Can you have a look at my 18W TMB?

[switchone]

Hi all, I purchased a 18W TMB used, it is a ceriatone build from 2008.

When I turn it on, it is a little noisy and the squeals a little when warming up. I'm not sure if it is the tubes, granted they are old.... or if the wires are not shielded etc.

It was not built by ceriatone. I just wanted to see if anyone here sees any glaring errors in the wiring. And give any feedback. It would be much appreciated.

[Daviedawg]

Hi Welcome. We will be happy to help you look for a cause and solution. The build looks neat and tidy so that is a good start.
But it would be useful to have some more information. What is the noise and does it occur on both channels? Does it vary with volume settings? Same for the feedback noise and when does it stop being audible, how long does that take? It is possible that the feedback oscillation just goes above hearing level when the amp is up to temp so is always there.

Dd

[switchone]

DD

Thank you for the reply.

https://drive.google.com/open?id=1THYvA ... PBZ4M0QKt3

the link above is a recording of the amp when turned on, nothing plugged into it

the TMB channel is Volume 10, Master around 1. At the 22 second mark I lower the TMB volume to 1 and put the master up to 5.

This noise is persistent in both channels. The noise is louder when the volume goes up.

I did not get any squeals when making this recording, but the squeal or feedback noise sometimes occurs when the amp is warming up.

[Daviedawg]

Hiss rather than hum. It sounds quite loud in the recording. It is normal to get some hiss at full volume but that seems excessive. It reduces significantly when you reduce the TMB preamp volume and raise the master volume. I assume it is the same effect on the normal channel with the TMB vol at zero?

The first and easiest thing to do is swap V2 and V3 around to see if that changes things. Then V1 and V2. Or better if you have spares to swap them instead.

Dd

[switchone]

I swapped in spare 12AX7's I had laying around and it did improve it. I did however get the feedback squeal when warming up, but once it is warm, it went away.

It seems to be quieter now, I believe it seems like he nature of these amps.

I am getting a AMPRX Brownbox this monday, I know he voltage in my how is probably around 124V, so the brownbox would give it a consistent 120 or lower if I want, maybe that will help it.