Dedicated phono-pre for MM only?

Hi Tom,
you say:
>>> Just seemed like a similar question in that having phono stages designed specifically for the type of cartridge engine makes sense. <<<

I have the idea that Raul will be the person to explain to you in his words why he has opted for two **dedicated** phono-pre option in his 3160 and NOT a one-serves-all (just with a jumper to switch from 40 to 60dB).

Having read all my and Kirkus' comments should have made the point, but let's see if Raul can put it into a 'nut-shell' for us.

Greetings,
Axel

In my view, one of the hard to resist features of the 3160 (Raul's product) is the completely separate MM and MC phono stages, not to mention the fact that both are balanced circuits (or at least I know that the MC one is balanced).

Raul might respond to Tom's question about why "high-end" phono preamps have switchable load resistances by saying that there is a demand for it among end-users, for the sake of convenience, not optimal sound quality. Most end-users of such products want remotely switchable everything, so they don't have to get off the couch. Raul wants optimum performance as his end-all and be-all. What I meant to infer when I said that most of us would not know whether switches degrade the sound is that most of us have not done the experiment properly in order to make a judgment. Most of us have one phono stage which either does or does not have switches in the signal path. And no one (other than Raul) has come forward to say that removing switches from phono inputs has made an audible improvement in sound. Or that adding same caused a deterioration. For my part, I own an Atma-sphere MP1 in which I have made considerable mods to the phono stage. The MP1, like Raul's preamp, has no switches in the phono input, but one can change load resistance by installing resistors between two screw terminals on the outside rear of the chassis. Purist that I am, I have never used those screw terminals for loading or for anything; I solder my load resistors right at the grids of the input tube (or the gates of an MAT02 NPN transistor, in the case of my modified unit). Oops, I am off-topic.

One thing that comes out of this so far, thanks to Kirkus and Quiddity, is the concept that there truly IS a difference, primarily at the input voltage amplifier stage, between an ideal MM phono and an ideal MC phono. One topology does not ideally fit all. I'd still like to hear more from Kirkus on balanced mode with an MM cartridge. Anyway, I've decided that I do want a separate dedicated MM phono stage, which is kind of where I started but now I have more info to go on.

Hi, Lewm, nicely stated explanation. And after reading Raul's responses again I see what was implied, that convenience may override preamp performance. I can certainly understand the convenience factor.

But Axel, I'm confused a bit by your comment that the 3160 has a jumper to change from 40 dB to 60 dB of gain. Are jumpers considered to be acceptable, that is, they do not degrade signal path, at least in the amplification portion of the circuit? Or did I interpret your comment incorrectly?

Tom

Tom,
>>> ... confused a bit by your comment that the 3160 has a jumper to change from 40 dB to 60 dB of gain.<<<

That is not what I said, neither implied, since the 3160 has dedicated (like two seperate units) MM & MC stage(s) inside the line-pre-amp.

Jumpers are just somewhere in the hierarchy of 'switches' and perhaps a bit preferable (but not for comfort). They are normally very closely placed to where things need to get 'switched', Raul will NOT have any of those either, I'm sure.
A solder joint, or no joint at all, is still THE BEST (as long as it does not create a diode :-)
A.

Dear Axel: Why in a MC commercial world any phono stage or any Phonolinepreamp manufacturer have to take care about the MM alternative? when the MM alternative almost does not " exist " by commercial business.

So in the last years almost everyone commercial manufacturer build phono stages for the MC market even the ones that are for MM because it does not have enough gain for MCs but that they recommended using with external SUTs.

Only a few of us ( like Kirkus. ) that understand and like the MM virtues start to care on the subject and that through a research find that the MM needs are way different that the needs for the MCs.

That's why our units has separate and dedicated MC and MM phono stages that cope totally the MC specific needs and the MM specific needs. These different topologies make a quality differences on the sound reproduction?, ABSOLUTELY YES.

Lew sum up correctly: " One topology does not ideally fit all. "

IMHO the MM alternative is so good an friendly that even if the phono stages are not designed on its specific needs the sound reproduction quality on these cartridges is just glorius.

Now, on the convenience to switch from one stage to other or to choose load impedance through switch/jmpers or the like Lew say " I'm purist " an even that my Atmasphere has those jumpers I solder the resistors directly. A switch/jumper or the like is always a compromise even if that compromise is at minimum even if you can't hear it. When we are talking of MC/MM we are talking of very delicate signal at very low output/gain where these low signal are easy to contaminate even if you " bread ". That's why I prefer ( between other things. ) integrated units ( Phonolinepreamplifiers. ) instead phono stage that has to be connected to a line stage through additional cable/connectors.

Btw Lew our uit is differential/balnaced too in the MM stage.

regards and enjoy the music,
Raul.