Dedicated phono-pre for MM only?


Hi All,
the subject of phono-pres, specifically 'adapted' to MM came up in some related postings.

IF, and only if, MMs are much to ones liking --- why spend your buck on some 'halve backed' 60dB plus, MC gain requirement, stage? Why not consider put the $$$ into a TOP 40dB gain stage of either SS or tube?

Raul had more thoughs on the subject as he mentioned before, and might share, why he knows that a TOP MM compared to MC stage circuit requirement might NOT be -one suit fits all-.

There could even be a nice argument to fit a tube gain stage only into an otherwise SS only system!?

Again, the $buck saved on the 20dB plus circuitry could be translated into the BEST circuit for an MM.
I realise, that most such stages were simply fitted inside some older TOP pre-amps, (e.g. Jadis...).
I have not come across a **dedicated** , current 40dB stage neither in nor outside a pre-amp.

Thank you,
Axel
axelwahl
As far as SUTs go, yes they need to be matched, well matched! But if done, they have some 'magic' of their own and can make an MC something more full of 'live' and vibrant.
Oh yes, absolutely agreed! Even in a purely technical sense, there are many inherent advantages to transformer-coupling a LOMC cartridge . . . and I obviously chose this approach myself. I simply wanted to give counterpoint for those that feel that SUTs are inherently inaccurate and colored - because I understand how one could come to this conclusion . . . as most implementations on the market IMO don't really realize the full performance possible in the transformer approach.
Not necessarily since there are errors to the (-) and (+) side of the curve, yes?
And we are actually talking about observed 'tolerances' just not quite the same as ERROR, in my vocab anyway.
Now, tolerances can be additive or subtractive.
From a statistical/tolerance standpoint, yes, this is purely additive error. In electronics design, there is a specific procedure called "monte-carlo" analysis . . . which takes the maximum allowable tolerances of each component and combines them all in the absolutely worst-case situations - and this gives you the performance tolerance of the entire circuit.

In the audio chain, to define frequency-response as a deviation from perfection . . . keep in mind that in this definition we may have no idea exactly what the particular error is for each part, only that they are within certain limits. So while we can hope for that perfect synergy where every error just happens to cancel each other out . . . if we are to truly take responsibility for the performance, we have to assume the "perfect storm" where all the errors just happen to add up in the worst way.
Hi Kirkus,
>>> ... assume the "perfect storm" where all the errors just happen to add up in the worst way.<<<

"Monte Carlo" analysis, OK... the inventor must have lost it ALL then - worst case.
BUT he did not consider any form of 'synergy'. The importance of synergy has been pointed out over and over, in fact lots and lots of times by Raul himself :-)
Must be some concession to this 0.075% perfection.

I worked in pcb, and later semiconductor assembly, that gives me that practical bias what can be done if it gets 'commercially' viable.
No way to have much better then 1% components on a tape-fed bonder doing SMDs, as I mentioned earlier.
Also no way to start improving tolerances after the stuff (not only SMDs) are on the pcb. (Note: >3x rework = reject)

I have a pretty good idea, that this is where some realism in terms of tolerances has to prevail, meaning ALL hand build, bespoke, and nothing done 'commercially' will qualify --- seriously, that doesn't float my boat yet.

Why? Because a lot of 'bespoke' products have plenty more hidden QA issues then something more 'commercial', where errors have been weeded out to a much higher degree.

Pablovila, Your list of candidate MM preamps looks like the one I posted on 6/26. I consider it incomplete. Below $1500 we also have the PS Audio GCPH and the Graham Slee Reflex, discussed above. Just to make it more confusing, I wonder how some of the highest end preamps from the "good old days" would fare if one were to upgrade the power supplies and the parts in the signal path. I am thinking of early Audio Research, for one example.
Thank you very much for the additions Lewm. I've already made an offer for an Allnic H 1200. Let's see if the seller accepts it and, eventually how it sounds with the Soundsmith The Voice. Pablo.
Hi,
I'm still looking for a clue, given that MM carts like the 'simpler' single-ended designs, and some that find:
- the fewer components in the signal path the better- it could make for a 'simple' but great MM only design. (Don't forget a tube)

In fact, having mentioned Jadis might just be that, alas too much $$$$ for their flavour of genius...

Next up I'd think of Tim de Paravicini's EAR834P MM only, as some would say the step-up for MC could very easily be bettered. So for MM only - no need.

One thing might be power supply 'simplicity' (no regulation at all?), and some other circuit issues, that sprouted a number of aftermarket mods.

Are there any other such designs we could add to this one?

Axel