Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Ambugaton on January 23, 2017, 11:08:37 pm

Title: Troubleshooting No Sound. Dead Rect. Tube (Resolved)
Post by: Ambugaton on January 23, 2017, 11:08:37 pm: Hey everyone. Its been quite the couple of months for issues for me... and I have the Stout TMB using Doug's schematic. All of a sudden I am getting absolutely no sound (No hum or hiss)

I have tested all the common sense items. Used a 9 volt to test the speaker, swapped guitars/cables/tubes.

I know that the issue lies with the rectifier. All the tubes glow except for the 5Y3, but I just want to verify before simply purchasing and swapping. As of now the Rectifier is getting 308v on pin #4 and #6. Pin #2 is getting roughly 3.5VAC but nothing on pin #8.

Could this just simply be solved by swapping it out? Or would you suspect something more complicated?
Title: Re: Troubleshooting No Sound. Dead Rect. Tube
Post by: Ambugaton on January 23, 2017, 11:13:40 pm: One corrections: There is a low level hum when powered on and if I push up on the rectifier tube it cuts out.
Title: Re: Troubleshooting No Sound. Dead Rect. Tube
Post by: HotBluePlates on January 24, 2017, 05:17:04 am: Are you using a socket for the rectifier which is re-used or very old?

I'm wondering if the socket contacts are loose and not making good contact with the tube pins.
Title: Re: Troubleshooting No Sound. Dead Rect. Tube
Post by: Ambugaton on January 24, 2017, 10:27:22 am: It was a new socket when I completed the build about 6 months ago. I did deoxit and reseat it a few times. Maybe I will try to re-tension.
Title: Re: Troubleshooting No Sound. Dead Rect. Tube
Post by: sluckey on January 24, 2017, 11:10:31 am: Quote
Pin #2 is getting roughly 3.5VAC but nothing on pin #8.
Measure voltage BETWEEN pin 2 and pin 8. Should be about 5VAC.
Title: Re: Troubleshooting No Sound. Dead Rect. Tube
Post by: Ambugaton on January 24, 2017, 11:57:43 am: Quote from: sluckey on January 24, 2017, 11:10:31 am
Quote
Pin #2 is getting roughly 3.5VAC but nothing on pin #8.
Measure voltage BETWEEN pin 2 and pin 8. Should be about 5VAC.

Yes it is! This tells me to just swap it out if cleaning/making sure the pins have good connections with socket doesn't solve it.
Title: Re: Troubleshooting No Sound. Dead Rect. Tube
Post by: Ambugaton on January 24, 2017, 05:42:44 pm: The only local music store we have happens to have a single Ruby 5Y3GTC. I will try it out and see what I get. I can't find a spec sheet on this or the Shuguang 5Z2P?? that it relabeled. I am reading that replacing the Sovtek might have been a good idea a while ago. First... I think something was loose in it as there was ringing coming from the tube itself when playing at higher volumes and it appears the Sovtek is not a true 5Y3
Title: Re: Troubleshooting No Sound. Dead Rect. Tube (Resolved)
Post by: Ambugaton on January 24, 2017, 07:44:25 pm: New tube solved the issue. All normal and sounds great.