Thank you for your detailed reply. I will initially be trying the 540ML on the nac 82 with the Naim 522 phono boards.
To my knowledge NA 522 schematic is exactly the same as with 322 boards, giving you 62k (R1) input impedance and 470pF input load but some are rarely seen with 100pF (at position C2) insteat of 470PF.
However, the AT 540 ML woul be pleased by seeing 47k at R1 and ~ 100pF (C2 value + capacitance of your phono cable shall equal to about 100 - 200 pF) at C2 position of the board.
2 Likes
This has come up in a few other threads. Naim tend to use 470pF in their MM phono preamps. Most (modern?) MM/MI manufacturers specify much less for their carts. Do you know which, if any, carts have a low enough inductance to be used with those? Or is it really just for HOMC ?
It will be interesting to compare with the Gold Note PH 10 that I have.
Next weekends playtime is organised. 
Edit: Research has started and a steep learning curve to go through.
Just looking up some specs for older carts and required phono stages. Most are 47K and 200pf. Why did Naim set the 522/322 at 62k and 47pf?
I assume theirs was a good reason at the time.
1 Like
The capacitance they still set at 470pF, input impedance is now at the standard 47k.
The AT 540 ML has arrived and been fitted. Early days yet but pleased with the purchase. Against the Grado gold it has a much greater separation and clarity. The Grado is warm and fuzzy to the point of being bland. Nothing wrong with it but nothing exciting either. I have been listening to these on both
First Joni, this isan original album much played and i find it a little boomy at the bottom end and Joniās voice has its usual highs which together test any cart/TT/phono combination. The AT loses the boomy feeling and smooths out Joniās toppyness and opens up the mid range. All compared to the Grado.
Side 1 of Tommy. Wow that kick drum is just so well expressed with the AT, and the guitar has that familiar crashing steely ring to it. The Grado is subdued when compared.
Coltrane. This pressing has some lumps and bumps in it and one section with what looks like scratch that fllows the groove, so not a scratch but a production defect. The Grado just rides over these, the AT will not. It displays the problem immediately and you canāt listen though the imperfections. I have to get up and move the stylus on. Both carts are tracking at 2gm. Other than that, again the separation and clarity is there.
I then ran the AT through the 522 cards on the 82 vs a phono stage with 47/200 standard settings. I donāt know what version of 522 cards I have, they came out of a 92 if that helps ID them. I have to say that the 522ās sound better than the phono stage. it was particularly noticeable on Tommy, the guitar work had that real rock amplified steel ring to it. Excitement a plenty, and again the separation of kick drum from bass guitar lies. On side 1 second to last track (Sparks, I think) there is a cymbal crash towards the end which is repeated as the track finishes, the 522ās give it the full effect as a crescendo, the phono stage allows the cymbal to full back in to the mix generally.
The only thing I have noticed with both the phono stage in to the aux, and the 522 direct is the volume position. Itās high compared to the input from the 2i or sqbox.
vs
Iām happy with the purchase for the price.
1 Like
Yes there was. Those caps shall block interference from radio Yerevan. 
Just to clarify why you experience a good sound although capacitance setting doesnĀ“t meet factory recommendations:
The high frequency resonance of the generator can only be shifted by setting the load capacitance and unfortunately wonĀ“t be eliminated. Thus you either move this resonance into or out of the audible frequency range what might litterally fit to the frequency behaviour in some setups - technically spoken.
Whether the result fits or not is of course purely subjective and everyone has to decide for themselves.
This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.