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Topic: Zeppelin too much for my Vibrolux Reverb |
Shaan Shirazi
From:
Austin, TX, USA
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Posted 13 Jul 2015 8:24 am |
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By the end of an epic rendering of Moby Dick on Saturday night my late 70's SFVR had lost most of it's output and had a crackling noise when I tried to play. Luckily the next band had a Dual Showman to let me finish the set. Can anyone help me diagnose the possible issue. Here are the clues:
I seemed to notice in the previous few days some chirping noises when the amp was on and not in stand by. They went away after a while. The output also seemed a little low as I was playing on about 5 when 3 was usually more than enough.
I was not using an overdrive pedal and instead just increased the output on by Boss EQ pedal to get a great natural distortion. This was the only song where I did that.
The amp had been on for about an hour and we had been playing for about 45 minutes of loud, rockin;, Surf tunes by that point.
I have not detected anything wrong with the tubes. The amp was hot but not too hot to touch.
The amp had the same problem whether I was in input 1 or 2 on the vibro channel. The tube was pulled from the dry channel so I couldn't use it.
Could I have done something to the output transformer or was it about to go anyway since I noticed the other signs of impending trouble earlier in the week?
The speakers look good too. They are Weber Californias, 80 watts each.
Thanks for any insight! |
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Bill Hatcher
From:
Atlanta Ga. USA
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Posted 13 Jul 2015 9:47 am
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did you ever see jimmy page use a vibrolux onstage with the zeps????  |
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Bill Sinclair
From:
Waynesboro, PA, USA
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Posted 13 Jul 2015 10:29 am
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| Have you tried it again since the gig? Plugged your guitar in direct to eliminate the stomp boxes? You can pull the oscillator tube for the vibrato (should be V5) and try it in your other preamp tube positions to see if it might be one of those. It can be used as a temporary substitute for any of the other preamp tubes although the gain will be a bit high for the phase inverter (V6). Of course, you won't have vibrato. You might also try rotating all the pots just in case you're loosing signal there. They can create a crackle and a signal loss. I can't think of much else to check outside of the chassis if you don't have spare tubes. I don't recommend opening it up if you don't know your way around tube amps. Dangerous voltages under the hood. |
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Michael Butler
From:
California, USA
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Posted 13 Jul 2015 12:14 pm
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i just had something similar happen to me. i pulled the tubes and sprayed deoxit in the sockets as well as the pots. i gave it a while, replaced the tubes and the lower power and crackling was gone. don't know for sure that this will help but sure can't hurt.
secondly, i would swap tubes to see if that may be the problem.
play music!
_________________
please see my Snakeskin's Virtual Music Museum below.
http://muscmp.wordpress.com/ |
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Shaan Shirazi
From:
Austin, TX, USA
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Posted 13 Jul 2015 7:51 pm
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| Bingo, pulling the tubes and reseating them brought it back to life. One must have been getting loose. Also, replaced the main 12AX7 with a NOS Sylvania and it really sparkles now! |
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