Ocelot Octave - Faint Distorted Signal

[finebyfine]

This ocelot build is giving me a faint distorted signal sort of “behind” the octave signals and dry signal. More noticeable on higher notes up the fretboard but it’s always there a little bit. It otherwise works exactly as expected.

Not sure what to be looking for for trouble shooting.

All ICs are from Tayda.

Ge diodes are a matched pair with Vf of 0.395v at 5mA.

2SK30As have Vgs(off) of -2.35v, Vgs(on) of .5v, gfs of 3mA/V, Idss of 3.50mA, Rds(on) of 570 ohms.

2N3904 has an Hfe of 329, Vbe of 0.764V, Vcesat of 0.026V.

I imagine the 2SK30As are the issue but I don’t know what to be looking for in a substitute or different 2SK30As. I have more on the way from Tayda. I have most of the common N channel JFETs we use in pedal building on hand and some 2SK193s.

I also have plenty of other germanium diodes if a different Vf is needed.

Appreciate any help and guidance, thanks!

Edit:
- tried subbing out j201s
- tried different tl072s
- tried tl022s in place of tl072s in the places where they can work

Edit:
- also tried replacing ge diodes with bat41s. no difference
- Shielded wire helps a lot, but still kind of there

 

[harmaes]

Shielded wire solved my issue with static/noise on the dry channel.
Did you also wire the mass of the shielded wire? Don’t see it connected?

 

[fig]

Hi Alex,

Have you tried routing that input wire around the long way?

 

[finebyfine]

Did you also wire the mass of the shielded wire?

I tried it after I took the photo. It helped but didn’t solve it.

Have you tried routing that input wire around the long way?

How so? Not sure how you mean. I did try moving the wires as far away from the transistors as possible with little effect if thats what you mean

 

[fig]

I tried it after I took the photo. It helped but didn’t solve it.


How so? Not sure how you mean. I did try moving the wires as far away from the transistors as possible with little effect if thats what you mean

That’s pretty much what I was getting at…routing alongside the output wire.