Need some serious tube help here
mccreadyisgod
Bumfuq, MT Posts: 6,395
Okay, so my 1966 Fender Vibro Champ, the blackface one in gorgeous condition, the love of my life, the source of all things holy to me, took a dive this weekend.
Here's the problem: My buddy was recording some slide guitar with the amp, and had her running pretty hot, like 7 out of 10 (sounded great on tape, by the way). He was playing a track while listening to the DI he was using, and went to play the track back and got no signal from the amp. Upon further inspection, the amp has very little output, and distorts badly when heavy notes are played (like an open low E-string) even if played at very low volume levels. There is no change in volume between 2 and 10 on the dial. There is only one power tube, and it got extremely hot after playing it for a couple minutes. Considerably more warm than the preamp tubes and tube rectifier. The tone is flat and buzzy. I have a feeling that the power tube is shot. It didn't glow bright red, but it got so hot that I'm pretty sure it's the culprit.
Will take it to see an amp tech this week after I get my car all fixed, but I wanted to ask the opinion of this board before I make a move. I definitely don't want to just replace the tube and end up with the same problem in a month, I want it fixed, and fixed right. So what do we think? Am I screwed?
This has effectively ruined my weekend... it's like I've lost a beloved pet or family member or something... when my buddy told me, I just felt sick. I hope she's alright...
Here's the problem: My buddy was recording some slide guitar with the amp, and had her running pretty hot, like 7 out of 10 (sounded great on tape, by the way). He was playing a track while listening to the DI he was using, and went to play the track back and got no signal from the amp. Upon further inspection, the amp has very little output, and distorts badly when heavy notes are played (like an open low E-string) even if played at very low volume levels. There is no change in volume between 2 and 10 on the dial. There is only one power tube, and it got extremely hot after playing it for a couple minutes. Considerably more warm than the preamp tubes and tube rectifier. The tone is flat and buzzy. I have a feeling that the power tube is shot. It didn't glow bright red, but it got so hot that I'm pretty sure it's the culprit.
Will take it to see an amp tech this week after I get my car all fixed, but I wanted to ask the opinion of this board before I make a move. I definitely don't want to just replace the tube and end up with the same problem in a month, I want it fixed, and fixed right. So what do we think? Am I screwed?
This has effectively ruined my weekend... it's like I've lost a beloved pet or family member or something... when my buddy told me, I just felt sick. I hope she's alright...
...and if you don't like it, you can suck on an egg.
Post edited by Unknown User on
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Comments
" Have your power output tubes changed (6V6, 6L6, 6BQ5, 6550, 6CA7, EL34, EL84 etc.) about once a year, or more often if you play every day for roughly six or eight hours, or if you notice a dullness in your sound. Always purchase matched pairs, or quads, of output tubes; they will sound and work much better than unmatched output tubes. Even if you only need a pair of matched output tubes, it is very wise to buy a matched quadruplet set so you will have a pair that is ready to use without a big change in tone . If you see glowing red plates in your output tubes, STOP! You either have failed tubes or circuitry trouble, and failure to shut the amp off usually results in major blown parts ($$$). The preamplifier tubes, the 12AX7`s and 12AT7 smaller type tubes might last for several changes of output tubes, but this is not a rule. If you hear jingles, rattles, pops, squeals or if the gain or attack decreases, it may be time to have these tubes changed out."
Quote from Sal Trentino
This amp is more important than any other single piece of gear in my collection. You can bet she'll get the best care possible.