SOLVED Viceroy

[SYLV9ST9R]

I finished my Viceroy build last night.

I used MMBF5457, and a trimpot for R4 to have 5V on Q1’s drain (as referenced here), and a BC549C instead of the 2N5089 (hence the reversed pinout).

Everything seems to be in working order (i.e. all the controls are doing something), but I feel that it’s not as "gainy/crunchy" as it should be. Even with the gain dime, it still feels in the low OD range (comparing to say, how a Monarch sounds in review videos).

I don't see anything outstanding, so is there in particular I should check out for?

 

[Chuck D. Bones]

-0.5V to -1.5V is a good ballpark Vp range. If you're going to test on a breadboard, then just replicate the Q2 circuit. 560Ω from source to gnd. Gate to gnd. 1K from +9V to drain. Measure voltage from source to gnd. 0.5 to 1V is good.

 

[SYLV9ST9R]

-0.5V to -1.5V is a good ballpark Vp range. If you're going to test on a breadboard, then just replicate the Q2 circuit. 560Ω from source to gnd. Gate to gnd. 1K from +9V to drain. Measure voltage from source to gnd. 0.5 to 1V is good.

Breadboard noob question, how do you deal with smd on breadboard?

 

[Chuck D. Bones]

Adapter boards. These are 2-sided and have dual footprints to accommodate various JFETs.

https://www.pedalpcb.com/product/sot23adapter/

 

[SYLV9ST9R]

Adapter boards. These are 2-sided and have dual footprints to accommodate various JFETs.

https://www.pedalpcb.com/product/sot23adapter/

I’ve used those, will get some in my next order (I might still have one). I was wondering if there was a MacGyver trick I didn’t know of

 

[Chuck D. Bones]

LoL. If there is, I don't know it either.

 

[SYLV9ST9R]

Put PF5102 in it tonight (thanks @fig !). They all had Vp around 0,8V.
I did another board/pot/component inspection and everything is fine.
The sound is better, loudness is there but I still feel that I'm missing a lot of crunch.

If someone has some sound clips from their build, just to confirm I'm not crazy, would be greatly appreciated.

 

[Chuck D. Bones]

Can you measure & report voltages on Q2-S & Q4-E? What value resistor are you using for R12?

Is it possible that your expectations are not in line with what this pedal is supposed to do? It's not a Big Muff.

 

[SYLV9ST9R]

Can you measure & report voltages on Q2-S & Q4-E? What value resistor are you using for R12?

R12 is a 560R per the build doc.
Q2-S 0,55V
Q4-E 4,2V

Is it possible that your expectations are not in line with what this pedal is supposed to do? It's not a Big Muff.

It's not so much expectations as I feel I'm missing something.
That's why I was looking to compare sound clips so I don't chase something that isn't there.

 

[Chuck D. Bones]

Those measurements say the last stage is biased correctly.

 

[SYLV9ST9R]

Those measurements say the last stage is biased correctly.

Thanks again for checkin' in. I'll try it tomorrow with a bit more volume on the amp.
As I said, the PF5102 were a definite improvement, but I feel that I really need to have the gain turned up to get some crunch.