Chriss, take this post with a very larger pinch of salt. It isn't intended to be very serious.

I have no idea whether XX (or even Arc Prediction on its own) could be programmed into an FPGA. And even if it could, the real beauty of doing things the way Peter currently does them is that changes to XX are much, much easier to make and test, compared to changes to FPGAs or ASICs. If we look at all the changes that XX has gone through over the last couple of years, I'd say that this would have been really difficult to achieve in any other way than on a computer OS.

HOWEVER... most of these changes have been about minimising the negative influence of exactly that OS. So, we're in the hands of MS here. What if the SP1 final release doesn't sound as good as the RC? Then we're back to changing settings and/or XX code. I was just wondering whether this reliance on the OS could be eliminated once and for all.

As you can probably gather, I really know very little about all this. I'm a totally armchair designer in this respect. But I do know that Linn have managed to make this work, and so have PS Audio. My understanding is that in both cases, the investment in R&D was very substantial. It wouldn't be a trivial endeavour, and maybe Phasure are better off continuing to use their limited and ultra valuable resources in the way they currently do.

But 'my' NOS2 would be really, really nice and I wouldn't need a computer to use it... which would be bliss.

Mani.

I'm sitting at my kitchen table feeling a little sorry for myself - just recovering from a cold/flu that has kept me house-bound for the last few days. Horrible. With no energy to get up and actually do something, I started thinking about what I would really like as a digital source...

Well, I've had enough of computers. Really. OK, I'm not throwing my computer out just yet, but will be really happy to do so once there's a good alternative. I've only got experience with PCs, but I'm not sure that a Mac or Linux machine would be any better. It seems to me that a computer was designed to be a 'Jack of all trades' and perhaps is proving that it really is 'Master of none'. XX helps of course, but are we really sure that we're not spending all this time and energy on 'polishing a turd' (sorry for the English colloquialism)?

So, in an ideal world, the NOS2 wouldn't even need a computer. It wouldn't be the 'World's Best DAC' (Peter's words, not mine)... it would be the 'World's Best Network Player'. I mean, it would take on, and handily beat, the Linn Klimax DS.

So, here's my wishlist for it:

- ethernet input (galvanically isolated, of course)
- full UPnP 2.0 support for third-party control
- built in XX player (on FPGAs, or wherever)
- accepts any input resolution up to 32/768
- auto Arc Prediction upsampling of all inputs resolutions to 32/705.6 (or 32/768)
- ultra-low jitter clocks (as NOS1)
- 8x (or 16x) BB PCM1704 D/A converter chips (as NOS1)
- linear power supply (as NOS1)

The NOS2 would be controlled from a dedicated touch screen remote control, iPhone (connected by wifi to netwrok) or indeed it's own touch screen on front face plate.

Now, I know that many people are dead against network players in general. If there is a good reason that is based on SQ, then I would love to hear it. Perhaps it's just the case that XX is simply too heavy for any FPGA. But, I really think this is the future of digital music. Linn are doing it. PS Audio are doing it. I just know that a Phasure NOS2 would do it better.

Mani.

I've never seen a Model Two for sale on the typical used equipment sites. But right now, there are two of them for sale over at Audiogon.com!

They are $17.5K and $20K respectively. For around 1/4 of the price, you can have a brand new NOS1!

Mani.

I'm hoping to do this in the near future. As well has hearing the affect it has on the sound, I would like to do some measurements. Does anyone know of a good-value-for-money oscilloscope I could buy?

Mani.

 

Hi pedal, my main system has changed a bit over the last year or so.

My Quad 2805 speakers have put on a bit of weight and grown to the Quad 2905 speakers (I use the smaller 2805s in my office system). One of the (many) things I like about the Quads is that they are crossover-less, so I've sold my Pass Labs XVR1 crossovers - they were excellent though, and I would highly recommend them to anyone who is looking for an analogue x-over.

I use a 'Sanders Magtech' power amp. This works really, really well with the Quads. The designer, Roger Sanders, is an electrostatic expert and really knows how to build an amp optimised for them.

I still have a Pass Labs X1 preamp (I used to have X600 monos also), but this is bypassed nowadays with the DAC (either the NOS1 or Model Two) driving the Magtech directly.

Overall, I like the sound I'm getting - it's very coherent. My only desire would be for more of a low-down 'kick', which I'm simply not going to get unless I introduce a sub or two. But no sub on the planet will keep up with the Quads, and I'd prefer a cohesive sound to one which gives me a LF thrill once in a while.

But bringing the subject slightly back on topic, I think this system is capable of getting the best out of the NOS1. It's a fast system, which is what I think you need with the NOS1.

Mani.

Yes, we should remember that we can 'manipulate' the sound not just through the XX settings but also through hardware changes. My feeling is that we should strive for ultimate transparency on the HW side and use XX settings to 'manipulate' the sound to one that is musically engaging - otherwise, things might start getting very complicated.

Mani.

I'd like to point out a few comments made by Peter and Nick that I think are interesting:





As Peter pointed out, most of us have switched to Engine#4, even though Engine#3 appears to be technically superior. It'll be very interesting to see how XX changes in the future to make highly transparent DACs such as the NOS1 more musically engaging. It'll also be interesting to see if these changes also sound good on OS DACs... I mean, who still uses Engine#3 even with an OS DAC?

Mani.

Nick, I use Ultimate in my main hifi PC and Home Premium in my office PC. Both seem to work perfectly with 0.9z-4-0 (including Straight Contiguous) . The reason I went for Ultimate in my main hifi PC was so that I could try out the remote desktop. However, it became apparent very quickly to me that this is a bad idea with XX and 'Stop Services'.

If you want to try JPlay (not recommended for NOS1 users for reasons cited in another thread), then I think you need to go for Ultimate - I'm not sure you can 'Lock Pages in Memory' with Home Premium... certainly I never managed to do this (but I'd be happy to be proved wrong).

Mani.

Hi Nick. Yes, I would love to try this, but as you suspected, it won't be possible with the Model Two unless I find a way of converting spdif to dual-wire AES. At the moment I'm using a Weiss AFI1 interface, though I also have an RME AES-32 here which I sometimes use. My experience with AES interfaces/cables is that they are incredibly important - they ultimately determine the SQ that you can get from an AES DAC. I've been told that the Merging Mykerinos is the best AES interface (and of course it should be for that sort of money!). When I'm next in the States for work, I might drop in on Tim Marutani - he has a Mykerinos feeding a Model Two. Meanwhile, I'm hoping to improve the Weiss AFI1 when I replace its stock SMPS with a Paul Hynes power supply, which should arrive in a couple of weeks time.

But actually this is a pretty moot point now, as I've decided that the NOS1 will be my main DAC. The Model Two will be resigned to ADC duties only. I really don't think I'll miss the sound of the Model Two, great as it is. With XX configured 'correctly', I'm getting what I consider to be a very musical sound now.

Mani.

Thanks guys.


Yes, I totally agree (see below)...


I've just tried the settings in your signature Peter, and I think they sound a lot more musical than the settings I was using over the weekend. Perhaps I should have used them...

Mani.

I'm now a month into the NOS1's burn-in period. In this time, the sound seems to have fleshed out a bit, though changes in my hardware and of course XX itself mean that it's difficult to assess this with complete accuracy. Hence why it’s so useful having another DAC (which I’m very familiar with) acting as a reference.

Over the weekend, we had a friend staying over. Although not a professional musician himself, Paul plays many instruments (very well) and has also spent some time in a professional recording studio. I trust his judgment and have used him on many occasions in the past as a sounding board (pun intended).

We played a number of tracks that he’s very familiar with. He really, really liked the NOS1. He said that he’d heard things in these tracks that he’d never ever heard before. The NOS1 gave him an insight into the recording/mixing/mastering process in a way that he’d never experienced.

He also liked the Model Two, but in a very different way. His exact words were, “My head is saying the NOS1 is better, but my body is saying the Model Two is better.” He went on to explain that what he means here is that the NOS1 sounds more accurate and is certainly technically better. But it doesn’t make his body want to move to the music – there’s no feet tapping going on for example. It’s almost as if he’s too drawn into the technical elements of the sound – the placement of musicians, the microphone techniques used, the overall realism of the instruments/voices. In contrast, he forgets all this with the Model Two and engages more with the music. We tried loads of different types of music and he always gave the same response. At one point, he said that he felt guilty because he thought I’d be disappointed that he hadn’t obviously liked my new DAC better than my old one.  But I explained that I was pretty impartial actually. On the one hand, I would love the NOS1 to be the better DAC – its internal design fulfils my own philosophy and in any case, I would love Peter to succeed in his endeavour. On the other hand, I would be quite happy if the Model Two is the better DAC – it’s almost impossible to obtain nowadays, and it’s nice knowing I’m one of the ‘lucky ones’.

After the session, I asked Paul a hypothetical question: He’s just walked into a hifi store which has a NOS1 and a Model Two for sale at exactly the same price. Which one would he buy? He said that he’d want to take the NOS1 home because he knows that his whole collection would sound totally different through it – he would finally be hearing what’s really on his recordings. However, for listening to and enjoying music, he’d buy the Model Two.

Is the NOS1 the World’s best DAC? I’m not sure we could claim this with certainty. The World’s most accurate DAC? Probably. The World's best value-for-money DAC? Yep, I reckon it could well be.

Mani.

I think this is where the quality of the recording/mastering/pressing chain comes in. In the past, I've found some of the MFSL CDs to sound too flat. I've never quite understood why this should be the case because they were transferred from the original analogue master tapes with no compression or equalisation. Anyhow, I'm currently listening to the MFSL release of Robert Cray's 'Strong Persuader'... and it sounds stunning. Certainly no ear-ache with this one

Also, 0.9z-4-0 works very well with my own vinyl transfers - they still sound ultra smooth (due in most part to the Denon 103) but now have some welcome extra dynamics.

Mani.

I didn't mean scared of XX itself, but more of staying up late into the night trying to optimise it. As it happens, it's working here with no issues whatsoever... pretty much like any earlier version. There's nothing that anyone should fear by trying it.

I don't think I've ever thought that music was too dynamic before, but with a low SFS and Straight Contiguous, that's how it comes across to me. I'm currently listening to SFS=100, Straight Contiguous and Clock Resolution=Nothing (with all other parameters as in my sig) and it's sounding pretty good here. But lots more listening required to make any real judgements.

Mani.

I don't think I've ever been so scared to try a new version, but will do so later this evening...

Mani.

I hope people realise how important system timer resolution is to sound quality.

If you're not doing anything yet, I suggest you download dpclat.exe and have it running in the background as you play music. Even better, download JPlay and simply minimise it... or use it to play 16/44.1 of course! Personally, I use JPlay minimised. This improves SQ substantially when playing XX. Peter, you should definitely incorporate this into XX if possible.

A massive thanks to Marcin for coming up with this, and for Josef for incorporating it into JPlay. Cheers guys.

Mani.