Tube Identification Help

[davec69]

I was hoping someone could help me identify the power tubes in my new Mark IV. I realize that I can just pull one, and as a last resort, I will, but I don't like messing with a good thing.

The tubes are blue glass, and the previous owner stated that they were labeled something like "ALTO"?

Any ideas on a blue tube labled Alto?

 

[mesanomad100]

Ive never heard of that company but jj do colored tubes but I think only for EL34's,blue and red are the colors they do....mmmmm as about someone here will know

 

[Russ]

They are probably relabeled Tesla's. Back in the day that blue glass was sought after by some.

 

[Boogiebabies]

Ahh, those old Tesla EL-34's sound sublime. The JJ can't touch it and even the GT E34L, which is a correct copy falls short. I keep mine in a cave with a tube troll on duty.

Like Russ said, Alto is probably an obscure re-label. Put a flashlight to it and see if it matches the GT E34L. It will have big heat wings.

 

[edgarallanpoe]

Ahh, those old Tesla EL-34's sound sublime. The JJ can't touch it and even the GT E34L, which is a correct copy falls short. I keep mine in a cave with a tube troll on duty.

+! IMHO these are the last of the great EL34s. The NOS Seimens are good, but not even in the same league IMHO. The old Teslas are the shiznitz.

 

[Russ]

My 800 just left last night and it had dimple tops in it. Those Seimens tubes rocked. I also like older Svetlanas.

I thought the GT E34L was a screened JJ...

 

[davec69]

Thanks for the responses. I broke down and pulled one of the power tubes. It is labeled "Audio Classics Select" blue glass gold lettering. I can't find anything on google, but I did see a set at a shop recently. Anyone got any further info?

 

[edgarallanpoe]

Thanks for the responses. I broke down and pulled one of the power tubes. It is labeled "Audio Classics Select" blue glass gold lettering. I can't find anything on google, but I did see a set at a shop recently. Anyone got any further info?

Bummer... Those are Audio Glassics...not Classics.... and aren't worth much. IIRC they were cheap Chinese or Russian tubes. Not very good. I would replace them immediately. Sorry to be the bearer of bad news, but those aren't even in the same league as the Teslas.

 

[davec69]

Man, I can't imagine what this amp is going to sound like with new tubes. It sounds amazing, now. Are you telling me that it gets better than this?

Come on....Are you pulling my leg?

I was running JJ's in my DC-3, and was happy with them. What's does one suggest for the best clean headroom and punch in the Mark IV?