Friday, 25 February 2011

Lovepedal Purple Plexi 800

A lot of people have said this is a great "Marshall in a box" and it's a pretty simple circuit so worth a try.  I did a big axial mojo layout for this a while ago, but have re-done it here using more commonly used (and space friendly) components.

It's funny but it occurred to me when doing this how similar it is to the Krank Distortus Maximus that I did a layout for a few weeks ago.  It's so unlike Lovepedal to use someone elses designs ........ ermwait ..

Update: Here's a slightly smaller version which allows you to use standard 9 row vero and so will be preferable for most people.  This is verified.


111 comments:

  1. man..thank you for this!!

    the pp800 is awesome!

    awaiting for the lovepedal amp 50...

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  2. Where can you buy this type of board and what is it called?

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  3. I haven't built it yet but I'll try to make time to do it over the weekend and verify it, although zeca's comment suggests that he may have made it successfully.

    The board is stripboard or vero. There are lots of places that sell it but it obviously depends what country you're in. Check out any electronics seller or you can find lots of different sellers on eBay.

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  4. Thanks for the answer. I have one other really dumb question. What is the second diagram for and what do the small red squares w/ the dot in the middle represent?

    Thanks again!

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  5. The second layout is just slightly more compact and only uses 9 rows instead of 10, so I expect most people will want to build that version. This will be the popular choice because the smallest stripboard is 25 x 9.
    The red square represents a cut in the track. If you twist an oversized drill bit in that location it will cut out the copper and create the required break in the track.

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  6. Might make this not that I want or need it just to fudge lovepedal over...

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  7. could you use a BAT85 in place of the schottky referenced? thnaks

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  8. Yes the BAT85 or any other Schottky would be fine. Or even a 1N4001 will do the same job but with a slightly greater voltage loss. It's just for reverse polarity protection so you could even omit it entirely.

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  9. Ok. Does a similar thing apply with the Box of Rock from zvex, who is using a 1n5817 I beleive...
    cant decide which "Marshall" Pedal to make...

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  10. Yes the BOR uses the 1N5817 for polarity protection but uses a slightly different method. With the PP800 the diode is in series with the supply so if you accidentally reverse the polarity the pedal simply won't work. The BOR has the diode between the supply and ground and will basically blow if the polarity is reversed and the pedal won't work until the diode is replaced or removed. The series method seems preferably but the disadvantage is the voltage drop, hence why using the Schottky is preferable. The BOR method should really be used with a fuse so that blows instead of the diode, making it easy to replace, but pedal builders rarely include it.

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  11. Cool I think I got that. Takehome message is that in either case a BAT85 should be a reasonable substitution?

    While you are around I wanted to ask. My red llama / green ringer got furnished with a decal. when ive reboxed it all, the red llama no longer works. The led lights up, but there is no signal at all. Any ideas?

    I will plan to check the cd4049 voltages later on, but it seems wierd to just die. Loose connections perhaps?

    Another case in point, my Wolly Mammoth has an irritating intermittent thing where it will turn on and functon fine, just at low volume. stomp off and on again, its fine, proper volume. Doesnt do it every time. Could it be a dodgy footswitch?

    Thanks for your help.

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  12. Yes the BAT85 will be fine.

    Not sure about the Llama, sounds strange to me if all you've done is reboxed it. Are you sure there are no dodgy solder joints or anything?

    The Mammoth sounds strange as well, if the switch were faulty I wouldn't expect it to be intermittent but it's always a possibility I suppose. Are the transistors socketed? It may be worth replacing them and seeing if the fault still occurs. It's just a case of trial and error, and trying to swap the most obvious or likely causes first to see if that solves the problem. I suppose the switch can be swapped easily enough to test, it's just 6 desolders and then resolder.

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  13. Holy cow my litle angel just started working. Found a tiny short. Still have no idea whats up with the first one. But...YAY !

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  14. sounds really nice but then I love a bit of chorus :)

    I will make some clips.

    Sunday night I made an Easy Vibe which sounds genuinely awesome. Very chuffed with that!

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  15. on closer inspection through my blackstar (rather than my 10w practice amp thing used for testing) it seems the chorus adds a bit of hiss. Im probing DIYSB for answers :)

    Ive also checked some voltages in my Red Llama, something is amiss, hope its not the chip as I only have that one.

    i half assed wrote up my Echobase build and decals. take a look. did you do any decals yet?

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  16. I've got a load of CD4049s if you need another. No I haven't tried any of the decals yet, I've made a template but I've been busy with work so haven't built anything for ages for me to try it with. Hopefully I'll get a bit more free time over the next few weeks and give it a go then. I'll check out your Echobase layout now.

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  17. missed this comment. Ive added a CD4049 with an order from banzai which should suffice once the lazy buggers decided to ship to me. Ive gone a for an £80 bulk order (!)

    Ordered some more decal vinyl too, almost used all mine up. You can get 3 or 4 pedals on a sheet of A4 which is nice. I got some more transparent and some white, if you fancy a sheet of both let me know for testing purposes.

    i owe you a PT2399 as well. maybe sort out a trade (!)

    Let me know. The decals I think are awesome. I am interested to try the white ones. Hard to apply but look really good and with clear coat mine have been very robust, no signs of fade or wear.

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  18. Update is up, with another incoming on decals

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  19. I have a Purple Plexi copy of some type...for a day or 2. Someone sent it to me by mistake.
    It is really boosted. I mean, it is really boosted. The tone knob seems to have no affect. The guy was sending it to someone for "more sparkle."

    Is there a cap or resister change that would add a little treble? I'm thinking the right cap might take away a little bass boost, and also ad some treble. I just don't know which.

    Any help?

    Thanks,
    Mike
    modestmike@att.net

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  20. OK, another newb here with a question. Don't understand the resistor marked 1K74 at the end of the IC chip. Could you explain that please? Or is my eyesight just that bad? :)

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  21. The original had a 1740 ohm resistor in that position (hence 1k74), just use a 1k8 which is a more common value.

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  22. I built this a few nights ago, super awesome Marshall sound! Thanks for the great layouts!

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  23. Thanks for all your feedback Mike

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  24. Hi Ivlark

    Wow this is a great pedal Built it with your SHO
    Just one little Question.
    The Gain stays the same the whole way up & only starts to increase at about 3 o'clock
    Any Ideas BTW I'm a novice so go easy on me

    Thanks in advance


    Heres a photo , Named after myself....


    [img]http://farm8.staticflickr.com/7173/6432306179_04aab4fef1_z.jpg[/img]

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  25. Oh , forgot to say I couldnt get a 370pf cap so used a 330 pf , If it makes a difference

    Pic wasnt working so try this

    http://www.flickr.com/photos/58852502@N06/6432306179/

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  26. I haven't built this one yet, but maybe someone on here who has built one can comment? Thanks a lot for the pic.

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  27. I built this one too.. It does sound very nice and would be nice to add to my pedalboard. Only problem is:

    I GET A HUGE HISS, HIGHFREQUENCY NOISE, an RUSSIAN RADIO FORECAST and with high gainsettings a EARDAMAGING HIGH FEEDBACK

    Think it has something to do with shielding or grounding. But I have shielde the cables from input to switch and from switch to Veroboard.

    Anyone with experience?

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    Replies
    1. You could try increasing the 47uF supply filter cap from pin 6 to ground. Try something like 220uF in there to see if that helps. Some mains supplies are very noisy and it makes it difficult to avoid the noise you can get in effects and amps. Are your other dirt pedals noisy or is this one much worse?

      Also have you tried swapping the LM386 for a different one?

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    2. Same thing is happening with my build. Though I only tested with clamps (didn't put it in a box yet). On higher volume and gain I can hear my heartbeat through the amp when the thing is on. The high feedback happens at the highest edge of the gain knob with the guitar plugged in, with the guitar unplugged it happens earlier. I think I used LM386-1, I wonder if another chip will make a difference.

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    3. I just swapped the IC with another LM386. The problem is gone. There's audible noise with the circuit outside a metal box on high gain, but no feedback at all.

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    4. Which LM386 did you use? I tried LM386L it didn't work. Tried LM386N-1 and again no luck.

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  28. Hi, Can someone tell me what the '370p' is? As a newby, I'm googling a lot of the components to make sure I purchase the right ones and I cannot find anything that resembles a 370p or pf etc...

    Thanks.

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  29. I can find 360 pf Caps? will they do?

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    1. Hi, yes 370p is 370pf, there's not a lot of room there so I always just use "p". 360pf is close enough.

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  30. Just put this together and yes it pretty bloody awesome sounding... deffo has that Marshall mid honk to it BUT, like 'wild turkey' said, I'm getting a VERY gradual gain increase and then everything right at the end of the sweep?

    Any ideas?
    Thanks.

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    1. The sweep may be more suited to a reverse log pot. It's definitely linear in the original, but that doesn't necessarily mean that the reverse log wouldn't be a better choice.

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    2. Just read that you found the circuit 'similar' to the Krank Distortus Maximus.. I probs would have bypassed this as I plan on making the Krank... oh well, I'll still make the Krank as it looks as if I'll have more control over tone etc with it

      Cheers

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    3. Yes the Krank has a Marshall tone stack which is a lot more useful

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    4. Having both this and the Krank, I think I prefer this.. it sounds warmer.. Only thing i would like on this is a tad more bass? would there be a component change anywhere to achieve this?

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    5. You could increase the 4n7 input cap which would let more bass into the circuit, but I don't know how effective that would be with this.

      However the LM386 datasheet does say that you can get a 6dB bass boost by putting a 10K resistor and 33nF cap in series between pins 1 and 5. There isn't enough room to add that neatly to the layout, but this is DIY so you could always fudge it and solder them in series over the opamp to see what you think. If it's a worthwhile mod I'll add a new layout with switchable bass boost.

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    6. Just tried the 10k & 33nf.. It does add a very slight bass increase but seems to take a bit of gain with the other hand so for me personally, I don't think it's a worthwhile mod.

      Thanks for the info though.... it's all a learning journey :)

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    7. Very true Vince, thanks for the feedback

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  31. Just received a message from someone I made this for and he A/B'ed it with the original.. Totally identical and said the clone might even be better... So deffo thumbs up for this layout :o)

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    1. That's always good to hear, you make better effects than Lovepedal! :o)

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    2. Haha... Shame I haven't the nerve to charge their prices though! :)

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  32. So, I feel like having a play with this, as the base tone is really good. I was wondering which parts I could experiment with?

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    1. I'd play with both the 4n7 cap values. I've seen schematics with 22n used in both positions which should give it more girth, and so there's certainly room to experiment there.

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    2. just made another and socketed the two 4n7's, huge difference with 22n's. I've just kept one 4n7 and a switchable 4n7/22n. Like a 'fat' switch. As two 22n's sounds too fat.It almost sounds like a fuzz.. I tried up to 100n which sounded like a Big Muff!... Very worthwhile little mod

      Cheers mate.

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  33. I sent you an email but thought I ask here too in case it would help others.

    Any possible 'squeal' preventions I can put in place?

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    1. Hee hee, sorry my phone is on charge so I don't know what email I've received! :o)

      You could try increasing the 47u filter cap to 220u or something like that. Also have you tried it with another LM386? That's another chip that seems to have temperamental examples.

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    2. Lol, no worries mate, I'll try increasing the cap. I've swapped a couple of the IC's with no change. The switch seems to have introduced the squeal. I'll try the cap and wrap everything in electrical tape and see if that changes anything.

      Would shielding the input/ouput wires make any difference do you think?

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    3. It would only make a difference if you could establish that the noise was being introduced through those cables which I think is unlikely. I know some builders like to do it, but I can think of several more likely sources of noise than the input and/or output wires. Check for any suspect joints too mate, on the board and pots.

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    4. Well tried all that, There's just no getting rid of that squeal. It seems very common in cloning this pedal. It only happens in the last 1% of the the gain sweep. If only there was a way of just cutting that part of the sweep, it would be perfect.

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    5. You could try reducing the 470R

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    6. I've just been messing with it again. I tried throwing random IC's in there as I don't know any equivalents. By the time I got around to the LM386's again, it works flawlessly?! man this pedal is fussy S.O.B!... I do think it's down to the IC as different 386's gave different levels of squeal. I'll check it again tomorrow and try the 470r if it starts again..

      Thanks mate.

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    7. No other ICs would be likely to work in there, this is only audio power amp you're likely to have. I just got 50 x LM386's from Tayda for around £6 shipped. Like the PT2399's it's obviously worth having a few lying around to swap! :o)

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  34. i just built the pedal ,
    it sounds much more better using LM 386N-3 (1 watt)
    than to use LM 386N or N-1 which are the same IC (0,5 watt)
    i had that terrible squeal too , i have read that JRC do not do that but i do not have JRC to test , so i measure the resistance of the GAIN when make the squeal so
    The answer is to use an 150 ohm ressistor on the pin 3 of the gain pot so you do not let to tottaly grounded to full gain and tha gain stops just a bit before squeal. The pedal now works great i do not think that you loose some more gain with this mod.

    thank you Michael

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    1. Excellent, thanks for the info Michael, Vince will love you! :o)

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    2. Haha..So do I understand this right... gain 3 wire from board to a 150k to lug 3?

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    3. 150 ohm. And are we understanding that right Michael, the 150 ohm goes in series with the wire to Gain 3 from the board, or do you mean it goes between lugs 1 & 2 and ground?

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  35. Yes GAIN 3 wire from board to a 150 ohm IN SERIES and after to lug 3 , LUGS 1 AND 2 NORMALY GROUNDED AS THE SCHEMATICS , it is simple i just measured the ohm ressistance when the pedal start to squeel , explain if the pot goes to full possition means 0 ressistance the pedal squeel so we start to turn back anticlocwise the pot till the pedal stop squeel and after we measure the pot ressistance between ground (means 1&2 lug) and lug 3 me i found 150 ohms,so i placed ( GAIN 3 wire from board to a 150 ohm IN SERIES and after to lug 3 an 150 ohm ressistor) and the problem stops , in another pedal i measured 45 ohm when stop squeel so i placed a 50 ohm ressistor 1/4 watt and the problem stoped , so i think that every IC is not the same and does not squeel in the same possition so if someone liked to "cut" the smaller amound of max gain to stop the problem it is better to measure as i explained before ,if you do not have the time to test just place 150 and it is OK, finaly with these small ressistors the deference between the max gain settings is so small so we could not understand any deference

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    1. Excellent Michael. Thanks for that.. This might be handy for the RAT issue to? As when the RAT is at max gain it has been known to squeal and the RAT has so much distortion at max that I don't think cutting a tiny bit will even be noticeable.

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  36. sure on a 1k pot or in case of a rat on 100k pot 150 ohm is nothing to cut maybe you are inside the 10% deviation of the pots

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  37. Hi there,

    I've just ordered electronic parts to make this sexy pedal.
    Meanwhile I'm trying to understand how to wire it.
    I'm a beginner in DIY, I only made a booster last week, it was not difficult at all but it seems to be harder now...

    1- Where is the output point on the layout ?
    2- how to wire my 3PDT switch ?

    Thanks a lot

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    Replies
    1. If you look in the notes the Volume 2 lug goes to the output, and chek this out for the offboard wiring:

      http://tagboardeffects.blogspot.com/2012/02/offboard-wiring.html

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    2. Thank you Ivlark, it's a good thing !!!
      The matter is that I cannot see any "OUTPUT" on the board. "INPUT" is on the left and still not "OUTPUT".
      In other words, I'm looking for the end point of the circuit...

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  38. I just barely understand, in fact there's no "OUTPUT" on the board, it's the volume 2 log that makes this output.
    While volume 1&3 lugs goes to the layout and volume 1 to the ground.

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    Replies
    1. The output of the board is Volume 3, Volume 1 is then grounded and Volume 2 is your output to the switch. So then when you turn the Volume knob some or all of the signal is dumped to ground which is how the signal is attenuated.

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  39. Thank you,

    I'm worried cause I found several shematics of the PP800.
    The one I printed and worked on is a vero with 2 47uF capacitors in place of 3. Have you already heard about it ?
    What could be the diference if I only put two ?

    http://revolutiondeux.blogspot.fr/2008/10/lovepimple-purple-pills-lovepedal.html
    PLease take a look at the vero here

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  40. Hello Ivlark,

    I quickly drew how pedal could be wire.

    However I would like to know if it's right or if it's wrong... please could you tell me by checking the link below... It would be very nice of you dude.

    http://imageshack.us/photo/my-images/23/purpleplexi800.jpg/

    I'm sure you'll love my drawing, what's more... I'm searching for a drawing software, which one are you using ?

    Thank you so much

    John

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  41. Hi IvIark, can I substitute caps & resistors with like values? Specifically, can I use a 390pF instead of 370pf and a 1.8k resistor instead of 1.72. I couldn't find the actual values in the layout.

    Thanks, Jason

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    Replies
    1. Those two substitutions won't affect the overall tone enough to notice it. Both are well within 10% range, so go for it.
      +m

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  42. I built this today, it sounds great overall, but theres an issue that I'm not sure if it's just part of the pedal's sound, or a problem. It sounds really good, but instead of the notes sustaining out, they decay into a sputtery/farty/fuzzy sound. It's not terribly overbearing, but its annoying me! All the traces are clean, and my wiring is good, the pedal works and is super quiet, I just cant stand this annoying sound haha!

    I used an LM386L, and then also tried an LM386N, and the issue persists with both IC's. I used a BAT41 schottky because I couldn't find a 46, as well as a 390p instead of a 370p as listed on the layout. I also used a 1.8 resistor over the IC instead of the 1.74 listed. Could any of those be the issues? The problem really is more evident with either or both of the frequency and gain knobs over 12noon, could it be a pot problem? I'm new to pedal building and have no idea where to troubleshoot this haha! Thanks in advance to anyone that can help!

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  43. also, the gain knob doesnt really do anything until 3-4 oclock on the sweep, then it gets kinda noisy with a huge jump in the gain...

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  44. That's one of the standard complaints about this pedal, and others that use the LM386 unfortunately. You can get lucky if you have a few that you can swap, and manage to find one that doesn't have the fizzy decay, and I believe the LM386N-3 doesn't have the same problem if you can get hold of some of those.

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    Replies
    1. Hello Mark I built both the Purple Plexi that Sonic Titan. Only the first has whistle problems with the gain at maximum. Both have the problem of sputtering decay. The whistle problem can be solvede changing IC. I have read that you can fix adding a zobel network between pin 5 and ground or by applying a resistance of 450 ohm and 1k ohm between pin 5 and ground. Could you give me explanations and apply these changes to the pedals in question. I know that many original Sonic Titan have the same problem and solved in this way. Bye

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    2. Is the JRC386 better than the LMC386 in this case? I also get the fuzzy, gated decaying notes, which is super annoying.

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  45. Yeah bummer. :-/ I was able to get some LM386N3's, and they were worse haha! I tried 3 each of the different LM types (386, 386N-1, 386N-3) and the fuzzy decay problem persisted with all of them. I ended up settling on a LM386N-1, (it ended up being the most quiet and smooth out of all of the 386's I tried) It's still a cool pedal, and the gain knob issue is a bit better now as well. I think I'm going to find a different Marshall-type pedal instead though, the fuzzy decay still annoys me haha! (maybe the Catalinbread DLS?) Thanks again for the awesome layouts and help!

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  46. I just finished up this pedal tonight and it works great.
    I did notice the squeal at the last part of the gain knob so I may have to try the resistor mod to stop the squeal. I used some caps that are too tall and it barely fits inside a 1590b LOL
    I used a 380p cap since I did not have a 370 and that works fine...
    I also had a big vishnay 1k74 resistor laying around that I used and a
    Bat46.
    I really love the sound of this pedal, it has very usable gain and cleans up great with the volume knob on the guitar! It may boot off some of my dirt pedals off my board :p
    Oh and I noticed if you put a buffered pedal in front of this thing, it sounds like ass so I would not use anything buffered in front.
    Not sure if that is normal but for my build, no buffers in front!

    Thanks IvIark for this! Hoping sometime you can go for an Emma Reeza !

    CHeers!

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    Replies
    1. I have to take back what I said about using a buffer in front... I hooked up a madbean kingslayer (Klon) in front of the PP800 that has the buffer and the PP800 sounds fine... even more so with the kingslayer boosting the front end! :-)

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  47. Hi guys, I just finished this pedal this morning. Everything's sounds great, I used an LM386n-1, a 470pf cap in place of the 370pf one and the standard 1k8 resistor in place of the 1k72. No problems with hiss or excessive squeal so maybe I got lucky with my IC, an awesome layout. Thanks Mark.

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  48. Hi Im David from Spain, I built this plexi 800 and tone marshall is wondefull. I use 375pF , 1k8 resistor and LM386L. Problem same.other user. It has noise of supply power, and gain up hum squeal and hiss. I will try JRC386D and 150ohm in pot gain. Too cap filter 47uF is neccesary? Other schematic plexi 800 dont found this cap filter! Thanks David.

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    Replies
    1. The 47u isn't necessary but it will probably be noisier without it, and may be quieter with a larger value there. Lovepedal definitely include a power supply filter cap in the original.

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    2. Hi Iviark many thanks. Other question. Do you have any layout relay system and switch-soft style lovepedal?

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  49. Nice pedal, built one this evening out of curiosity as i've never gotten into marshall style distortions before. Not had a chance to test it thoroughly yet but its sounding pretty good.
    Thanks
    Dave

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    Replies
    1. I like this circuit, so i'm going to put two in a box and do a 'double rock' kinda pedal.
      Thanks
      Dave

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  50. Very nice pedal, any suggestio to how to increase a little bass?

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    Replies
    1. Experiment with the 4n7 caps. I mentioned above that I increased one to a 22nf to increase bass

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  51. I was thinking about using a LM386n-4 with this pedal and running it on 12 - 18 volts with my PP2 to see if it responds better...
    Has anyone tried this out using more volts into the IC?

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  52. Hello, I have built this pedal and I got the noise problem at maximum gain so I did that resistor trick. In my case I found that for 40ohms the problem is solved. Less than that the hiss starts to appear. I am using a LM386L which I found sounds better to my ears than the LM386N-1 that I also tried. In trying different resistor values I found that with anything bigger than 180ohms the gain knob does nothing at all in my case, so I may suggest that the 150 ohms "generic" value proposed above could be a bit too high in many cases.
    Another thing is the already mentioned tone knob. I can here some effect, but very very subtle. Is there any way to give this nice stompbox a bigger tone variation range?
    Last thing. This is very loud and I am not sure if this is how it is supposed to be. With gain at minimum and tone at 12, I get unity gain a bit after 9 for the volume knob. Is this the case too for you guys?

    best

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  53. Hi,
    I built this one and to make the gain range more user friendly, I removed the 470 ohm resistor, and used a reverse log 1K pot instead of a linear pot. This makes the sweep much more manageable.
    One could also (still pop the 470R out and ) increase the pot value for less gain at the end of the sweep.
    In a few words: reverse log is better than linear, and the higher the value, the lower the gain.
    Hope this helps future builders. :)

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  54. Does anyone have any demo's on the their builds to share? Would love to see some and hear some, as I'm deciding on building one of these. This is my first post. Ran across this GREAT website last night. Can stop looking and reading and wanting to build every pedal here:) Thanks!

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  55. Hi listen to my demo here https://www.youtube.com/watch?v=ERjOkPEKVoY

    I increased the bass and followed the advice of Frederic to change the gain pot to a reverse log one. Also added a resistor to reduce the squeal as suggested by Miguel. However the gain knob doesn't really alter much of the tone.

    Good luck!

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  56. Hey lvlark Ive built your schematic I would like to make an observation it would be better if you numbered the IC pins in the schematic because I spent through hell putting it in the right position. Secondly it sound great the only problem is that is TOO LOUD! the pontetiometres do nothing. Could you help me how to reduce its power??? Thanks bro

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    Replies
    1. I wouldn't include the pin numbers on the layouts, they all follow the exact same convention and would just serve to clutter the layout. It's always the same:

      1----8
      2----7
      3----6
      4----5

      The half circle (or dot with some ICs) at the top always denotes where the 1 pin is.

      If the volume pot won't make the effect silent then I assume you haven't connected lug 1 to ground, or if you have you must have a bad joint on it or it must be damaged because that will dump the entire signal to ground in the counter clockwise position.

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    2. Yes you are right I connected the pins wrong in the pot. As for the IC I know about the orientation but the IC is in the opposite side of the vero instead of the other components.

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    3. I don't understand what you mean, the IC and components are all on the same side of the board?

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  57. IvIark - Just built the Purple Plexi this morning and wow does it sound great!!

    Thank you for sharing your talents with us, I have built 2 of your layouts now and most likely will now be required to build them all...I am hooked .. Cheers!!

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  58. Hi all

    Does it matter if I use metal or carbon resistors? I only have metal film ones, didn't know if the carbon helps with the tone at all?

    Cheers

    Steve

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  59. Definitely better with gain C1K.

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  60. Sounds amazing. I didn't have a 370pf cap so I put a 270 and a 100 parallel. That was my only change.

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  61. Hi ! Did someone solve the squeal issue with a LM386-N4 ?
    I've read that the N3 doesn't solve anything, ,but no one review his experience when the swap for a N4.
    That pedal sounds huge ! (And The mod on the gain pot affects the sound a lot)

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    1. I've triied a LM386 n4, didn't change anything, even worse than my "best" LM386 ,
      in my opinion, it's necessary to try several chipsets and be lucky with it.
      And the Reverse Log pot could help?

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  62. Vince and Mark,

    Did the switch for switching between 4.7n and 22n at the first 4.7n cap. Amazing results! It absolutely adds that low end. Such a great mod! I've been running it though my old Oliver G150 and it has that JTM45 overdriven tone when the gain is slightly backed off. I also added the 1k reverse log pot which really helps to dial in the gain. Great job fellas!

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    1. Nice one, glad it worked well for you

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