Phono board in NAC 72?

Posted by: Peter Voigt on 18 March 2003

greetings.

How do I know what kind of catridge my amplifier (nac72) supports?

(Always used a cd, want to try a turntable)

I've noticed a letter on the back.. I suspect this letter indicates what kind of board is installed.. the letter is either "m" or "n"... dammit or is it an "h"?

I really like this site Smile - but lament the disease it carries Frown (For what it's worth, I'm wasting money on the lottery every week(fingers crossed) thanks to Naim)

"Damn braces; bless relaxes"
Posted on: 18 March 2003 by Dan M
Hi Peter,

The only way to really know is to look inside. There should be two boards labeled with either 322 (MM) or 323 (MC). It might be that you have straight through boards (326) or worse 328 variable gain boards - neither of which is designed to support a phono cart.

cheers

Dan
Posted on: 18 March 2003 by Peter Voigt
ok.And thanks.

I'll be able to do that myself.. open it and have a look, without destroying everything in the process?

"Damn braces; bless relaxes"
Posted on: 19 March 2003 by Noel
SmilePeter, 'N' is Normal, this means moving magnet. 'S' is Special, this means moving coil. 'K' is for Linn moving coils. There is a slightly different impedance and they were originally for the Troika, Karma and Asaka cartridges. However all of these boards are interchangeable and look the same.
Dan is right and there could be straight line or variable CD boards in there. If you put a cartridge through it will have a massively lower output than a CD, tuner etc and so will not cause a problem, but there'll be no useable signal. The only awkward combination is a moving magnet cartridge being put through moving coil boards. This is because the moving magnet has a much greater output than the moving coil, so the moving coil boards will overload. I've done this before and it wasn't a problem. If you have the volume set to zero and increase it slowly you'll not cause a problem for your speakers.
Noel.
Posted on: 19 March 2003 by Richard Dane
The NA 328 boards were designed to make listening to early CD players a little more palatable (this was in the days before Naim released a CD player... Big Grin). The input level was attenuated and the top end was gently rolled-off with high frequency filtering.

CD replay has come a long way since then so best results with modern CD players would be had by changing the NA 328 boards for NA 326 line-level link boards.

Richard
Posted on: 19 March 2003 by Peter Voigt
Once again, thank you for your help.

It seems that there are NO phono boards in my 72! Frown

Bother!

there are 7 boards inside, room for 4 more..
When looked at from behind no 3,4,5 and 6 counting from left to right is missing.. (no 3+4 appears to be where the phono boards are not)
Does that mean anything?
What do I do?

Regards
PEter

"Damn braces; bless relaxes"
Posted on: 19 March 2003 by ET
If you don't yet have a turntable and phono cartridge, I would wait until you do, as the cartridge will determine your boards. If you do know what you are going to get. Keep an eye out for boards. Audiogon.com currently has some boards from Gene Rubin on sale, who is considered a top flight US Naim dealer. I would assume he would ship internationally.