For now there are only 3 brands using Leedh processing: Soulution, Lumin, 3D lab. Vermeer audio has a partnership, but I don’t see using it for now.
So the end of analog preamps is not soon to come. Maybe in the future.
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Previously in the thread I expressed my preference for my pre-amp’s analogue control over the streamer’s DVC (the technology of which I do not know). The experience of the DVC was similar to listening the the streamer utilising its onboard Space Optimisation…it just didn’t sound right. I guess I might be sensitive to DSP (I do not think of A2D and D2A as DSP…but, on the other hand, I do seem to get most pleasure from pure analogue). These are my experiences only…and, with no prejudice, I will not respond to comments which state that I am incorrect in my personal conclusions.
In situations where the pre and power are both part of increasing the signal level to that required to drive the speakers or headphones, yes: but that not the case when the signal level is already higher than that required by the power amp, as in the case of digital sources.
In the latter case, the “preamp” isn’t an amplifier at all (though I recognise that at least in some designs it may amplify after attenuating), rather it is an attenuator with control functions (volume, and generally source switching), and a buffer stage. Maybe some also tweak the frequency response, as you suggest the NACs do to complement NAPs, or have a UHF filter, or maybe provide some other modification - but that is not part of amplification. The VC (whether LeedH or some other approach not adversely affecting sound quality such as however Chord does it), output buffering, and perhaps UHF filter, can easily be put in the DAC, making preamp superfluous for digital-only sources, removing any signal degradation from the extra electronics. The basic challenge for the DAC manufacturer then reduces to whatever impedance and source current requirements a power amp may have are met by the DAC, only if a power amp has some quite unusual source requirement would there be a need for an intervening additional buffer device.
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Gosh! That sent me on a nostalgia trip.
A good many years ago my amplifier setup consisted of a pair of Musical Fidelity MA65 monoblock power amplifiers which were fully class A. Preamp was a matching MF model and front end was a Meridian CD transport and separate DAC. Eventually, I concluded that the preamp was a weak link. I bought a Meridian 518 to be used for volume control and removed the preamp. So I had:
[CD Transport] --> [518] --> [DAC] --> [MA65s]
No preamp! And this was in the late 90s. So the practice of using digital control pre-DAC rather than analogue post-DAC, so that “the preamp is no longer necessary” has been around for more than a couple of decades.
The system went to my son when I went Naim and still sounds good. 
Roger
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But are you not falling into the simplistic trap that it’s about signal voltage levels? Where is source/input impedance / frequency matching in your example. These are important if an amp is to sound natural.
Analogue sources going back many years used to have very high signal levels… advantageous to reduce relative noise from signal interconnects… so I don’t think it’s a ‘digital source’ thing… more like these things go in fads.
The Naim design in its NAC handle a massive range in signal, so the line signal can be a few 10s of mV to a couple of volts or more to cater for all sources.
Also remember nearly all DACs create current not voltage, so they need a current to voltage generator to create a given signal voltage that can be usefully used. This i2v converter needs to be crucially accurate for high performance. This in itself is a type of preamp, or post source amp ahead of the DAC source analogue filtering acting as the audio pass band tone control … which can be as simple or elaborate as the DAC designer wishes.
So it is, in my opinion, a schoolboy error to think of a preamp as a volume control. I think such things are called variable attenuators or similar.
https://www.electronics-tutorials.ws/attenuators/attenuator.html
In a Naim system, the NAC is the heart of the system and typically you use the best one you can afford… if you can, get a 552… it’s a huge amount of money I know, but chances are you won’t regret it…
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You can have my NAC72 when you take it from my cold, dead hands…
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or use a Urika2 into a DVC equipped DAC?
The Linn approach is that the streamer is the preamp, and they do not make any analog pre-amp anymore.
Crying shame…the KK is just sublime, in the way that a pre-amp can be…it seems to be absent apart from source selection and volume control.
So a 272 without a built in psu would make room for more seperation of the rest of the components. Or the dac/preamp to come sometimes in an uncertain future.
Claus
My wife asks whether you have someone to pass it on …
We have the very same pre and it is going nowhere too 
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It would, yes.
The buffer, and ultrasonic filter - beyond the latter I don’t know what you refer to with frequency matching, other than Naim pre/power to which you had previously referred and I acknowledged. It is more common for quality power amps to be designed with flat frequency response within the audio range so no matching required, other than limiting any unwanted high frequencies if present from the source, and in some applications manufacturers having a LF cut (which may be switchable). If Naim power amps do not have a flat frequency response it is not in their specification.
I was confusing nothing in referring to signal levels with a preamp the splitting off of an amplifier into two parts, that we call pre and power amplifiers, was generally found to be beneficial because of the high sensitivity requirements for analogue sources - had all analogue sources been as high a level as the norm with digital sources then I very much doubt that splitting the input selection and buffer stages, and volume control, into the form that we know now as a preamp would become popular, though of course there could be situations where a separate control unit would be beneficial for a variety of reasons, though then more likely to be a dedicated device than has become the norm for hifi preamps where the norm became adherence to conventions that then enabled the two boxes to be considered as independent units, though I accept that some may not do that and may therefore need to be each used only with the other part from the same stable, as I am led to believe applies to Naim.
I do not think of a preamp as just a volume control - but I do consider it as doing more than is needed with digital sources (unless designed specifically for such sources and without greater input sensitivity on other sources, which may exist though I have not come across them). Given that input selection with a DAC is done already, then the remaining requirements, including though I have yet to come across one in my view could be built into a DAC without compromising it. If that is confusing a preamp with a volume control (not something that I said) and so a schoolboy error, then I must be a schoolboy, though who has played truant for decades!
I am talking about impedance matching. That is the impedance between the source and input and a specific frequency will likely all vary. Therefore designed to have a flat FR i am sure is the case for most, but when you couple across an interface, say between an amp and a preamp, where the amp is expecting a particular source impedance frequency response can result in a less than optimum frequency response across the audio band.
This is one of the key capabilities of a preamp. Power amps, unless they have integrated preamps typically won’t have this circuitry as they are designed to be connected to a preamp of some sort.
So a pure digital source with this correct preamp circuitry built in will likely perform as designed with a matched power amp. The N272 is an example of this. Albeit the closely packed electronics of disparate functions ultimately limits the SQ potential of the N272 according to Naim.
Anyway ultimately different manufacturers do it different ways and focus on different aspects… the Naim philosophy and design approach is certainly clear when you have talk to their product and electronics designers on a day visit.
I guess if the Naim approach is not for you there are plenty alternatives to choose from. One chooses the products that perform and sound best for you.
I can’t say whether I’d like the Naim approach as I’ve never heard a Naim amp - though I am wary when people refer to a Naim ‘sound’. I was attracted to what I have read regarding their power amp design, and the cost of a 500 is not such a huge amount compared to if I were to upgrade my Brystons (not planned, but not ruled out), but rather more if it would require a 552. This using Dave. I doubt I will ever hear, unless a big lottery win and lots of time come my way…
Incidentally I was interested to read that with your new headphones you found Dave better driving them direct than through a Naim amp, but with speakerS preferring the Naim - I guess to a large part that is a combination of speaker character and room effects as well as amp, but reinforces my own impression of Dave.
Naim don’t currently provide a headphone amplifier, so I have no idea what my headphones would sound like with a Naim headphone amplifier.
But yes I enjoy my Naim amplification driving my ATCs
Considering, as few have posted here, that Naim’s uniti range use digital volume control for all inputs including analog, I think this is an interesting question. My bedroom system is a nait1 with a lumin A1 and I think using this tech to get a better gain structure and have digital volume control will work out well.
All Naim preamps use analogue volume control. That includes the preamps in the Unitis.
It has been pointed out that Naim digitise analogue sources in the Uniti range, their most recent products with analogue inputs, but I don’t know if that means that volume control is done digitally - I don’t think anyone has posted here that it is. In the context of this thread’s subject that is the interesting question, and if it is done digitally (using the Leedh algorithm or some other).
Edit: I was writing this as ChrisSU was posting his note that they use analogue VC.
The analog inputs in all Uniti products are digitized. You’re saying they’re converted to analog before attenuation?