Ceriatone Forum

Hello I've ordered my Overtone as a Kit and build it like the Layout.
It works but I have two problems.

First is a high pitch tone even with all controls set to 0.
This stops when I set the Bias to 20mA or lower.

Second is a very large difference between Jazz & Rock.
Rock is at least two times louder than the Jazz setting.
Or is this normal?

Any suggestions are very welcome.

Have you tried to reverse the OT primaries? In my kit the colors of the wires were mixed compared to the layout.
Check all the groundings. Have you connected the ground bus (over the pots) to ground?
 No, there should not be that difference between jazz & rock, just difference in eq. Check your layout and values!
Just hard work..check & check & check and.... ;D

Thanks, that was what I was thinking.
I saw some good pictures of a build Overtone and indeed, the
blue and brown OT wires were soldered to the other tube socket.

I will try this tomorrow, its almost midnight overhere.

OK, I have changed the OT wires and no more high pitch tone.  ;D
The BIAS now is at 41,5mA, a little cold but thats no problem.

Only problem to solve is the Rock/Jazz switch, I checked all the wires
and can't  find any mistakes.
Still a big volume difference when I switch between Rock & Jazz.

The tone is fantastic, cleans are very rich and warm.
OD is a little harsh but I will mod the 150k to 220k & the caps to 330pF.

Thanks for your help so far.
If anyone has thoughts about the Rock/Jazz switch, your posts are welcome.

what voltage are the snubber caps?

The 330pF I ordered are rated 500V.

Thank you, I plan the do those same mods in the future. Let me know how they work.