Buy an Audio Research SP10 MkII or an SP11 MkII ?

Another vote for the SP-10 if you are dead set on this or the SP-11. I owned the SP-10 for 8 years and loved it, even with its rolled-off frequency extremes, rather high noise floor, and yes, constant replacement of the phono-stage tubes. But oh man, the midrange bloom and dynamic contrasts to die for at the time. The ultra-low noise RAM 6DJ8 tubes worked beautifully in the 80s.

When ARC returned to all-tubed preamps in the early-mid 90s, the LS5, one listen to this with the companion solid-state PH2 and my SP-10 was for sale.

If you want what the SP-10 offers, I suggest you use the same $2500-3000 or so and listen to an LS5 II or III and keep your eyes out for the matching PH2 on the used market. This combination has ALL (yes, all) the strengths of the SP-10 but has refinements across the board. The SP-10 really is only good for phono playback as its line stage is mediocre at best. I realized how true this was when the LS5 destroyed the SP-10 for line level sources. So if CD playback is also a big part of your listening session, I would consider other options.

Concerning the SP-10's claimed gain of 72db, I would be skeptical of this claim relative to newer products. What good is the gain if there is so much more noise in the background. The LS5 II has 30db and the PH2 48db for a total of 78db and this combination had far more gain and S/N than the SP-10 when I made the change. The SP-10 just barely worked with cartridges at 1mv so I stayed with such models: Sumiko Virtuoso and Shinon Red in the 80s and early 90s. The Benz Glider of today would be a comparable output cartridge.

When I upgraded to the Koetsu Rosewood Signature 2 years ago, the LS5/PH2 combination was not enough to handle this so I changed to the BAT VK-P10 and then Aesthetix Io phono stages which have upwards of 70db each! But I ran each of these at 54 db - the extra 6db over the PH2 was what I needed. There is no way the 0.6 mv Koetsu will work well with the SP-10 unless you have found miracle tubes and the unit has gone through a major upgrade of parts.

John

I have to disagree with Jafox on the gain. I am currently using the SP10 with a Spectral MCR at around 0.2 mv. Also used it with other cartridges in that range. While I will agree it will be better with higer output cartridges, I have gobs of gain at 12 oclock volume setting. The real issue is if your amp is not enough power for your speaker sensitivity, then there will be an issue.
On the line stage, yes I think there are better. I personally do not use my SP10 for line stage. But the reason is not sonics. Its tubes. I dont want to "waste" the tubes in my SP10 for non-phono listening. I use a Cary SLP98 for my CD stuff. The 98 has a decent phono stage but not up to the caliber of the 10. Also, one other note. If you plan to make CD from your records, you cant use a low output cartridge on your table with the SP10. That low output is all your gonna get at the tape record terminals. You need high output if you are going to record your vinyl. I make CD /digital of my records for use in my Ipod (great for travel) and for my car.

Holy cow, I never could have had success with a 0.2mv cartridge with my SP-10. Mine was an unmodified MK II, and like I mentioned above, used RAM tubes. Perhaps the Sovteks or other available tubes of today are quieter which allows for higher gain. But still, the SP-10 was simply too noisy for me after I switched to the LS5/PH2. And, I kept the low noise RAM tubes when I sold the SP-10 and used them in the LS5 which worked mighty well. But again, they were not used in a highly critical phono stage. So it could indeed come down to quieter tubes of today.

Yes, the SP-10 was an outstanding product, but much has happened in the 20 years since then and to spend $2500-3000 here, unless you are a collector, just makes little sense.

John

One thing to note is that while the LS5 is a great product-I still like it better than virtually every line stage ARC has made because it has the tube-like qualities they seemed to move away from in the SP 11, SP 15 and LS 2 hybrid designs-and an excellent alternative (with a good phono stage) to the SP-10, it is a balanced only output design, as I recall (Jafox, am I correct in my recollection?) so you'll need a balanced setup, something I couldn't do in my system. There are adapters available from companies like BAT and I'd imagine ARC, but they will to some extent degrade the sound. Of course, you could always replace the amp with the VT150s that ARC came out with around the same time as the LS5, but I didn't get the impression that the original poster wanted to do much changing to the rest of the system.

So if I look at a LS5, should it be Mark I, II or III and what should I use for a Phono stage, Audion Research ???