTo be clear though, after thinking about the boxing question again, I did test it without the bottom attached ( as I usually do ). Don't know if that would have an effect not being screwed on and sitting on top of my amp head.....I'll screw that on and test again in the morning after getting the transistors re-seated.
ReplyDeleteI think the culprit may be the vint/mod wires. I have them arcing over the component board to the other side where the vint/mod switch is located. When I move them ( mainly vint/mod2 )around a little the squealing/whistling noise changes/subsides a bit. When I have time this afternoon I am going to try to lengthen these wires so that I can route them around the edge of the enclosure instead of over the board. Will let you know how that turns out.
ReplyDeleteI've routed these two wires all over the enclosure. I can get the squeal to stop but in weird positions that I can't really leave the wires in. I think I must have done something wrong in the build. If these wires are this sensitive to position, I think someone else would have had a similar issue. Going to walk away from it for a day or two - work on another. Probably time for the rebuild of this one...
ReplyDeleteHelp! Having probs with the circuit. Its working upto the output of q3 and q4. But I have no signal coming through and the gate voltages on q5 and q6 are both 0.6 volts. Any Ideas?
ReplyDeleteCheers in advance
Have you run through the Troubleshooting post Andy? If so post a high res front and back pic for us to look at.
DeleteHello, I built the pedal but I have a very strange behavior, when I put the Gain to zero there is no signal at all, also the pedal is very noisy, that's normal because of the J201? I have readings very close to the Mark's Post on July 2012 00:28 Thx.
ReplyDeleteYes when the gain is right down the signal is dumped to ground so that is right. Have you tried other J201's to see if they are just as noisy?
DeleteSomeone knows why the pedal squeals in boost mode? Is there a way to fix that problem?, do I have to trim the J201?
ReplyDeleteThanks.
Whenever I've had squealing other than a silicon Fuzz Face which is prone to this oscillation, it's almost always been a poor solder joint or bad ground somewhere. Check all your ground points for continuity and reflow any dodgy looking solder.
DeleteWe know that this should be a quiet(ish) circuit so you shouldn't be getting any excessive noise which suggests a physical fault of some sort.
I mad a RAT recently that squealed then noticed I didn't solder one of the IC pins... Also my fender guitar cable squeals on some fuzzes at max gain while my cheap crappy cable doesn't? tut tut...
Delete*made.. dammit!
Deletecan i use 2n5457 instead of j201? because I only have a 2n5457
ReplyDeletethanks
Just finished this one. I had some issues with getting the correct voltage values on Q5 & Q6. I found a schematic with 15k resistor to Drain (instead of 22k). I ended up with two 22k in parallel (=11k) to Drain on both and that did the trick :)
ReplyDeleteBuilt this one last night, followed the layout exactly. Sounds excellent in my initial testing of the board, will measure the FET's with my meter later tonight to see how close they are to the original. But so far it's sounding great without any changes. I picked 6 J201's that had the same batch number, that seems to be working great for me so far (did the same with the OKKO Diablo). Thanks for the great layout...
ReplyDeleteMichael, what where the voltage values you got on the FET's, close to original?
DeleteI have them written down, it was pretty close to the values of the original posted above. I'll post mine tonight when I get home.
DeleteI did swap a few J201's around to get values closer to what was reported, and it did tighten up the sound a bit.
Here is what I get...
DeletePower supply = 9.1v
When all knobs cranked 100%:
Q1 - D = 4.89v - G = 0v
Q2 - D = 9.10v - G = 4.31v
Q3 - D = 4.68v - G = 0v
Q4 - D = 9.10v - G = 4.25v
Q5 - D = 3.43v - G = -2.57v
Q6 - D = 3.67v - G = 0v
All knobs at zero:
Q1 - D = 5.19v - G = 0v
Q2 - D = 9.10v - G = 4.32v
Q3 - D = 5.06v - G = 0v
Q4 - D = 9.10v - G = 4.26v
Q5 - D = 4.22v - G = 0v
Q6 - D = 3.97v - G = 0v
The only issue I have with the pedal now that it is on my board is that it whines a bit when using it with other pedals, by itself it was pretty silent. Need to check for a bad ground somewhere... there are 20 pedals on my board (17 DIY). Still the Pinnacle sounds amazing...
I just built this, but when I tried it out the 10R resistor on the far left side of the layout burned up. Any suggestions?
ReplyDeleteWeird. That's a current limiting resistor for the supply and is definitely the value in the original. Try making it 47R or even 100R. If you still get problems you could omit it entirely and just connect the supply 3 rows higher. But if it burnt out it means too much current was going through it which may point to a fault and so that needs checking first. Maybe connect 9V 3 rows up and see if the main circuit is working first and take it from there
DeleteI tried a 100R resistor and still got nothing. I then removed it and moved the supply 3 rows higher like you said and got the same result. When I turn the volume knob there's no sound. When I turn the gain knob I hear the "wooshing" sound of the sweeper arm in the pot.
DeleteIt's kinda funny because when I built torchy's KOT project I had the exact same problem. I never figured out what it was because I just rebuilt the whole thing and It's worked perfectly ever since.
I just tried plugging it in to test voltages based on the lists above but the 10R resistor got extremely hot the second I plugged it in... :(
DeleteUpdate: I just realized I had the volume and gain pots confused. I rewired them but it doesn't seem to have made a difference. The 10R resistor still starts to burn up as soon as I plug it in and I'm also getting no sound whatsoever.
Deletebut it doesn't get hot when I disconnect the *now correct* gain pot...
DeleteHi guys, I made this pedal yesterday but it does not work fine. I made the same exactly schematic, same values, same pieces. I checked the circuit many times and I didn't find anything wrong. All it does is a smooth distortion, gain pot work as a volume pot, boost switch decrease gain when 1k resistors are connectet to ground. Others pots and vint/mod switch does nothing. Can anyone help me please? I promised this pedal to a friend...
ReplyDeleteThanks!
i just changed the drain resistor to 15k but nothing new... still not working
Deleteeven changing the two 10n caps into 47n doesn't fix the problem... it seems like the second half of the circuit, from gain to out, doesn't exist
DeleteMy problem seems to be around Q3. Could we see the schematic?
Deletehttp://freestompboxes.org/viewtopic.php?f=7&t=14966&hilit=pinnacle&start=40#p198689
DeleteThank you! :)
DeleteIs the 10R resistor related to the boost? Why is the 1N4001 diode not in the layout? Just to be sure, is the "bright 1&2" the vintage/modern switch?
DeleteIt's weird how some people have the same problems and some others work fine with the same layout...
DeleteMy problem seems to be the biasing of Q5 and Q6, because the second part of the schematic is dead, but I'm not an expert and i don't have a multimeter to test the voltage. I can just try others resistors decreasing the value step by step, does anyone know if this may demage the transistors or everyrthing elese? Any other ideas?
The 10R resistor is a current limiting resistor for the supply and the 1N4001 isn't in the layout because I almost always omit parallel reverse polarity protection diodes which don't make sense to me unless they're used with a fuse. Under reverse polarity the diode will basically blow up which can take a chunk out of the board and make it unusable. With a fuse in series that would blow instead of the diode, but without the fuse is just bad engineering IMO. And yes the bright switch is the vintage / modern switch, it is named differently on different versions of the pedal. Rocky, the transistor would be perfectly happy with the full 9V on it so you're not going to damage it by swapping resistors. You may spend a long time doing it though because you're relying on guesswork, whereas a multimeter would point you in the direction of where the problem is.
DeleteThanks, will I be able to test the voltages accurately if I omit the 10R and move the power supply up like you said earlier? Nothing seems to heat up when I do that so I'm assuming it's safe, I just want to make sure my measurements would be accurate. I guess I need to study the schematic more. I can't seem to figure out what the deal is... hopefully it's just one issue...
DeleteThanks Ivlark, i know it's not the best way to solve a problem, but for the moment i can't do otherwise. Anyway i put a trimmer insted of the resistors and sweeped it back to zero, nothing happened. Just volume pot seems to decrease volume just a little bit, but it could be my immagination. Other pots and the wint/mod switch doesn't work. I'm not an engeneer, but how can a pot (which is a resistor, isn't it?) do NOTHING inside a circuit? That's what I cannot understand, the output comes from the center of the volume pot, so how is it possile that i hear a full signal when i turn the pot all the way to the ground? I checked the jumpers and the ground line, it seems to be allright, according to the schematic...
DeleteOk I made up a 300R resistor and replaced the 10R with that. I tested on every single joint and track.
DeleteHere's what I found while testing:
The top and bottom tracks are ground so of course, I get 0
The track just above the bottom track is completely shorted.
Everything on the left of the track cut is shorted on the track just below the top track.
The only other place I get 0 is on the 9v power rail between the two track cuts, which I think is correct since there's supposed to be a jumper going there from ground.
DeleteRocky Balboa13 November 2012 17:30
My problem was that the top rail didn't join the ground, so i took off the longest jumper and sand a wire directly from the main ground. Now everything works but there's a noise coming from the tone cicuit and the whole pedal doesn't sounds like the original, at my ears... It seems more an overdrive that a havy fuzz, even contour can't get out of the mid range. I'll try some of the tricks listed in the posts above...
The long jumper should be going to the 9v power rail, with track cuts on either side of it (to prevent the rest of that rail from shorting to ground) then also on that 9v power rail between the cuts, there should be a jumper going to the bottom ground rail. this connects the top rail to the bottom.
DeleteMike, I don't understand what you say. I see only four jumpers, two for the mu-amps and two for the ground. I don't see any jumper for the 9v
DeleteMy point was that the two jumpers for ground connect on the same track as the 9v. It looks like the two track cuts on either side of them is to prevent the rest of that track from shorting. So it looks like there are actually three ground points, the 220uf cap is connected to ground where those jumpers meet.
ReplyDeleteI can't seem to figure out why the tracks adjacent to the top and bottom ground rails are getting no voltage, I have a feeling this is the biggest part of my problem.
Sorry, I misunderstood... Yes, there are three points to ground, top and bottom rails and the center for the 220uf cap. The cuts are made to use the same rail for different parts of the circuit, so to prevent shorting. The second rail from the bottom, the boost rail, is grounded only when the switch is on. The second rail from the top is part of the tone stack and there are no grounding point in this rail. My problem was that there was no ground in the top rail. It was the long jumper, i don't know why. Anyway I fixed the problem with another jumper and now it works, but it seems there's not enough gain, according to the video above, and with the tone settings all the way to the bright, there's a noisy whistle... I think I'll change the value of the tone caps and the boost resistance..
DeleteHello everybody.
ReplyDeletei am as well getting the dreaded squeal issue.
Did anybody find an ultimate solution to get this damn thing working?
It looks like some do not experience the problem,but most do.
Also, since it's my first time dealing with j201s, i ask some practical info on how to proceed to bias these. The way i see this, is i have to swap values on the resistors going on the drain Rail for every transistor. Am i right? Maybe a trimmed version of the layout would have been more practical, since there is this problem?
I am at a loss, it's now been 1 full day of fighting this little bugger.
You can tell it sounds heavenly, but the squeal is making it useless.
HELP please!!!!
I took the output directly from the tone pot and the squeal is gone, so i guess the problem is something wrong with the high pass filters caps... But there still is an annoying hiss, not enough gain and it catch too much noise from my pickups (seymour duncan mini humbuckers), none of my others distortion pedals brings so much noise from the same pickups. Can anyone figure out the problem? Thank you all!
DeleteI just learned that I read the vero wrong. I built it as a mirror image of the component picture, so I made the track cuts exactly like the picture says, but with the copper side facing me.
ReplyDeleteI'll rebuild it as soon as possible and post the results.
Sorry for cluttering up your comments section Mark.
Your not the first Mike and you won't be the last, but the layouts are always component side up, so the image needs mirroring to reflect the true cut layout when looking track side.
DeleteI did try to use the Tone pot leg 3 to get the output from and the squeal is indeed gone (but not with the gain switch up)
ReplyDeleteBut i am now left with no volume pot and no tone pot.
I think i will build a completely new one , to see if i get any better luck starting fresh. Seems that for some this pedal has worked right away, wtf!?
Mark, any ideas?
One thing, what kind of capacitors did the guys that had successful builds ? I am using regular ceramic disc, except for the 1uF ones, wich are MKPs. Might this make a difference?
ReplyDeleteNo the capacitors you've used should be fine Chris. It's very difficult to fault find over the internet, you really need to sit down with the layout, check the connections are right, and all the values you've used. Check all cuts are in the correct place. Check for bridges making unwanted connections and cold solder joint making bad or intermittent connections.
DeleteAt the end of the day we know the layout works, so there has to be a problem either with the build or with a components and they're both things that you are really going to have to go through carefully.
Thanks Mark for the reply. I am building another one while i type. so to start fresh and see how this one goes.
ReplyDeleteBottome line is, the layout should work as is, and who has got the squeal, has misplaced something, or has a faulty component. There is no black magic going on with this one, right? I tought it was a biasing issue, but you changed my mindset man.
I really hope to get this second one working, i love the sound!!!!
No good, the second one does just like the first.
ReplyDeleteDamn!
Sounds like you've either got a faulty component or maybe you've taken something the wrong way and have replicated the mistake. Post a high res front and back pic of the board
DeleteMark, i'll have it posted in the next few days, i am not home now. Thanks so much for your help!
ReplyDeleteHi boys!
ReplyDeletePlease,i need help...
I've built it, it works,but the volume is loooow!
With volume at max and boost on.it arrives at least to the same level of clean signal...
What do you think is the problem?
What can i do?
Thanks!!!
Well if you're getting some sound out of it, albeit quiet, then it makes it less likely that you have a misplaced component (although it is still possible and so should of course be checked and an incorrect value is also a possibility). But I would say in instances where it sounds good but quiet, the vast majority of the time the problem is a poor solder joint somewhere, the other main thing to check for is an unwanted bridge making a connection that it shouldn't. Reflow the solder around any joints which look suspect, including all the offboard wiring including grounds. Score between the tracks with a knife and re-do any track cuts to make sure there are no burrs causing bridges.
DeleteDone, now it works, but now it's a sort of...tremolo...
ReplyDeleteWhen i pick the guitar, the sound arrives "later"...it seems like there were a volume pedal befor pinnacle...
Pick...whait half second, and the sound arrives...
Do you think is a transistor problem?
Please, help...
Thanks a lot!
These are my values:
ReplyDeleteQ : D/S/G
Q1: 5,1/1/0
Q2: 9,3/5,1/0
Q3: 5,1/1/0
Q4: 9,3/5,1/0
Q5: 1/0,2/0
Q6: 1/0,2/0
Anybody can help me?
Q5 & Q6 seem just wrong. There is 22K resistor for both of those drains, so i believe the 1V is not the voltage we want.
DeleteDid you check the usual suspects? All cuts where they should be, solder bridges and component postioning? Those 22Ks could be a good suspect.
+m
I've resoldered everything...the same results...
ReplyDeleteAlso, checked all the resistor values, by colors...
But...
if I remove the transistor Q5,inside pin D, I measure 5 V
The same if i remove Q6...
Ideas???
Thanks a lot guys!
Also...around R15 and R25 (22K) (fsb schematic) i've found 9V by one side, and 1 V by the other, in both resistors...
ReplyDelete:(
Hello
ReplyDeleteJust finished this, my first pedal build. It appears to work, the controls affect the sound but it is Very quiet and unusable...Could it be the J201s? reading about matching them? I just bought 6 J201s so i dont know it this is the problem..any ideas??
Thanks
Toby
Hello sorry, i just saw a similar question above, will try the suggestion from there first
DeleteHi!
ReplyDeleteI have read all the question here, i've already build a Plexi Drive and work perfectly after biasing the drain of transistor with trim, i want only know if for biasing the j201s in the Pinnacle i've only put two trimmer instead of the 22k on the drain of Q6 and Q6 or i have to trim also the 1M resistors?!
Thanks in advance! :)
Hey everyone, im currently building this and i dont have a C50k pot. If i used a C100k pot with a 100k resistor across 3 & 1 would that be ok or would if affect the antilog taper?
ReplyDeleteThanks
I built one but but got the problem of the sound coming in late... then got crazy ass squeal when the boost was engaged... it was late I was sleep so I went with the smash everything and start over the next day approach... not smart but damn cathartic... has anyone built from this layout and not had a problem?
ReplyDeleteHi everyone,
ReplyDeleteI’m a bit new to pedal building but have successfully built a few with op amps and LEDs that sounded great. Now I’m gung-ho to do more, and after lots of research I decided to try one with J201 jfets for the so-called “tube emulation” only to find that I’m too late arriving at the party - the J201 has been discontinued! (i.e., obsolete on Mouser, unavailable on Small Bear.) What should I do?!? Should I NOT try to do J201 builds like the Wampler Pinnacle and Dr. Boogey? Should I try to adapt a SMD to do veroboard work? I see Tayda has J201’s available - are they any good? I read there are lots of fake J201’s floating around on Ebay. I am sure this is an old topic to seasoned builders like all of you, so you need not rehash everything here. But perhaps some quick advice and a few links to threads that discuss this issue. I’d really appreciate some direction.
Alternately, are there ‘new ways’ of designing high gain pedals that used to use J201’s? Thanks for any insights.
Tayda are definitely a reputable seller so I'd be surprised if they were selling anything fake, but I'm absolutely sure they'd take them back without question if you found anything wrong with them. I've bought J201s a couple of times from Chinese sellers on eBay and have had no problems with them. I used to get them from dpi4parts on eBay who is a US seller, but he seems to have run out too.
DeleteI bought a few hundred of all the JFETs that I heard were being discontinued so I knew I had enough to last me forever, but you can still get them in quantity pretty cheaply on eBay and so I'd recommend maybe stocking up while you can.
I can confirm that the J201 from Tayda are great, and I'm running out of them, so in my next order, I'll include a few dozens.
DeleteBR
Thanks to you both for the input. I'll get an order in today. Cheers!
Deletebuild this today and it works like a charm (using the original resistor values, 22K...);-). Thanks again Mark!
ReplyDeleteHello, I tried to build this pedal, but it did not work, I'm in doubt with 1uf Caps are not polarized polyester, or are electrolytic? thanks for listening, congratulations blog, greetings from Brazil.
ReplyDeleteHi! I made this pedal with PCB layout and checked it with this layout... schematics are the same, but still there is something wrong... It squeels at higher gain settings (vol and gain @ max) and it becomes worse after engaging the boost.... The strangest thing is... the original seems to oscilate too. Just listen to this demo @ 4:00-4:15 http://www.youtube.com/watch?v=OAWFAeSu7mg
ReplyDeleteJust finished this one today finally, after plans and working on it for a couple months. A few JFET issues at first, but it sounds pretty good now. My only issue is with the switches. I used ON-ON switches, could this be why? In the non-boost setting it just sounds really bassy and dead, I'm not sure if the Vintage/Modern switch sounds right either, but it's not as glaringly bad an issue? Are ON/OFF required for proper sound? I can't seem to find them anywhere.
ReplyDeleteI finally got around to finishing this and it sounds great. The only issue i have is that there seems to be a significantly less amount of bass compared to the bypassed signal.
ReplyDeleteThe contour knob seems to be a mid scoop.
In one vintage/modern mode (not sure which sound is vintage or modern) the sound is very open and clear, in the other mode its a bit muffled but also smoother (I suppose this would be the vintage "brown sound"?) I needed to turn up the tone a bit to compensate.
Other than the bass issue I'm happy with it.
Just a Quick question.
ReplyDeleteI just got the resisters and caps to build this one but I noticed that the 1U caps I got are Tantalum wich are ploarised I believe. What is the orientation for these?
Thank you in advance.
Cheers,
Scott
I meant polarized ... These iPads! Doh!
ReplyDeleteHi i tried to build it and it works very nice..Pinnacle is so interesting..
ReplyDeleteThank you so much Mark!
any idea why I don't see where to hook up boost 1 and 4 and vint/mod 3?
ReplyDeleteI know I should be able to figure this out but I'm beyond frustrated at the moment and could use some help.
ReplyDeleteI have no gain without the boost engaged, and some nice crunch when it is engaged. But nothing close to Pinnacle-ish.
All pots appear to be working and I have the following Q voltags with all pots on 10 and boost engaged:
Q1
4.7/0.29/0
Q2
9.0/4.8/4.2
Q3
4.8/0.29/0
Q4
9.0/4.8/4.2
Q5
4.5/0.16/0 (changed 22k to 27k to get 4.5)
Q6
4.1/0.22/0
The other voltages posted from other builders seem to have a negative reading at the gate of Q5, mine is always 0 regardless of pot settings. Is this a clue?
Also, I pulled Q1 & 3 and with the boost disengaged I read 10k between the S and ground on both transistors which I believe is correct when the boost is off.
It seems like the gain needs to be increased before the signal hits the boost portion of the circuit, not sure how to do that.
Thanks for any help,
Mike
Mike, could it be a solder bridge or missing/wrong component? My transistors weren't matching, etc and I was getting either crazy gain or it wouldn't work(depending where the trimmer was on Q5 and Q6). I'm a n00b, but if I had to take a guess it's not the transisitors, especially if you get something with the boost engaged.
DeleteDo you hear anything with the pedal on?
Thanks for the help!
DeleteI had run a knife up and down the tracks and checked continuity with my meter so I don't think there is a bridge.
The sound is clean without the boost, with both volume and gain at 10, it's about the same level as when bypassed. All knobs function, but no distortion.
I have had two builds in the last month that had similar problems. BOTH times, it was a pin somewhere that I just completely didn't soldier. I just clipped it at the board as if it was soldiered. Once, was an IC socket pin. They don't protrude much, so it's easy to miss one when the board is flipped over for soldiering. The other time it was a resistor in a crowded area of the board. I must have clipped it when I was clipping the soldiered leads off.
DeleteI guess that's kinda like the opposite of a soldier bridge. Haha. Both times, it was amazing I was getting any sound at all!
Mojo, that happened on my zendrive! For the life of me I couldn't figure out why it would work, then stop working. Then, as I was looking for a solder bridge I noticed that I didn't solder one of the jumper wires on one side. Like you mentioned, it was barely sticking out, so I must have missed it. Once I soldered it, it was solid.
DeleteMike, have you double checked that all the components are in the right spots and you have the right component values? As for solder bridges, I actually use a hacksaw to saw between the rails, some of my bridges/blobs were pretty decent back when I was using a junk iron. Oh, you also might want to try reflowing solder on all the points as well, takes only a few mins...
Another thought is you can make an audio probe, it's easy to make and cheap. With that, you can jump from point to point to see what's going on. It might help you narrow down the problem. But from my limited experience, I bet it's something simpler...let us know how you do!
BTW, you said your j201 values were with everything on 10 AND the boost on. What is the values with the boost off? I think the values people were using from Wampler was with the boost being off.
DeleteThanks guys, I will check it out as advised when I get home, but here were the voltage readings with the boost off.
DeleteQ1
5.1/0.61/0
Q2
9.0/5.1/4.27
Q3
5.13/0.62/0
Q4
9.0/5.13/4.28
Q5
4.5/0.16/0
Q6
4.11/0.22/0
Well, your experience proved true.
ReplyDeleteI'm embarrassed to say it was indeed a component that was soldered to the wrong rail. Even though I checked and was sure everything was in it's proper place, it wasn't.
But maybe my troubleshooting experience will help others.
I suspected something was wrong before the gain pot due to the symptoms: all the pots worked, the transistor readings were close, unity gain without the boost and some gain/distortion with the boost engaged. When I grounded boost 3 by itself there was little volume change and then grounded boost 6 by itself and there was a bit more volume and distortion, but ugly sounding. That convinced me the problem was around Q1 and Q2.
I googled Foolin' with FETs to find out what actually creates the gain in this type of setup for Q1 and Q2 and I gathered that the 1uf source cap on Q1 influences the gain. I went to check it with my capacitor meter and found I had the top of the cap soldered to the 4th rail by mistake. It needed to be on the 5th rail. Ouch!
Now the pedal sounds as it should.
Had I taken more care when double checking component placement, I would have saved myself hours of frustration and would not have wasted your time.
Thanks guys
Awesome that you got it working! I'm finding out that usually if there's a problem it's something I did...I will say, you got some really good readings on your j201s, I was never able to get it right, had to do all kinds of stuff to get it working right. Congrats!!
DeleteThanks Jon, As for the voltages, I originally used 4 matched J201s for Q1 thru Q4, but after reading Fooling with FETs it sounded like that wasn't necessary so I replaced them with 4 random J201s and their voltages stayed the same. I'll save the matched set for another project. I also increased Q5's drain resistor to 27k to get the readings I posted earlier and today lowered Q6's to 20k. I now have 4.5V on Q6.
DeletePedal sounds really good, can't wait to crank it tomorrow.
yah, I think I read in a few places Q1-Q4 didn't matter, especially because 2 of them are on the 9v rail. I think for me, I have the resistors for Q5 and Q6 at 2.xK! I decided screw what the other pedal was set to, I'll go by ear. And it sounds pretty good! I'll have to swing by the music store and try a real one out to make sure I'm not missing out on too much. :P
DeleteFor anyone that built a mirror image of this like me & Mike Stahl invert the 6 jfets to get it working.
ReplyDeleteHi, just finished but tone control I have to crossed 1 and 3 for working in the right way, the sound is very very dark and bad gated when I play loud.. something wrong but never traces touching each other and all the components are in the right place.. idea?
ReplyDeleteAnd with boost engaged the volume have a jump very too loud
DeleteNo one?
DeleteHi, have triple checked all and I found nothing to change..
DeleteI finished wiring this one yesterday, it sounds absolutely awesome, even better than my beloved BSIAB2.
ReplyDeleteI randomly put 4 J201 for Q1-Q4, and tried a few to finally end with 4.5 to 5V on Q5 &Q6 drains with the stock 22k resistors.
I will put it in a BB enclosure with the boost on a 3pdt like the deluxe version.
Awesome layout BTW
Thanks for the layout! I also get a squeal with the boost engaged, but only in the modern position with the gain past 1 o' clock. It's pretty weird but it doesn't bother me because I wouldn't want that much gain.
ReplyDeleteI don't find the error for this oriole dark tone and lower gain..
ReplyDeleteHi,
ReplyDeleteMark, what are right values (how much in difference can they vary) for this pedal and which of 201's need to be biased?
Values for what? Q1 to Q4 are two muamp pairs which should be less susceptible to biasing issues, so really it's only Q5 and Q6 that may need their bias tweaking. I'd remove the 22K drain resistors for each and use the middle and one of the outer legs of a trimmer where the resistor leads should go.
DeleteValues for drain and gate of 201's...I mean with what values is it original sound of pinnacle? This pedal can be adjusted to many variants of sounds. I do have trimmers on 5 and 6 but don't know what voltage is original. With resistor I get squeal. Just that. Thanks.
DeleteIt is normally suggested to aim for 4.5V at the drain, but in all honesty I'd do it by ear anyway. You could set it for 4.5V but prefer the sound at 4.7
DeleteOk. Thanks. Will do that. I have also found that "tuning" it by ear is better, but I was afraid to loos the original sound. Now I know it is ok that way. :-)
Deleteanyone knows how to get rid of the squeal with the boost engaged? I have sound from the pedal but would love to get rid of the squeal when boosted even with gain at the max. Could the squeal happen because my drain voltages for Q5 and 6 aren't at 4.5V? Thanks!
ReplyDeleteI had squeal from the boost switch as well , my drains were at about 4.5v , but I found that the boost switch wires were very fussy about where they were so I would suggest moving them around, I eventually got mine to work without squealing.Good luck
DeleteThanks chadster. I tried resoldering and moving them around but the squeal still happens on very high gain settings. It still sounds very good without the boost though. I think i won't play with the boost setting anyway.
DeleteKeep in mind that in my stock pinnacle the imput resistor is 510R, not 470!
ReplyDeleteBrian has changed little things here and there with this circuit a number of times, it was definitely a 470R in the one that was traced. And It's close enough to not make any difference at all so I wouldn't worry too much about it.
Deletehello IvIark and everybody,
ReplyDeletebut..if I would remove the boost section??? :)
The boost section only adds 2 extra components to the board. If you don't want to add it, just omit the wires and switch and if you really need to, the two 1K resistors the wires attach to. Considering how little it adds to the build I don't think I would bother removing it.
Deleteyes, you're right, but I would add an other boost with it, so I thought to rimove redundant stuff, what do you think?
DeleteWhy bother when it only needs a couple of extra components? It won't save you any board space. Just have another boost as well :o)
DeleteIf you want to save on a stomp switch just add the boost to a toggle so at least you still have the ability to switch it on if you want to.
Delete:) ok thanks so much!
DeleteI'm re-verifying this (for the fact that it seems to be causing people a lot of trouble, and I am never quick enough to actually be first, haha.) I built the board exactly per the layout. I used a 3PDT stomp for the Boost switch so that I could use the 3rd pole throw for an LED. I get the ground for that LED from the switched ground of the bypass stomp's LED. That way, the Boost LED goes off automatically in bypass.
ReplyDeleteAnyway, it sounds fantastic. All pots and switches do exactly what they are supposed to do. VERIFIED. Now, as for the problem, which is squealing in Boost mode with Gain turned up, I have removed the input wire to the switch and the input wire to the board, and replaced them both with shielded cable. (You have to actually ground the shield by the way, haha). Problem solved. No more squeal. Awesome pedal. Just like John, I had built the Ecstasy and love it, so I had high hopes for this one. It delivers. Super loud. Not sure if I like it better than Ecstasy yet, because the tone shaping on it with all these controls is going to take me a while to explore! Look out Eddie.
Other comments: I used 6 random transistors from a bag of 18. Then I swapped Q5 and Q6 from the bag until the drains matched. I did nothing on Q 1,2,3,4...just random.
The only proof I needed before swapping out the input wires for shielded cable was, I took my fingernail and scratched at the plastic coating of the input wire. In boost mode, there is so much gain on this thing you could hear my fingernail through the amp! I'll get some photos up after I make a decal for it.
Excellent, thanks for that matey
DeleteNo problem! Also, a quick update, since I got the squealing to stop, now after playing it for 2 hours, I've decided I do like it better than the Ecstacy. YES!
DeleteHey Mojo321, I can't really tell which ones are your shielded wire. Are they the thick black wires from the input and the input jack?
DeleteYes, it's like putting a fire wall between the input and the high gain output. Basically, there are two ways to create that fire wall. Two ways to shield the circuit from having a feedback loop.
Delete1. Shield the input wires BEFORE the circuit so they don't absorb the high gain output that is leaking everywhere.
2. Shield every wire and component AFTER the circuit, so it can't leak out in the first place.
Now, I don't know about you, but to me, it is easier to protect two input wires than it is to painstakingly source and shield every potential leak in the circuit! Hope that helps. :/
Thanks! I'll try this and post my findings!
DeletePictures of my finished Pinnacle:
ReplyDeletehttp://tinypic.com/r/5ovzmg/8
I think I am done using these water slide decals. They are nothing but frustrating. The edges curl up when you are trying to get them in position. I end up having to slice off a bunch of the curled edges. Which just ends up scratching the metal so the edges are noticeable now. On this one, I had to cut the whole bottom off, which had the words BYPASS BOOST on it. Dang. And to top it all off, it's crooked. Grrrr.... Oh well, it sounds good, and that's all that really matters. :D
Notice the two shielded cables add a bunch of pushing stress to the board because they want to straighten themselves with that plastic core. That's why it got shoved over to the right. I wish there was a good small sized shielded cable that would hold the shape you bend it into. Anyone have any experience with that?
Think I want to try this one again since you've tamed the squeal. I've never used shielded wire before though. I am assuming that you just connect the interior wire to the board as usual and then attach the shielded braid to a convenient ground point?
DeleteThanks
Yup. In my photo, you can see I hooked both wire shields together and then to the 3PDT grounds. You don't need to connect shield at the other ends of the wires, because, hey, if it's grounded, it's grounded!
DeleteCool. Going to start the rebuild tomorrow. Thanks!
Deleteoops - my response pulled wrong profile. Texas Pete is me ( and I'm not in Texas...)
DeleteSo - finished this over the weekend. Used shielded cable for the input wires this time. Took the short lengths of shielding wire, attached them to short lengths of insulated wire ( spliced/soldered portion covered with shrink wrap ) so I could route to the jack ground without worrying about it shorting to anything else. Happy to report no squealing whatsoever in boost mode. Very happy to have this one back in the arsenal now. The boost mode is nice for me since I play single coils predominately and I need that "little" push over the edge.
DeleteThanks Mojo for the tip. Mark - I know you've suggested shielded wire in other high gainers too, so thanks to you as well ( and thanks always to you and M for all the great layouts...)
Awesome---so glad to hear it! Great idea on connecting the shield to ground with insulated wire.
DeleteHi guys I tried the method suggested by Mojo, using the vintage shielded wires from vintage Les Pauls, as I could only get those. Unfortunately the squeal is still present! :( I shielded the metal part of the wire to ground but the squeal still occurs!
DeleteBoard input AND jack input?
DeleteYes those two inputs. Still doesn't work :( Do you have pictures of your build tinkercreak? Thanks
ReplyDeleteAt work now. I'll try to load a picture when I get home tonight.
DeleteOk. Here is a picture of the shielded wiring. Not very good quality but maybe you can see how I did the wiring. I used some leftover shielded cable from some Humbuckers that I had swapped out on one of my guitars.
Deletehttp://i1060.photobucket.com/albums/t449/tinkercreak/photo1_zps2c36c20d.jpg
Hope you get it sorted out. It really is a good sounding pedal. Notice that I did socket the drain resistors for Q5 and Q6. I had to adjust those a bit. For my jfets I think I ended up with 20k. Hope this helps
wow what neat wiring you have! Maybe I should try wire from old humbuckers! Thanks for the tips!
DeleteWould you say the pedal is performing in all other regards properly, but the squeal is only in boost mode with the gain turned up?
ReplyDeleteYou can take a flat screwdriver and use it to scratch at the coated wires in the pedal. Find the hyper-sensitive wires! Also, make sure you actually connected the shielding to ground. The shields have to send what they absorb to ground. If they can't, they really aren't doing anything. Also, that vintage shielded cable may have a very "open" or "loose" mesh. There are a lot of holes in that shielding. You need a dense mesh, or aluminum wrap. The problem with the aluminum wrap is, it is tough to get a good connecting by soldering. Shielded cable has come a long way in the last 30 years.
DeleteYes the pedal is working great and I really love the tones. I'll try to look for other sources of shielded wire, but I'll try probing around the other wires first. Thanks!
DeleteJust difnished, this is my issue the sound is very dark and clipping feel.. all the pots working almost well but the vintage/modern never effect.
ReplyDeleteThe voltages are pretty ok, traces cuts and components value seems like ok..
Any one?
Post your voltages, that will give us a lot of info
DeleteThis is my voltages:
DeleteQ1 D 4,66 S 0,11 G 0,00
Q2 D 9,00 S 4,65 G 2,99
Q3 D 4,78 S 0,78 G 0,00
Q4 D 9,00 S 4,16 G 3,00
Q5 D 4,50 S 4,50 G 0,00
Q6 D 4,57 S 0,15 G 0,00
All Pots set at 0 !
ReplyDeleteYour voltages mostly look good to me but there are a couple of areas that don't look quite right. The source of Q4 is connected directly by a link to the drain of Q3 and yet the voltages are different. Check your soldering on that link because they should measure the same like Q2 source and Q1 drain. Q5 source also looks high to me. You have 4.5V on the drain which looks right, but the source is also 4.5V which is only 1K away from ground so something doesn't look right there to me. It certainly looks like you may have an unwanted bridge between source and drain rows and/or maybe a bad joint on the 1K resistor. That area needs checking anyway because that's the part that looks suspicious.
Deletethe voltages right for Q4 S and Q3 D are right now! And also the source of Q5 but I have see that Q5 D oscillates from 4,7 to 8,9v ??
ReplyDeleteAny
DeleteThe voltage on Q5 drain shouldn't be oscillating which immediately makes me think of an intermittent connection of one of the resistors or it could be that the JFET is damaged. Personally I'd look at swapping the JFET and the resistors around there, measure the new ones to be sure they are 100% correct and be careful about any unwanted bridges and soldering quality.
DeleteI try to swap tone pot, also the layout connection for tone pot make the pot working reverse.
DeleteI have changed the FET, and 22K resistor and 1Uf cond. When I plug the power I have 9,0v in 22k res side Q4 drain and 8,81v side q5 drain.. after 5 minutes I have same 9v side q4 and 6,5 side Q5 ??!!!
ReplyDeleteStill something very wrong around there then. The vintage and modern switch not working is even more bizarre. All that does is switch the source resistors of the first two muamp stages between 10K and around 909 ohms and so increase the gain from those two stages. If you can't hear any difference then there could be something wrong with the switch, or more likely the problem that you've got around Q5 if pulling it back down so you're not getting the benefit of them at the output. I bet if you used an audio probe you'd notice the difference at the gate of Q5 (and so before the problems come in). Have you tried swapping the tone pot?
DeleteI try to swap tone pot, also the layout connection for tone pot make the pot working reverse.
DeleteThe voltage changing come and gone random and the sound never change when it comes in.
Deletevintage/modern still never working
ReplyDeleteno ideas?
ReplyDeleteJust finished building this and it fired up right away with all controls working. Unboxed and thru practice amp. Gotta try this with my rig before boxing it up and seeing if I need to play with bias voltages or not. I will update. Thanks so far! Rock!
ReplyDeleteBoxed and rock'n! This thing is awesome BUT...it squealed like a pig until I used shielded wires. Shielded wires on inputs, tone control and boost switch. Phew. That made it dead quiet. Quite a bit of off board wiring, especially with all the jumbo shielded stuff, but worth it in the end. Tons of tones and sounds. Light gain all the way to high gain and even some fuzz sounds. Very versatile pedal. Links to pics posted below. Thanks very much!
ReplyDeletehttp://i892.photobucket.com/albums/ac124/digthebigrigg/Eddie_zps288c4043.jpg
http://i892.photobucket.com/albums/ac124/digthebigrigg/EddieGutShot_zps88658895.jpg
I tried building this, but I get absolutely no noise... The true bypass switching works as intended, but when I switch it on, no sound whatsoever. I had to redo a few joints, but now I'm completely positive that all joints are solid and all components are in the right spot... I can't figure out what's wrong for the life of me. Help, anyone?
ReplyDeletePost your transistor pin voltages, that will always give us the best clue and a good idea where to look for an error
DeleteHere are my voltages (D/S/G) for each (my multimeter reads my power supply as 9.37V):
DeleteQ1: 0.14/0.12/0 (clearly wrong...)
Q2: 9.37/0.14/0.14 (One of a few problems I'll touch on after the voltages)
Q3: 5.32/0.71/0.12
Q4: 9.37/5.32/4.44
Q5: 6.81/0.24/0
Q6: 6.42/0.28/0
I ended up removing the 22K resistors for Q5 and Q6 and replacing them with 10K since the voltage was below 4.5, but I might go a bit higher than 10K now it's over 6V.
Now here are the problems I noticed... First, I used an audio probe to trace the signal path starting at the input, and things were fine up to the first lead of the 220pF cap. I got signal there, but I didn't get a signal on the other lead of it going to the ground rail. I thought it was the cap, but the 1M resistor from input to ground does the same thing... I reconnected every component on the ground rail, but the issue still persists. Also, I'm not sure if the sections of the rails where the source and gate of Q2 are supposed to be connected in any way (I assume they aren't), but I keep finding continuity there no matter how thoroughly I check for solder bridges and clean everything up. It explains why the S and G voltages are the same (and probably wrong) on Q2, but I can't find what's causing that connection... My offboard wiring works, as my sound is normal when bypassed, and none of the issues are resolved when the input and output from the board are connected directly to their respective jacks. I'm not sure if either of the above issues can explain the near-zero voltage at Q1, if that voltage is what's causing the issues, or they're entirely separate problems, but I'm trying to provide as much information as possible at the expense of you reading my novel of a response so you might be able to help find a specific problem that I just keep missing.
q2 is strange.i agree. you could check again all your cuts around there for tinny pieces of cooper that make that unwanted bridge.
Deleteand i don't know why, but my first thought was for the socket.you could check that too. do you use a solid 3hole piece of socket, or you brake one by one the legs?
I ended up connecting the transistors to the board directly. The batch of sockets I got were awful... They were way too big and the leads came right out with the slightest touch, especially when trying to test voltages.
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ReplyDeleteI have problems with time whistle that drives the booster and also when I put the tone in 7 pot. Someone went through the same problem?
ReplyDeletelo termine el pedal pero el pedal suena a una distorsion algo ahogada, parecida al bsiab2 cuando no tiene regulado el trimmer, ¿alguna solucion a esto?
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