Tube Preamps...I'm sold

Crem1: Your advice is good for someone totally focused on LP playback. Unfortunately, the SP-10 as a line stage for other sources is mediocre at best. Tubed line stage performance has come a long long way since then.

I ran with the SP-10 II for 8 years from the mid 80s-90s and loved it. But the LS5/PH2 pair that replaced it was far far beyond the SP-10 for both LPs and CDs. Finally CD playback was tolerable! And even though the PH2 was solid state, this with the LS5 had the incredible dimensionality of the SP-10 but with far more extended frequency extremes and without the noise level. I never would have believed the PH2 could do this ..... but it did.

Steve Huntley at GNSC does some incredible rework for the SP-10 but this can be costly when you're all done. I cannot imagine tolerating the stock SP-10's weaknesses after hearing the many refinements in products over the last 10 years. But for LPs anyway, the GNSC SP-10 rework is a totally different sonic performer altogether. I know a vinyl guru in Canada who has one and he loves it.

Just recently I got an ARC MCP-33 to support multiple arms/cartridges. The MCP-33 came out after the SP-10 to support MCs with other ARC preamps like the SP-8 and SP-6 which only supported MM cartridges. I understand that the MCP-33 and SP-10 have very similar MC input design.

After some major parts updates and IEC connector to this MCP-33, the performance is outstanding. I don't know how much improvement was gained by the various Dynamicaps and Vishay resistors, but changing from a stock power cable to something like a Stealth Dream power cable is HUGE. This alone should be done to all older tube gear with attached power cables. And this modified MCP-33 is very quiet .... something I was concerned about when I took on this MCP-33 modification project.

I have been playing with this MCP-33 into an Aesthetix Io Signature set at 56db gain....and comparing to the Io Sig. on its own at 68 db gain. Both units render the 3D of the music incredibly well. But it is clear there are hints of the SP-10's rolled-off frequency extremes, primarily in the bass, with the MCP-33. Perhaps beefing up the power supply would help things here. I might just have Steve Huntley take a look at this one of these days.

For someone that has a decent full-function preamp but perhaps does not have enough gain for their favorite MC cartridge, or they are looking to bring on some tube magic to their system, an MCP-33, RAM RM-4 or Counterpoint SA2 might be a perfect and less costly solution. Unfortunately the added cost of an IC and a PC, both must be at the top of their class, takes the price quite high. And then the quest for the perfect set of tubes begins and this too can add up. Top-tier performance does not come cheap.

John

Crem1 - Thanks for the tip on the MC demag device. I never heard of this process. Now I have the itch to try.

I always wonder where my SP-10 might be today ... no doubt it has changed hands a few times since I sold it in 95. You describe this very well as portraying floating images. This is why it took me so long to find a product that had the SP-10 magic but then went to the next level of refinement. It was no surprise that it took the LS5, a return to an all-tubed line stage since the SP-10 a decade before, to bring back that musicality. All of the ARC "hybrid" designs from the SP-11 through the LS2 were too sterile for me.

As for SP-10 MK II status, as I recall, one can tell of this by seeing 2 pairs of 1 or 2-watt resistors, each pair in series and sitting on the board in a teepee fashion. I have since forgotten what the benefit or "fix" that came with the MK II update.

I would be reluctant to do any serious circuit design changes but rather simply focus to replace passive components in "critical" areas. But I would also be aware that some of the musicality/dimensionality might be lost for the sake of greater resolution and detail with "refined" passive parts. Getting both of these improvements would likely require a change to a different product.

I made one slight change in the MCP-33 to allow for the MC load to be as high as 200 ohms instead of the maximum 100 ohms. The MCP-33 owner's manual talks about this as a possible limitation of this product for some cartridges. And ideally my Clearaudio and Koetsu cartridges perform their best at a 500 ohm load but they work very well with the MCP-33 with a 200 ohm load...even the 100 load. I am reluctant to change the one resistor value any higher as this could affect any number of critical circuit parameters. And I would be reluctant to do anything similar in the SP-10. Having a circuit guru helps a lot.

John

Atmasphere, I sure hope you are talking about the MP1 when you mention the bottom octave, because the MP3 up against a BAT 31SE a couple years ago was severely lacking extension at both frequency extremes. Perhaps it was ill but it was a Mpls Atmasphere dealer demo. And the comparison was made at the Mpls BAT dealer and later on, my home. Upon switching from the 31SE to the MP3, the BAT dealer and I just looked at each other with total surprise as we never could have imagined the MP3 to have such issues.

Bart really nails it here on the significant improvements that are possible if the owner is willing to put forth the effort to investigate tube options. With some starting points as advised by Albert, I have taken the Aesthetix Io/Callisto and CAT UII and JL-3's to levels that transform these products far beyond their showroom performance.

I had an ARC LS5 which I traded for a 30SE after hearing the 31SE at HiFiSound in Mpls. The 30SE to 31SE upgrade was very affordable and I was convinced I would do this upgrade. But I wanted to give the MP3 a shot before I sent my 30SE for the upgrade. As I think more, this was closer to 5 or so years ago. I was thinking it was only a couple years but time flies when you're having fun. 8-)

I went to Audio Perfection to borrow the MP3 demo unit. It was fair to assume it was in good working order, all original tubes, etc.,.....at least I would think so if a dealer is using this to sell such a product. I was not able to hear it there that day but they let me play for the weekend.

I took the MP3 to HiFiSound where Bill (salesman) hooked it up in the very back room with B&W N802 speakers. The amps were Classe mono blocks. As much as Bill and I had such high expectations on the MP3 from all the praise on the Atma amps, to say that we were both disappointed on the MP3's performance would be an understatement. I remember the look we both had when the bottom and top octaves were gone ..... not lacking .... but GONE. A return to the 31SE and we could again here the string bass player going up and down the register. And there was so much detail, decays and ambiance with the 31SE. Music was Miles Davis, "Kind of Blue". Even the ARC LS5 that I had taken there a week before was not so severely destroyed by the 31SE as was the MP3.

Almost forgot - I was able to borrow the 31SE and take it home to compare to the MP3 and my 30SE .... and the results were the same. Ultimately, the MP3 was not my cup of tea.

I have since moved onto the Aesthetix Io and Callisto, and am waiting for the Michael Elliot WV preamp. Perhaps one of these days I will try out the MP1.

John

Yes, a member indeed......I got on board just as the ship was to sail. I've had some recent correspondence with 2 people who got to play with the WV prototype this summer. I understand that there will be official news before the holiday season.

Development can't take that long, can it?

Well, I guess with this being a one-man show, in the context of development anyway (other than software development for the volume control), I can see how it takes this long. Clearly the power supply design is first rate, the perfectionist approach to the volume control and line stage, the attention to support various source levels and amplifier input sensitivities AND the ultra quiet phono-stage as reported by the people who got to play with the prototype ..... well, I can not imagine this all happening in less than a couple years. Then if you add up all the time to listen to several passive components (e.g., look at his capacitor writeup), step-up transformers, evaluate wiring harnesses from PS to audio chassis, etc., you can easily understand why it's well into year 3. I much prefer this approach than simply going with a capacitor or any other part that may work well now and then have the view that this can later be replaced when all remaining components are evaluated ... and then cause a "MK II" update that ends up costing the customer $500-1000 more and the hassle and risk of shipping the unit back and forth. No thanks! There will always be improved components but I applaud the designer to make every effort to audition all the components available to him before the product is delivered.

My only uncertainty is how the step-up transformers will perform. One of the two people wrote to me that the phono performance in his setup was a step above his line and phono stages....and he uses the Io Signature as well; this is encouraging information. But I also have a highly modified ARC MCP-33 on the shelf to use as a step-up device to compare with the WV's Sowter-based MC input. Of course the MCP-33 will require another IC pair (Jade Hybrids are not cheap) and another Stealth Dream or Dream State PC which are not cheap. Clearly the MCP-33 solution quickly gets expensive but I can "borrow" these cables from the digital setup to try it all out before I buy more cables.

The cool thing about the WV is that you can get it with 2 MM inputs, two Sowter-based MC inputs or one of each. I will likely do the latter which allows me to compare the Sowters to the MCP-33. I suspect that both will have their pros/cons based on the music type, recording quality, etc. I like the flexibility. And of course I can run the Io Sig into a line input to compare to these two options and also compare vs. the Callisto Sig line stage. Lots of evaluations to do once the WV arrives in a few months. It should be very cool, especially based on the high praise of the two people that got to play with the WV this summer.

I have gone crazy trying so many many tubes in the Aesthetix and CAT gear to a point where JD teases me about this regularly. But it has paid off. I just hope I do not get too obsessed with this on the WV and MCP-33. 8-)

John

Atma - thanks for the updated news. Some day I will have to try the MP-1 in my system.....put it up against the Io/Callisto and WV.

Last Fall I had the opportunity to hear the Einstein line stage in my system compared to the Aesthetix Callisto Sig.. The Einstein with stock tubes was rather 2D and lifeless. It was no match to the Callisto with its set of hand-picked tubes. But after playing with the 6922 tubes (Tele 6DJ8, Philips 7DJ8 and Amperex 7308) on the Einstein's inputs and a Tungsram E80CC in the 12au7 slot, the Einstein's magic came to life. This is a most musical piece.

Time did not allow me to live with the Einstein for awhile and then return back to the Callisto for any kind of comparison. But when the Einstein left and the Callisto returned to operation, I did sense just a little less clarity and not as much extension at the frequency extremes with the Callisto. I just never had the opportunity to confirm this. Both pieces aced in the areas of portrayal of space....a major weakness by so many line stages.

The coolest thing about the Einstein is the ability to use diff tubes for each input. I can see this as a major advantage to optimize each source to the system. And this feature also makes for quick comparisons between input tubes without turning off the Einstein.

As for using so many tubes, for every input that does not have an associated source, you can remove that pair of 6922's. This can reduce the tube count by 6 or 8 for those using only one or two sources.

If the cost of the Einstein was not so high, I would have given it serious consideration. But with the Aria WV full-function preamp coming in at half the cost, $15k-20k line stages are a tough sell for me.