Here's a collection of vero (stripboard) and tagboard guitar and bass effect layouts that we have put together covering many classic and popular effects in growing numbers. Many of these have been posted on freestompboxes.org, so check that site out for great discussions on building your own effect pedals. Enjoy the builds and please also visit us on Facebook and Twitter
The TL062 is often chosen for the LFO in effects like this because its low current draw makes it less likely to induce noise in the power supply which could be audible at the output. A TL072 would probably "work" but you might hear a thumping or clicking noise that corresponds to the chorus modulation rate.
I totally just got the PCB for this and was waiting to build it as it requires 1/8 watt resistors and I had to order them. Nice timing! Might try this layout if I can't wait any longer.
Hi Ralf, don't take Madbeans' parts list as a case of "must be these values". They specify the MINIMUM voltage ratings for resistors and capacitors, in order to get a successful build.
In other words, if you have 1/4 Watt resistors, you can happily use them - you could use 5 Watt resistors and it would still work.
You can happily use 1/8 Watt or 1/4 Watt resistors for ALL of the 9V and 18V circuits on here.
The same applies to capacitors. If Madbean specify (for example) 47uF 16V you can happily use any voltage higher than that, so if you only have a 100V cap, use it - it will not make any difference.
Just remember when dealing with electrolytic capacitors that you want to use one rated at (roughly) twice the supply voltage. In other words if you building a 9V circuit, the caps should be 16V or higher, and if you are building a 18V circuit, 24V should be your minimum rating. You don't want them exploding in your face!
You don't have to worry with film, box and ceramic caps - most are rated at 50V.
Good info Breaker. I meant 1/8 watt resistors are required for the Madbean PCB layout as it is is quite small, designed to fit in a 1590G enclosure.
Wattage and voltage, why and when, were things that confused me when I started building some months ago. I've learned a lot from the comments on this site. Keep up the good work.
Sorry, I did not realise there was a size issue on the PCB - I should have checked first. The PCB should still be possible with 1/4 Watt resistors, but will not look as neat - you might need to stand the resistors.
Hi Alex. All built up but currently the LFO isn't working. I'll start looking for the usual suspects now. Depth is doing what it should and audio passes just fine. But the Rate pot does nothing and all voltages on the IC are steady at 4.50v ish.
Tag it VERIFIED lad. The top right link was only soldered on one side. Time to book an opticians appointment methinks.
Sounds great! There's no denying its a PT2399 based effect. They're not as fast as BBD chips so you get the slightest (and I mean slightest) feeling that its lagging behind a bit. It's not as "lush" but has a sound I would call its own. Can easily pull off some 80's Mark King type sounds. Its definitely getting a box anyway!
I'll try to get a demo recorded once I get it in a box and send you the link.
Good info Sean cheers. The data sheet makes no mention of any other supply voltages but 5V, so I've never really considered giving it any more.
Don't get me wrong though...when playing normally there's no hint of latency...just when you really scrutinise it one note at a time. It doesn't put me off at all. It's not filtered as heavily as some BBD designs so it really shimmers. Loving that!
I suppose the circuit would really benefit from a dry signal mixed in at the end. I may try that at some point but I'm quite happy for now.
Have not built that many PT2399 choruses, but damn this sounds sweet. You can almost forget that it's on... But when you turn it off it's back to cold, ugly dystopia we know as reality. +m
Yeah so if you want the speed LED to be on even when the effect is bypassed, just take the speed LED cathode to a ground. The LED will always be on and lit up even when the effect is bypassed.
The bypass LED will have it's cathode to the 3PDT switch at the LED ground spot. This will be ur usual indicator LED.
I did away with the LED 1 (bypass LED) altogether. I took the LED 2 cathode to the usual spot on the bypass switch so when you kick it in, it lights up AND pulses to the rate. No popping. The 1K is its CLR so I would play with that to get your desired brightness.
Thanks C. Great idea. 1 led 2 functions. I'll do that. I finished this and it seems noisey. Good effect but a kind of 'rush' behind the effect. Is yours dead quiet? I am waiting on 2399's. Might be that causing the noise. Thanks from Terre Haute, IN., USA.
Sorry I missed this Jeff. Yeah, there is a slight "rush" as you call it behind the notes. You can hear it in the demo I just posted to Alex above. I only had 6 chips left and this was the quietest one of the bunch.
I'd deffs recommend buying a large stock and auditioning them. Some are quieter than others.
I just double-checked all of the little caps by the 2399 and now it works great. I is easy to get them confused down there. This is one of the nicer choruses I think even if it is not very versatile.
Mine seems not to work properly. I get the sound out and clean (a bit saturated if I strum too powerfull, but I think that's pretty obvious), but both the pots do nothing. From CCW to CW I get the same sound out, that has very little chorus on it. Double checked the solders, the voltages on the ICs and transistors and changed the pots, but I have no idea what to do now.
Anyway, I still don't have any chorus working, a little frustrating eheh
Might be "PT2399 lock out" - symptoms are similar to what you describe (ie no delayed signal) - though connecting pins 3 to 4 to ground, which is the case with this layout, should stop this happening. You didn't miss the link under the ic, did you?
Against my better judgement (and past experience) I went ahead and gave this one a shot.
First of all the effect is very nice. Like Miro said, it can be left on and you'll forget it's there until you turn it off and things go "ugh..."
HOWEVER... mine is noisy as hell. I tried over 30 different PT2399 chips and they all sounded exactly the same, so I don't think it's that chip doing it. It's almost like a fuzzy buzz clinging to every note. Dead quiet until I hit a string and then there's this layer of buzzy noise all over it. As a matter of fact, play the low E string high up on the neck gives an almost synth type sound, like an ugly brother of a Green Ringer.
Anyone got any idea what could be causing that? I spent the last few hours going through PT2399 chips and it got late. Tomorrow I'll try tracing it with a probe to see where the buzziness starts coming in.
I'll give that a shot. Mine is dead quiet until the strings are touched. Once I'm generating any sound whatsoever through the circuit, there's an "aura" of fuzzy noise clinging to it. It's very hard to describe. I'll try to record it.
the solution of the green led between the pin 7 of the pt and ground is correct, after putting it it has eliminated the small distortion that he was dreaming of every note, thank you Michael, now the pedal sounds very well, I have used tl082 instead of tl062
Seems like the chorus progressively tightened up but also got a bit darker and less lush. It seems like the depth is backed off somewhat with the higher voltages.
I think there may be some tweaking needed for the higher voltages. 5.7v was still pretty good as is.
Going to see if adjusting R18 and/or R19 evens it back out with 6.7v supplied to pin 1.
Finished mine, works well but I have a continuous high frequency noise, like a biiip. I used a TL072 until TL062. I tried differents trimmer position, but nothing to do, this high sound is continuous. Have you any idea where can come that sound?
I've built this, and it works as a chorus, but if I strum normally it starts to distort. The green LED lights up very prettily. Any ideas? Otherwise, it's clean, but that distortion is quite a nice crunch... It also boosts the volume a touch, but my little angle did that too.
The IC is the part of the LFO and not in the audio path, but I would change it to a TL062 just to be safe. Using high output pickups? You could add a pad resistor 100K? on your input...or up the right 10K (next to the 2 20Ks) to something like 100K and see if that helps.
Just to be a little clearer, I changed the 10k next to the 20k resistors to 100k which caused the volume decrease. I was also using a 2n5484, and the test guitar used a JB pickup.
I'm losing signal at pins 14 and 16. Voltages check out in the LFO and on the 2399 within reasonable variation. I've audio probed the signal path and retain signal to pins 13 and 15 (lpf ins). Checked the caps around the 2399 and everything seems fine. Auditioned about 4 chips and the problem persists for each. Chip removal results in signal retention at the output, albeit very attenuated. Scratching my head on this one. Any ideas?
Just finished it and testing unboxed at the moment.
It has a nice Chorus-ish effect and it does not introduce any noise that I can detect into the signal chain which is great. The signal is nice and clean with no distortion that I can hear.
I am experiencing a percussive effect when picking and strumming. It's a little like a delay or reverb sound. Reading the comments someone mentioned a distortion they were getting and resolved it by some resistor value changes and removing the LED in the D1 position. Is there any consensus about that? Is this percussive side effect something consistent with the effect or do I need to do some troubleshooting?
Hello. I'm starting this just now. I was wondering how come nobody ever talked about that trimmer. If its usefull can we make it a pot? If its just sitting there, cant we swap to a resistor? If yes, what value and where should it be attached?
Thanks! I guess for the moment im gonna go with a 100k trimmer chopped down by resistor because i dont have any 47k arround.
The trimmer is used to Bias the 2N5457 transistor to 6 volts, which is going to be different from one build to another so a static resistance wouldn’t be recommended. You’re going to want to adjust the trimmer to see 6 volts on the drain of the 5457.
It’s mentioned on the layout but click the link to the Mad Bean website that is referenced in the description at the top of this page and it will explain how to bias the transistor in the build notes. Your 100k should be fine.
This is a nice chorus but I cant enjoy it because the rate is high since the beginning. When it is compared to another chorus, like zombie, the rate effect is evidencied. Any suggestion to control the rate efficiently ?
That’s odd. Post your recording. I built one a couple of weeks ago and the rate seems to be quite useful. It sounds a little hollow compared to an analogue chorus but the rate and depth seem to be ok.
Built it with a 7805 regulator (6V) sounds good. 18ms min delay.
Originally ticked a lot. Completely solved by: 1. Isolate the LFO grounds (pin4 of the TL062, C17 (10uF in upper left), and the new cap I will address in a moment). I did not isolate the ground of the rate LED as I wanted it to turn on with the effect. It doesn't seem to be causing ticking.
2. Make a new, isolated power rail for the TL062. Run from 9v, through a 100R to pin 8. Then off that junction, run a 10uF cap to ground - the isolated LFO ground mentioned above.
No ticking.
Oh, I also changed R9 (10K nearest the 4u7 in lower right) to a trimmer. This allows you to adjust the output volume to match the effect off volume.
hey. i have ticking too and noise but i dont think its coming from the LFO. i think it starts from the pt2399 because when i take the tl072 completely out of the board the same noise appears until i take the pt2399 out. althought with the tl072 there, seems as if the noise starts chorusing (if thats what ticking is). just to mention i used a 3mm red led for D1. nobody seems to mention anything about it and prolly its irelevant. and i didnt use i added you to hangouts perhaps you could help me. thx
by the way i just (isolated) the ground of the top left 10uf with tl072 pin 4 and the other 10uf that runs from pin 8 to pin 4 of tl072 and i provided straing from 9v throught a 100r on to pin 8. all as you suggested. this thing is still ticking.
Sorry just trying to get peoples attention on old post here.
I finished building this today. It turns on and the signal passes through but is unaffected so the effect doesn't do anything. I've biased the JFET to 6V still no chorus effect.
Just built this and cannot use the 50k trimmer to get from 9v down to 6v - the lowest it will go is about 7.5v. I tried using a 100k trimmer, instead, but the voltage still won't get all the way down to 6v - got it as low as 6.5v. Any ideas?
But without power, measure the resistance from the middle pin of the 5457 to ground. Should be 10k.(remove the 5457 if if you used a socket, and measure from the middle socket to ground)
Then with power, measure voltage from the link to the left of the trimmer to ground, should be near 9v.
JFET only affects the signal after being processed by the PT2399.
Now, what voltages you have on the PT2399 pin 1 and on the regulator? Delay line needs to have 5V.
If you probe it, what kind of signal you have at PT2399 pins 13-16? Those are the delay line inputs/outputs, so if the chip is working right you should have delayed/chorused signal there.
Thanks for the help. The problem was just a misplaced resistor in the end which goes to show to always double check where you place your components. Again thank you.
Hi, Thank you for the very nice layout ! I am building it, and i have a question about capacitors :
1-The 10µF electro cap going to the 78L05's G&O is marked as being a Tantalum on the Madbean BoM : is it safe to use an electrolytic, or should i get a tantalum as specified ?
2- Yellow, rectangle caps are box type (or Mylar), ok. But I also notice some 100nF and 220nF red caps with a small rounded shape : Should I use ceramic caps ? I mean : Is it mandatory to NOT use box caps for these 100nF & 220nF ? Would it change the sound, or make the circuitb ehave differently ?
Tantalum caps do a better job reducing noise in digital circuits, the pt2399 is a digital delay that is "mimicking" an analog delay.
Mandatory no, but may give a more stable, quieter effect.
You can certainly use an electrolytic and let your ears decide.
The red caps can be box, mylar, monolithic etc. I believe the only reason the smaller red caps were used for the layout deawing is just that they span 2 rows rather than typical 3 rows that a box cap takes. The yellow caps look funny/crammed when spanning just 2 rows.
So yes, a box cap can be used, either fold one leg back under itself to fit the exact layout, or angle the box cap diagonally and move the connections accordingly.
That's where you want to make cuts in the trace. I usually drill them out very carefully and then use my multi-meter to check that there's no continuity (you'd be surprised by how just a tiny piece of copper hanging on can sneak past and ruin your whole build)
I had already built 2 diy chorus(mxr micro chorus and p dimension chorus). Like the angel chorus, im also going to try build this one sure!,, just to compare there output signal and see whats the best ! Tnx guyz and more power! Regards fr Philippines! Jun.
I built this last night. Used a TL072 for the op amp and it works great and I love the sound. really fantastic build. Possibly my Favourite effect that I have built from here so far.
any other jfet opamp that could work in here you know of by chance instead of teh tl062?
ReplyDeleteim guessing the tl072 will work just fine ..we will find out soon !
DeleteAs seen elsewhere:
Delete- TL062 is the low power version of the TL082.
- TL072 is the low noise version of the TL082.
TL062 draws less current from your supply.
The TL062 is often chosen for the LFO in effects like this because its low current draw makes it less likely to induce noise in the power supply which could be audible at the output. A TL072 would probably "work" but you might hear a thumping or clicking noise that corresponds to the chorus modulation rate.
Deletei used tl072 and it works find
DeleteCalling Heath :0
ReplyDeletehaha!!!
DeleteBwahaha. I think he should be the one to verify any pt chorus pedals after how amazing his little angel came out. :p
DeleteSon of a bitch...
DeletePT2399 Chorus... we meet again.
haha. heath, don't worry, it's nowhere near as finicky as your favorite little bastard chorus.
DeleteTime to sprinkle my soldering iron with holy water, sharpen my dremel, and trying hunting--er... building this thing...
DeleteI totally just got the PCB for this and was waiting to build it as it requires 1/8 watt resistors and I had to order them. Nice timing! Might try this layout if I can't wait any longer.
ReplyDeleteHi Ralf, don't take Madbeans' parts list as a case of "must be these values". They specify the MINIMUM voltage ratings for resistors and capacitors, in order to get a successful build.
DeleteIn other words, if you have 1/4 Watt resistors, you can happily use them - you could use 5 Watt resistors and it would still work.
You can happily use 1/8 Watt or 1/4 Watt resistors for ALL of the 9V and 18V circuits on here.
The same applies to capacitors. If Madbean specify (for example) 47uF 16V you can happily use any voltage higher than that, so if you only have a 100V cap, use it - it will not make any difference.
Just remember when dealing with electrolytic capacitors that you want to use one rated at (roughly) twice the supply voltage. In other words if you building a 9V circuit, the caps should be 16V or higher, and if you are building a 18V circuit, 24V should be your minimum rating.
You don't want them exploding in your face!
You don't have to worry with film, box and ceramic caps - most are rated at 50V.
Yep and the Madbean layout is quite tight, hence why it calls for 1/8W resistors. They are very small.
DeleteGood info Breaker. I meant 1/8 watt resistors are required for the Madbean PCB layout as it is is quite small, designed to fit in a 1590G enclosure.
DeleteWattage and voltage, why and when, were things that confused me when I started building some months ago. I've learned a lot from the comments on this site. Keep up the good work.
Sorry, I did not realise there was a size issue on the PCB - I should have checked first. The PCB should still be possible with 1/4 Watt resistors, but will not look as neat - you might need to stand the resistors.
DeleteHi Alex. All built up but currently the LFO isn't working. I'll start looking for the usual suspects now. Depth is doing what it should and audio passes just fine. But the Rate pot does nothing and all voltages on the IC are steady at 4.50v ish.
ReplyDeleteI'll keep you posted. Cheers
Tag it VERIFIED lad. The top right link was only soldered on one side. Time to book an opticians appointment methinks.
DeleteSounds great! There's no denying its a PT2399 based effect. They're not as fast as BBD chips so you get the slightest (and I mean slightest) feeling that its lagging behind a bit. It's not as "lush" but has a sound I would call its own. Can easily pull off some 80's Mark King type sounds. Its definitely getting a box anyway!
I'll try to get a demo recorded once I get it in a box and send you the link.
Cheers again lad.
Cool!
DeleteThanks Ciaran!
A video would be great!
Hi Alex. Short demo found here...
Deletehttps://www.youtube.com/watch?v=-W4uEJiIiS8&feature=youtu.be
Cheers again lad.
Thanks Ciaran!
DeleteIt sounds great!
If you feed the pt2399 6 volts it clocks faster and you get less of a delay.
ReplyDeleteFound this info: Delay times for pt2399
Deletewith pin 6 grounded,
5V supply = 24ms
6V = 18ms
6.5V = 16.5ms
7V = 15ms
7.5V = 14ms
8.5V = dead chip
Good info Sean cheers. The data sheet makes no mention of any other supply voltages but 5V, so I've never really considered giving it any more.
DeleteDon't get me wrong though...when playing normally there's no hint of latency...just when you really scrutinise it one note at a time. It doesn't put me off at all. It's not filtered as heavily as some BBD designs so it really shimmers. Loving that!
I suppose the circuit would really benefit from a dry signal mixed in at the end. I may try that at some point but I'm quite happy for now.
Cheers
I want that dead chip tone so I'm gonna feed it with 9V. B)
DeleteSean - hopefully you're still being notified by this thread....
DeleteWhere did you find the info about delay times vs. supply voltage? The datasheet specified 6.5V as absolute maximum....
Thanks!
Have not built that many PT2399 choruses, but damn this sounds sweet. You can almost forget that it's on... But when you turn it off it's back to cold, ugly dystopia we know as reality.
ReplyDelete+m
Haha! Somebody needs a hug...and an Easter Egg
DeleteHi all. Does the (-) leg of led 2 just go to any ground? or even with the
ReplyDelete(-) leg of led 1 going to the 3pdt sw?
Yeah so if you want the speed LED to be on even when the effect is bypassed, just take the speed LED cathode to a ground. The LED will always be on and lit up even when the effect is bypassed.
DeleteThe bypass LED will have it's cathode to the 3PDT switch at the LED ground spot. This will be ur usual indicator LED.
Thank you Charles. If I want the rate light off when effect is off, how is it wired?
DeleteI would put the - led 2 lug to the 3pdt switch along with the on/off led - wire. Right?
DeleteI did away with the LED 1 (bypass LED) altogether. I took the LED 2 cathode to the usual spot on the bypass switch so when you kick it in, it lights up AND pulses to the rate. No popping. The 1K is its CLR so I would play with that to get your desired brightness.
DeleteThanks C.
DeleteGreat idea. 1 led 2 functions. I'll do that. I finished this and it seems noisey. Good effect but a kind of 'rush' behind the effect. Is yours dead quiet? I am waiting on 2399's. Might be that causing the noise. Thanks from Terre Haute, IN., USA.
Sorry I missed this Jeff. Yeah, there is a slight "rush" as you call it behind the notes. You can hear it in the demo I just posted to Alex above. I only had 6 chips left and this was the quietest one of the bunch.
DeleteI'd deffs recommend buying a large stock and auditioning them. Some are quieter than others.
Is it verified? No LFO noises?
ReplyDeleteThanks
My attempt came out as a warbling distortion, anyone else run into this?
ReplyDeleteReally liking this one. Have only the slightest hint of noise. Thanks all.
ReplyDeleteI just double-checked all of the little caps by the 2399 and now it works great. I is easy to get them confused down there. This is one of the nicer choruses I think even if it is not very versatile.
DeleteThe 1N5817 is use as polarity protection, and can be replaced by an other diode ? Or must be exclusively a Schottky diode?
ReplyDeleteIt is just a series polarity protection. Any diode will work. Schottkys just have lower voltage drop than other types. But. Any will work.
Delete+m
Thanks mirosol
DeleteMine seems not to work properly. I get the sound out and clean (a bit saturated if I strum too powerfull, but I think that's pretty obvious), but both the pots do nothing. From CCW to CW I get the same sound out, that has very little chorus on it. Double checked the solders, the voltages on the ICs and transistors and changed the pots, but I have no idea what to do now.
ReplyDeleteAnyway, I still don't have any chorus working, a little frustrating eheh
Hi Dan,
ReplyDeleteMight be "PT2399 lock out" - symptoms are similar to what you describe (ie no delayed signal) - though connecting pins 3 to 4 to ground, which is the case with this layout, should stop this happening. You didn't miss the link under the ic, did you?
Against my better judgement (and past experience) I went ahead and gave this one a shot.
ReplyDeleteFirst of all the effect is very nice. Like Miro said, it can be left on and you'll forget it's there until you turn it off and things go "ugh..."
HOWEVER... mine is noisy as hell. I tried over 30 different PT2399 chips and they all sounded exactly the same, so I don't think it's that chip doing it. It's almost like a fuzzy buzz clinging to every note. Dead quiet until I hit a string and then there's this layer of buzzy noise all over it. As a matter of fact, play the low E string high up on the neck gives an almost synth type sound, like an ugly brother of a Green Ringer.
Anyone got any idea what could be causing that? I spent the last few hours going through PT2399 chips and it got late. Tomorrow I'll try tracing it with a probe to see where the buzziness starts coming in.
No one else got anything like this?
Not constant, but when strumming hard.
DeleteCheck your voltage on pin 7, if above 2v the PT is being overdriven. If so, put a green LED from pin 7 to ground, should help.
I've done this on every PT build. I usually see the LED flicker when playing so it seems to do the trick for me.
I think Jon Patton is credited for the idea.
This comment has been removed by the author.
DeleteI'll give that a shot. Mine is dead quiet until the strings are touched. Once I'm generating any sound whatsoever through the circuit, there's an "aura" of fuzzy noise clinging to it. It's very hard to describe. I'll try to record it.
Deletethe solution of the green led between the pin 7 of the pt and ground is correct, after putting it it has eliminated the small distortion that he was dreaming of every note, thank you Michael, now the pedal sounds very well, I have used tl082 instead of tl062
DeleteWhat's the blue 50K thing in the middle?
ReplyDeleteThat's a 50k trimmer to bias the jfet. Be sure to check the build doc for instructions.
DeleteGot mine working today, nice but I think I'm going to try and up the PT voltage to 6V for shorter delay times as noted by Sean Caskey.
ReplyDelete6V = 18ms
6.5V = 16.5ms
Also, I think the LED on pin 7 is a must if using humbuckers or other hot pickups. Mine was also noisy without it.
I tried 5.7v, 6 and 6.7v.
ReplyDeleteSeems like the chorus progressively tightened up but also got a bit darker and less lush. It seems like the depth is backed off somewhat with the higher voltages.
I think there may be some tweaking needed for the higher voltages. 5.7v was still pretty good as is.
Going to see if adjusting R18 and/or R19 evens it back out with 6.7v supplied to pin 1.
Finished mine, works well but I have a continuous high frequency noise, like a biiip.
ReplyDeleteI used a TL072 until TL062.
I tried differents trimmer position, but nothing to do, this high sound is continuous.
Have you any idea where can come that sound?
Just wasted my day debugging a noisy Glam chorus I built today. Turned out it as a crappy power supply. Sounds great and I don't have any noise at all
ReplyDeletemade it and works great. just a silly question.
ReplyDeletewhat's the purpose of D1? i have the same result with and without it.
I've built this, and it works as a chorus, but if I strum normally it starts to distort. The green LED lights up very prettily. Any ideas? Otherwise, it's clean, but that distortion is quite a nice crunch... It also boosts the volume a touch, but my little angle did that too.
ReplyDeleteShould mention I only have the Green LED connected, LED 1 or 2 hooked up. Also using a TL072.
DeleteThe IC is the part of the LFO and not in the audio path, but I would change it to a TL062 just to be safe. Using high output pickups? You could add a pad resistor 100K? on your input...or up the right 10K (next to the 2 20Ks) to something like 100K and see if that helps.
DeleteOk, I tried all these things:
ReplyDeletePads across input to ground, started at 100k, went to 33k (getting there) to 10k and 2k (inaudible signal)
Changed that 10k to 100k. Some difference in overall volume (it decreased)
What fixed it was removing the green LED, which shall now be known as the clipping diode!
Just to be a little clearer, I changed the 10k next to the 20k resistors to 100k which caused the volume decrease. I was also using a 2n5484, and the test guitar used a JB pickup.
DeleteI'm losing signal at pins 14 and 16. Voltages check out in the LFO and on the 2399 within reasonable variation. I've audio probed the signal path and retain signal to pins 13 and 15 (lpf ins). Checked the caps around the 2399 and everything seems fine. Auditioned about 4 chips and the problem persists for each. Chip removal results in signal retention at the output, albeit very attenuated. Scratching my head on this one. Any ideas?
ReplyDeleteHi
ReplyDeleteTnx For the Pedal
I need a mix volume for this pedal can somebody help me ?
MIX pot or MODE switch? (chorus / vibrato)
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteMay I change the 10K resistor between the pin 13-14 of the PT2399 for a 10KA pot and do a volume control ?
ReplyDeleteDid someone think that it is too dark (low end) ?
ReplyDeleteHow could I fix the unity gain ?
ReplyDeleteThis comment has been removed by the author.
DeleteTo fix it, I increased the R09 (10k) for a 15k value. Now it´s perfect !
DeleteAny idea what the problem is if it sounds more like a tremolo than a chorus?
ReplyDeleteSad to say, but possibly with your expectations. The PT2399 won't sound all that close to classic BBD-based choruses.
Delete+m
This comment has been removed by the author.
ReplyDeleteJust finished it and testing unboxed at the moment.
ReplyDeleteIt has a nice Chorus-ish effect and it does not introduce any noise that I can detect into the signal chain which is great. The signal is nice and clean with no distortion that I can hear.
I am experiencing a percussive effect when picking and strumming. It's a little like a delay or reverb sound. Reading the comments someone mentioned a distortion they were getting and resolved it by some resistor value changes and removing the LED in the D1 position. Is there any consensus about that? Is this percussive side effect something consistent with the effect or do I need to do some troubleshooting?
Great layout as always.
Hello. I'm starting this just now.
ReplyDeleteI was wondering how come nobody ever talked about that trimmer.
If its usefull can we make it a pot?
If its just sitting there, cant we swap to a resistor? If yes, what value and where should it be attached?
Thanks! I guess for the moment im gonna go with a 100k trimmer chopped down by resistor because i dont have any 47k arround.
The trimmer is used to Bias the 2N5457 transistor to 6 volts, which is going to be different from one build to another so a static resistance wouldn’t be recommended. You’re going to want to adjust the trimmer to see 6 volts on the drain of the 5457.
DeleteIt’s mentioned on the layout but click the link to the Mad Bean website that is referenced in the description at the top of this page and it will explain how to bias the transistor in the build notes. Your 100k should be fine.
Hello,
ReplyDeleteThis is a nice chorus but I cant enjoy it because the rate is high since the beginning. When it is compared to another chorus, like zombie, the rate effect is evidencied. Any suggestion to control the rate efficiently ?
Thanks guys !
Did you use a 100k reverse log for the rate control?
DeleteYes, I did.
DeleteI could record a video to show it.
I already build more than 5 of this pedal, and all of them present this characteristic.
Could be the pt2399 ?!
That’s odd. Post your recording. I built one a couple of weeks ago and the rate seems to be quite useful. It sounds a little hollow compared to an analogue chorus but the rate and depth seem to be ok.
DeleteBuilt it with a 7805 regulator (6V) sounds good. 18ms min delay.
ReplyDeleteOriginally ticked a lot. Completely solved by:
1. Isolate the LFO grounds (pin4 of the TL062, C17 (10uF in upper left), and the new cap I will address in a moment). I did not isolate the ground of the rate LED as I wanted it to turn on with the effect. It doesn't seem to be causing ticking.
2. Make a new, isolated power rail for the TL062. Run from 9v, through a 100R to pin 8. Then off that junction, run a 10uF cap to ground - the isolated LFO ground mentioned above.
No ticking.
Oh, I also changed R9 (10K nearest the 4u7 in lower right) to a trimmer. This allows you to adjust the output volume to match the effect off volume.
I I meant 7806 regulator, obviously...
Deletehey. i have ticking too and noise but i dont think its coming from the LFO. i think it starts from the pt2399 because when i take the tl072 completely out of the board the same noise appears until i take the pt2399 out. althought with the tl072 there, seems as if the noise starts chorusing (if thats what ticking is). just to mention i used a 3mm red led for D1. nobody seems to mention anything about it and prolly its irelevant. and i didnt use i added you to hangouts perhaps you could help me. thx
Deleteby the way i just (isolated) the ground of the top left 10uf with tl072 pin 4 and the other 10uf that runs from pin 8 to pin 4 of tl072 and i provided straing from 9v throught a 100r on to pin 8. all as you suggested. this thing is still ticking.
Deleteokay i reversed everything to the original layout. it was my PT2399 that was outputing noise. not my lfo :O
DeleteSorry just trying to get peoples attention on old post here.
DeleteI finished building this today. It turns on and the signal passes through but is unaffected so the effect doesn't do anything. I've biased the JFET to 6V still no chorus effect.
Built this today, works like a charm and sounds good. No noise or ticks just perfection.
ReplyDeleteThanks.
The build docs moved to here
ReplyDeleteJust built this and cannot use the 50k trimmer to get from 9v down to 6v - the lowest it will go is about 7.5v. I tried using a 100k trimmer, instead, but the voltage still won't get all the way down to 6v - got it as low as 6.5v. Any ideas?
ReplyDeletetry to use a B50k pot so u can adjust well. i am using linear pot instead of trimmer
DeleteSounds like an out of spec 5457.
ReplyDeleteBut without power, measure the resistance from the middle pin of the 5457 to ground. Should be 10k.(remove the 5457 if if you used a socket, and measure from the middle socket to ground)
Then with power, measure voltage from the link to the left of the trimmer to ground, should be near 9v.
you can use j201
DeleteI just built this yesterday and it works great. thank you for this great layout. check out my demo https://www.youtube.com/watch?v=HD0cyFImFXQ
ReplyDeleteI finished building this today. It turns on and the signal passes through but is unaffected so the effect doesn't do anything. Any ideas?
ReplyDeleteDoes this have anything to do with the "dead" chip voltage?
DeleteUpdate: Ive biased the JFET to 6V still no chorus effect. Signal still passes through when on. Would love to get some input on this.
DeleteJFET only affects the signal after being processed by the PT2399.
DeleteNow, what voltages you have on the PT2399 pin 1 and on the regulator? Delay line needs to have 5V.
If you probe it, what kind of signal you have at PT2399 pins 13-16? Those are the delay line inputs/outputs, so if the chip is working right you should have delayed/chorused signal there.
Those should help you to figure out what's wrong.
Pin 1 and regulator are getting 5V
DeleteHow do I check the signal on pins 13-16?
I've also tried a second PT2399 chip but it didnt fix the issue
DeletePin 15 beeps once when checking continuity
DeleteCheck this out:
ReplyDeletehttps://www.diystompboxes.com/pedals/debug.html
With a probe like that you can, well, probe to see where the signal is present and were it is not.
On the other note, you should probably knife the gaps and triple check your trace cuts.
Hmm.. On pin 15, what is the other point you have continuity with?
+m
Thanks for the help. The problem was just a misplaced resistor in the end which goes to show to always double check where you place your components. Again thank you.
DeleteGood to hear you got it running!
Delete+m
Hi,
ReplyDeleteThank you for the very nice layout !
I am building it, and i have a question about capacitors :
1-The 10µF electro cap going to the 78L05's G&O is marked as being a Tantalum on the Madbean BoM : is it safe to use an electrolytic, or should i get a tantalum as specified ?
2- Yellow, rectangle caps are box type (or Mylar), ok. But I also notice some 100nF and 220nF red caps with a small rounded shape : Should I use ceramic caps ? I mean : Is it mandatory to NOT use box caps for these 100nF & 220nF ? Would it change the sound, or make the circuitb ehave differently ?
Tantalum caps do a better job reducing noise in digital circuits, the pt2399 is a digital delay that is "mimicking" an analog delay.
DeleteMandatory no, but may give a more stable, quieter effect.
You can certainly use an electrolytic and let your ears decide.
The red caps can be box, mylar, monolithic etc. I believe the only reason the smaller red caps were used for the layout deawing is just that they span 2 rows rather than typical 3 rows that a box cap takes. The yellow caps look funny/crammed when spanning just 2 rows.
So yes, a box cap can be used, either fold one leg back under itself to fit the exact layout, or angle the box cap diagonally and move the connections accordingly.
Perfect, thank you MAO.
Deletehello, can anybody tell me what the red square symbols mean? please c:
ReplyDeleteThat's where you want to make cuts in the trace. I usually drill them out very carefully and then use my multi-meter to check that there's no continuity (you'd be surprised by how just a tiny piece of copper hanging on can sneak past and ruin your whole build)
DeleteRed square are the cuts in the pcb Jdz.
DeleteI had already built 2 diy chorus(mxr micro chorus and p dimension chorus). Like the angel chorus, im also going to try build this one sure!,, just to compare there output signal and see whats the best ! Tnx guyz and more power!
ReplyDeleteRegards fr Philippines! Jun.
I was getting a volume drop. Tried a J201 instead of the 5457 and it restored to unity gain.
ReplyDeleteI was getting a volume drop. Tried a J201 instead of the 5457 and it restored to unity gain.
ReplyDeleteI was getting a volume drop. Tried a J201 instead of the 5457 and it restored to unity gain.
ReplyDeleteI finish my third glam chorus... I reeplace 2n5457 with J112, j113 and 2n5458...and works perfect with all.Thanks.. Sorry for my english ahaha
ReplyDeleteIts verified it works fine
ReplyDeleteIt works ! Super thank you, love it!
ReplyDeleteI built this last night. Used a TL072 for the op amp and it works great and I love the sound. really fantastic build. Possibly my Favourite effect that I have built from here so far.
ReplyDelete