Dangers of using unmatched tubes in amp

[Slimey]

I have a Blue Angel 4x10.

I have a large box of NOS tubes dug out of a lab years ago.

I was looking through my box and found a pair of GE 6L6GC. I put them in the 6V6 sockets like others have recommended and got some great tone out of the amp.

I was planning on ordering a matched pair of 6L6 but was wondering if I can damage the amp (output tranny or other hardware) by running this unmatched pair of tubes. I highly doubt that I got lucky and randomly have a matched pair.

The Blue Angel is a cathode biased Class A amp.

Thanks.

 

[Slimey]

FWIW, I'll answer my own thread with what I found on the internet after some googling.

There are two completely divergent opinions...shocking! Who'd of thunk there'd be opposing opinion on the internet!

1) Matching is complete BS and unnecessary. The very nature of electron tube based amplification depends on the relative inconsistencies in the electronics. Matching is a recent concept and tube amps of the 50s & 60s did not depend on this. The circuit design was made to tolerate imperfections.

2) Unmatched tubes in push/pull circuits cause uneven strain on the output transformer and will cause it to wear prematurely and possibly fail.

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Additionaly, I found one comment that putting a 6L6 in a 6V6 based amplifier will cause wear on the power transformer as the 6L6 requires double the current flow to keep the filiment glowing. That being said, there are tons of people out there running 6L6 in 6V6 amps without issue. The zealouts suggest you beef up your power transformer though. This mostly had to do with 60s era Fenders. Mesa seems to be relatively bullet proof.

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Please comment if you have an opinion.

I did go ahead and order a mathced pair of SED 6L6 for the amp. We'll see how they compare to my NOS GEs.

 

[Surfcaster]

I don't have a lot to add to this...especially the matched pair part. But concerning the 6v6 and 6L6, I'm having a single ended tube amp built for me and it has a high and low power switch on it (kind of like a THD Univalve, which has LoV and HiV) and he stressed the importance of having the amp set to low power when using 6v6 tubes...the THD site also points out that you should only use the 6v6 on the LoV setting. So, this is coming from people who know a lot more about tubes and amps than me, so I'll probably follow their advice. Personally, I'd hate to mess up a perfectly fine amp because they ain't cheap and I ain't loaded, so I tend towards being extra cautious.

 

[old-guy]

Agree with Surfcaster
I have a Lonestar Classic and the manual states that you CAN substitute 6V6 for the 6L6 but you must turn the amp to "tweed power" which is the lower power setting. If your amp was set up for 6V6 I don't think I'd take a chance and run the higher power tubes in it. (Unless I didn't care about the amp) Do the 6L6's really change the tone that much?
Serious question, I never swapped the two, I'm curious.

Good luck with whatever you do!

 

[Slimey]

Yes. The 6L6 tubes do change the tone. Less flubby as they say. The 6L6 seems to have a more complete sound, more rounder maybe. 6V6 is not at all bad, just a bit different, and I like experimenting.

I think the issue is different when changing a 6V6 based amp to 6L6 tubes versus the opposite. Looking around here, a number of Blue Angel owners have gone to 6L6 without issues. Looking around the net, a number of 6V6 Fender amps (champ, deluxe, etc) get changed to 6L6 without issues.

 

[old-guy]

Slimey,

Then go for it! It sounds like you've done your homework. Just one last suggestion. (if you haven't already done it) I would waste a call to Mesa, just as a final check, just to see what they say. Nobody knows more about your amp than the guys that built it. If their tech says "no problem"
you're home free.

Thanks for the info on the 6V6's. I was thinking about trying them down the road but now I think I'll stay with the "L's". Why waste the money.

Enjoy your new "tone".

By the way "NICE GEAR!"