Visual Sound - Garagetone Chainsaw

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Visual Sound - Garagetone Chainsaw

Postby mirosol » 03 Oct 2013, 09:53

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!
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Re: Visual Sound Garagetone Chainsaw

Postby commathe » 21 Oct 2013, 04:36

I like garage rock. I'm really curious.
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Re: Visual Sound Garagetone Chainsaw

Postby MoonWatcher » 21 Oct 2013, 13:40

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.
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Re: Visual Sound Garagetone Chainsaw

Postby MoonWatcher » 21 Oct 2013, 13:57

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.
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Re: Visual Sound Garagetone Ctrahainsaw

Postby lborl » 10 May 2018, 17:31

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 :roll:
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Re: Visual Sound Garagetone Chainsaw

Postby lborl » 20 Jul 2019, 13:41

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?

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Re: Visual Sound Garagetone Chainsaw

Postby roseblood11 » 17 Feb 2020, 01:30

Can you post some more pictures, please?

Here's a thread about the Visual Sound Custom Shop OD which *might* be based on the Chainsaw Distortion.
viewtopic.php?f=33&t=30427&p=278948#p278948


It would be great to have schematics of both pedals...
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Re: Visual Sound Garagetone Chainsaw

Postby roseblood11 » 17 Feb 2020, 02:05

There's a NEW Chainsaw Distortion pedal on Ebay France at the moment, for 55€
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Re: Visual Sound Garagetone Chainsaw

Postby soulsonic » 17 Feb 2020, 06:27

lborl wrote: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?

This is so confusing. In that previously posted image, you can definitely see visible traces.


Can't help but say the name suggests an HM-2, but I wouldn't be shocked in the least if it wasn't
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Re: Visual Sound Garagetone Chainsaw

Postby soulsonic » 17 Feb 2020, 06:35

and this one pic of the board doesn't tell us much of anything. Since this appears to be mostly SMD, there could very easily be several more opamps on the other side!
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Re: Visual Sound Garagetone Chainsaw

Postby Hanky- » 17 Feb 2020, 07:01

There are some components that looked like transistors but could be diode pairs in smd form, located under the pots. They aren't visible in the pics but can be seen from the side.
The reason I say smd diode pairs is because their Drivetrain pcb has no visible diodes on it but a three legged component that looks like a transistor with a label on the pcb printed DD1, I don't know what that is supposed to mean but the reverend drivetrain had pair of diodes in it. It's been a while since I opened the chainsaw pedal but I don't know what its based on.

Their Custom OD from the gutshot pics I found online has the garagetone pcb in there. Guessing by the fact that I found a post once mention that VS support had said that the Custom OD was derived/based on the chainsaw pedal ckt, I'm pretty sure it is a modded chainsaw with a added bass boost switch, tone pot change & with changes to components on the the pcb perhaps. I don't the chainsaw sold very well cause it wasn't quite high gain metal genre distortion, so VS may have modded a few and sold them as the Custom OD.
https://reverb.com/au/item/3538159-visu ... al-pd-2768
Image
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Re: Visual Sound Garagetone Chainsaw

Postby soulsonic » 17 Feb 2020, 07:44

There is no way of knowing from this picture if it's the same thing.
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Re: Visual Sound Garagetone Chainsaw

Postby Hanky- » 17 Feb 2020, 16:44

soulsonic wrote:There is no way of knowing from this picture if it's the same thing.

Yeah unless I happen to have one of the two in hand :wink:

The DC jack is changed to a panel mount-bolt on type but the pcb is the same, along with the in/out jacks & footswitch.
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Re: Visual Sound - Garagetone Chainsaw

Postby soulsonic » 18 Feb 2020, 04:03

well, since you've got one in-hand, you're welcome try tracing it. :horsey:
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Re: Visual Sound - Garagetone Chainsaw

Postby Hanky- » 18 Feb 2020, 08:00

I can try to verify if the ckt is based on a particular schematic but I'm no good at drawing a new one. :oops:

These are a little difficult to trace because the back side of the board is like not bare at certain common points, the component side is easier to trace except for the parts located underneath the pots, light doesnt seem to reach some of them & if a cap is present whose value can only be determined when its out of ckt then thats a dead end for me cause the only way I know to remove these pots is to nip them which destroys them :block:

If you guys need values for the caps I can help with that :)
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Re: Visual Sound - Garagetone Chainsaw

Postby lborl » 08 Mar 2020, 12:39

I only just discovered myself that they'd hidden things under the potentiometers, the devious bastards. I see a 'Q103' under the rightmost pot (Volume), so I'm going to carefully desolder all the pots on mine so that we see what's in there.

All the traces seem to be on the top-side of the board, I'm not looking forward to tracing all that part. Also the leftmost IC seems just to be for bypass switching. The other one is an '0728 eZ945' if that means anything to anyone?

Got to say I'm surprised how many parts went into this circuit - it sounds much simpler, if you see what I mean. 'Chainsaw' is a really bad name for it - it's nothing like an HM-2 - I'd have called it something more like 'Brown Paper'. The stamp on the PCB is 'GT Ripper'.

https://drive.google.com/open?id=19l_4j ... _W1OXa4cwg
https://drive.google.com/open?id=1kE-_n ... RXBtBOLt_X
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Re: Visual Sound - Garagetone Chainsaw

Postby lborl » 08 Mar 2020, 13:01

Can't seem to get Google Drive images to embed nicely so here's another go at it:

Image
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Re: Visual Sound - Garagetone Chainsaw

Postby Hanky- » 08 Mar 2020, 18:12

lborl wrote:I only just discovered myself that they'd hidden things under the potentiometers, the devious bastards. I see a 'Q103' under the rightmost pot (Volume), so I'm going to carefully desolder all the pots on mine so that we see what's in there.

All the traces seem to be on the top-side of the board, I'm not looking forward to tracing all that part. Also the leftmost IC seems just to be for bypass switching. The other one is an '0728 eZ945' if that means anything to anyone?

Got to say I'm surprised how many parts went into this circuit - it sounds much simpler, if you see what I mean. 'Chainsaw' is a really bad name for it - it's nothing like an HM-2 - I'd have called it something more like 'Brown Paper'. The stamp on the PCB is 'GT Ripper'.

https://drive.google.com/open?id=19l_4j ... _W1OXa4cwg
https://drive.google.com/open?id=1kE-_n ... RXBtBOLt_X

The large IC on the left is part of switching ckt. You can find in the millenium bypass 2+ schematics at geofex. The ez945 is a tl072 opamp.

If you are able to the get the pots off, just let us know like in the pics you posted, that where those out of sight parts trace is connecting. You can put a flashlight underneath the pcb to see clearly where the traces lead to. If you can help with that then I could help out in tracing the rest & drawing out something.
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Re: Visual Sound - Garagetone Chainsaw

Postby lborl » 26 Mar 2020, 14:02

One desoldering gun purchase later...

Image

Three maybe-transistors and five more resistors under there.

The maybe-transistors are marked 'Z9' (with my loupe thing on) with '- +' underneath it - to the left of the Z9 in the top-left corner is a tiny square character that may be a letter or a manufacturer logo - I've misplaced the more powerful lenses for my magnifying thing. From looking online it seems that they could be three-legged Zener diodes or a JFET? http://www.s-manuals.com/smd/z9

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Re: Visual Sound - Garagetone Chainsaw

Postby lborl » 26 Mar 2020, 16:00

Image

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