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Discussion Starter #1
I was playing my Epi VJ this morning and noticed that the sound was cutting in and out at times. Actually it was more like fading. I thought it was a bad cable or the like. But when I plugged directly into the amp the problem persisted. Is it possible that my power tube is close to death. I always play it cranked through an attenuator.

Don't have any spare tubes right now and I thought I would ask before running out and buying a new tube.
 

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I was playing my Epi VJ this morning and noticed that the sound was cutting in and out at times. Actually it was more like fading. I thought it was a bad cable or the like. But when I plugged directly into the amp the problem persisted. Is it possible that my power tube is close to death. I always play it cranked through an attenuator.

Don't have any spare tubes right now and I thought I would ask before running out and buying a new tube.
Actually, it could be any one of the tubes. Or something inside the amp. Too many things to make a guess but the tubes are the first thing to check. Change them one by one till the problem goes away. That will tell you which specific tube was the problem and you don't have to change them all.

:food-smiley-004:
 

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If you are using an attenuator all the time, that power tube has been running pretty hot in that chassis. I've seen something like this in a couple of these. Check the solder connections on the board. The heat generated by the tubes tends to crystalize the joints sometimes. While you have it open, you should do the heater supply mod (just google valvejunior mods and you'll find it), it helps as well.
 

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Hi,

Another cause can be a crummy socket. If you wiggle the tube (with a work glove on) and it gets crackly or cuts in and out, you can try and retension the socket pins inless they are the "sealed" Shuguang types, in which case they need replacement.

Cheers!
 

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Discussion Starter #5
Thanks for the tips you guys. I'll have to mess around with the Tubes and check out that heater mod. I'll let you know the results. :food-smiley-004:
 

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Discussion Starter #6
So I messed around with the head and tubes today and isolated the problem. It was in fact......drum roll please.....the attenuator. Don't know what the hell is wrong with it but I guess I can take it apart and see what's going on. It is one of those Bitmo Attenuators from Bruce Hutchins??son??? can't remember his last name. Anyways, worked great since I got it a few months ago and now - not so much.

Thanks for the input and tips. As for the attenuator, any idea how I would check for problems. It was a pretty simple build, very few parts...:bow:
 

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Have you got a schematic for it? Do the normal visual inspection on the solder joints, connections etc. Does it do it right as soon as you start using it, or does it start after it "warms up".
 

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Discussion Starter #8
It starts doing it within a couple of minutes. It almost sounds like a bad connection of some kind. Once it starts happening it just goes on and on and gets more frequent as I keep playing. Here's a picture of the schematic:

 

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It could just be a joint going bad once it heats up, or one of your resistors going way off value after it's warmed up.
 

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Discussion Starter #10
Thanks. Maybe I'll put in new resistors. Is it possible that the L-Pad (that's what it says on the box - don't know if that what it is commonly referred to as) is burned out or defective??

What I liked about this attenuator was that it did not affect the sound at all (no loss of high end sparkle or anything. Also, it had a nice gradually climb on the volume. Now it is either really low or almost full blast. No in between.

Had to go back to my Weber Mini Mass which works well but robs the me of the highs.
 
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