How much damage could a dodgy NAPSC do?

Posted by: Alex S. on 30 August 2001

With rico's prompting and some wit of my own I have decided that I must make sure that there is nothing actually wrong with my 82 before I get rid of it, for my sake and the sake of any potential purchaser.

The only noticable difference inside the preamp box is a cut cable tie and I know this is supposed to improve matters.

There is a potential anomaly with regard to the NAPSC. I can see no physical evidence of damage.

The question is: If there is something wrong with the NAPSC, how much could it damage the sound of the 82, and in what possible way(s)?

Posted on: 30 August 2001 by Martin Payne

Alex,

the voltage from the NAPSC is used to hold the source selection relays closed, and a noisy line will not hold these shut firmly.

I think this is partly why the NAPSC is a good upgrade for the 102?

I also think this was the reason why using two SuperCaps on a 52 was discussed as an improvement over one on the old conference. The second one just drove the digital & switching circuitry with a lower overall noise level and achieved a firmer contact within the relays.

cheers, Martin

Posted on: 30 August 2001 by Alex S.

so if one had a napsc which was not performing optimally how would you expect that to manifest itself sonically in the 82?

Posted on: 30 August 2001 by Martin Payne

Alex,

sorry, no idea.

Martin

Posted on: 30 August 2001 by Alex S.

I'll give you my prized FEP collection.

Posted on: 30 August 2001 by Mike Hanson

quote:
2) Make up a cable so your SC can do the NAPSC's job.

We went through this topic in depth a while back. IIRC, the voltage from that plug on your Super-Cap is pre-regulated to 12V, while the regular NAPSC provides 18V. With the extra regulation inside the 82, it might not provide enough voltage for its duties. Or was that the other way around? Ultimated, we were dissuaded from using it for that purpose (at least I was).

-=> Mike Hanson <=-

Posted on: 30 August 2001 by Mike Hanson

The 82 requires the NAPSC. It doesn't have the link plug option that allows the 102 to feed the switching circuits from the *-cap supply.

The NAPSC provides 18V, which the 82 regulates down to 12V, IIRC. If you tried using a Flat-Cap at 24V, there's a good chance that you would burn-out the regulator circuit in the 82. Some (all?) SNAPS models have a setting to lower the voltage, so it could supply the proper NAPSC voltage to the 82. Since the NAPSC is such a noisy device, if you have a spare SNAPS around, then this is worth considering.

-=> Mike Hanson <=-

[This message was edited by Mike Hanson on FRIDAY 31 August 2001 at 01:38.]

Posted on: 30 August 2001 by Jens

Alex,

If I were you I would take some time out, take a weekend break away from your hifi before deciding to get rid of the 82. I have been thinking about your comments regarding its "shouty" nature. I think you are really describing attributes of CD rather than the preamp itself. I agree that an 82 based system can sound fairly 'in your face' when playing certain (but by no means all) CDs. However, I never get this impression when when playing the LP12. I think that by going back to the future to tame your agressive CDs you run the risk of making your normal CDs and possibly all your LPs sound less dynamic, and I don't know if you'll be happy with that in the long term. Also, aren't you moving away from your long term goal of 52 ownership by getting rid of the 82? Why not wait until the cash is available, and then trade up?

Cheers,
Jens
PS Actually I think I know the answer to my questions: perhaps the fun is more in the journey than in the final arrival?

Posted on: 31 August 2001 by Alex S.

I will contact the dealer who sold me the perhaps dodgy NAPSC and get it all tested today. The wheels are set too far in motion to suddenly time out and keep the 82. (Replacement 32.5 paid for, Linto ordered, Troika paid for, 250 sold).

If it turns out that the 82 is defective then I will get so medieval on the arse of said dealer that Pulp Fiction will look like the censored version of The Sound of Music. I will also invite him to buy the thing back for what I paid for it.

Going back to CD presentation, you may be right but a CDS2 just about sorts it. If the 82 is a wonderful preamp but at the same time accentuates CDs' digital unpleasantness then its just bad luck it has to go since a S-Capped 32.5 doesn't do that, even if it is by showing less.

I hope to more than compensate for any vinyl losses with the additon of Troika, Linto and record cleaner.

As far as 52 is concerned, I would not buy one new anyway, and at least I have an S-Cap already. The nature of my self-employed business is windfall - starvation - windfall - starvation - so the next big windfall will get me a 52 followed by more or longer starvation (a familiar cycle - my wife suggests that 52 should be the final piece in my jigsaw, and I think she's right).

Posted on: 02 September 2001 by Alex S.

I have now sourced the napsc with the same serial number as what's written on my 82 box. I have checked that the 82 and napsc are in perfect working order.

In a way I am both happy and sad to report that I will not find it difficult to live without the 82.

Posted on: 02 September 2001 by Martin Payne

Alex,

I'm quite convinced that this problem is either a system setup or a room issue.

I have suffered quite badly from these over the last few years, as has a friend of mine. He's got his pretty much sorted now, and I'm getting there myself.

Your money, though.

Martin