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What's in a name/number? Quality? Performance? Value?




I'm just getting into tubes having only recently discovered the sweet tube sound by acquiring a small custom tube amp at a garage sale (see attached image). One guy said that it appears to be rebuilt amp from a console (maybe a Fisher) and it's probably pushing about 12.5 watts per side. Anyone else care to guess at the origin and specs? The sweet sound of this little amp prompted me to purchase a rebuilt Dynaco ST-70 that I really love. Having caught the tube amp bug, I'm now looking at a Bob Latino ST-120 kit. All this means that I need to learn more about tubes.

I understand that the 7199 driver tubes that my Dynaco ST-70 uses are no longer being manufactured and that good 7199 tubes with quality sound are becoming both rare and more expensive. In order to stock up now, what brands, vintage and type should I be looking for or avoiding and what is a fair price for them?

I have also seen adapters for sale that allow 6GH8A and/or 6U8A tubes to be used as substitute drivers in the 7199 plug. What can anyone tell me about these? Are they a worthy alternative? If so what can be said about the difference in the 6GH8A and 6U8A tubes as far as sound quality and characteristics in comparison to each other and the original 7199? What brand, vintage and type of 6GH8A and/or 6U8A tube should I look for and what's a fair price for them?

I have even noticed some completely new electronics boards for the Dyanco ST-70 being sold with upgraded capacitors etc. and they have been built to handle 12AU7 type drivers tubes or their suitable equivalents. What is the general consensus on that route being a viable alternative?

For my small amp with the 6BQ5/EL84 power tubes, I have purchased a few matched pairs (at least that's what the listings claimed) of 12AU7, 12AX7 and 12AT7 driver tubes to see which type I think sounds best. What I'm just now learning about, but don’t have any of yet, are the 6189 or 5963 tubes and I'm intrigued with them. Aren't they supposed to be a good substitute for the 12AU7? If so, why do you suppose most of them are so much less expensive than the 12AU7? Are you familiar with their general sound characteristics in comparison to the 12AU7 or each other? Does anyone have an opinion of them? I also found that the 5814A are offered as a substitute for 12AU7 and are also much less expensive. Please let me know your thoughts and opinions about these tubes as well. If they are a viable sound quality alternative to 12AU7 I would be rally interested in which brands, vintage and type I should look for and the prices I should accept for them.

I'm also looking for education on the different tube types in the same model numbers. Do you happen to know what the difference is between a 12AU7A and a 12AU7WA if any? Also, who explain anything about all the different plate configurations (smooth, ribbed, long, short etc.) and which are more desirable and why? Likewise for the different Getter types (round, large O, square, D, A etc.) and which might be best and why?

The last bit of info I'm curious about is Cryogenic treatment of tubes. what is everyone's opinion about this treatment? Does it improve sound quality, service life, both? Do the tubes need to be treated when new or can vintage tubes reap an added benefit as well (without affecting their service life)?

Is there anything else I should know about the tube types I have listed here, but don't know enough to ask about?

I intend to have and enjoy these sweet sounding tube amps for a very long time and then hand them down to my sons. For that reason I'm very interested in stocking up now on some of the compatible tubes that are most worth listening to. I value your opinions to guide me in the right direction.

Thank you so much for your time.

Steve


The beatings will continue until morale improves!


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Topic - What's in a name/number? Quality? Performance? Value? - Galaxyoilcan 23:33:50 12/4/12 (6)

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