Is the pre-amp a thing of the past?

Hi-Fi Corner
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There are two different questions being discussed in this thread, albeit related:

  1. is there still merit in separating out the amplification into two boxes, pre and power?

  2. Does a preamp make a positive difference where a source is capable of driving a power amp withou using a pre? [but unspoken: preamp = as currently implemented, with power amps as currently implemented]

Regarding the first question, I don’t think anyone has either countered or bettered my argument earlier in this thread (post 8, on the first day), namely that it depends on whether sources include low level signals, the challenge with low level signals being the original reason for separating out into pre- and power-. In that post I included a suggestion for what would be a better approach given that many sources these days are high level, unlike when the splitting originally became recognised as desirable.

As for the second question, it almost certainly will depend at least in part on the source and the power amp in question (their characteristics and how they interact), and on whether the preamp under consideration adds a sound signature that the listener likes. And of course that can only be determined for certain by hearing: hearing the specific source and power amp, with and without a preamp, and likely differing with different preamps.

For myself I compared Hugo into Bryston power amp direct compared to through a Tag MacLaren preamp, and found no obvious difference (I didn’t do extensive comparisons) so I simply went for the direct route, and when replaced Hugo with Dave nothing made me feel any need to try a preamp, it sounding so good. One day I might be tempted to hear Naim power amps in my system, and if I do then that would be an obvious time to try a Naim pre - but at present with no Naim dealer in reach it won’t happen, and a NAC is an awful lot of money for a buffer/modifier!

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Hello Innocent_Bystander

I agree with your above statement, but as Perizoqui and I have both found out and been discussing here, it depends strongly on the implementation of the volume control in the DAC. DAVE seems to have gone to great lengths to make it as good as possible while Naim has apparently not in the ND555 nor their other streamers for good reason I am sure.

I was in the no preamp camp, but did the experiment and my ND555 definitely is better with preamp, and I am matching impedance’s properly. I also noticed this affect a lot more with HiRes music and much less with Core ripped CD’s. I have not switched to the Needs Preamp camp with most of todays equipment. That might change in the future as design topologies change.

Bailyhill

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So what will you put up with?

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Besides, didn’t Naim once say they implemented volume control on streamers simply to tick a required box for one of the certifications?

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Yes that is right, it was for Apple AirPlay, I believe.
Bailyhill

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IB, the TAG MacLaren preamp circuit is quite flat in presentation (even after the switch from a TL82 to an OPA2134 as the line driver). It doesn’t surprise me that you didn’t hear much of a difference (in fact It wouldn’t have surprised me if the direct connection had sounded better).

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Too tempting…

Counter argument: all sources include low level signals. Some (i.e. phono stages) contain lower voltage signals than others (i.e. streamers). But! It’s not the voltage that matters most, rather the current. Whether milivolts (phono stage) or up to a volt or so (streamer), a source is driving a Naim preamp (47 kΩ) or tube (>100kΩ) load. So you’re talking very small numbers of microamps (I=V/R). By comparison a power amp is driving a few volts into a 2-8 Ω load. You’re talking amps.

It’s current that generates magnetic fields when traveling through the traces in the PCB and wire jumpers to the output speaker terminals. Those fields (like the ones from power transformers), are what couple all over the place, in particular contaminating the tiny aforementioned source signals traveling from the input to their PCB and then along those traces to the first gain stage.

So it’s just as important to separate the power amp from the preamp as it is to separate the power supply from either.

As to your second point, the question is whether the source has the drive capability (effectively a built-in preamp) to do the job. Some (Chord Dave) seem to (though I haven’t tried). The Naim NDX 2 clearly does not.

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By placing the volume/linedriver in the preamp it gets its own power-supply that can be optimized rather than placing it with the high-current environment in the power-amp.

If you place it in the streamer you steal valuable power-supply feeds from that function. And you need to duplicate it for every source, CD … RIAA …

Then you have the 272 which I think is a very musical box. But however nice I think it is, it is a compromise.

So unless you go completely software like Devialet the preamp is well motivated in hi-end Naim, especially when you listen to it.

As for the ”naim-sound” it is not a distortion, it is the result of optimising the information transfer with grear care on earthing and separte fast/powerful power supplies for each stage and this allows bass/kick/hihat dont duck/mask each other … i.e. sound more rythmical and musical. In addition all components are carefully selected by the same priorities. CB/Olive has a skightly different priority and was designed for those times. The circuits used in all Naim power amps up to 250/135 at least is based on an old quite simple AB design, it is the execution of it and context it is placed in (provided by naim) that makes it sound special.

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I’ve not said anything on this thread as I think people will have their strong views and may even have experimented to confirm.

Personally over many years, even decades, of experience building my own system I initially did not invest as much in the Pre in the thought that it was ‘just a volume control’ but friends that had spent a lot more on good Pre in their systems got better results than me, even though I had a better source, power Amp and speakers than they did - so I came to think there was more to it.

Tried passive-Pre - not for me - gave a gutless bass-light sound which had no dynamic stability or floor to the performance which I like to experience.

My first real quality Pre - surprisingly perhaps - was the 552. It did everything I wanted to the system performance compared to my very early NAC12 and Exposure Pre I had until then. After that the rest of my system got up-grades gradually as funds presented around the 552 as the heart of my system and I never felt anything was missing.

Then came the chance to audition the S1 Pre. This was silly money and came at a time I though I needed to really confirm it was the right way to go, given the possibility of implementing a digital pre …etc. I had a few demos of another manufacturers all-digital pre …and was underwhelmed would be too kind a thing to say - it had nothing going for it but a sterile bland presentation. The 552 was in a different league.

The S1 Audition - in the context of my otherwise by then ‘bottom-heavy’ system with three NAP500 Active showed that as good as the 552 was (it is very good) it was totally outclassed in every respect by the S1 Pre which was silly-better. I now have one. I do not recommend a demo of this item unless you can afford it as it will upset you if you do the comparison - but at its price perhaps it is no surprise and makes the 552 a bargain!

So IMO not a thing of the past - if you actually try it in your system.

As an engineer and scientist I could identify multiple things why it is important - first large gain stage after pre - very good analogue volume control - fewer LF poles so very good bass supported by superb PSU, input isolation and buffering…it all adds up - but it is theory and conjecture until you try a good Pre - it does not need to be 552 but any good Pre in the range below in the right system context will reveal what it brings if you listen to the music.

DB.

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I have always thought that in Naimland the preamp was key. Nothing has changed this belief over the years. That is precisely why I refuse to listen to a 552. I can’t afford one! And as for the S1…

Stu

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I totally agree, if the Preamp becomes redundant, then so has Naim’s strategy on how to achieve the best replay. The Preamp/NAC is the most essential component and heart of a Naim system. It sets the standard for the rest of your system.
Without a preamp how are you going to enjoy the various characters from your different sources…
If you want an all in one, get a Sonos, or prefereably a Mu-so, if you want to appreciate high end audio replay and its various characters get a system like a Naim… certainly it’s the path I have chosen… and Naim’s strategy of hooking new customers with all-in-1’s who then wish to look forward and upgrade to preamps and separates I understand is hugely successful for the company.

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@Darkebear @Simon-in-Suffolk I couldn’t agree more.

The NAC552 is amazing and I just can’t imagine what a S1 could do.

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I mainly use Matrix Sabre Pro and Chord Hugo DACs.
Both pretty good DACs and both have volume control, so I experimented with each directly into the power amp, in the hope of reducing box count.
Both sounded deeply horrible in comparison to using a dedicated pre-amp. Experiment didn’t need to last long.

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It would nice to hear a bit more from Naim (@Richard.Dane) about the importance of the preamp.

To my ears… the clue is in what Naim actually call it, Naim audio control (NAC 282,NAC 552), and indeed I now understand that the preamp is the key what Naim are able to achieve with their amplifiers in terms of Rhythm and Pacing.

I don’t think that Naim could charge so much for even a NAC 282, if it all it was doing was a volume control !

What I do hear when listening to music through a Naim amplifier is the grip over the music, in other words… control…

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That is how I understand it. And the power amp delivers the current to drive the signals through the speakers.

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It’s important I think to consider that the pre-amp is just one half of the pairing that makes the whole amplifier.

I wrote the following some years back with regard to Naim pre-amplifiers. I’ll post it here as it’s still pertinent.

So, why have a preamplifier at all? Surely, the best preamplifier is to have none at all?” While it is true that less can often be more, it’s also the case that in Vereker’s words, “less is sometimes just less”.

The preamplifier is one half of the preamp/power amp partnership, which makes up the whole of the “amplifier”. It is separated from the power amplifier to ensure that the electromagnetic fields from the power amplifier’s transformer do not interfere with the sensitive low-level signals within the preamplifier. This way, the preamp provides an ideal quiet room environment, further isolating the low level signals from the effects of microphonics, and ensuring that power supplies are kept well away where they can provide benefit without doing harm.

The preamp has a whole set of complex and vital tasks to perform; the input circuitry must accept the entire output of the chosen source without overload; the frequency response and level of the input signals must be normalised; the preamplifer then conditions the signal to ensure that the power amplifier is driven within its optimum operating parameters. On the latter point, Naim have traditionally taken the route of “bandwidth limiting” the signal, to ensure that ultrasonic signals do not upset or limit amplifier performance.

All Naim’s preamplifiers, from the first NAC12 of 1974 right up to the current flagship of the range, the NAC552, have been designed to have a frequency response flat to within +/- 1dB between the critical 20Hz -20kHz audio frequency range and to offer “perfect stability under all working conditions”.

When designing the first Naim preamp, Vereker saw switched filters, loudness and tone controls as unnecessary impediments to good sound. He felt that their inclusion could never improve the quality of the original signal and always resulted in a loss of information. Instead he looked to design something with excellent stability, high overload margins (over 7 volts!) and with outstanding handling of music transients. The phono circuit had a linear first stage with relatively low gain, followed by RIAA equalisation which was split into two parts, active and passive. This way, complete theoretical and practical stability was attained, with a much wider open loop bandwidth than usual. Exceptional overload capability was thus maintained right across the entire audio frequency range.

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A few years back a chap on Hifi Wigwam had a beautiful Wadia CDP with built in volume control, Plinius power amp and big speakers convinced in the knowledge that a pre-amp would “take away” from the sound. Partly out of curiosity and partly out of being persuaded by other audiophools keen to invest his money he eventually tried various pre amps and all added to the sound with improved soundstage and resolution. I can’t remember which actual pre he eventually purchased but i know it was rather expensive!

Recognising that manufacturers are continuing to develop Digital source components with built in pre-amp functionality with great success at the same time I note that Naim are not alone amongst the high-end manufacturers in manufacturing dedicated pre-amps Vitus and Chord amongst them.

Regards,

Lindsay

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Quite, as Richard D states the Naim preamp is part of the overall amplifier, not a seperate adjunct. Whether the source is digital, analogue or what ever is irrelevant.

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Richard

Is there any way I could send a message to you off line about another issue I would value your input on?

Peter

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