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surfingjack
16 posts
Mar 27, 2014
12:04 AM
So i was changing the the V1 tube and bent one of the pins. Replaced the bent tube with another 12ay7 turned on the amp and it made a crackle and squeel. turned it off and on a couple of times same noise. Now when i turn it on no sound what so ever. Eg no sound from speakers. Any ideas ?

Last Edited by surfingjack on Mar 27, 2014 4:24 AM
SuperBee
1827 posts
Mar 27, 2014
3:45 AM
How did it happen that you bent the pin? Like, did you shove it in, realise it wasn't going in right and find a new tube, or did you put it in, switch on, something's wrong here, switch off?
surfingjack
17 posts
Mar 27, 2014
4:14 AM
I thought i had the tube in, but when i turned the amp on there was a hum that was not there before. I removed the tube from V1 and noticed the bent pin. Replaced it with another tube and thats when the amp began to crackle and pop. The amp is still lights up but when mic is hooked up no sound.

Last Edited by surfingjack on Mar 27, 2014 4:59 AM
SuperBee
1828 posts
Mar 27, 2014
4:45 AM
Seems possible you had pins in wrong holes, thus possibly shorted a component. I think you're gonna have to open this one up anyway. No bangs, smoke, bad smells?
jbone
1569 posts
Mar 27, 2014
5:40 AM
Sounds like a probably trip to the shop...
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Bass410man
12 posts
Mar 27, 2014
7:16 AM
Surfingjack,

Have a look at resisters R28 and R29. These are just half watt resistors, and when you start using lower gain pre-amp tubes it really taxes these resistors, they can easily run over 1/2 watt and burn up. If you are going to run lower pre-amp tubes I suggest having them changed to full one watt resistors. Don't change the value just the size to one watt. Hope this helps its all I can think of.
HawkeyeKane
2429 posts
Mar 27, 2014
7:19 AM
The amp prolly wouldn't power up at all if the fuse was the issue. And it's kind of hard to get wrong pins in the holes of mini-noval sockets...nine pins to nine holes in a matching arrangement. I would bet that either the AY7 you put in to replace the bent one is bad, or the bent pin of the original tube has also bent its socket contacts in a way that they, or components mounted to them, are coming into contact with other components that they shouldn't touch. Definitely a trip to the amp doctor.
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surfingjack
19 posts
Mar 27, 2014
1:15 PM
Thanks everyone for your input. I am off the amp guy.


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