Tried to reverse engineer these 2 pedals.

[PAGOON]

On reverb there were two pedals that were for sale by a music shop. The pedals were originally sold by one of my favorite bands and they only made a 100 of each and they are very expensive if they come up for sale… so I emailed the seller of these pedals and asked him if he could take pictures of both sides of the circuit board and give me the values or numbers of the components. So that I could possibly build one of theses pedals…. Well at first he sent me like 19 photos and when I told him I need to see the other side of the board and need to see the values of the pots… he said he would get back to me and never did until I asked for them again a week later… and he didn’t want to unsolder the 9v input plug. And the guy told me before I payed him that he builds and repairs pedals and amps…. Well here’s the question I was wondering if anyone recognizes what circuit these pedals are based off of. And or I doubt this would it be possible for anyone to figure out the schematics and recreate the pedals from these pictures and do maybe a point to point build or even better a pcb… if someone could sketch up a diagram of the two pedals if possible it would be awesome thanks

 

[PunchySunshine]

Looks like a simple enough circuit tbh, luuuuuv the carbon mojo!

 

[hamerfan]

I don‘t see carbons comps, these are Ceramic Film resistors and the cheaper ones with a tolerance of 5%.

 

[PunchySunshine]

I don‘t see carbons comps, these are Ceramic Film resistors and the cheaper ones with a tolerance of 5%.

Lol. Shows what I know! Awesome, even more punk rock than the uncleared flux!

 

[swyse]

Can't really do much with those photos since they are only one side. The transistor on the ska pedal might give a lot of insight as to what its based on. If you ended up getting the values for everything and both sides of the circuit board it would be pretty easy to reverse engineer it since they are both low parts count.

I don‘t see carbons comps, these are Ceramic Film resistors and the cheaper ones with a tolerance of 5%.

They look like carbon film resistors to me, definitely 5% tolerance though.

 

[PAGOON]

Lol. Shows what I know! Awesome, even more punk rock than the uncleared flux!

Elvis Cortez “left alone” and Tim Armstrong “rancid,transplants,operation ivy and head cat @ hellcat records” supposedly built them.

 

[PAGOON]

Can't really do much with those photos since they are only one side. The transistor on the ska pedal might give a lot of insight as to what its based on. If you ended up getting the values for everything and both sides of the circuit board it would be pretty easy to reverse engineer it since they are both low parts count.



They look like carbon film resistors to me, definitely 5% tolerance though.

I don’t think there’s any components underneath besides the potentiometers … it’s just a bummer he wouldn’t take the 9v input out so I could get a picture of the underside… I was wondering if this was a common type of circuit … no op amps just one electrolytic two transistors two diodes 9 resistors and 5 film caps. It definitely was a lucrative paddle for them to make and I just wonder how it sounds

 

[PunchySunshine]

and I just wonder how it sounds

Very punk rock I'm sure!

 

[swyse]

I don’t think there’s any components underneath besides the potentiometers … it’s just a bummer he wouldn’t take the 9v input out so I could get a picture of the underside… I was wondering if this was a common type of circuit … no op amps just one electrolytic two transistors two diodes 9 resistors and 5 film caps. It definitely was a lucrative paddle for them to make and I just wonder how it sounds

The issue is the traces, for example on the Ska pedal, there is a 4.7k resistor next to the transistor that seemingly has no connections, and they could go anywhere on the other layer so it's hard to say where it goes. As far as a common circuits goes, I don't know of any classic circuits that feature 3 knobs with only one transistor or two npn transistors and two diodes. I did notice the 1n4148 diodes don't appear to have a spoke pad which is interesting as I expected them to have a connection to ground for hard clipping, so they may be arranged like one of the stages on a big muff.

 

[hamerfan]

They look like carbon film resistors to me, definitely 5% tolerance though.

Just for the records: The dark brown ones are carbon comps, the beige ones are Ceramic Film, the small blue one is Metall Film and the big green is a Metal Wire.

 

[swyse]

Just for the records: The dark brown ones are carbon comps, the beige ones are Ceramic Film, the small blue one is Metall Film and the big green is a Metal Wire.

I wonder if this is a regional thing, I've always seen it as the old school dark brown ones being carbon comps and blue ones being metal film resistors like you, but the beige ones I usually see listed as carbon film and the large green ones as metal oxide. The ceramic resistors to me are the beefy rectangular white ones.

 

[Fingolfen]

I wonder if this is a regional thing, I've always seen it as the old school dark brown ones being carbon comps and blue ones being metal film resistors like you, but the beige ones I usually see listed as carbon film and the large green ones as metal oxide. The ceramic resistors to me are the beefy rectangular white ones.

The light brown ones I get are not ceramic, they're usually carbon film (not carbon comp) - though conventions may vary.

 

[Feral Feline]

On reverb there were two pedals that were for sale by a music shop. The pedals were originally sold by one of my favorite bands and they only made a 100 of each and they are very expensive if they come up for sale… so I emailed the seller of these pedals and asked him if he could take pictures of both sides of the circuit board and give me the values or numbers of the components. So that I could possibly build one of theses pedals…. Well at first he sent me like 19 photos and when I told him I need to see the other side of the board and need to see the values of the pots… he said he would get back to me and never did until I asked for them again a week later… and he didn’t want to unsolder the 9v input plug. And the guy told me before I payed him that he builds and repairs pedals and amps…. Well here’s the question I was wondering if anyone recognizes what circuit these pedals are based off of. And or I doubt this would it be possible for anyone to figure out the schematics and recreate the pedals from these pictures and do maybe a point to point build or even better a pcb… if someone could sketch up a diagram of the two pedals if possible it would be awesome thanks

[Bold emphasis in the quote mine]


I can totally understand the seller not wanting to desolder anything, why risk accident/damage if it can be avoided with the pedal already in good working order. He desolders the power-jack and accidentally burns a cap while doing so, well now the pedal won't fetch as much money.

SO...

What did you pay him for? Did you buy these?

Best bet would be to buy them, get the pics & info needed; and with the actual pedal in hand probe it to help map out what's connected and derive the schematic from the physical pedal;
THEN you can keep the pedals or resell them to recoup your cost.

 

[music6000]

From what I have seen, the Punk sounds like a tube screamer but does it with 2 MPSA18 Transistors.

 

[Feral Feline]

I find that highly interesting, that a couple of BJTs can accomplish an op-amp sound!
Especially so as the MPSA18 is NOT a Darlington like most other MPSAxx transistors.

Maybe Robert should purchase these two pedals...

 

[PAGOON]

Ohhh very interesting…I tell you it’s not worth the 500-700 dollars they go for but nothing is worth the money theses days.. pedalpcbs ACTUAL OVERDRIVE is one of my favorite overdrives. i use my magical secret diodes… here’s a clue…. Not Telling Everyone…

 

[Laundryroom David]

To complicate things even more (not for this pedal, but still) Gorva has molded metal film resistors that look like carbon comps.

 

[swyse]

To complicate things even more (not for this pedal, but still) Gorva has molded metal film resistors that look like carbon comps.

I didn't know about those, that seems like something that could easily cause a mess down the road like the TGP 920d PIO cap and gibson bumblebee drama.

 

[Coda]

Probably just a pair of Tubescreamers...

 

[Cybercow]

The problem with trying to reverse engineer (trace) a populated PCB based on photos alone is insufficient info to conduct a successful trace. With the PCB thus populated, one will miss any vias (if they exist) underneath components. A successful trace usually requires a hands-on with a DMM approach at the very least. There is not enough info in the photos to do such a trace.