Issue with a Summit TPA-200 Preamp

RYAN LOUDMUSIC JENKINS

RYAN LOUDMUSIC JENKINS

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Jan 11, 2011
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A buddy of mine has a couple of these units and is having issue with one of them so I figured I would throw this out there to see if anyone has advice.



One of the channels sounds to him like it has a LPF and it is just a bunch of mud. Summit has been less than helpful and has not returned any of his emails or calls and no one ever answers their phone for him.



He has the original tubes in it and the units are fairly old. Could a bad preamp tube cause this type of problem in a preamp? I believe that are 12AX7s. In my guitar amp when the tubes are going bad I hear wierd artifacts and buzzes but I have never lost all of the top end.



Anyone have any ideas on these units or know anyone with experience working on summit gear?



Thanks a bunch, Ryan
 
Re: Issue with a Summit TPA-200 Preamp

I am not a tube guy.. but IIRC tubes degrade with age by losing transconductance or gain.



So in a high gain circuit like a preamp those could be symptoms of the tired tubes running out of loop gain.



JR
 
Re: Issue with a Summit TPA-200 Preamp

Do you have access to Smaart? You could take a transfer function measurement of the pre and verify what you hearing.
 
Re: Issue with a Summit TPA-200 Preamp

Call up Summit or email them. I have a Summit 2BA-221 preamp that had an issue; they fixed it no questions or charges. Great customer service.



I've dealt there with Paul Grove, senior Product Manager. 775-782-8838 or [email protected].



Love their stuff. I also bought a TLA-50 used and together the 2 make a great 1RU channel strip.
 
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