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Projects => Tech Help - Projects Page => Topic started by: jimilee on February 19, 2015, 08:18:50 PM

Title: Eggnator tweaker fizzle
Post by: jimilee on February 19, 2015, 08:18:50 PM
I have a tweaker head that after it heats up, sort of fizzles out. I then flip it to standby and back and it works again for a little while, is this a 12ax... Tube issue or a power tube issue?


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Title: Re: Eggnator tweaker fizzle
Post by: pryde on February 19, 2015, 08:59:15 PM
Quote from: jimilee on February 19, 2015, 08:18:50 PM
I have a tweaker head that after it heats up, sort of fizzles out. I then flip it to standby and back and it works again for a little while, is this a 12ax... Tube issue or a power tube issue?


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The answer is yep  :)
Could be either. Need to start isolating. If you have a known good preamp tube, start swapping it in one at a time and see if issue goes away. Do the same with a good power tube, one at a time as well.

Man I kid you not I have had so many egnaters in for repair it is crazy. Everything from failing filter caps, burned up dropping resistors, bad pots, etc. 

EDIT: Didn't mean to come off as condemning your amp jimilee. Just weird coincidence I have repaired a lot of egnaters lately. Anyway tubes are always the best bet to try first.   
Title: Re: Eggnator tweaker fizzle
Post by: jimilee on February 19, 2015, 11:02:39 PM
Hey thanks Pryde? No offense taken. I've been doing some reading, seems they go through phases with issues.


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Title: Re: Eggnator tweaker fizzle
Post by: AntKnee on February 24, 2015, 09:03:42 PM
I had similar problems with a JCM900 head back in the 90s. It was always having odd tube problems. I won't  buy another one of those. Sorry, I know that doesn't help you, but thought I would  share.
Title: Re: Eggnator tweaker fizzle
Post by: GermanCdn on February 24, 2015, 10:14:45 PM
Early Tweakers had some PCB issues IIRC, which might explain the repair frequency.
Title: Re: Eggnator tweaker fizzle
Post by: pryde on February 24, 2015, 11:41:03 PM
Quote from: GermanCdn on February 24, 2015, 10:14:45 PM
Early Tweakers had some PCB issues IIRC, which might explain the repair frequency.

See a lot of Tweakers and Rebel 20/30s. Both have an under powered dropping resistor in the power supply that burns up often. Have had a lot of premature filter cap failure in both models as well. Bad batch of caps I suppose.