«Leedh Processing» - The end of analog preamps?

Hi-Fi Corner
22

Yep.it was. The issue in them there days (pushing 20 years now) was that the potential sources for a home theatre system were Sky boxes, DVD players, Video Tape Recorders, Games Consoles, Analogue TV tuners etc. and they all had different audio outputs: digital SPDIF coax, optical, and analogue RCA. HDMI was in its infancy, I think we had one of the first HDMI DVD/TV setups. It was a 50" Pioneer Plasma TV & DVD system, bought in the early “noughties” - 6 grand from Peter Tyson - and the screen is still good! Not a single dead pixel (in fact I half wish the buqqer would die and I could get a bigger screen, LOL ).

Note that the Video switching was equally problematic, SCART, VGA, HDMI and so on, but the Pioneer had four assorted video inputs which we could utilise.

Anyway, the audio “base units” were Meridian, 562V preamp, 518 processor, and 565Z3 Surround Decoder, with a 421 HDMI video switcher into the Pioneer’s single HMDI input. I also needed a couple of optical to digital audio stream converters due to the limitations of the 562.

A right bl00dy rats nest of cables, and wall warts but it worked. And with four DSP5000, a DSP5000C(entre) and a DSP1500 Sub, the sound could be excellent - some of the explosions in the Star Wars movies could rattle the shelves :grin:

So, move forward twenty years, the daughters have taken their consoles, and the sources are now all HDMI (audio & video). Which means that the four main base units plus converters have morphed into a wholely digital system - 621 HDMI video switcher/audio extractor and 568mm Surround Processor. Looks a d@mn sight tidier on the rack, and it sounds better as well.

The LP12 has been “relegated” :grinning: to the old 82-SNAXO-250s-SBLs system.

1 Like
23

Not really, for many designs, especially Naim, the preamp or with Naim, the NAC, is far more than simply a ‘volume control’. It’s the first stage of the Power amp, matching the impedance and shaping the FR of the source to match the NAP stage for optimum performance.
Bypassing the NAC will provide potentially unintended performance from the Naim NAP, though of course you might like.

I think your statement might be more appropriate to the death of power amps with the increased popularity of active speakers. In truth however it is a choice with pros and cons.

In my experience with Naim, the NAC is the most crucial component in the replay electronics chain bringing the performance of everything along with it.

Other manufacturer options exist and may operate quite differently from Naim.

6 Likes
24

Not the case if you don’t have analogue sources, as the preamp is the superfluous part adding complexity with extra electronics. Of course, if you prefer the sound imparted by the electronics then that is a different matter. Likewise if your power amp has source needs that are not provided by the DAC output.

From a different angle if you do need or prefer to gave a preamp, many digital devices output a signal that is far too high for the preamp: This results in the usable volume control range being a very small part of its rotation, with possible loss of fine control, and with some preamps in that range also having less perfectly matched channel balance. It also creates a greater risk of speaker damage should the volume control accidentally (e.g. by a child, or if electrically operated perhaps by a glitch in the control app as sometimes is reported). Volume control capability in the DAC allows you to set a level that gives you optimum controllability by the preamp, and/or set for optimum sound quality.

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26

Agree totally and it would be my preferred route if I could kick my vinyl habit.

Hans

27

This is my experience. However, I can’t see why it wouldn’t be possible to include all the other pre-amp electronics and capabilities into a DAC or streamer.

Best regards

Hans

28

272 ?

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29

This is possible, but Naim believe (they state it as their design ‘DNA’) that the best performance is achieved through physical separation and decoupling. I agree and matches much of my experience.
So yes there the all in one products like the Nova, and they offer a convenient and enjoyable performance, but they are seen as a gateway or stepping stone to higher performing products for customers that wish this such as from the Classic and 500 series.
Of course Naim have the NAC-N products such as the 272. But talk to the designers, and they believe / believed that performance is pretty much the best they can do currently with all the electronics packed into one physical enclosure. Not to take anything away from the 272, but to get higher performance then with Naim you need separation and decoupling,

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30

I’m not 100% sure of that there’s a lot of high end manufacturers that produce high quality streaming pre amp and integrated amps. I struggle to believe they’re all wrong.

I do understand there’s always compromises but I think they’re sometimes overstated.

31

I believe that whole point of the thread is getting “lost in translation”…

The idea behind the the Leedh tech is to get rid of the preamp and to control the volume directly at the DAC level.

The system would be :

[DAC]—[Power Amp]

Most audio systems, including Naim’s, control the volume with a preamp :

[DAC]—[Preamp]----[Power Amp]

Of course, in Naim’s ecosystem, the preamp and amp are designed together meaning a direct connection from DAC to Amp is not obvious.

This is not the case for brands like CH Precision and Soulution.

1 Like
32

Adding a lot to the DAC, and potentially negating the benefit of simplicity and less electronics. I can picture more a preamp with DAC (but not renderer, taking digital feed from an external “transport” just like the analogue side does) than DAC with preamp, if my distinction makes sense.

I have analogue sources, though music making rather than music replay. For that I swap cables, connecting a preamp in place of the DAC - a bit of a faf, but maintains best quality with music replay (using Chord Dave without a preamp). I am contemplating getting an ADC so I can feed the analogue to Dave, then simply selectable as one of the DAC’s digital inputs (but would have to be a low latency ADC).

33

This appears not being a problem for CH Precision or Soulution amps.

In fact, the result is so good with Soulution amps that they fear for their preamp sales.

34

As an exponent of KISS, I want a single volume control. All the inputs, analogue and digital, in to my pre amp need to be uncontrolled by me. Don’t give me more knobs to twiddle.

35

The idea behind Leedh processing is not to include any additional electronics into the DAC.

Leedh processing is software.

Information about Leedh Processing :

Google for :

“Leedh Processing Lossless Digital Volume control”
(will lead to Leedh home page)

37

In the context of a single digital source, the analog preamp is no longer necessary, for certain brands.

1 Like
38

This is understood. My post was in response to Simon-in-Suffolk who pointed out, correctly in my opinion, that a pre-amp is not only a volume control but includes other capabilities that enhances sound quality. If Soulution DACs can drive a power amp as well as their pre-amps so much the better. Linn have (without Leedh so far) already gone down this route and to not sell stand-alone pre-amps any more having integrated their streamers and pre-amps into one combined unit.

Of course software solutions also add complexity and cost as many with experience from software updates of their streamers can attest. In the latest HiFi Critic, Stan Curtis vents his frustration with software in audio products, the unpredictability and unintended consequences that seem inherent.

Best regards

Hans

40

I don’t disagree - there are many ways to skin a rabbit - and it depends how you like your rabbit skinned :slight_smile: I did try to suggest that different manufacturers have different approaches

However with Naim designs and constructions it is very evident, and their designers will tell you this as well. To be honest I don’t find this unique to Naim and I have yet to find an all-in-1 that sounds as performant as I am used to - especially with streaming and DACs. Now there is a high end Scottish hifi manufacture and they tend to focus on concentrated electronics - and whether its a coincidence or not - the sound and performance is just not for me - or at least it hasn’t when ever I have listened in demos.

I have found separating the streaming front end from the DAC often makes a huge difference- and removes a lot of this faff around network cables and switches etc, as they then have no or minimal influence.

I have found that with Naim and none Naim.

3 Likes
41

I know at least one high end DAC manufacturer that focus on very fast transient and timing performance as part of their reconstruction approach, that advise against Class D amplification with their DACs, because of its relatively poor transient and timing performance that would simply under mine much of the benefit of using that DAC

42

But the preamp is part of the amp. its a bit like saying the wheels are part of the car.
Sure you can use different wheels from your car manufacturer, but the performance and ride might not be as intended, although you might prefer.
The same is with preamps and power amps.
The point is what is integrated into the preamp - such as a DAC or streamer. We then move off into the area of EMC and decoupling, as well as ground plane modulation. In my experience with high end - perturbations here do start to detract from the overall performance. When you get close to reality- you don’t need much to interact or affect the sound for the sound to jar or simply sound off.

43

And my understanding is that some class AB integrated players, like Naim’s Atom and Nova, do the same with all analogue inputs.

2 Likes
46

Interesting that Soulution charge €5000 for the Leedh upgrade, whereas LUMIN give it away as part of a free firmware upgrade.

Roger