Zendrive... not so Zen.

[digi2t]

OK, I built this a while back, but I never got around to quizing folks here on why it does what it does, or not, or... I don't know!!!

Anyway, down to the meat an taters. This is what I based my build on;

So, I build it... and the Voice pot did nada. Zip. Ziltch. I mean, nothing my ears could pickup. Maybe the neighbour's dog was picking something up, but not me.

EDIT: READ BELOW.

Now... Tone? Check. Voice? Check.

What's the deallio???

[thermionix]

I see no difference in the two schemos except the depiction (not wiring) of the gain pot...?

[vigilante397]

Looks like the schematic hasn't been changed, just the layout. The resistors on the tone and voice pots have been changed.

Apparently Zendrives are in season right now There's a debugging thread for one, I just finished one, you just finished one...

Seriously though, interesting mod. Any chance we can get an audio clip to hear what your modded version sounds like? My voice pot definitely affects the sound, but as I recall I usually leave it cranked. I'll have to take a look at the schematic I used for my layout (I made a PCB, I don't have the patience for eyelets ) and see what you moved around.

[Marcos - Munky]

Apparently Zendrives are in season right now There's a debugging thread for one, I just finished one, you just finished one...

Guess what is the last board I made this week, just waiting for some pots to arrive by mail .

Also, I built one for a friend and I really liked the sound of it, so that's why I'm building me one. I remember the voice pot affects the sound, but me too leaved it cranked when I played with it.

[reddesert]

The only difference I see in both the two schematics and the two layouts is that the direction of the drive pot has reversed (and an "R6" label in the BOM became "R7"). But the connections of the resistors on the tone/drive/voice pots are equivalent if you take into account the reverse.

I built one from the tagboardeffects vero layout and the Voice pot did do something. Madbean says that it adjusts gain and bass inversely.

[digi2t]

Nope... I screwed up. Took another look, and realized my memory had faultered.

THIS is the layout posted on the net (that I initially followed, and Voice pot did nothing discernable)...



and THIS is what I actually have (Voice pot is now really effective)...



As you can see, the resistor between the tone and gain pots is changed, as well flipping the lugs on the tone pot to the second opamp around. That, brings life to the Voice pot, for some reason.

If anyone would be kind enough to try it, and tell me if that's what they hear, just so I don't feel like I'm losing my noodle.

[Kipper4]

Hey Dino.
I love my zen. But I kinda use it to make my tube amp bloom by pushing the front end with it rather than a deeply compressed distortion.

This guy Nalle Colt loves his too.

http://youtu.be/p8IarWJSaLY

See what you think.....

[digi2t]

Yeah Rich, exactly it. It's not gainy enough for distortion, but "bloom" is just the right descriptor.

Insofar as my Voice issue is concerned, could it be that by switching the resistor/lug connections around on the tone pot shifted the circuit's frequency into a range that my ears could hear? Maybe that's why I couldn't hear the Voice pot doing anything when the tone pot was wired as per the layout?

I dunno... I'm spitballin' here.