Carbon Black

What value pots are you supposed to use, I’ve got my board ready and my enclosure drilled but there’s still no build doc up yet

If I was at home I could tell you, but I just got to work so I’m a ways off from being able to answer that...someone else can chime in hopefully!
 
I built mine with the bias control as an external pot; the sweep is actually pretty subtle and I keep meaning to swap out a different value to see if it can go into gated/zippery territory.
 
You mean trim to 4.5V between q3 collector and ground?
Unless otherwise specified, all voltage measurements are with respect to ground.

I built mine with the bias control as an external pot; the sweep is actually pretty subtle and I keep meaning to swap out a different value to see if it can go into gated/zippery territory.

Making the BIAS pot larger will do it, try B25K. If that doesn't quite get you there, try lowering the 46K/47K resistor to 33K. The values you need for the collector resistors depend on Q2 & Q3's hFE (mostly Q2).
 
Unless otherwise specified, all voltage measurements are with respect to ground.



Making the BIAS pot larger will do it, try B25K. If that doesn't quite get you there, try lowering the 46K/47K resistor to 33K. The values you need for the collector resistors depend on Q2 & Q3's hFE (mostly Q2).
About to give the Bias pot a shot. You mentioned also lowering R6 from 46k to 33k for a wider range. Looking at the schematic I’m wondering if the same could be achieved with lowering R8 instead of R6 and if one would be better than the other? Please excuse my ignorance if this is a dumb suggestion.
 
Measure Q3-C first, you might not need to change any resistors.
Once you make & report your measurements, then we'll know what to do next.

If Q3-C is too high for any trimmer setting, then lowering R8 will only make it worse.
 
Measure Q3-C first, you might not need to change any resistors.
Once you make & report your measurements, then we'll know what to do next.

If Q3-C is too high for any trimmer setting, then lowering R8 will only make it worse.
Of course. I have it socketed just in case. I was just curious why R6 and not R8. I socketed both to see for myself. Figured I’d also ask.


 
I really like the aesthetic. Super clean looking build, and luxury components. Ooo la la. Is that a water slide decal?

Edit: I just realized this build was originally posted a few years ago. I apologize for bringing us back to that time in our lives. No one wants to go back to 2020.
 
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