Bearfoot - Mint Green Mini Vibe - Trace and Build

The sound is okay, but we’re still getting to know each other...
For now, I have the following observations:
- the aforementioned taper of the RATE and VOL potentiometers—in my opinion, not quite the best choice,
- the minimum LFO frequency is a bit too high (at least on my unit),
- there is a fairly significant boost to the output signal when DEPTH is set to the maximum. In this case, I have to keep the VOL setting below the 9 o'clock position; anything higher drives too much next effect in the signal path (clean preamp).
 
Is this fine work what ended up as the stripboard layout on Dirtbox Layouts?

I've built this, and it works, but mine is considerably brighter than my base tone at all settings.

My JFETs: (Q1, 2, 4, 5 are 2N5485, Q3 and Q6 are 2N5457)
Q1: 6.5, -2.4
Q2: 6.38, -2.4
Q3: 2.745, -1.395
Q4: 6.78, -2.5
Q5: 6.92, -2.52
Q6: 2.69, -1.39

I've tried swapping them around. I've tried 2N5485s in all positions. There are tonal changes when swapping them around, but the tone is always brighter than I would like.
 
Hey looks like that links right back here, I had no idea this reached a wider audience!

Mine was very bright the first go round too. Maybe I was lucky with the swaps.

The transistor numbering threw me off a bit, he put Q3 and Q6 as the LFO inverter transistors (not logical numbering), whereas I followed the trace numbering, so I see you’ve matched transistors.

There’s a bunch of 100n/200k at the end that seem to form a high pass filter (but I think it’s low frequency probably to filter out LFO ticking noise. You could try tapping you audio probe before those to see if it helps.

Otherwise, I’d probably consider installing trimmers on 1 or more of the 14k7 drains, or the 47k mixing transistors so you can balance it by ear.
 
phi1 said:
Hey looks like that links right back here, I had no idea this reached a wider audience!

Mine was very bright the first go round too. Maybe I was lucky with the swaps.

The transistor numbering threw me off a bit, he put Q3 and Q6 as the LFO inverter transistors (not logical numbering), whereas I followed the trace numbering, so I see you’ve matched transistors.

There’s a bunch of 100n/200k at the end that seem to form a high pass filter (but I think it’s low frequency probably to filter out LFO ticking noise. You could try tapping you audio probe before those to see if it helps.

Otherwise, I’d probably consider installing trimmers on 1 or more of the 14k7 drains, or the 47k mixing transistors so you can balance it by ear.
Click to expand...
I just transposed Q1 and Q2, and the same with Q4 and Q5. Seems a bit chewier now. Also powering at 18v seems to make the throb a bit deeper - kind of the opposite of what I would have expected. Aural fatigue is probably setting in now, so perhaps I'm just hearing what I want to hear. I will revisit in a few hours or tomorrow and see (hear).
 
My middle pot acts much more like a level control, whereas in this video it behaves more like a sort-of gain control (watch from about 1 min in).

On mine when fully CCW, the pedal passes little or no signal. In the video linked, that control seems much subtler. I'm wondering if my build is wonky or if there were different versions of this pedal released where the function of that control changed?
 
According to my schematic the volume pot will definitely mute the signal. It’s not out of the question that my trace was wrong, though I tried to double and triple check things as I went and I have notes about all the pot wiring I can read back through. I wish I had done more to document the original behavior of all the pots.
 
Yeah it was a Bearfoot, special artwork edition, you can just make out the Bearfoot writing on the enclosure in my first post. I believe the very original MGMV didn’t have an external volume pot.
 
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