Roadster pre amp tube problems

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gtr2go

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I need some help advise. I bought a used roadster combo that was only a few months lol. It was damaged in shipping. The guy doesn't know how to package an amp for shipping. But here's the deal. Several of the tubes fell out of there sockets during shipping. I put them back in and powered it up.channels 1&2 worked fine 3&4 not at all. 1&2 were very noisy. I tested the power tubes and found them to be fine. I removed the shields from the preamp tubes and found a couple were discolored and the tips of the glass was broken off on both. I have a bunch of 12ax7 tubes so I replaced them. 3&4 began working. But the amp was still extreamly noisy. I then searched the forum here and found recommendations for tubes and positions to use them in. I ordered the rock tube combo of tubes from one of the sites recommended. Tung Sol in V1 and so on. The amp came alive and sounded great. The amp was at our practice space for the last few months and not moved. But the last couple of weeks it has become increasingly noisy and the tone and my effects in the loop sound horrible. I brought the amp home and ran my pod HD direct to the return in the loop. Sounds great and very little noise. So I checked the preamp tubes. The same two tubes are discolored. It seems my amp is eating preamp tubes. Any suggestions? I am new to the forum as a registered member. But I have enjoyed reading and following many threads. Any help will be greatly appreciated. :mrgreen:
 
You don't say which two preamp tube positions are failing so I'm going to guess that the cathode follower tubes are failing.

In the Roadster, V3 and V5 are the cathode follower positions. Use Chinese made tubes in those positions. Simply shove current production JJ / Mesa tubes in there. Don't use Russian made tubes.

Tubes that are known to fail in those positions are: Tung-Sol, EH, & Sovtek.

If you want to read more, google mesa roadster cathode follower . You'll get a few hits.

-B
 
Thanks Blaklynx. Yes it is V3 and V5 positions. I've ordered replacement JJ's
 
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