Is the pre-amp a thing of the past?

Well let’s see: A preamp does four things:

  1. Amplify small-signal sources like phono.
    Many, including Naim, often do this in a dedicated additional box. Further, for a digital source, which is already at line-level, this is not necessary.

  2. Filter unwanted out of band frequency content, and common mode noise, from the source input.
    For a digital source, working from a quality recording, neither noise source should be present, and the addition of a preamp might very well introduce these sources of noise. This is the argument for minimizing component count, shortening signal paths, and minimizing features like equalizers, splashy digital screens (which I love!), motorized potentiometers, etc…

  3. Active impedance match (i.e. buffer) the source to the power amp.
    Some sources have a higher output impedance, some power amps have a lower input impedance. Digital sources have analog output stages (the A in DAC) with typically low output impedance, power amps typically have tube (~100kΩ) or transistor (~50kΩ) input impedances. What matters is the ratio of power amp input impedance to source output impedance. This should be as high as possible when driving the former with a voltage presented by the latter, so as to not overload the current-producing capabilities of the source. It should be close to 1, when driving power, as the power amp does with the speaker. Naim streamers have an output impedance of 10Ω, and are spec’d to an input impedance of >10kΩ. Naim power amps have an input impedance of 18kΩ, which should be fine, but may be less optimal than the 47kΩ presented by a Naim pre. On the other hand, many Naim users report excellent results using preamps with lower input impedances. Andrew Everard and Martin Colloms writing for HiFi Critic in a review linked by Naim in their website, use a Constellation Inspiration 1.0 preamp ( 10kΩ RCA input impedance, less than a Naim power amp). Still, maybe they were doing it wrong, and a buffer at the streamer output really would drive the power amp better.

  4. Attenuate the signal (i.e. volume control) to the desired listening level.
    Andrew Everard and Martin Colloms writing for HiFi Critic, also use a Townshend Allegri passive preamp (presumably not in series with the Constellation preamp, though they don’t say, and don’t distinguish between the sound from the two preamps in their review). The Allegri doesn’t do 1-3 above, but it does 4. I’m not sure I understand how a physical device that introduces wires, solder connections, RCA jacks, interconnects, and so on, can sound better than lossless digital volume control which has none of the above. Rob Watts seem to agree:

“With the appropriate bit width and noise shaping/dithering strategies, a perfectly transparent distortion-free volume function is possible… The benefit of digital volume is transparency since an analogue volume control also has low-level (and some high signal level) distortion issues.”

Based on all this many of us, or me at least, are thoroughly confused. 1-2 shouldn’t matter for those of us who only stream. 4 should be better in a DAC than a physical volume knob, I don’t care how precious the wiper, ladder, or transformer. So we’re left with 3, as the only thing a preamp might do for those of us who only use a streamer. Possibly 4, if Naim’s digital volume implementation isn’t as good as Chord’s. I think that’s what many of us on this thread are asking for: a 252 or 552 caliber buffer, with one DIN input and output, possibly internal volume control, system integration, separate box for the power supply.

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That is exactly what i am waiting for on a 372 or 572 or what ever number Naim wants to put on it. I only do digital, I don’t even have any physical media any more, thus waiting to upgrade my 272. I already purchased a 555 DR while waiting for it to happens and improve the performance of the 272. I am giving Naim this year, if not, moving to a different brand.

I doubt that Naim will build such a system with the SQ of a ND555…they’ll do seperates instead I’m afraid…

I don’t think the V1 was developed as a stepping stone in Naim’s separates upgrade path. Rather, it was aimed very specifically at those who wanted to use a computer as an audio source, and sits apart from the main streamer/DAC + separate preamp range.
Of course, if anyone can make it work well in a different setup, so much the better.

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Yes, I agree, ‘a stop en route’ was a poor choice of words, but the point is that although with the V1 there is a DAC with volume control/digital preamp in the Naim range, there isn’t a ‘proper’ one, ie full size, Classic range, at N-DAC/282 or similar level for those who don’t want/need analogue sources. I’m sure the V1 is lovely and great at its job, but the above isn’t its job. I think it likely that a device will come along which does do that job.

I don’t think Naim will release a stand-alone preamp with 1 channel. But I do think they might release something along the lines of a 372 with no analogue inputs or an NDX2/N-DAC with a proper volume control.

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Can’t help feeling that I may have wasted a lot of money on my 552 if I continue to use ND555 as a sole source based on this discussion. Correct?

Not at all - you’ve spent a huge amount of money on something which presumably makes you blissfully happy. Only if that isn’t the case has the money been wasted in comparison with spending it on any similar alternative. And that would apply regardless of this discussion or any other.

that’s why I’m struggling as well…one source only here… guess my ideal setup in future is streamer+volume connected to a power amp or streamer + integrated…

Yes, but that’ll be a compromise for those who’ve gone all separates. They already have a line of new streamers (ND5XS2, NDX2, and ND555) with matching power amps (NAP200, 300, 500). All we might need is one box in the middle. A NAC 252D for those with only one digital source… in a shoebox, powered by a HiCap.

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Perhaps your answer lies in an ND555/Townshend Allegri+/NAP500 system?

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Passive pre? Never thought about such option…

The trouble with passive “preamps” is that, to work optimally, the power amp needs to be specifically designed to be controlled by a passive preamp.

Indeed. I suggested the Allegri on the basis that 2 people whose views I respect have heard it with Naim Statement & 500 series electronics. They both preferred the Statement pre-amp (who wouldn’t…) but thought that the Allegri held its own against the 552 with each having its respective pros & cons versus the other. That might make it worth an audition, though it’s not one for me as I have multiple digital & analogue inputs, so a Naim pre will remain in our system for quite some time to come.

Best regards, FT

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It was this claim that bought the Allegri to my attention, so I was a little disappointed that it wasn’t up to the standard of my 282.
By the way, it does have 6 inputs and 2 outputs, so it’s not a non-starter for people with multiple sources.

Could you elaborate a little bit on this? Is this confined to the older designs that use only a volume control potentiometer? I was under the impression that the TVA type (Music First, Townshend Allegri+, etc) meet the requirement to match the impedances and should work fine.

Thanks
Bailyhill

Interesting question! I have heard that some owners of the Linn Klimax were saying that their streamers sounded better if they did not not use the streamers’ internal digital volume.

However, it seems to me that it is right direction, but we need to make the streamer’s internal digital volume control sound as good if not better than the analogue one.

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iam guessing that most only need 2 inputs stream /vinyl . a well designed passive is all they need . /assume that most use a separate pre for vinyl…digital volumes seem to be flawed at low volume to my ears

If you look at the music scene, and especially live performances, it would be the other way round…
Most of the time, power amps and speakers are gone… it’s pre-amps only, active monitors or in-ears.

Pre-amp is the heart of any system - it defines and shapes the overal sound.

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May I ask is new Uniti’s pre-amp analogue or digital?

Web page says: adjusts level in the analogue domain to a premium digital resolution. The design is taken from our NAC-N 272 streaming preamplifier

But on forum I found there is ADC in Uniti’s analog input, if new Uniti use analogue volume control, why ADC on analog input?

@OuYang, I believe the inputs are either digital, or ADC. After processing, everything goes through a DAC before feeding the power amp. I’m not sure, but I believe the volume control is still in the analog domain.

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