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
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Monday, 18 February 2013
Roger Mayer Voodoo-1
The bass version was requested, so i thought i'd draw these both, as only main difference between the two is the tone stack.
.....also what does the 1M6 resistor between the base of Q1 and emitter of Q2 do, electronically speaking? Just noticed it isn't present in the bass version.
Miro, which schematic did you follow for this one? Just looking at Analoguru's and I can't see a feedback resistor and it doesn't have a 70k resistor but a 10k. Thanks!
Phew! At last!...... I can't tell you how many "deliberate" mistakes I made with this ( think I need a break too, Miro)! Verified and lovely it is. Thanks, once again :-)
Reversed the pots, added suggestion for lin taper for gain and tagged it. Super! You're the man!
Are you implying that i'm on a break! That's outrageous! I just thought i'd finish some builds for a change :) Started yesterday morning and now i have 7 new boxes and 3 more waiting for finishing touch. +m
I have built this but as it stands but I don't think that the tone stack caps are helpful. At full treble virtually the whole signal has to pass through a 100p cap and at full bass there is just a 100pf cap to suck away treble. You might imagine that at full treble the volume would all but disappear leaving a bit of a reedy tone and at full bass you would have a middling tone - and you would be right! Also the 70k resistor makes little sense. On the bass version it is 10K. So I looked at the interweb and found the analogguru schematic and applied those tone-stack values (and reduced the 70K resistor to 10K - several opinions being being that 70K was a typo for 10K on other schematics) and the result is that the tone control now gives a fuller range of bass to treble with less volume drop and the middle tone is in the middle of the pot rotation and also there is more volume overall. I temporarily pulled the 1M6 feedback and that tightened up the signal which is perhaps why it is missing on the bass version but I think that it makes the sound too brittle for guitar and with the 1M6 in place it gives a more mellow sound. As to the 50K gain control I used a linear pot but I think that John Kallas is right in that reverse log would be better and in fact this is what analogguru specifies in his schematic. Its just my opinion but if anyone feels that their Voodoo-1 clone is a bit lacking they could try these mods (Col-Row):- Replace 100pf at 17-1/17-2 with 4n7 Replace 100pf at 14-13/14-15 with 2n2 Replace 100pf at 12-15/12-16 with 3n3 Replace 70K at 17-7/17-11 with 10K
Did one of these. Very nice vintage distortion. Sounds very much like a fuzz face when ran into an amp with no headroom. Starts spitting and splatting all over the place. With a 100% clean amp it's somewhat similiar to EVH's "brown sound" I think. I found the 50k LIN pot very bad. The first half of the taper was useless as distortion started happening around 20k resistance so I swapped a 25k LIN there. Now there's no useless taper and the taper itself is decent enough. Rev log might be better but I don't feel the need to order one. Cheers!
I have an original here that I'm currently fixing. I don't know if it's a revision difference but it's fairly different from this layout. It has 3n3, 2n2 and 4n7 caps where this layout uses 100pf. The chip is LM301. There's 3 BC550C trannies and one 2N546. 5 1N4148 diodes instead of 4. But yeah. Also it has the 47k REV LOG pot just like we've noticed that this layout needs. I have to A/B this to my clone which is built according to this schem! I think this real one is a bit fuzzier and softer with more bottom end but we'll see.
Yep, the PCB says 1.1 so it might be that this is an old version. I tried tracing the PCB a little bit and subbing the cap values as they seemed to be related to the fatness control. I felt the fatness control was weird and it was not even relatively close to what the original pedal did. I suggest you try this because it brought it alive! Now it's very close to the original I have here. The fatness range goes from overly screeching bumblebee stuff to fat Hendrixy tones.
Swap the 100p directly connected to tone 3 with a 2n2 And the 100p adjacent to it with the other side connected to ground with a 3n3 And the last 100p at Output 1 with a 4n7
Looks like he selected resistor values carefully :)
ReplyDeleteHi Miro, small point, but the lower pic has some cuts missing where the IC goes :-)
ReplyDeleteFixed. Thanks.
Delete+m
.....also what does the 1M6 resistor between the base of Q1 and emitter of Q2 do, electronically speaking? Just noticed it isn't present in the bass version.
DeleteFeedback resistor, passing current back to Q1 base
DeleteCheers Mark,
DeleteMiro, which schematic did you follow for this one? Just looking at Analoguru's and I can't see a feedback resistor and it doesn't have a 70k resistor but a 10k. Thanks!
Mark
.....forget that, I've just found the correct Justin Philpot schematic!! oops :-)
DeletePhew! At last!...... I can't tell you how many "deliberate" mistakes I made with this ( think I need a break too, Miro)! Verified and lovely it is. Thanks, once again :-)
Delete....oh, I think tone 1 and 3 need swapping?
DeleteMark
Me again! Gain on lugs 2 and 3 is better :-)
ReplyDelete.....and I don't recommend a log pot for the gain either.... All the action is at the very end. Over and out!!
DeleteReversed the pots, added suggestion for lin taper for gain and tagged it. Super! You're the man!
DeleteAre you implying that i'm on a break! That's outrageous! I just thought i'd finish some builds for a change :) Started yesterday morning and now i have 7 new boxes and 3 more waiting for finishing touch.
+m
Seriously? I knew you wouldn't have your feet up! Just old, piss taking fuckers like me do that. Now.... Pass me my zimmer frame and let's rock!! :-D
DeleteI have built this but as it stands but I don't think that the tone stack caps are helpful. At full treble virtually the whole signal has to pass through a 100p cap and at full bass there is just a 100pf cap to suck away treble. You might imagine that at full treble the volume would all but disappear leaving a bit of a reedy tone and at full bass you would have a middling tone - and you would be right! Also the 70k resistor makes little sense. On the bass version it is 10K. So I looked at the interweb and found the analogguru schematic and applied those tone-stack values (and reduced the 70K resistor to 10K - several opinions being being that 70K was a typo for 10K on other schematics) and the result is that the tone control now gives a fuller range of bass to treble with less volume drop and the middle tone is in the middle of the pot rotation and also there is more volume overall. I temporarily pulled the 1M6 feedback and that tightened up the signal which is perhaps why it is missing on the bass version but I think that it makes the sound too brittle for guitar and with the 1M6 in place it gives a more mellow sound. As to the 50K gain control I used a linear pot but I think that John Kallas is right in that reverse log would be better and in fact this is what analogguru specifies in his schematic. Its just my opinion but if anyone feels that their Voodoo-1 clone is a bit lacking they could try these mods (Col-Row):-
ReplyDeleteReplace 100pf at 17-1/17-2 with 4n7
Replace 100pf at 14-13/14-15 with 2n2
Replace 100pf at 12-15/12-16 with 3n3
Replace 70K at 17-7/17-11 with 10K
Built as per layout above... AB'd against an original voodoo-1 and no difference what so ever.
ReplyDeleteWhilst in the studio a person of not popped in and had a poke around... said its not 100% exact but close enough!.
Very much verified.
Have pics if you want em...
****person of NOTE...
DeleteDid one of these. Very nice vintage distortion. Sounds very much like a fuzz face when ran into an amp with no headroom. Starts spitting and splatting all over the place. With a 100% clean amp it's somewhat similiar to EVH's "brown sound" I think. I found the 50k LIN pot very bad. The first half of the taper was useless as distortion started happening around 20k resistance so I swapped a 25k LIN there. Now there's no useless taper and the taper itself is decent enough. Rev log might be better but I don't feel the need to order one. Cheers!
ReplyDeleteAgh, I was wrong. The 25k lin was awful too. Lucked out and found a 50k rev log. Now it's perfect!
DeleteThanks for the info matey
DeleteI have an original here that I'm currently fixing. I don't know if it's a revision difference but it's fairly different from this layout. It has 3n3, 2n2 and 4n7 caps where this layout uses 100pf. The chip is LM301. There's 3 BC550C trannies and one 2N546. 5 1N4148 diodes instead of 4. But yeah. Also it has the 47k REV LOG pot just like we've noticed that this layout needs. I have to A/B this to my clone which is built according to this schem! I think this real one is a bit fuzzier and softer with more bottom end but we'll see.
ReplyDeleteYep, the PCB says 1.1 so it might be that this is an old version. I tried tracing the PCB a little bit and subbing the cap values as they seemed to be related to the fatness control. I felt the fatness control was weird and it was not even relatively close to what the original pedal did. I suggest you try this because it brought it alive! Now it's very close to the original I have here. The fatness range goes from overly screeching bumblebee stuff to fat Hendrixy tones.
DeleteSwap the 100p directly connected to tone 3 with a 2n2
And the 100p adjacent to it with the other side connected to ground with a 3n3
And the last 100p at Output 1 with a 4n7