Toob Noob questions

[treserious]

Well, up until now, the only fully working tube gear I had is a modern Chinese made TLA Fatman 182 amp.

I just obtained a Traynor guitar amplifier, which has a complement of 3 12ax7a tubes, and 2 6bq5 output tubes.
all mismatched, made by different manufacturers, and the innards of the tubes have slight differences between them.

Is this a big deal?
should I be sourcing matched tubes?

Now a very kind fellow is testing a quad of tele ECC83 12ax7 tubes for me.

are 12ax7 tubes interchangeable with 12ax7a tubes?
according to http://www.radiomuseum.org/tubes/tube_12ax7a.html it seems that they can be in most circumstances, but I would like it if you guys confirm or deny that.

Thanks.

 

[ke4mcl]

i'd at least get a matched set of output tubes, the 6bq5's since they work in unison. all the other tubes are probably for different input channels or effects channels and i wouldnt be soo worried about those unless you have a problem with sound quality.

if your strapped for cash see if your buddy with the tube tester will test the 6bq5's for you. they *might* be matched on the tube tester despite the different brands. still better off to get a matched set of output tubes of the same style and brand.

dont get rid of the 12ax7's you have in the amp now. you might have some good stuff in there. let us know what brands of what tubes you got and we'll give you some feedback.

 

[klama2006]

Through trial and error, I have found that different branded tubes sound different to me. But who knows, maybe its all in my head.

I did a quick search on the TLA Fatman 182 amp, and it appears to be a duel channel amp. If thats the case, I would make sure the left and right channels have matching tubes. If nothing else, flipping a few tubes would provide to be a fun experiment.

 

[klama2006]

I've swapped "12ax7 eh", 12ax7, and ecc83's in the same preamp. I've never tried 12ax7a's.

I not a pro on this myself, but they all worked. If I'm doing something wrong, I hope someone steps in to correct me.

 

[treserious]

I've swapped "12ax7 eh", 12ax7, and ecc83's in the same preamp. I've never tried 12ax7a's.

I not a pro on this myself, but they all worked. If I'm doing something wrong, I hope someone steps in to correct me.

The amp I am asking about here is my Traynor guitar amp, which is vintage, and in need of some love.

ECC83 is the European naming for a 12ax7. same thing as far as I know.

I'm not to sure what the differences are between 12ax7, 12ax7a, 12ax7eh

 

[klama2006]

I've gone through these guys before, and had a good experience. They were able to help me with my own questions. They also have a nice selection.

http://www.tubedepot.com/index.html

 

[kvflyer]

...I'm not to sure what the differences are between 12ax7, 12ax7a, 12ax7eh

12AX7, original tube design from the late 40s.

12AX7A is a controlled warm up filament, an improvement often used for series strings. Other than that, same as the 12AX7.

12AX7EH sounds like a modern tube made by Electro Harmonics. I don't know much about them.

 

[Rex Everything]

Is that a little 1x12 Guitarmate combo? I really like mine.

 

[bt908]

My personal hobby is guitar amps, I have just started thinking about a tube hi fi system and was going to ask some questions when I saw your post.

Guitar amps are a different world. Most of these circuits are made to clip and distort. Different tubes may sound different but "better" is your opinion.

Mismatched power tubes might give you a certain tone that you will miss if you put in a matched set, some amps will intentionally model the signal differently to the two power tubes.

I would just check the power dissipation on the output tubes to make sure they are not too hot and about the same.

 

[marty59]

You can experiment with different preamp tubes. Some people like cheap chinese 12AX7's because they will break up and distort sooner.
A different thought, a 7025 tube is a spiral wound filament 12AX7 that Fenders' used in the first gain stage to minamize any hum issues. However the Sovtek 12AX7LPS is designed this way too and there are others.