Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: PuertoRicanDavey on September 20, 2016, 02:53:33 pm

Title: Weird Amp Noise Troubleshoot
Post by: PuertoRicanDavey on September 20, 2016, 02:53:33 pm
Hello everyone. Looking for some help. I built up a tweed pro about 9 months ago and everything has worked great until a couple of days ago it started making this strange noise that kind of sounds like a squeaky door. I tried swapping out all the tubes (except the rectifier because I don't have a replacement), but the sound was still there. It sounds like it might be a power issue. I don't think it is any of the capacitors leaking DC because they are all new, but I am not sure. I put a quick clip of it on youtube to give an idea. (It's kind of quiet so you might need to turn the volume up.)

https://www.youtube.com/watch?v=scYKeMf4sLg (https://www.youtube.com/watch?v=scYKeMf4sLg)

Maybe it's the rectifier? Hoping there is an obvious answer based on the sound. Any help would be great! Thanks!
Title: Re: Weird Amp Noise Troubleshoot
Post by: PRR on September 20, 2016, 05:02:09 pm
Can hardly hear it.

Turn off ALL other stuff in the room. PCs. TVs. Cellfones. CFL and LED lights. Nest and other too-smart thermostats? Cellphone chargers? Kids toys? Stuff on the other side of the wall? Here I could take the amp out in the yard on 50 foot cord, get away from it all, though I would have to wait for neighbors to be quiet.
Title: Re: Weird Amp Noise Troubleshoot
Post by: xm52 on September 22, 2016, 11:58:46 am

Turn off ALL other stuff in the room. PCs. TVs. Cellfones. CFL and LED lights. Nest and other too-smart thermostats? Cellphone chargers? Kids toys? Stuff on the other side of the wall? Here I could take the amp out in the yard on 50 foot cord, get away from it all, though I would have to wait for neighbors to be quiet.

It does sound like high frequency interference. Cell phones and routers are prime sources of these problems. Also, effect box switching power supplies. You have to eliminate all these possibilities.