Damned amp

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jestaudio
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Damned amp

Post by jestaudio »

Thought I would start this as a new topic as I now own the Rengade that was on my bench, long and short is the customer had had enough of the amp and did,nt want to spend any more on it so I foolishly bought him out.

Got to the bottom of most of the issues but the last one is bugging me, the amp has 2 6L6 tubes and 2 El34,s with a tube mix, with all of the tubes in and the preamp and PI tube out I have the odd static sound over the speakers, pull either pair it disappears , both sets are known to be good test sets I use and well matched, bias is set slightly cold at around 30ma per tube to save tube life, in short it appears to be common to the complete power section.
Fresh ideas would be appreciated before my head goes awol :lol:
Stevem
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Re: Damned amp

Post by Stevem »

This could be two or three things, but lets go with the two easy ones to check out!
1) would be the amps power supply is acting up under the current draw of all 4 output tubes.
To prove this out just install two of the outputs, but bias them up to match the idle current draw that would equal all four of them installed in the amp.

2) would be the same current draw issue but the OT could be arcing over, is the amp outputting its proper rms power?

When you check voltage on pins 3 and 4 with all 4 tubes in does the B+ check stable on pins 4, but go up and down on pin 3 in response to the noise?
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jestaudio
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Re: Damned amp

Post by jestaudio »

Sorted, loose plug on the tube mix board making intermittent contact, found it total y by chance after getting a mag light out to inspect the boards, never ever again will I repair one of these amps, far to much hassle and next to zippo interest from the UK tech support
Zippy
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Re: Damned amp

Post by Zippy »

jestaudio wrote:Sorted, loose plug on the tube mix board making intermittent contact, found it total y by chance after getting a mag light out to inspect the boards, never ever again will I repair one of these amps, far to much hassle and next to zippo interest from the UK tech support
Plugs...

yech!

Glad you were able to find it. Intermittent failures are tough to troubleshoot.

Now what are you going to do about it so it doesn't happen again?
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Reeltarded
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Re: Damned amp

Post by Reeltarded »

LUCKY!!

It's better than good, it'n it? Damn you could have chased that all the way down to the deck. Congrats!!
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jestaudio
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Re: Damned amp

Post by jestaudio »

Zippy wrote:
jestaudio wrote:Sorted, loose plug on the tube mix board making intermittent contact, found it total y by chance after getting a mag light out to inspect the boards, never ever again will I repair one of these amps, far to much hassle and next to zippo interest from the UK tech support
Plugs...

yech!

Glad you were able to find it. Intermittent failures are tough to troubleshoot.

Now what are you going to do about it so it doesn't happen again?
Burn the friggin thing preferably :lol: the issue was the plug was never snapped in correctly, the worst being there was some glue used to hold it in, what the hell the QC process was god knows, at this point the hot glue gun comes to mind, I want to test it on the bench for 4 hours or so and make sure the POS doesn't chuck another curved ball :shock:
Assuming all is good a dot of glue on both tube mix boards and reassemble then get rid of it, I like the sound but I sure as hell do not trust it
jestaudio
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Re: Damned amp

Post by jestaudio »

Reeltarded wrote:LUCKY!!

It's better than good, it'n it? Damn you could have chased that all the way down to the deck. Congrats!!
Cheers Reel, I did pull the main board to reflow the contacts round the power tubes as a precaution but yep I think I was due a dose of luck, I don't mind trouble shooting older stuff on tag board or similar and its thanks to guys on here that I have the knowledge and confidence to track down faults but I sure as hell hate PCB amps a real PITA 8)
Zippy
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Re: Damned amp

Post by Zippy »

jestaudio wrote:Burn the friggin thing preferably :lol: the issue was the plug was never snapped in correctly, the worst being there was some glue used to hold it in, what the hell the QC process was god knows, at this point the hot glue gun comes to mind, I want to test it on the bench for 4 hours or so and make sure the POS doesn't chuck another curved ball :shock:
Assuming all is good a dot of glue on both tube mix boards and reassemble then get rid of it, I like the sound but I sure as hell do not trust it
Put some blue goop on it, and tell the buyer that it is a Dumble-inspired mod that you read about on the internet. :lol:
jestaudio
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Re: Damned amp

Post by jestaudio »

Zippy wrote:
jestaudio wrote:Burn the friggin thing preferably :lol: the issue was the plug was never snapped in correctly, the worst being there was some glue used to hold it in, what the hell the QC process was god knows, at this point the hot glue gun comes to mind, I want to test it on the bench for 4 hours or so and make sure the POS doesn't chuck another curved ball :shock:
Assuming all is good a dot of glue on both tube mix boards and reassemble then get rid of it, I like the sound but I sure as hell do not trust it
Put some blue goop on it, and tell the buyer that it is a Dumble-inspired mod that you read about on the internet. :lol:
Sure Mesa haven't got a patent on blue goop :lol:
Zippy
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Re: Damned amp

Post by Zippy »

jestaudio wrote:
Zippy wrote:
jestaudio wrote:Burn the friggin thing preferably :lol: the issue was the plug was never snapped in correctly, the worst being there was some glue used to hold it in, what the hell the QC process was god knows, at this point the hot glue gun comes to mind, I want to test it on the bench for 4 hours or so and make sure the POS doesn't chuck another curved ball :shock:
Assuming all is good a dot of glue on both tube mix boards and reassemble then get rid of it, I like the sound but I sure as hell do not trust it
Put some blue goop on it, and tell the buyer that it is a Dumble-inspired mod that you read about on the internet. :lol:
Sure Mesa haven't got a patent on blue goop :lol:
If they do, AutoZone and PepBoys are in some deep doo doo (aka goop).
jestaudio
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Re: Damned amp

Post by jestaudio »

Zippy wrote:
jestaudio wrote:
Zippy wrote: Put some blue goop on it, and tell the buyer that it is a Dumble-inspired mod that you read about on the internet. :lol:
Sure Mesa haven't got a patent on blue goop :lol:
If they do, AutoZone and PepBoys are in some deep doo doo (aka goop).
:lol:
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Leo_Gnardo
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Re: Damned amp

Post by Leo_Gnardo »

jestaudio wrote:
Zippy wrote:
jestaudio wrote: Sure Mesa haven't got a patent on blue goop :lol:
If they do, AutoZone and PepBoys are in some deep doo doo (aka goop).
:lol:
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Zippy
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Re: Damned amp

Post by Zippy »

Leo_Gnardo wrote:Permatex Gasket Seal, in case you're ever looking for the Authentic Item. Approved by Smurfs all around the Smurf world.
'Cause AutoZone knows Tone!
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Leo_Gnardo
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Re: Damned amp

Post by Leo_Gnardo »

Zippy wrote:
Leo_Gnardo wrote:Permatex Gasket Seal, in case you're ever looking for the Authentic Item. Approved by Smurfs all around the Smurf world.
'Cause AutoZone knows Tone!
(with a lung full of helium) yehhhh, Smurf Tone. Play the blues, dudes!
down technical blind alleys . . .
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Colossal
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Re: Damned amp

Post by Colossal »

jestaudio wrote:Thought I would start this as a new topic as I now own the Rengade that was on my bench, long and short is the customer had had enough of the amp and did,nt want to spend any more on it so I foolishly bought him out.
Oh no dude!! what did you do?!?

Take that thing to the nearest Guitar Center and heave it through the window :lol:
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