Valvette Custom Drive  [traced]

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Ice-9
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Post by Ice-9 »

Here are some gut shots of the Valvette custom drive taken during dissasembly.

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Ahh ! all gooped up
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newly de-gooped

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diodes have no markings, they look like germaniums

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The opamp is a OPA2107AP
the fets are N channel 2N7000 used as part of the clipping circuit along with the diodes.

quite a nice sounding low gain overdrive that cleans up very nicely at minimum gain.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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culturejam
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Post by culturejam »

Thanks for posting!

But, uh, where is the part where the pedal is "Re'd"?

I'm assuming that means "reverse engineered". :D

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Ice-9
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Post by Ice-9 »

culturejam wrote:Thanks for posting!

But, uh, where is the part where the pedal is "Re'd"?

I'm assuming that means "reverse engineered". :D
Yes thats exactly what it means, I am just drawing up the schematic now to post having just double checked it. I only got this pedal delivered this morning, So this is quite fast work to take some pics and de goop and trace it, then get it all posted in a matter of a few hours. :)

You asked for it so here it is, next post
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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Ice-9
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Post by Ice-9 »

Schematic

Image

VR1A and B is a dual gang pot to control the gain.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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culturejam
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Post by culturejam »

Ice-9 wrote: So this is quite fast work to take some pics and de goop and trace it, then get it all posted in a matter of a few hours. :)
Whoops! :oops: :lol:

Nice work!

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Post by Hides-His-Eyes »

So is the second part of the dual ganger to reduce the effect of the diodes to ground at low gain values?
Testing, testing, won too fwee

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Post by IvIark »

Nice work! And yet another Zendrive added to the list.
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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Ice-9
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Post by Ice-9 »

Hides-His-Eyes wrote:So is the second part of the dual ganger to reduce the effect of the diodes to ground at low gain values?
When the gain is at max the the pot VR1A is at max resistance (IC1a feedback loop) and VR1B is at minimum resistance (Hard clipping ) So yes you are correct.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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Post by DimebuGG »

Hmmmm clipping section in both feedback loop and to ground sounds like the pedal is being choked!
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Post by okgb »

Nice work
I don't feel bad about seeing degooped circuits when it turns out
to not be their own circuits , dual pot , anything use these in a
simular manor ?

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Post by DougH »

IvIark wrote:Nice work! And yet another Zendrive added to the list.
Not exactly... Shunt diode clipping with variable resistance adj by gain control. Hammer's SWTC too.
"You have just tubescreamered or fuzzfaced yourself " -polarbearfx

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Post by Ice-9 »

okgb wrote:Nice work
I don't feel bad about seeing degooped circuits when it turns out
to not be their own circuits , dual pot , anything use these in a
simular manor ?
I agree, when this pedal arrived today and i seen the goop i thought good it may be something a bit special in which case i would not have posted the schematic, but after working out the schematic and it turned out pretty standard stuff then i decided to post it as this pedal cost me £130 uk. which is a lot for a circuit that is based on others and modded a bit. Thats why I posted the schematic.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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Post by IvIark »

DougH wrote:Not exactly... Shunt diode clipping with variable resistance adj by gain control. Hammer's SWTC too.
No not exactly, but Supercharged Zendrive would still be a more appropriate name.
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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Post by mcaviel »

Ice-9 wrote: I agree, when this pedal arrived today and i seen the goop i thought good it may be something a bit special in which case...
This is what i always thought about my gooped pedals, that the builder is hiding his special circuit when the truth is that he is hiding a clone.

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Post by DougH »

IvIark wrote:
DougH wrote:Not exactly... Shunt diode clipping with variable resistance adj by gain control. Hammer's SWTC too.
No not exactly, but Supercharged Zendrive would still be a more appropriate name.
Yes, it's the same theme.
"You have just tubescreamered or fuzzfaced yourself " -polarbearfx

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Post by culturejam »

Ice-9 wrote:I agree, when this pedal arrived today and i seen the goop i thought good it may be something a bit special in which case i would not have posted the schematic,
Why not?

I'd much rather see a schematic posted from something creative or innovative instead of the same old crap in a different box.

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Post by Ice-9 »

culturejam wrote:
Ice-9 wrote:I agree, when this pedal arrived today and i seen the goop i thought good it may be something a bit special in which case i would not have posted the schematic,
Why not?

I'd much rather see a schematic posted from something creative or innovative instead of the same old crap in a different box.
Yeah ! I see your point and agree, I was hoping this was going to be an interesting and innovative but its not.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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Post by Adji »

Guess there is no need for my pics then hehe.
Sorry I missed all this, been busy this week.

I know the guy who makes these and I have one, I like it, really good low gain overdrive / boost. Never played an actual ZenDrive before so do not know how close they sound. I thought this was an original circuit, shame.

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Post by IvIark »

DougH wrote:Yes, it's the same theme.
Yup. Here's the originality layout.

Image

So the red bit is very slightly tweaked Zendrive, the yellow bit is very slightly tweaked Gain Stage Red, the green bit is the R&D effort which is a very slightly tweaked feedback loop clipping config and what must be a very slightly tweaked something!

To be fair he's not claiming any originality in the marketing copy. Yay to him!
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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Post by salocin »

This pedal has the lamest goop ever! It doesn't even seem to hide anything, other than maybe the IC and transistor types. I can't believe they used jumpers on the circuit board either.

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