Is it worth Prefixing an LP12?

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Originally posted by Top Cat:

...and if I have a criticism it is that on average and slightly scratchy vinyl I find the LP12 is easily outclassed by my cd player.

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I'll bet that's due to all the work you've done to make sure that your system has a good electricity supply. I'm thinking, more and more, that a lot of what ills CD is due to poor electricity supply.

Peter

User34 at Laposte dot net

TC you need to clean your vinyl!

Fwiw I didn't really 'get' the Prefix in a dem when powered from the amp (I was a bit demmed out from choosing between Lingo and Geddon tho). I did get it once a hicap entered the equation. This is still less of a change than better power supply and imo, the prefix really comes alive with a s/c.

System as yours except sc-prefix, 17D2

Regards
Steve

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TC you need to clean your vinyl!

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Well, I have a VPI 16.5 but though it cleans stuff up it can't fix damage that's already been done - and I have a lot of older LPs that are a little scratchy, etc. VPI thoroughly recommended, though.

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Fwiw I didn't really 'get' the Prefix in a dem when powered from the amp (I was a bit demmed out from choosing between Lingo and Geddon tho). I did get it once a hicap entered the equation. This is still less of a change than better power supply and imo, the prefix really comes alive with a s/c.

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Hmmmm... in the short term the funds saved by not using the HC would probably also go partly into a 250->135 opportunistic upgrade (this is something I hadn't planned but what the heck)...

By powering from the 52 I can always add a SC should one turn up at a cheap price (and should pigs fly )

John

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Originally posted by marky L:
I don't understand why a Supercap should power a Prefix any better than a Hi-cap.

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neither do i. but it does; and emphatically so.
in fact this input 1 on the supercap also weaved its magic on my nac112 during the time i was waiting for my 252. i was shocked.

i have said this before, but i believe that there is a gap in the naim p/s range. what is missing is whatever it is that the prefix uses within the supecap when powered by it. and i said i would buy such a p/s for my prefix; but fully understand that there may not be many people like me around to make it a viable business proposition. ah well...

i guess one can get a pre-loved supercap for reasonable money these day, so... just sold one of mine -- went superfast!!

enjoy

ken

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if you set normal vinyl volume level and select phono input on the Pre (with no sources playing), you will hear a certain amount of background noise through the speakers. If you then select your CD source you will hear a much reduced level of background noise. Now imagine your phono stage about 80% quieter; that's what a Prefix does.

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I just tried this test on my Nait (with LP12 and MM boards). For any given setting of the volume control, I was unable to detect any difference in the background noise level between phono and CD inputs.

Actually there was barely any discernible noise at all on either input until the volume control was around 3pm, far higher than I'm ever likely to set it for 'normal' listening.

Surely the Prefix needs to offer more than this to make it worth the (considerable) extra money

David

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Originally posted by Top Cat:
What benefits over K boards in a 52 will a Prefix actually bring?

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TC, I cannot speak from experience as I don't (currently) have a Prefix, but IMHO the thing is a thoughtfull and truly clever piece of design.

1. Reducing the length of the cable which conducts truly tiny voltages from a few feet to a few inches makes a lot of sense.

2. Elimenating the effect and potential inconsistencies of the critical dressing of the arm cable on the LP12 makes a lot of sense.

3. Powering a Prefix separately means less demand on the preamp power supply than phono boards, so other sources should also improve -- makes a lot of sense.

4. All this means that from the manufacturer's POV, the Prefix has big benefits, so you can charge quite a lot for it. Even better, internal plinth fitting means you save the cost of a case, not to mention transport costs, PLUS you have potential upgrade power supply sales at a later date, AND your dealers get to charge labour for installation.

The whole thing is magnificently brilliant. Damn, I want one now.

Best;

Mark

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Originally posted by David Stewart:
Actually there was barely any discernible noise at all on either input until the volume control was around 3pm...

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David, that's because you have MM boards. The gain in MC boards is many times more.

Best;

Mark

Ah right! - I hadn't thought of that, but even then the gain of MM boards must be many times more than line level inputs. Some of the other points you raised are interesting though, but I still question the VFM of a prefix upgrade. No doubt others will dissent though.

David

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So whilst I can understand that if you have a Nait2 and a MM cartridge your priorities will be elsewhere

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OK Patrick, I feel suitably 'put-down'. Thank you for helping me to understand that for 'big-hitters' like yourself and TC the Prefix really is excellent VFM

David

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David, I'm very happy to have been able to help.

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It's what life's all about - n'est pas?

David

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The prefix is sold to 'big-hitters'

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Most probably the principal factor in determining its RRP

David

Has anyone compared a Stageline/Hicap with a Prefix/lesser power supply?

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Still not clear why a Supercap should do a better job than a hi-cap

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Why does a Hicap sound better than a Flatcap?

The argument is the same and I doubt Naim will tell you the reasons why.

On a Prefix it is an unnecessary sledgehammer to crack a nut (from an engineering perspective), but it DOES work - very well.

Andy.

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However, using just 1/7 of the supercap is like having 7 sledgehammers to crack a nut, 6 of which have no handles

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LOL!



A.

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Still not clear why a Supercap should do a better job than a hi-cap.

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Because it has a bigger/better transformer

I`m puzzled by the suggestion that only "part" of a supercap is being used in cases like a prefix. I would suggest that 99% is in fact used

Laurie S

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am just curious why given what the two units are designed to do would one be better

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Simply because there is much more to PSU's, sonically, than a cursory glance at the components used or a circuit diagram can reveal.

It's a map only, it's not the world.

Andy.

For what is worth (long hand for those who prefer the full expression of the written English language) - (FTWPTFEOTWEL) - I recently had a home demo 552 vs my 82 (BIG jump !!) into active SNAXO/SC/250's/SBL's.
Using as source a prefix/Hicap/LP12/Ittok/Karma (rebuilt by Linn) the immediate benefit of the combination (was it the 552 gaining the benefit of the source or the source strength being revealed) but the vinyl reproduction was ecstatically enhanced. My advice - Prefix ANY LP12 and at least power the prefix with a Hicap - you won't regret it. Then add a S/cap to the prefix and let your ears be the judge.

Ken C - you are on the right track - but why did you sell your S/cap !!!

Alan
(Saving for the replacement of the 82 with a 552,
Then the 250's with 500's)

I power the Prefix directly from sk 7 on the 552 and it is much better than using a Hicap. The noise floor drops considerably and the music is as close to live short of the concert hall!

By the way JTC has still not made it round yet ;O)

Charles, I thought you were in London anyway? I am free tomorrow afternoon if you are - just let me know.

John

Patrick said:

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TC, I really think you should get a Nuno Award for your Prefix deliberations.

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Secoonded. Nice one, Patrick! Motion carried.

TC - buy the prefix, your LP12 will love you for it, you're certainly got a great enough cartridge for it.

MarkyL said:

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I don't understand why a Supercap should power a Prefix any better than a Hi-cap. .... Or am I missing some black magic?

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Could it be something to do with the bigger toroid in the Supercap? That the S/C gets the best of the selected coils on grading? Greater number of selected parts than a hicap? Whatever the weather, don't worry about the logic of "why" - just sit back and let the music wash over you.

James wondered

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Marky, the PrefixK and K-Boards share the same circuit and mostly identical componentry, so why is the former 5x more expensive and twice as good?

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Hmmm - interesting one, James. The 72 is a good step forward from the 32.5 - almost the same amp, but look at the major differences in motherboard circuit layout!? Sure there's the different filters etc. Same layout improvements apply to the prefix, amongst other aspects. We must note, that with the Prefix vs boards argument, you're not entirely comparing apples. Aside from the greater cost of manufacturing a component in a case, with cabling and terminations (all hand-made, remember), new PCB into production, the continuous R&D that goes into the prefix (the new superior RF model), the R&D that went into the careful board layout, hand-selected components... is it any wonder it costs a lot more? As you know, it's an inexpensive upgrade in the context of a great system, something that 'completes' a great LP12.
I think sometimes we forget that Naim aren't a collective, they're a company; and will price their products where they'll sell with a reasonable margin.

Oh having written this, seems I've followed the words of Patrick. Oh well, great minds and all...

Rico - SM/Mullet Audio

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Otherwise, there is no logical reason why a pair of 135s sells for twice the price of a 250,

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errr, I think the 135 pricing seemed pretty clear (the performance and market selected for the 250, the shiftup to 135 pricing straightforward).

Coil, box, R&D, amplifier module - the 250 has two amplifier channels, the 135 one amplifier channel, a big heatsink tube, fan, and thermostatic fanspeed control module. One might say "swings and roundabouts" in costs. 135's => two boxes, twice the price. I'm sure I'm missing something.

cheers!

Rico - SM/Mullet Audio

I don't know how precise Naim internal costing is, but I'd be very surprised if a NAP135 cost noticeably less to make than NAP250 (old style of course).

Similarly with the crossovers, the incremental cost of the components going from 2 to 3 channels is lost in the mix of case, assembly, PCB, etc etc. A NAXO-3 might cost 1 or 2% more than a NAXO-2. Keep it simple and make the crossover price constant.

I remember that Ivor Tiefenbrun once said that Linn always priced at cost plus. I think it's the only sensible approach with something as ephemeral as hifi. (And that's also why Quad Electrostatics are such bargains, even new today.)

Paul

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posted Tue 24 February 04 08:42
Hi folks.

I had been planning to complete my system with the addition of a Prefix K phono stage (to replace the K boards in the 52) but lately I have been wondering whether it's really worth it.

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IMHO it is very well worth it.

I don`t have an LP12, though I do use a 52, and a Helikon.

Using a dedicated hicap for the prefix brings further gains, as it relieves the scap driving the 52 of extra "load"....

Pulling the k boards in the 52 brings benefit to ALL inputs


I have heard (though not tried myself) that using a scap for the prefix lifts the sound substantially.

You should easily be able to discern the above improvements with a catridge like the Helikon.

IMHO, for the gains achievable, a Prefix is very good value for money

Laurie S

Marky

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However, the mains capacitors feed 6 pairs of regulators i.e. 12 x 24V supplies. How many rails does the prefix take? I can only assume one for each channel. That makes about 17% usage,

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It all comes down to the quality of the power supply feeding the prefix...the fact that other regulators are not being used means that the prefix has the psu in the scap "all to itself", rather than sharing it...in the same way as some 52 owners only use one source, does not make it wasteful, just because the other five inputs are not used

Laurie S

Prefix on LP12 is definitely worth doing if it is a serious source for you. I've just had mine done and the improvements are substantial although I did add a cirkus too. I did the dem one step at a time though and its a no brainer assuming you use the turntable a reasonable amount.

Smike