Duplicate pedals don't sound the same?

[shimster]

Hey guys,
  I'm new at this.  I've only built a few pedals, a couple 386 boosts, distortion, and a tube overdrive with boost.  My latest pedal was a twin tube overdrive.  I spent weeks with it on my breadboard until I thought I stumbled upon the sweet spot of tube overdrive so I built it and it was pretty sweet, except I want to give it more mid range punch and tone down the drive... So I put it on the breadboard again with identical components, and it sounds nothing like the one I built. I've checked my notes and traced the connections on the pedal itself, and there are small differences, like I don't have all the pots installed on the breadboard, but it just doesn't get nearly as much gain as the pedal.  I would say it sounds about half as overdriven.
  Does this happen to anyone else? I think I may have fried a component and didn't realize that it was the secret ingredient... I'd hate to take apart my pedal and reverse-engineer it but I'm tempted to do just that.  Anyway, I'll pull all the components and try to breadboard from scratch and see if it comes back to life.
  Do you guys find that when you build a copy of a pedal that it sounds different?  How frustrating is that?
-Dan

[dschwartz]

are you using the same tube?

[aron]

>Does this happen to anyone else? I think I may have fried a component and didn't realize that it was the secret ingredient... I'd hate to take apart my pedal and reverse-engineer it but I'm tempted to do just that.  Anyway, I'll pull all the components and try to breadboard from scratch and see if it comes back to life.

It's frustrating YES!!!!!!!!!

It depends on the design and the components. It happens to everyone. How many amps have you heard that sound different? Try a number of pedals that are supposed to be identical. All you can do is try and match what you can as closely as you gain. hFE, capacitors, resistor tolerances... Yes, this has happened to me for sure!

[R.G.]

I pop this in here every few months to a year, but this is a beautiful opening.

If you're making effects, consistency is far more to be valued than a few magically great results.

If you have consistency, you can work your way towards being consistently good. If it's erratically good, you have no clue what to improve.

[shimster]

Thanks Aron and R. G. for the advice.  I told myself over and over that it was too good to be true when I achieved that sweet overdrive sound.  I'll put in the time analyzing every component in that pedal until I can duplicate then improve the circuit.  I love this new hobby so I'm willing to go the extra mile...  The laws of physics be a harsh mistress!

Edit: Daniel, I just saw your reply. Yes, I'm using the same type of tubes.  And I do plan to swap them out to see if there is a change in sound.

[aron]

Start with the components that have the most variance. Tubes first.

[Rob Strand]

Measuring and comparing DC voltages can pin-point differences very quickly.  It can also give you a hint about how to make the bad sound good.

[dschwartz]

Thanks Aron and R. G. for the advice.  I told myself over and over that it was too good to be true when I achieved that sweet overdrive sound.  I'll put in the time analyzing every component in that pedal until I can duplicate then improve the circuit.  I love this new hobby so I'm willing to go the extra mile...  The laws of physics be a harsh mistress!

Edit: Daniel, I just saw your reply. Yes, I'm using the same type of tubes.  And I do plan to swap them out to see if there is a change in sound.

Yes, try that,.in my experience, tubes, even the same type and brand may sound very different, specially with pedals with only one tube..in hi gain preamps the effect is not that noticeable, but in 1-tube OD´s is pretty evident..ask anyone with tube drivers.
The rest of the components may vary the results, but i think in a much more subtle way.

[ocg]

i got a ts9 copy, i recently compare it with a original one...there was a mid range tone in both but the original ts9 has a "back" low end i can't explain....so im going to do a exact copy of that ts9 (same pcb, same components, same fet switching)...if after that the clone doesn't sound the same i will retire of the D.I.Y life for ever.

...and yeah of course is frustrating

[BAARON]

Don't forget tolerance on components!

I've seen pots that are 30% out of spec.  Most film and ceramic caps are ± 10% or so, while electrolytics can be up to -20%/+50%.  Most carbon film resistors are ±5%, and most metal film are 1% or 2%.  And tubes?  Oh man.  Tubes are SO inconsistent.

So for example, if your first build had a gain pot that was +30% out of spec and the second one was -30% out of spec... you might notice a difference. 

A lot of tube amp builders seem to swear by certain brands of capacitors, because they swap caps in and out and say "oh, this one sounds best, I guess Orange Drops work best for this part of the circuit," and fail to take into account the fact that they're swapping parts that could have a 20% variance in value between them... and that'll make more of an audio difference than Mullard vs Orange Drop ever would!

[Mark Hammer]

This is why I constantly remind people that many of the widely circulated rumours concerning "this issue" or that of a certain pedal, or use of "this transistor" or that, or "this cap type" or that, and so on, should be treated as very VERY tentative until someone has sat down with multiple copies of the same pedal and sorted out what stems from the individual differences in the specifics of the components used in THAT specific pedal, and what is common to all pedals of that type, or all pedals using that chip/transistor/cap, etc.

Otherwise, it becomes a bit like pronouncements that "all women are blonde and skinny, and all men are scruffy and overweight", arrived at by looking at one example from each sex.

Just out of curiosity, I will ask the more experienced folks here to list their "top ten" (or however many items they deem worthy of mentioning) most variable components, in order of variability.

So, for example, I'll nominate diodes, LDRs, pots, and caps, and point out that:
- diodes can vary a good 20% between lowest and highest forward voltage for any given part number (eg, 1N34a) in my experience.
- LDRs can vary a great deal in terms of both their maximum and minimum resistance, as well as the illumination-vs-resistance gradient.
- pots vary, as mentioned.  Not sure whether the degree of variation has any correspondance with diameter (i.e., are 24mm pots more "precise" and on-spec than 16mm?)
- as has been pointed out many many times over, caps vary in value, not only when brand new out oft he box, but over time as well.

[Sir H C]

Don't forget gear too.  Often someone will hear a demo with a Les Paul and wonder why they don't get such a heavy sound or that crunch with their strat. 

[MikeH]

I built myself an OD that I really like- it's my main OD.  My friend decides he wants one too; bugs me for weeks and finally gets me to build him one.  And the one I built for him sounds even better!  I was so pissed...

[Mark Hammer]

I made a Rangemaster and demoed it for a guy who, until recently, ran one of the best vintage gear stores in the region.  The guy offers me some cash for it, and I say "Sure", thinking I can make myself another.  Well, I may have a mountain of NOS GE transistors to play around with, but try as I might, I have NEVER been able to make/get one sound as good as the one I sold that guy.

[analogmike]

I made a Rangemaster and demoed it for a guy who, until recently, ran one of the best vintage gear stores in the region.  The guy offers me some cash for it, and I say "Sure", thinking I can make myself another.  Well, I may have a mountain of NOS GE transistors to play around with, but try as I might, I have NEVER been able to make/get one sound as good as the one I sold that guy.

Same here, 3 transistor SUPAFUZZ/ MKII pedal. I even documented the gains and type of each transistor. I should have kept it.

[Paul Marossy]

I pop this in here every few months to a year, but this is a beautiful opening.

If you're making effects, consistency is far more to be valued than a few magically great results.

If you have consistency, you can work your way towards being consistently good. If it's erratically good, you have no clue what to improve.

Lots of wisdom in this statement!

[Sir H C]

I pop this in here every few months to a year, but this is a beautiful opening.

If you're making effects, consistency is far more to be valued than a few magically great results.

If you have consistency, you can work your way towards being consistently good. If it's erratically good, you have no clue what to improve.

Lots of wisdom in this statement!

Yes, that is what impresses me with Budwieser and the like, every time it is the same.  Not to my liking, but it is spot on the same.

[MikeH]

I pop this in here every few months to a year, but this is a beautiful opening.

If you're making effects, consistency is far more to be valued than a few magically great results.

If you have consistency, you can work your way towards being consistently good. If it's erratically good, you have no clue what to improve.

Lots of wisdom in this statement!

Yes, that is what impresses me with Budwieser and the like, every time it is the same.  Not to my liking, but it is spot on the same.

Hey if my urine tasted the same every time would you be impressed?   

Sorry, that was soooo crass.

[Sir H C]

I pop this in here every few months to a year, but this is a beautiful opening.

If you're making effects, consistency is far more to be valued than a few magically great results.

If you have consistency, you can work your way towards being consistently good. If it's erratically good, you have no clue what to improve.

Lots of wisdom in this statement!

Yes, that is what impresses me with Budwieser and the like, every time it is the same.  Not to my liking, but it is spot on the same.

Hey if my urine tasted the same every time would you be impressed?   

Sorry, that was soooo crass.

But somewhat true.  Still if you could eat asparagus and have it smell the same, that would be a feat.

[MikeH]

Ha ha ha.  *Topic thoroughly and unpleasantly derailed*