• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

VAC Ren 30/30 amp low hum

Our shop just re-capped the main filter caps in a vac 30 30 300b amp that now has a low hum. when the 6sn7 tubes are pulled, the hum is still there. I installed high quality, 105c, charged and tested caps.
do these amps have a low hum?
 
Capacitors have no inherent hum, it's all about component placement and the layout/schematic.

Do you have a shot of the underneath of the amplifier showing the lead dress and wiring? The website is 100% marketing jargon and not helpful at all other than the fact that it's saying that it's a Williamson type design. There is also a "ground switch" according to the manual- have you experienced this issue in each of the "AC/AF", "DC" and "RF" positions? Does this take place with all the feedback positions as well?

http://www.vac-amps.com/manuals/Manual_Ren30-30.pdf
 
The owner's manual is not intended to be, and is not, a service manual.

Valve Amplification Company is a well known and respected multigeneration company,
in business for over 30 years. You should contact them directly.
 
Last edited: