£3,648 for a volume knob (i.e. why not DAC into Power Amp)?

ROOG posted:

Simon-in-Suffolk posted:

Absolutely, for best overall performance (minimum digital quantising distortion/errors) the output should be fixed and one uses the preamp to attenuate the analogue signal.

Hi Simon, Is it your understanding that the Chord, Hugo, TT2 and Dave suffer loss of quality as a result of including digital volume control?   

No, I was talking with respect to the Naim architecture and why Naim recommend that the fixed output is used.. Chord use a somewhat different approach and as far as I am aware don’t need to adhere to Apple licensing requirements. With Chord devices (that support it) absolutely you can use the volume control on the DAC without loss of performance.. at least with the Hugo.. and in fact when connecting with Naim NACs many find setting to ‘cyan’ provides the optimum performance.

OuYang posted:

If you want to try option 2, my suggestion is upsample everything in Roon then using it's DSP volume as a temporary solution.

You might be getting confused... volume is nothing to do with sample rate or up sampling... its to do with the sample word size value of the discrete sample.  Changing sample size usually needs to be done with care if relative values are to be maintained to avoid aliasing noise... which is a non harmonic low level  noise that will add a feel of artificiality to the audio. This is sometime countered by deliberately adding dither.. or digital noise to the signal. On more specialist digital equipment/software one  can usually choose what dither algorithm to use to cause minimum artefacts.

Although Roon allows for gain management and volume control if you enable those functions, as it support AirPlay after all, unless I missed it I saw no area where you could increase the sample word size... or add dither so as to reduce digital artefacts in using digital volume control.

With NDX2 I note Roon defaults to fixed volume control for that Roon endpoint, perhaps so as to provide max SQ?

perizoqui posted:

I know it's taboo to drive power amps with DACs, but I've never gotten a good technical explanation as to why. 

It's a great idea to connect a DAC/pre directly to a power amp. In fact this is what Rob Watts, designer of Chord Electronics DACS, recommends. However, for Naim products they only recommend their own DAC/pres, such as V1 or 272, not any third party product. That's the reason I haven't purchased a Naim power amp as yet.

With most other manufacturers of power amps, such as Bryston, or ATC, they are perfectly fine with connecting a third party DAC/pre directly into them. 

Simon-in-Suffolk posted:

OuYang posted:

If you want to try option 2, my suggestion is upsample everything in Roon then using it's DSP volume as a temporary solution.

You might be getting confused... volume is nothing to do with sample rate or up sampling... its to do with the sample word size value of the discrete sample.  Changing sample size usually needs to be done with care if relative values are to be maintained to avoid aliasing noise... which is a non harmonic low level  noise that will add a feel of artificiality to the audio. This is sometime countered by deliberately adding dither.. or digital noise to the signal. On more specialist digital equipment/software one  can usually choose what dither algorithm to use to cause minimum artefacts.

Although Roon allows for gain management and volume control if you enable those functions, as it support AirPlay after all, unless I missed it I saw no area where you could increase the sample word size... or add dither so as to reduce digital artefacts in using digital volume control.

With NDX2 I note Roon defaults to fixed volume control for that Roon endpoint, perhaps so as to provide max SQ?

Up sampling also include bit depth, for example up sampling all PCM to 32/768. Actually many Roon DSP effects will do up sampling then processing automatically. You can try and check signal path. Digital voluming using 32bit depth usually is better than 16bit.

I believe a Pre does many more things than being a volume control. My humble Nac 72 has various cards and they mean something. There seems to be a 'Time Alignment' circuit (whatever that does) and buffer boards. These boards seem to do the magic which is called 'Naim sound'. It is difficult to explain, but I'm addicted to it.

perizoqui posted:

Ardbeg10y posted:

If you are in for an adventure, get a Nac 72 and a hicap of your choice. I got mine somewhere between 600 and 700 GBP.

Very interesting idea! Let me see what I can find online...

Either wait until you see some good offering, or email some Naim Dealers. I did the latter and I was surprised by the good offer I got (which was not published on their site). Some Naim Dealers seem to dislike online customers, but there are a couple around which are really helpful and they get my business along with my kind-of-local dealer.

Halloween Man posted:

 

 

It's a great idea to connect a DAC/pre directly to a power amp. In fact this is what Rob Watts, designer of Chord Electronics DACS, recommends. However, for Naim products they only recommend their own DAC/pres, such as V1 or 272, not any third party product. That's the reason I haven't purchased a Naim power amp as yet.

With most other manufacturers of power amps, such as Bryston, or ATC, they are perfectly fine with connecting a third party DAC/pre directly into them. 

And not recommending is not the same as saying it will be a problem, though it could be in terms of stability if the DAC output contains high energy ultrasonics, which a Naim pre will filter out (as do at least some of the Chord DACs) and can suffer in sound quality if the DAC has unduly high output impedance or inadequate drive capability.

perizoqui posted:

ROOG posted:

I also have a hankering to build a Nelson Pass B1 buffered volume control, or some such similar buffered volume control as that is all the functionality I require.

Another very interesting idea! Thanks! Might be a fun inexpensive thing to try, though I'd need IR volume control to avoid the dangers associated with exercise.

A few people have mentioned here that they have tried passive preamps in Naim systems, in particular the Townshend Allegri. It seems like a neat solution, no power cord, never mind PSUs, just one small box with a few inputs and a volume control. I’ve been experimenting with this myself recently, but so far it hasn’t sounded good enough to persuade me to get rid of my 282. 

ChrisSU posted:

A few people have mentioned here that they have tried passive preamps in Naim systems, in particular the Townshend Allegri. It seems like a neat solution, no power cord, never mind PSUs, just one small box with a few inputs and a volume control. I’ve been experimenting with this myself recently, but so far it hasn’t sounded good enough to persuade me to get rid of my 282. 

Indeed, that's basically option 3 in my original post, as the Schiit can operate in fully passive mode (but with IR remote). 

Simon-in-Suffolk posted:

Although Roon allows for gain management and volume control if you enable those functions, as it support AirPlay after all, unless I missed it I saw no area where you could increase the sample word size... or add dither so as to reduce digital artefacts in using digital volume control.

I believe Roon does both these things. It first converts 16 (or higher) bit words to 64 bit floating point, then applies volume control, before converting back to the native resolution of the DAC (32 bits for the NDX). So for data streaming between 16 and 24 bit resolutions (everything I own), it's demonstrably lossless.

Get a serviced Nac72 if you don't want to spend too much money - but do go for a HiCapDR or better a SuperCap. :-)

I also wonder what kind of a dealer is allowing you to buy a NDX2 and a Nap300 and letting you trying to figure out what preamp you should get. @Manu needs to vet his dealer selection process.

Innocent Bystander posted:

And not recommending is not the same as saying it will be a problem, though it could be in terms of stability if the DAC output contains high energy ultrasonics, which a Naim pre will filter out (as do at least some of the Chord DACs) and can suffer in sound quality if the DAC has unduly high output impedance or inadequate drive capability.

This is definitely true. At the same time, I find it hard to believe the NDX will introduce high-energy ultrasonics, or have stability issues! Naim may recommend driving their power amps from preamps, but surely you can use a Naim streamer in a non-Naim system? It would seem a pretty poor design, for Naim to sell DACs that are so noisy and/or unstable that they require thousands of dollars of Naim preamps added to them to work...

So far the only argument I'm really buying is that the sound introduced (rather than already present) into the music by the Naim pre, is delightful and unique to Naim. This is like the argument I often hear from fans of tube amps, and may very well be true! I've always thought a good preamp should be an invisible preamp though... I'll try the NDX into 300 and report back.

No quarter posted:

The taboo is driving “NAIM” amps with DACs,I drove my Anthem amp directly from a Hugo 2 and it was sublime.May I suggest selling the 300DR,still getting the NDX2 as a source.Then buy a Chord Mscaler/Hugo TT 2 and drive your Sopra’s directly off the TT2’s 18 Watts.Thats What I will be doing with my Sopra 1’s.

No chance. They'll have to pry the 300DR from my cold dead hands 

Innocent Bystander posted:

... can suffer in sound quality if the DAC has unduly high output impedance or inadequate drive capability.

This is definitely true. The NDX doesn't publish output impedance, like the preamps do (all < 50 ?). But it would see about 18 k? at the input of the 300, rather than the 47 k? it would see at the input of any of the preamps. This is probably okay, as 18 k? is still a fairly easy load, but I wonder. Anyone know the output impedance of the NDX 2?

MangoMonkey posted:

I also wonder what kind of a dealer is allowing you to buy a NDX2 and a Nap300 and letting you trying to figure out what preamp you should get. @Manu needs to vet his dealer selection process.

I remember at the covered market in Oxford, the cheese vendor "letting" people buy cheeses only if he felt they were going to pair them correctly. This is a very odd concept for an American! I think I should be able to buy whatever the heck I please (cheese or hifi), given that it's my money.

Regardless, please don't blame the dealer. I already have the 300, and have been driving it with a Classé streaming preamp for two years to great effect. And in the dealer's defense, he told me not to drive the 300 directly from the NDX, but keep the Classé in the middle until I can trade it in for a Naim preamp. 

That conversation partly triggered the original post.

NDX DIN & RCA outputs are 30? maximum & the required minimum load impedance is 10k?

perizoqui posted:

.. I'll try the NDX into 300 and report back.

Hi perizoqui, I would be very interested to hear your findings from this test.

I wrestled with the same question. Previously I ran an Exposure VII and VIII pre / power set up. My only source was digital, either streaming or from Nas into a Cambridge DAC via Sonos Connect. The Sonos app has a volume control, one day I wondered what would happen if I plugged the Dac directly into the VII, the result was a definite improvement. In place of the Exposure setup  I now have a DAC-V1 and 250. While I’m very tempted to replace the Connect with a Naim streamer the need to also add a preamp with lots of inputs that I don’t need is a major barrier for me

ROOG posted:

perizoqui posted:

.. I'll try the NDX into 300 and report back.

Hi perizoqui, I would be very interested to hear your findings from this test.

Oh, please don't.  The kit was not designed to be used this way.  As has been explained the NDX2 is a source only and should not be used directly into a power amp.

Get it wrong and you might be looking at some costly speaker repairs. My Opp 205 has a volume control and I’ve not once been tempted to play with it  for this very reason. Others might, but I’m far too cautious! Lugging 70kg speakers back to the dealership is also best avoided.

No quarter posted:

perizoqui posted:

Halloween Man posted:

Before ordering extremely expensive gear it's always a good idea to know your onions first!

 

Yep, I think I know my onions. Plan right now is to start with 2, and end with 1 if that doesn't satisfy. I'm posting to learn what to expect and why. I know it's taboo to drive power amps with DACs, but I've never gotten a good technical explanation as to why. Many times in the past I've felt that way about things (like run-in for an amplifier) and learned a ton by asking on this forum. So here i am!

 

The taboo is driving “NAIM” amps with DACs,I drove my Anthem amp directly from a Hugo 2 and it was sublime.May I suggest selling the 300DR,still getting the NDX2 as a source.Then buy a Chord Mscaler/Hugo TT 2 and drive your Sopra’s directly off the TT2’s 18 Watts.Thats What I will be doing with my Sopra 1’s.

Something to test carefully before commitment!

IIRC from test measurements on the original TT that was its maximum output before clipping - i.e. no additional headroom. Whilst 18w output maximum output, if that is what it is, would be adequate with efficient speakers like full horns, with Sopra 1s middling 89dB/W sensitivity the maximum peak sound level say just 2m away from the pair playing would be only just a bit over 98 dB. Whilst loud if you play music with limited dynamic range, that may be rather limiting for music with a good dynamic range.

When I first tried hooking up a Hugo 2 to my Anthem amp,I Too was worried about blowing up my Sopra 1’s.So I grabbed an old pair of mission speakers I have to try it first.Sounded awesome,so I hooked up the Sopra’s,and I was sold immediately.Now this was a DAC with volume control,and remote,directly to an amp...but I plan on going TT2 directly to my Sopra’s.There is a guy on the Chord TT2 headfi forum that just bought Focal Aria 936’s,and connected them directly to his TT 2,he says it is stunning,and he can crank them to Nightclub volumes with no problem...he previously owned a Naim 300DR.Rob Watts drives B&W 803’s directly from his TT2,believe it or not.

Mike-B posted:

NDX DIN & RCA outputs are 30? maximum & the required minimum load impedance is 10k?

Thank you sir! I couldn't find that anywhere. 

Ravenswood10 posted:

Get it wrong and you might be looking at some costly speaker repairs. 

Very very true. With Roon, I can set the maximum volume output. But with Airplay I'm not sure I can. With my MuSo I can set the max volume for Airplay, I'll check to see if I can do this on the NDX as well.

Richard Dane posted:
Oh, please don't.  The kit was not designed to be used this way.  As has been explained the NDX2 is a source only and should not be used directly into a power amp.

Well, I may not for long. I'll try it, and compare it to a Classé preamp in the middle, and compare it to a Naim preamp in the middle if I can get a loaner. Of course, I'm hearing that a 252 is the requirement to match the NDX 2 and 300, so it'd be a $19,000 add-on if I were to buy new. More than I paid for NDX and 300 put together!