Ceriatone Forum

The OTS is operational. But, I am having issues with an annoying buzz, or, hum that shows up as soon as I turn the preamp volume to anything above 1. This noise is not effected by the preamp volume once it is audible, but, it is by the master volume. AND  there is a distorted buzzing on low frequency notes in the CLEAN channel. ??? The annoying buzz all but disappears when I switch to OD and the amp sounds amazing, but, switch back to clean and buzz comes back and the distorted lows show up as well. >:( :( ??? :'(   I am also having trouble biasing the power tubes as I am not getting a reading on my DMM. BTW the annoying buzz is effected when I turn the bias pot.    Help...PLEASE!!!      Thank you :-[

Hi there,

It sounds like you could have missed a ground connection somewhere in the preamp section Or have a missing/cold soldering somewhere.

Check the ground connections all the way from the jack input to the master volume. there are around 5 black wires the needs to be soldere to the chassis ground lugs and to the brass bar that runs above the pots.

I missed grounding the brass bar and had a loud hum when engaging the OD

Remember patience and thourough-ness will get you past this amp issue

You were right on the money! I had an electrical engineer look at the thing and he fixed a couple of very minor issues, but, didn't have a guitar, or, speaker to test it. When I got it home I noticed all the noise. Well, I poked around with a chopstick with the amp on and plugged into a speaker and found that one end of the grid resistor on the first preamp tube looked like it was soldered in, but, the lead was actually moving around in the terminal. I soldered it real good and VOILA!!! no more noise, just clean ringing, rich, fat, awesome tone! Thanks! Bill

Great !! congratulations, It's a nice amp ;-)

my buzz is in both channels, more noticeable in gain, the amp came assembled but without the ground switch wired. I got the schematic and had my tech try and wire it but there were some confusing inconsistancies, long story short, still buzzing, ground switch does not appear to do anything.

any ideas, please keep in mind I am not electronically savvy and will have to take the amp somewhere

thanks

First, undo the ground switch if you are in an area with well grounded, 3 wire outlets. Next, have your tech trace the signal from input to output. Try different preamp tubes. There may be a bad solder or two. Also, Nik at ceriatone is very good about answering questions. It's probably something simple, just need to use the process of elimination. Take it slow and thorough. It's worth the wait.