2. amps-preamps
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Preamp for Aesthetix / Atma-sphere

Hi

I have the Aesthetix Io Eclipse with volume and dual power supplies, Atma-sphere MA-1 monoblocs (140 watts) and Audiokinesis Dream Maker (93 db sensitive) speakers. These are great components. My question is about system synergy, how to make them play together.

I have been running the Io direct to my amps since I first bought the Mk2 version back in 2004. At the time, I had a Krell FPB600, and in that context, it was a blessing, and a great step up from the Krell KAV 250p preamp. I'll never forget my first impression with the Io - it was like going from the wooded hills up into the mountains. There was no going back.

With volume, the Io functions as a preamp. It looks like a preamp. Someone here on A-gon said going direct is best - which I interpreted as: it IS a preamp! So I thought, OK I have a combined phono and preamp - problem fixed. But it wasn't.

From recent testing I have finally become convinced that the Io does benefit from a separarate preamp. Even if clarity and detail is better going direct from the Io to the amps, the punch and "here-ness" of the music is clearly better with a preamp in the chain, at least in my system.

Trouble is, which preamp? I am testing a small solid state Musical Innovation preamp, which helps with the punch but veils the music. An optimal solution might be the Aesthetix Callisto, preferably with dual power - but I don't have the space, and I already have a lot of tubes and tube heat. I have space for one or possibly two boxes.

From what I have heard so far, a solid state might do the job well (in my tube-rich context), however it should not impart any s-state artifacts or reduce the resolution from the Io Eclipse.

The ideal would be to test a few tube and s-state preamps, and then decide. However, this is difficult where I live, so advice is welcome.

My question relates to my own setup of course, but is relevant for everyone with a top phono stage on the one hand and amps on the other. What is best in the middle?

From recent testing I have learned that problems that I thought were related to the speakers, the phono pre, the pickup and so on, were in fact related to the preamp issue. For example, the Dream Makers straight from the Io may sound a bit lazy and washed out in the bass, very clear in mid and treble but not fully embodied. Plugging in the solid state pre, the situation becomes dramatically different, now the speakers are driving, propulsive. Very enjoyable, but some detail is lost and some transistor things added that I don't want.

So I am looking for a solution with most of the plusses, and not much of the minuses. The preamp must be fully balanced with XLR in / out.
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Ag insider logo xs@2xo_holter
Ag insider logo xs@2x
o_holter OP
977 posts
 
Re tube matching in Einstein The tube mk2:
Brent Jessee who sold the two Siemens tubes for the phono inputs, and the Telefunken 12au7, has mailed that these are really NOS and need to be broken in. Whereas the CBS Hytron I bought on Ebay has been used,, broken in, "mellowed". Brent suggests: Give them another 50-100 hours to see if they calm down and bloom more.
So, I need more time.
audiolabyrinth's avatar
audiolabyrinth
4,555 posts
 
I look forward to what you say, I really want to know the outcome of the Hytron tube, like, is it what the both of us like?, we both like emotional and musicality, so I trust your impressions.
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o_holter OP
977 posts
 
Audiolabyrinth - CBS Hytron - I have not A/B tested much, but what I can say is, it stays, compared to the stock Jan Philips. Very enjoyable, although perhaps the one I got is a bit used, I dont know. My system now is very chameleon-like, the "sound" changes according to the recording - like it should.

The Hytron that I bought was advertised thus: "Vintage CBS Hytron 5814 A Black Plates D-Getter Stereo Tube 1959" (from Greengirl613 at Ebay). Seller said it measured 3100/3060 on his Hickock 6000a. It sounds very good to my ears. I paid only 37 usd - so it was a great buy for me (btw - ridiculous how the 12ax7 have become uber-expensive, and good that 12au7 can still be more reasonable).

But as noted, the Telefunken 12au7 is probably not broken in yet, so my ranking may change - even if it is a bit hard and harsh for now, it may outperform the Hytron. That has happened with Telefunken tubes in my system before. But for now, I very much enjoy the Hytron.

It feels like it has some extra magic when the music is in the same terrain, like, I play Booker T and The MGs: Right now, the Sundazed LP (one of their good reissues), and wonder, was it the same tube sitting in Booker's organ?

Jafox - I have four RCA 12BH7s on the way, not arrived yet.
Will be very interesting.

Probably I wont be able to give a good comparison until August.
atmasphere's avatar
atmasphere
11,849 posts
 
Not sure, is the RCA 12bh7 tube equal to other 12au7 variants, regarding gain?

The gain, or mu, is the same however the 12BH7 is based on the 6SN7 tooling. If you examine the 12AU7 you will see that it is a 6SN7 plate structure that has been sawed in half. The 12BH7 is the whole thing and IME a better sounding tube.

The filament specs are double that of the 12AU7- you might want to check with Einstein before using the tube in your preamp.
audiolabyrinth's avatar
audiolabyrinth
4,555 posts
 
Thankyou O_holter, great post, this will be interesting to see if the Telefunken's are as good as the Hytron tube, @ Atmasphere, wow!, you are saying that we may or may not can use a 12BH7 tube in place of the 12au7 tube, I believe that was information was of grave importance!, thanks, welcome back to the thread.
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