2. amps-preamps
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tube preamp in SS receiver loop

From noob, a very basic and probably very stupid question that I can't seem to find answered elsewhere:

I want to experiment with inexpensive tube sound to augment a modest solid state receiver. I have looked at tube buffers marketed expressly for that purpose, that is, for those who want to insert tube "warmth," which I know is a kind of distortion that many hate, into solid state setups (e.g., the Grant Fidelity B-283). But I would like a tube phono stage as well. So I am looking at a tube preamp with one line level input and one RIAA input. But I would like to use it on all the line level sources coming through the receiver (tuner, CD, computer, ipod, whatever), so it would go between the pre out and main in on the receiver, or else in the tape loop. In other words, the line level signal would go through the SS preamp, then the tubed one (the turntable would of course go straight into the tube preamp). Is it kosher to use a preamp in this way? That is, as a buffer stage that comes after the solid state receiver's preamp circuit? In other words, can you use a variable gain preamp as a (passive?) buffer? Clearly I have no idea what I'm talking about. Thanks for any thoughts you may have.
vesuvio
ivan_nosnibor's avatar
ivan_nosnibor
782 posts
 
Sorry Vesuvio, I see now where your preamp would only have one line input in addition to the phono input - didn't pick up on that the first time around. But my advice is still essentially the same as for the buffer - you'd still end up needing a selector switching box for the all the line sources, again, as Y-adapters just wouldn't work in either case here. A selector box may be ok with you or possibly you may just prefer to bite the bullet and find a linestage-with-phono preamp that can handle the number of sources you need. Post again if you want, if I still don't have it right.
seattlehifi
70 posts
 
I would avoid the Y adapters if possible. Ivan is correct but then, again, we're back at the multi-input tube preamp vs. a tube buffer PLUS a multi-input selector box.

My advice is to try and simplify the signal path as much as possible. Now that I know this is just for 2-channel audio - the preamp makes additional sense because it positions you to eventually replace the receiver for a dedicated 2 channel SS or tube amplifier.
vesuvio OP
5 posts
 
Thanks, Ivan. You have it right. I have a typical vintage solid state midfi receiver with phono, tape, tuner, aux inputs. I started looking into this controversial buffer business, which led me to a reasonable and fairly popular tube preamp, with the phono stage as well, the Yaqin 12B, which I thought might make a good buffer.

But then I wondered if it would work in the tape or pre-out, main-in loop as a tube preamp in series with the solid state preamp in the receiver. Maybe a little redundant, and, as you say, there is the problem with the two volume controls. I don't want to completely bypass the receiver's preamp because I need its tone controls.

So I'm leaning toward the single-tube Yaqin buffer (cd1), and maybe later a phono stage. And one day, maybe either a more expensive preamp with multiple inputs or a complete tube setup. Part of the fun of all this is the journey.

Much appreciate your thoughtful comments.

John
vesuvio OP
5 posts
 
Thanks, Seattlehifi. I see what you're saying about the preamp over a buffer. Clearly I have a lot of factors to consider.

I'm still leaning toward the buffer for now, maybe the yaqin cd3 (of course, the whole cd1,2 or 3 issue is another big debate in itself! my eyes are blurry from skimming boards). It would fit better in my space and be more of a small mod to my existing Marantz, which I already like quite a lot.

But if I find I really like the tube sound, then eventually I could splurge on an honest-to-goodness tube preamp. Or even integrated. Vintage, maybe. The last time I saw a tube was about 1965 in the back of my parents' monaural Magnavox, which I can still recall sounding awesome. Meanwhile I could ease into rolling tubes in the buffer.
ivan_nosnibor's avatar
ivan_nosnibor
782 posts
 
If you go with the buffer don't forget to expirement with using it plugged straight into the main ins on your Marantz - even if you bought it with the full intent of using it as you describe above. The difference in sound quality just may surprise you...or not, but it would be worth it just try it out long enough to see for yourself. But, I believe you're on the right track and good luck with it all, either way.
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