Visual Sound Garagetone Chainsaw

[mirosol]

Not much info around, so i thought i'd ask if anyone has tinkered around with this? Would surely like to see the schematic - mainly to see which classic circuit it's based on.
It's all SMD, so rather than modding it, i would draw a electronic switching-less stripboard layout and perform the mods there... I haven't even heard what the box sounds like, but i'm told it's really good.

Got one shot of the board from a guy who wants to tame the hiss and reduce overall bass content.

All input is welcome!

[commathe]

I like garage rock. I'm really curious.

[MoonWatcher]

I only see a single op amp there, so if that's the case, it kind of limits what Visual Sound might have based it on.

If there's a transistor that isn't used in the bypass circuitry, it could probably be a modified DS-1. If not, it is probably like a Crunch Box or similar, I might think.

What is the value of the distortion pot? If it's 100K, that could reveal some stuff right there. Figuring out the clipping diodes would help, too.

A Crunch Box thing is more likely to have 100nF or 220nF caps in between the stages, so they would be ceramic SMT. The DS-1 uses 470nF, so those could be electrolytic.

[MoonWatcher]

I looked at the picture again. The two electrolytic caps that are vertical appear to be for filtering/biasing. The four electrolytic caps that are flush with the board look like signal caps, and I think they are all 1uF.

I only see what looks like a single diode bridge that would be used for clipping diodes.

I also see what looks like resistors for the transistor stage in the DS-1 - 102, 103, 473, and 221. There is also what looks like it would be a small value cap in proximity, which would be parallel to the 473 resistor.

I just can't make out a transistor anywhere. There should also be a 472 resistor at the op amp's input.

Something Guv'nor-based is also going to have a lot of the same resistor values that you won't find in a DS-1 - lots of 102's and 104's.

The DS-1 will also have a pair of 682 resistors for the tone circuit.

Those 4 electrolytic caps that look like they are in the signal path are too many for something like a Crunch Box. If there's an electrolytic connected to the distortion pot with a 472 resistor in series, that should connect to an op amp pin. There will also be a 103 resistor and another small value cap like the one that will be in series with the 473 resistor mentioned above.

Just more clues one way or the other. You almost don't need to know the values of the ceramic caps to figure out what this is derived from.

[lborl]

Apologies for digging this old thread up but did anyone ever manage to identify or trace this circuit? The last post on this thread makes it sound like it's too obvious to bother saying, but I'm at a loss with it. For example, there's two IC's in that photo, not one as stated: one is slightly obscured by the shadow of that third pot shaft (and also the visible CD4053 onboard is clearly labelled 'IC2'...)

I used to have one of these that I now regret selling - they were ridiculously cheap and seemingly easy to replace at the time, but now they seem to be out of production. I'm weirdly picky with overdrives but I really liked this one. It sounded similar to the original (non-'Big') Muff but with a little bit more life in it: I liked it so much that I started to feel I was using it too much and that, by some twisted self-defeating logic (and being cash-poor at the time), I decided I should just be trying to get my basic amp settings dialed in to replicate it

[lborl]

So, an anticlimactic update: I ended up buying another one of these partly to get a shot of the traces for this thread and partly because I kind of missed having it around. But, there are no visible traces - they're buried in the middle layer of the board.

I guess I could potentially trace connections by checking for continuity with a multimeter?