shindo vs. atma-sphere

I don't see the point of tube preamps. Since they don't amplify anything, the primary benefits of using tubes (i.e. preserving the nuances of the signal during the gain stage) are not realized, and what you DO GET is tube hiss added to the low level signals (inside the preamp) which go on to be amplified. (BTW, tube amps, if they are even halfway decent don't produce audible hiss.) So, in my ever so humble opinion, the only place for tubes is in devices that amplify: power amps, mic amps, and phono amps; and certain miscellaneous pro gear. Don't argue with me, my mind is made up!

All that said, about two years ago, due to a series of very unusual and sad events (the death of an audiophile friend), I had the opportunity to listen to an Atma-Sphere MP-3 preamp in my system. I wouldn't have bothered, really, but I couldn't let it out of my hands without hearing the MP-3 preamp's phonostage. As someone mentioned earlier, Ralph doesn't make a standalone phonoamp. And the phonostage in the MP-3 represented my "dream" phonostage, which is:
1. Fully balanced differential circuit (best with MC cartridges which are balanced output devices to begin with.)
2. All tube gain stages from input to output! No FET's or SUT's! And unless your MC cartridge is "old technology" and has an output below .4 mV, you shouldn't need those "crutches" anyway. At .4mV cartridge output and above, there will be enough gain to keep any hiss to a minimum -- especially if you're willing to spring for the strongest 12AT7's on the planet -- the GEC A2900 ;~)
3. Believe me, I'd been searching for such a phonoamp for a long long time (but not thinking to look for one buried in a preamp!) and I never found one designed like the phonostage in the MP-3 (as well as in the more expensive MP-1).

So I removed my Levinson 26S preamp and 25S phonoamp from the system, and inserted the MP-3. Things were never the same! I use a Transfiguration Temper W (same as Ralph ;~) and at right around .6mV there was just a little hiss, but only with phono source, and cranked up pretty high. The linestage in the MP-3 is also extremely quiet for a tube preamp (no doubt because it also uses fully balanced differential circuits.)

The Levinson gear is gone. To Singapore, and at a profit well over what I paid for it 10 years ago! The MP-3 went back to Ralph for (most of) the upgrades, and to have him add two more pairs of balanced outputs (one pair isn't enough for most applications, in my opinion.) I really love this preamp and feel it equals many others at three times the price, that don't do (for me) what it does.

I only have one issue with the MP-3 (not a "problem", just an "issue" ;~) and it's the fact that the phonostage (in which I use 3 pairs of very expensive tubes,) is always ON, even when listening to other sources! I've begged and pleaded, but Ralph doesn't seem inclined to make a standalone phonoamp. I even know one person (an audio manufacturer) who only uses his MP-3 for playing vinyl! Must be nice . . . .
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Neil - have you rolled any tubes yet? The chinese tubes that come stock tend to be quiet and pretty reliable (though not super long lived) but their top end is, uh, well let's say less than sweet. MP-1 and MP-3 are gorgeous sounding preamps.

what's the difference between the mp-1 and mp-3? also, what is the impact of the v-cap and caddock resistor upgrades?

Hi Tim,

My (deceased) friend,Michael, had already purchased and installed some fairly 'tasty' NOS tubes which he'd purchased from Andy at Vintage Tube Services. Some better than others; all overpriced IMO.

Anyway, the MP-3 linestage takes a pair of 12AU7's And a pair of 6SN7's; and Micheal had/has some dandies. Sylvania and RCA (red base!) 6SN7's, and a range of 12AU7's: Telefunken, Phillips, Raytheon (windmill getter!), Tung Sol blackplates, etc. I guess I like the RCA 6SN7's and the Telefunken 12AU7's best so far; but they all sound great.

The phonostage takes 3 pairs (gainstages) of 12AT7's plus one more 12AT7 which is a 'constant current' modulator (not in the signal path). I have become addicted to the GEC A2900, or its military version CV6091 (same tube.) I use them everywhere I need a 12AT7: 7 in the MP-3, 2 in my headphone amp, and four in my MC275 (McIntosh) amp. They now cost (minimum) $125 each! They have great sonics, but more important, they have the highest transconductance (a measure of a tube's gain, or 'strength') of any 12AT7. As such, they provide the best signal to noise ratio in situations like the 3 gainstages in the MP-3 phonostage -- which is what makes it actually possible to use the MP-3 with a .6mv MC cartridge and without any SUT! In my power amplifier, the 12AT7's are drivers for the KT88's, and if you use any of the four strongest KT88's as I do (EAT, GEC, Psvane, Shuguang) then this is the only driver strong enough to accurately control the grid voltage in those ultra-high-power tubes and get the best (cleanest) bass out of them. (Those four tubes all have transconductance values of 12,000 micromnhos. Every other KT88 out there is 7500 or less - usually 4500 -5500 ;~)
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For the differences between the MP-3 and MP-1 preamps, the best place to start is the Atma-Sphere website, as well as discussions and reviews.

I can tell you though that the MP-3 is not a 'baby' MP-1. They both use balanced differential circuits but different tubes. And the MP-1 is a two chassis unit (with a separate power supply.) It's also about 3x or 4x the price of the MP-3 ;~)

Capacitor upgrades are generally a good idea. Whether V-Caps are the preferred upgrade, I don't know. Capacitors are like tubes - they are to taste ;~) Ralph thinks Chris Van Hul's V-caps are special; a lot of other people like other caps better . . .

Caddock resistors can provide a warmer, smoother sound, but to hear any difference, you have to change ALL OF THEM!
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