XXHighEnd

Peter, not sure if this is the most appropriate thread for it, but I have question...

When developing the 1.04 driver, would there be any possibility of including some sort of automatic upsampling for use with the NOS1(a)? I'm talking about using internet radio, etc. I'm currently  setting the output to 24/192 in 'Manage Audio Devices', but am uncertain whether this is effective. Certainly, my FM tuner (with roof antenna) sounds better than internet radio through the NOS1, both being fed through a preamp.

It'd be great if I could finally eliminate the preamp.

Mani.

Hi Mani,

Doing such thing at the driver side is quite undoable. It could including hardware design, but otherwise the sampling rate is too much bound to the implied rate of obtaining the "data" (audio) from the PC.
So yes I thought about this, but no it is too difficult in the current setup.

Otherwise what you are doing (setting the "Shared Mode" audio device to output at 192 etc.) should work. How to prove that it really works is not easy because it can be expected that the software concerned at least can overrule it. But this would not be normal.
Example : When we (all) watch a movie through a movie player it will be quite "default" that it goes through the Windows Audio Chain and thus is subject to the output sample rate you set. However, might you find a setting in that player that reads "Exclusive Mode" then no OS will overrule and most 100% probably no upsampling will take place either (so audio output is 48KHz only for "normal audio" movies).

But how to test it ? Put a movie in that player (exact same settings as normal) with a testsignal. See ? that won't exist.
Even more undoable for your internet radio of course.

OK re-set

Only now you make me think of something that made it obvious to me that this is hard to test, while actually it is easy to test BUT I myself must have something very wrong or I don't understand ...

If I play a movie, I have to set the Driver Control Panel to 48KHz. This, while I am pretty sure that the same setting you mentioned is at 192KHz (but I'd have to check). In my theory this should upsample 48KHz player output to 192KHz. *That* now implies that this won't play when so, or all the movies we watch are 4 times longer in length always and we never noticed (speed of "movie" is driven by audio speed).
Especially regarding the latter I now suddenly think that this upsampling can't even work for movies (they would play too fast). So is it an exclusion (/exception) ?

Anyway for your internet radio the same check applies : Do you manually set the Driver Panel to 192KHz or what ? But whatever it's set to, that will be what the NOS1 receives and thus that is in order ...

Hmm ...


PS: I'll move this to a new topic so wait for that before further replying.
(done)

Further to this how can I run online radio or spotify through XXhighend to upsample the sound?

Hi Robert - Not.
Well careful, because I think I myself would be able to get that running but it is not made for it at all.

Regards,
Peter

I thought these steaming sites were offering only low resolution feeds. Is this not right? If so why upsample? If they offer high resolution files/feeds that would be interesting

Have a Look to www.wimp.com. They have 16/44,1 Flac files for EURO,s 20 per month in some countries.

Imho this OS question is specific for the NOS1(a).

The NOS1(a) is a NOS or Non-OverSampling DAC. So it does NOT Oversample itself to push the DAC-Aliasses starting at 22.2KHz to much higher frequencies. NOS at 16/44.1 produces a LOT of HF for any system and requires serious analog filtering (not present in NOS1), but it may work though especially in low bandwidth tube setups.

So some oversampling would be better, I used to wire the streaming outputs via the program "Virtual Cable" to a DSP program that did the DSP and OS and wire its output to the DAC driver. This was before the NOS1 entered my system.

I wonder if Spotify allows for such a setup. Afaik it has some protection against tapping the bits for rights protection.

Anyway as should be clear by now the OS algorithm matters for SQ so we really would like Peter to take care of that!

regards, Coen

Yes, exactly. I'm currently using my new iFi Nano iDSD DAC for internet radio and streaming and it does a great job. (It's actually a great DAC for the money.) So why don't I just use the Nano for internet stuff and the NOS1 for >16/44.1 files? Well because this requires some sort of source switching device and I really want to feed the NOS1 directly into the active speakers. I'm currently using my old Pass Labs X1 - it's a good preamp, but it's obvious that even at this level, preamps are not totally transparent.

Mani.

I get the best SQ with a Dartzeel preamp and XXH volume control at -3dB. This combination is superior to the direct connection from the NOS1 to the power amp.

Joachim

That's interesting Joachim. I've heard great things about the Dartzeel preamp. But at €30K, I guess it should be pretty good.

I wonder though if your preference for having the NOS1 at -3dB hasn't got more to do with the 1704s working more in their 'sweet spot' than anything else. I've always found -9dB to be the sweet spot with the NOS1 here. But even so, the sound is better with a direct connection and without the Pass Labs X1 (obviously not in the same league as your Dartzeel).

Mani.

Hi Mani,

that's the point. With another DAC (Weiss) I had the impression that XXH sounds at -3dB superior than at - 24dB.

As far as I remember CoenP wrote the same a couple of month (>12) ago.

Joachim

EDIT: What I wrote sounds not logical. My impression was that the XXH SQ at -3dB was better than with -24dB with the preamp and/or the WEISS DAC.

I totally agree, unbelievable quality for the money. Finally now the USB compatability with my MBPro has been solved it can even enjoy HiRes source material. It also sings with XXHighEnd as player (better than I've managed with Audirvana/Izotope). Anyway I purchased it for quality sound on the move and it does just that!


What you need is a good selector, not a preamp. Something with a "direct-out" function like on HT amplifiers. I guess in the end no switch is always optimal (no extra switching contacts, no soldering, no different cables, etc) but convenience also counts.

Maybe Peter can solve this riddle...

regards, Coen

That wasn't me (afaicr).

I once took the NOS1 to a local audio friends gathering and I had to play XX real loud because there was no preamp available for the low gain amplifiers. The sound definitively changed for the worse between 0 and -6dB. This was so clear that everybody noticed it (without me paying attention to it).

With my own high gain amps I usually play between -48 and -24dB and that sounds just fine. No apparent change in SQ in this range for my system.

regards, Coen

/edit/ Other dacs may be more sensitive to volumechanges of XX, I experienced that with my M-Audio in the early days. I actually preferred the build in volume control (on chip) back then with XX full out -or was it -3dB?!-.

Oh, sorry, beg your pardon (my age ........ .)

Joachim

And then to think you depend on me. :old:

Yo,

The sweetspot of the 1704's will be around -21dB with a bandwidth of ~6dB. I'd have to dig up old measurements to see from exactly where to where it reaches, but that band is pretty flat.
Notice that this is fairly theoretical because it's very marginal. Think like a virtual difference of 0.0018% THD+N and 0.0030%. "Virtual" because this is including noise, and the SNR matters (read : the more output the better THD+N anyway).

I honestly don't care; I set the digital volume to whatever it needs (goes automatically as well of course when using the Normalized Volume, which I do). Otoh, when a (new) DAC measures 0.0030% at full scale, I hear that (for the worse) and that DAC will be rejected (it will already at 0.0021%). So I guess if you really sit down for it and would be able to keep the levels the same (preamp) and try to find that sweetspot, you might be able to (and which is what people report of course). But all a bit moot in my view because using the preamp deteriorates to begin with.

Peter

Eh? Not intended!!!  :) :grin:

see this thread please = http://www.phasure.com/index.php?topic=1482.msg15553#msg15553

What we are writing here, are our own impressions to be discussed, nothing more.

Brian wrote a comment in this topic.

Joachim

Yes Joachim, and with the notice that that topic wasn't about any DAC sweet spots as such;
That topic emerged about 4 weeks before your NOS1 got stuck in the snow somewhere around Frankfurt. And 20 others somewhere else. :swoon:

Peter

The topic was not my main reference Peter,
it was Brians comment on 2011-01-14 with the -3dB.

I started with the NOS1 (volume at ~ -24dB) connected to the power amp (no pre amp). 
During 2011 fuses blew at the PA 2 times and I implemented the preamp. Volume was set to 0,0dB and my impression was a better SQ. After some tests with the volume settings the final set was -3dB (on my system with the preamp).

At present the NOS1 (volume at ~ -30dB) is connected directly to a different PA, which has a fast DC Offset protection (so, no preamp), and I'm quite satisfied with the amazing SQ at 8x PA.

Joachim