Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Tonelab on January 19, 2019, 12:32:07 pm

Title: Ampeg VR-40 was Distorted, Humming now zip
Post by: Tonelab on January 19, 2019, 12:32:07 pm
A friend asked me to change the filter caps to his VR-40 which was very distorted zero cleans with a hum that could be described as 60 cycle. So, after changing them out with direct replacement cans, the amp operated still distorted, until i turned it off and them back on. Now, it has no sound coming through until it's switched into (standby) then you can plainly hear the sound your amp makes if your guitar was still ringing a chord until it fully off...I'd hesitate to guess if any preamp, power tube or, the OT were going or has gone bad, but, what direction might I need to focus? This isnt a pedal or, a guitar so, even looking through the schematics has given me no initial clue...
Title: Re: Ampeg VR-40 was Distorted, Humming now zip
Post by: shooter on January 20, 2019, 05:47:30 am
verify your cap polarity again, take PS voltage readings, post a schematic or link, keep your meter battery's fresh  :laugh: