Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Tubes and Hybrids => Topic started by: rhythm player on August 26, 2009, 01:30:55 PM

Title: VOX AD50VT hum
Post by: rhythm player on August 26, 2009, 01:30:55 PM
I have a VOX AD50VT that suddenly stopped working. Everything was fine at a friends house but when I took the amp home and turned it on it had a terrible hum. None of the controls have any effect on the noise. This amp has 1 12ax7 pre-amp tube so I swapped it with a known good one but that had no effect either. Before I tear into this thing does anyone have any suggestions on what the problem may be?
Title: Re: VOX AD50VT hum
Post by: joecool85 on August 26, 2009, 02:55:48 PM
Quote from: rhythm player on August 26, 2009, 01:30:55 PM
I have a VOX AD50VT that suddenly stopped working. Everything was fine at a friends house but when I took the amp home and turned it on it had a terrible hum. None of the controls have any effect on the noise. This amp has 1 12ax7 pre-amp tube so I swapped it with a known good one but that had no effect either. Before I tear into this thing does anyone have any suggestions on what the problem may be?

Sounds like an issue with your poweramp to me, not sure what though, but I'm guessing maybe a blown cap somewhere.
Title: Re: VOX AD50VT hum
Post by: rhythm player on September 09, 2009, 12:54:41 PM
Thanks for the reply. I have checked everything I know how to check and can not identify the problem. I guess I will have to take it to the shop.
Title: Re: VOX AD50VT hum
Post by: awdman on September 09, 2009, 10:28:49 PM
You can email support@korgusa.com and request a wiring diagram if you are familiar with working on electronics just let them know it is out of warranty if it is. or go to http://www.korg.com/DealerLocator.aspx?type=service (http://www.korg.com/DealerLocator.aspx?type=service) for a service center.