2. amps-preamps
  3. 1397501648

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.
-
Ag insider logo xs@2xo_holter
audioquest4life
772 posts
 
Not sure if you heard about the German brand Octave. I had the HP500 SE for a while than sold that and purchased the Octave Jubilee preamp. Before I purchased the Octave Jubilee, I tested the Einstein preamp. Though it was good, and bass was articulate, I feel the Octave Jubilee is better due to its ability to create uncanny realism with music. I use a pair of Mcintosh MC2301 300 watt tube amps with the Jubilee. Previously, I had Octave MRE 130's which I used with all three preamps. The Einstein was better than the HP500 SE, however not the Jubilee.
Good luck
Audioquest4life
Ag insider logo xs@2x
o_holter OP
977 posts
 
Two days ago I got the RCA 12BH7A black plates. Wow! Best so far. The sound stage is larger, more bass especially. This really engages the room, I can hear it from the next room (kitchen) too. I’ve never heard Pink Floyd: Pulse (the LP box) this good, with such a great “being there” factor. Or the (incredibly ambitious) first Ambrosia LP. "Nice, nice, very nice" - indeed!

I have checked with Einstein, will I be OK using a 12bh7 in the 12au7 position, but the answer wasn’t quite clear, so I’ve asked again. However I hear nothing wrong and the trafo temperature seems about the same.

So for now, using Io Eclipse as source and the pair of Siemens Halske 6922s in the phono inputs of the Einstein, the RCA 12BH7A moves to the top of my list, even better than the CBS Hytron. Both of these sound better in the 12au7 position than the Telefunken (needs more break-in) and the stock Sylvania green label 5963. So thanks to Jafox (and Atmasphere) for bringing the 12bh7 into the discussion. The gain seems to be about the same, with the RCA / CBS / Tele / Sylvania I have tried (no change of the volume control) - but the music *feels* larger and more present with the RCA.

An interesting effect of this discussion is that I have stopped worrying about (1) was it the right preamp and (2) is it too solid-state sounding. Instead I am enjoying it a lot - the tube investigation is exciting. This preamp really changes personality, so when people write, “I heard the Tube but preferred preamp X”, I am wondering what tubes were in the Einstein.

Audioquest4life – I would love to hear an Octave Jubilee one day. I have read many of your comments, very helpful and informative, in this forum. Are you still using the Io Signature as input to your preamp?
Ag insider logo xs@2x
o_holter OP
977 posts
 
Jafox - sorry, I see now that you did try the 12bh7 in the Einstein. I guess it is fine, but I want to double check with them.

Albertporter - power cable - yes, I have seen other users reporting this also. I will change from the stock cable, but it requires that I put the angled stock cable plug, made to fit the underside of the preamp, on the new cable, it is not just plug and play. So suggestions for a good cable are welcome. The seller suggested Nordost Heimdal. I am using JPS, Wywires, Kimber etc other places in my system, but truth to be told, the power cable area is not the one I associate with the most improvements, perhaps because I have a dedicated audio grade 25 ampere / 240 volts AC line already.

I have also read about two other worthwhile tweaks - putting some extra feet under the stock feet, and some damping at the top of the trafos. These are not so easy for me, since the Einstein stands on a rather confined second shelf in my rack. But I will do a power cord upgrade.

I have done one tweak of my own. Since the Einstein has less than an inch of clearing from the top of the trafos to the shelf above, I bought a 12V computer fan, and installed it behind the preamp. Using 4.5V transformer plus an extra resistor, the fan speed is down to 200 rpm or so. I have to help it going, when plugging it in. It is absolutely silent even when I listen close to the rack. I can plug it into another AC line, different from my dedicated audio line. The effect is that the trafo and chassis temperature of the Einstein goes down 10-15 degrees C (from 75 to 60). I don't want too much "kool-aid" effect, since the sound seems to become poorer, so this is why I have adjusted the fan speed even further down.
audiolabyrinth's avatar
audiolabyrinth
4,555 posts
 
Hi O_holter, interesting news about the RCA 12BH7A Black plates tubes, question- what the sound stage presatation like?, Is it up front and personal, forward sounding, or in the middle of the room and deep sounding?, oh, and about your fan, scrap that idea, get you a small battery powered fan that is quite, I believe I am going to have to invest in one myself, My amp seems to heat the house, the amp gets HOT, However, I want to keep alot of the heat off the amp, I do not mind Heat of pure class A operation, to me, It's like a jet engine going off, kinda awsome, cheers.
Ag insider logo xs@2x
o_holter OP
977 posts
 
Hi Audiolab, for now I am just enjoying the system including the 12BH7A, listening to two new Rainbow boxes I've bought, Munchen 77 and Rockpalast 95 (even if its not always my style, Ritchie Blackmore's guitar is a joy). I associate the tube with some xtra feeling of big music, you are there. So 'middle of the room deep sounding' yes check. 'Up front personal' well I think some yes check also. It is like the whole thing sounds bigger than with the 12au7s, and therefore also more detailed. Perhaps I hear some grunge also, but it may be the recording, etc. I have three more 12bh7s on the way. But I have to switch back to the CBS and burn in the Telefunken before I can say more. In my case A/B testing is a bit difficult, and I prefer to listen for longer periods before changing.
More to discover