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In Reply to: Re: CAT SL-1 tube trouble anyone??? posted by Jwm on February 17, 2007 at 13:18:55:
Hi Jwm,
I googled Aesthetix Io. Pretty impressive and serious stuff. May I ask if you have heard the Audio Research Phono Reference? Does your opinion about transformers being bright also apply to the ARC unit? Have you heard one in a friendly environment? It uses internal transformers and all tubes. I've not heard one or even talked to someone who has listening experience. The reviews have been excellent. One should expect a lot of performance for the price which is high. Do you think ARC products are generally bright? I'm only trying to establish a context for your comments. No criticism is implied or intended.I must admit that I have stayed away from transformers but if they are well done, they could offer a good solution. I do know that J. Gordon Holt, of Stereophile fame, used an extremely low output Ortofon MC for many years as his reference. I believe that cartridge was rated at 2 microvolts output!!! Obviously, it used external, in-line, tranformers typical of other Otofon's. I have always wondered if he had hum problems. He liked it. I have no idea if you or I would. I do think that Holt has great ears and he would not put up with a bright signature.
Aesthetix's tech description mentions the use of specially selected low noise tubes. I wonder how many tubes must be tested before the magic ones are found. I wonder if this is a long term issue. At the least, one would want the company to stay in business just to be able to supply the specially selected tubes. Do you think Aesthetix is a stable company? Until now, I knew nothing about them.
Personally, I have never heard a pure tube based high gain stage that I could live with. But it sounds like with the right tubes and good design it can be done. Do you know the signal to noise ratio your preamp achieves in the high gain mode? It may offer an alternative path for me. I doubt that I will be able to audition one. So, your experiences would be very helpful. Also, what is the output rating of your cartridge? How long have you owned your Io?
Of course, noise is only one of the parameters one would use to select a preamp. How you would characterize the sound? What are your sonic goals?
Whew, lots of questions. Sorry. Thanks for your help.
BTW, it might be helpful for you to check my profile to get an indication of my goals.
Follow Ups:
HI jwm,
Update. I just found your review. Good job. You answered most of the questions I asked in my above post. I wish we could edit on this forum. Terrible format, IMO.However, all of my questions concerning the ARC Phono Reference and transformers are still on the table.
I think your review leaves unanswered your sonic goals. All true audiophiles will state they are after reality. I would too. But, as you know, everyone's idea of what that represents differs, often radically. And everyone is right, for themselves, if they are serious and experienced audiophiles. But it may not be right for me. Thus, I think knowing your goals are important so I can evaluate your comments.
I especially worry about your comments concerning Audio Research. You indicate that there was a time when you admired their products. My equipment was designed kind of in the middle of their history. My SP-11 Mk II preamp is more neutral and resolving than the previous SP-10 (which I owned brand new) but more "musical" (whatever the hell THAT means) than their later designs. I don't like the later one's either. Of course, my D-250 Mk II Servo amp is an all tube design which I love and think represents ARC's high point for power amps. All in all I love the sound of my ARC stuff. They are very synergistic.
I don't know what time frame your comments refer to. As you might know, there is a fairly active controversy concerning the SP-10 and the SP-11 preamps. It’s a classic issue pitting the more romantic sound of the SP-10 against the more neutral, highly resolving SP-11. I'm solidly in the SP-11 camp. These differences are important with respect to your ARC comments.
Now, I must tell you that I would own Maggies (I do love them) if I did not own my Martin Logan CLS IIA electrostatics. I think the CLS's are the most revealing speakers I have ever heard. They are also the most demanding of the upstream electronics. These speakers are brutally honest. More so, I think, than Maggies of any stripe. However, that is not a vote against Maggies. Not at all. I just prefer what the CLS's offer. But the differences in our speaker signatures may deflect our electronic choices in different directions. That is what I want to determine, if possible.
You did not discuss the interface between the Io and non-Aesthetix preamps. I assume it has a line level output that would plug into a line input on my SP-11. I don't think that's confirmed.
Please don't try to convince me to get rid of my SP-11. You will be wasting our time.
I don't think we can meaningfully discuss the synergy between our electronics and our speakers. Assuming we have both achieved what we want is reasonable. I'll go with that.
Thanks for the good review. Had I found it earlier I would not have spent so many words on my previous post.
Please reply to this. I'm very seriously interested in the Io.
Again, thanks for your time and the review. We need more of these very thoughtful reviews on good but obscure equipment.
I don't know what the signal to noise ratio is. I don't care because it sounds great. I am using an Audio Research Ref 2 Mark 2 with it and have no problems. I have a friend who has the same Aethetix with his Audio Research Preamp and new Martin Logan hybrids. He use to own a Audio Research Phono stage. The Aesthetix is much better. I use the tubes Aesthetix provides with their Phono and never had a noise issue. Jim White of Aesthetix has been around for about ten years. He use to design for Theta Digital before that. I have heard the Audio Research Ref. Phono stage at past CES shows in Vegas. I did not like the sound of the phono preamp when they switched on the internal transformers. The gain of the Aesthetix can be set at 50, 62, 68, 74, and 80 db. I am using a ZYX cartridge with .47mv output.
HI Jwm,
Thank you. Your cartridge is not really a low output MC. For example, I have a Monster Sigma Genesis 2000 on my second turntable which is rated at .2 mv. This, or less, is generally considered low output. On my ARC SP-11 noise is simply not present, even when music is not, with this cartridge. I would consider yours to be on the low end of medium output. I'm sure it is a better match for the Io or any other pure tube MC amplifier than my Sigma 2000. Your cartridge has more than 6dB more output which is quite a bit. I'll stand by what I said earlier in this thread. Low output MC's are very difficult (impossible?) for pure tube stages to amplify to useful levels and achieve noise free operation.You know, the noise problem is not addressed by magic or wishful thinking. Preamp design is not immune to physical laws. Great designers have been trying to solve this problem for decades. Consider how low noise performance is achieved with digital astrological photographic sensors and also radiation detectors. Heat related noise is their enemy. Cryogenic technology is used to overcome thermal noise. It’s an extreme but useful solution. But, it’s not available to audiophiles and their tube phono stages. Watch out; it’s probably on its way!
Every conceivable configuration has been tried. The results are predictable and Aesthetix products are no exception to the rules. Noise is a very nasty customer. All of the good solutions are trade offs. Components have improved and circuit board technology has helped but the physical laws governing thermal noise have not been rescinded. You, being a physicist, know this is true.
I’m not a dreamer. While I would like perfection I don't expect it. And we haven't even mentioned microphonics in this discussion.
I want zero audible noise if possible which my SP-11 actually can accomplish with a .2mv cartridge. It's very impressive from that point of view. I'm guessing that you are less picky on the noise issue. Just because the preamp has sufficient gain does not mean it is useful gain. Reviews have noted that noise is present with the Io. I believe it especially with low output MC's.
My other turntable, OTH, uses a Clearaudio Discovery cartridge which is rated at .6 mv. This cartridge would probably be a good match for Aesthetix preamps; even better than yours with respect to noise.
I have been researching Aesthetix phono stages since you first mentioned them. I realized that your set-up, besides being very expensive (and, I'm sure, wonderful), will not physically fit into my rack situation. So, I looked for other options and came up with the Rhea.
Since I use two turntables, both with MC's, each with different characteristics, the programmable multi-cartridge features of the Rhea are very inviting. According to the reviews, the Rhea gives up performance to Io which is to be expected. However, the Rhea has had rave reviews and it will fit into my system situation. Hmmm, my little calculating mind considers......
I am a firm believer in the concept that we get what we pay for. There are few shortcuts to great sound. Thus, I would prefer the Io but it is not possible. That thing is a monster!!! That plus I can’t comfortably afford it. So, understanding that I'm giving up some performance, I went shopping for a used Rhea. I didn't expect to find anything given that there are probably not many out in the field and those that are are not going to be given up often.
Well, I was surprised to find very nice, low hours used Rhea on Audiogon at a price that, if I decide I don't like it, I can resell at no loss. I don't think that is likely but it could happen. Buying good used equipment is one viable shortcut that I have successfully used before. "Good" is the operative word. I wish I could audition the Rhea first but this seems to be a good second option. I'm buying it and have you to thank.
Thanks. And my two cartridges thank you. And my ears. And my parrots. And…… well, you get the idea.
The Rhea is a good alternative. I have a friend using one with a Benz LP, I think the Benz is in the .25mv category. He has no problem driving it. Of course there will be a little noise in low quiet backgrounds. This does not bother me, because the sound is more important to me. I have not heard a better phono stage than the Io bar none. If you want dead quiet backgrounds my recommendation would be for a solid state phono stage like the Klyne. Good luck with your endeavers.
HI Jwm,
Operation with the Benz is good news. While I am buying the Rhea primarily for use with my Discovery, I also want good performance with the Sigma 2000. It sounds as though it will work.I have no illusions about the Io vs. the Rhea. I just hope the Rhea will be good enough. I think it will be.
I do prefer black backgrounds. The price is transformers or FET's. I want better than that if possible. For the moment, I'll trade black for outstanding sound. The only way I can know for sure is to live with the Rhea for a while.
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