Phasure NOS1 24/768 async USB DAC

General

The Phasure NOS1 24/768 async USB D/A Converter again defines new standards. Not only the technical level is up to the extreme, but sonically it superceeds the original Phasure NOS1 by far. And that was already considered to be the best ...

Thinking about the explicit Sound Quality Control always incurred for by the XXHighEnd software, we are now greatly proud to anounce that all what could be done so indirectly in PC software before, can now be done directly in-DAC. A world's first once again !
Although at this moment the DAC operates with the best sonic settings we could find, the firmware -which directly controls the hardware- is upgradeable in a whimp. And, like with XXHighEnd, more versions of it could be readily available on your computer, you picking the best sounding one. Changing the firmware is nothing more than reconnecting the DAC to the USB cable ...

With the knowledge of XXHighEnd and SQ control, together with the development experience of the original NOS1 - at last it was achieved that the software influence has been eliminated. SQ Controls in XXHighEnd won't do a thing to the sonic performance of the new NOS1, as won't different software sound different anymore (no Digital Sound Processing assumed to begin with).
It is to be kept in mind though that the Phasure NOS1 async USB requires external filtering, so it is there where software still will matter. But, this is completely intentional (and is a form of DSP).

The NOS1 USB will work on any MAC just the same, but here too it is to be kept in mind that the external filtering is required for Redbook material. This is not the case for HiRes where all filtering just should be out of the way. On this matter the NOS1 does not contain any filtering of any kind, so its inherent impulse response (which is the mimimum of one sample long) will uniquely 100% show you what HiRes really brings.
An optional Direct DSD/DSF (no conversion to PCM) input is due shortly as a user installable add-on board.

Where the original NOS1 already was fameous for its accuracy, the NOS1 USB dives into a whole new world of that. You will be shocked about the detail coming from your regular favorites. Basses will be basses like never before (including the original NOS1) and even at breaking in it will be noticed that no woman voice is able to go wrong ever anymore. The high frequency output has increased to a virtual crazy level, with the notice that here some break-in is needed (approx. 14 days).
After that, distinguishing from live performers in your listening room will be the most tough. The sizes of instruments will show as never before. A piano sounds like a real piano. A sax can't go wrong. 60's recordings suddenly appear to be the best ever. The effortlessness of it all ...

Again assuming no preamp will be used (which is the explicit advice), a more than average good playback chain is assumed. This is related to the sheer speed of transients, and the requirement of the chain to be able to follow that. Without this, the sound may become somewhat aggressive.
The NOS1 USB is targeted on the highest degree of audiophile music reproduction through loudspeakers, so most probably it will be allright - assuming all is aranged for to the best of knowledge anyway. Still, there is the usual 90 day money back guarantee just in case it isn't working out (Edit : see Phasure NOS1 Refund Model).
However, for those experiencing problems in this realm, it is good to know that the beforementioned add-on board will contain an A/D section and with the help of the totally unique XXHighEnd analysis software (sadly not available for Mac) you will be able to create groundpaths for your chain with the least noise. See Measuring XXHighEnd from over two years back to get an idea of what this software can do, which sure is not only about eliminating noise. If you think cables matter, this will show you the truth without any doubts left.

Availability : Today (first unit ships July 20).
This doesn't mean short delivery times though;
We have very limited stock only, that coming from sample productions of the USB boards. This means a larger batch of that has to be produced first in order to be able to start assembling a sufficient amount of DAC units. It may take 4 weeks or more to obtain some free stock, but we may keep running behind forever.
It is to be taken that the current stock already has been consumed by orders from the last few weeks because these orders were put on hold - knowing about this "upgrade" being due. These orders have obtained priority obviously.

Existing NOS1 users can fully upgrade to the NOS1 USB, but it will require to send over the DAC. In the mean time they might like to change the colour which is very well possible, but which will be relatively expensive, already because the DAC has to be fully de- and reassembled for that.
After upgrading, the NOS1 USB will be as extensible with the options mentioned below in the Features list.

General Features Phasure NOS1 24/768 async USB :

(x) denotes a standard feature, contained in the price shown at the bottom

Asynchronous USB with maximum input of 32 bit 768KHz. Output : 24/768 max. All further sample rates supported. (x)
Automatic track to track selection of bit depth and sample rate. (x)
Needs XXHighEnd at this time. Settable (Control Panel) otherwise.
Fully upgradeable extremely robust Driver and Firmware for ASIO, WASAPI and Kernel Streaming. (x)
Notice that XXHighEnd does *not* support ASIO at this time, but other playback software will.
See below *) notations for planned near future software upgrades. The more * the lower the priority of development.
Direct instant volume control via the Driver using the known XXHighEnd algorithms. *) (x)
Does *not* need XXHighEnd.
Meant for Windows PC and Apple Mac (32 and 64 bit Operaring Systems) (Mac at max 32/384 input at this time).
Playback software is allowed to (and should) provide the filtering means (the DAC carries no destructive means of any sort). HiRes material is (and should be) passed 100% untouched. This means a truly "bit perfect" complete chain.
At this time it is unknown what additional time it needs to develop the additional software extensions for the Mac.
Edit August 22-2011 : By now it is clear that at least Audirvana does a fine job on the filtering.
Configuration hardware options/extensions available.
See below +) notations for planned near future hardware upgrades. The more + the lower the priority of development.
Notice that these are hardware extensions, and generally a not available extension at the moment of ordering/delivering will allow upgrading yourself by minimal soldering (if at all).
SPDIF Input.
SPDIF Output / Throughput.
i2s Input. +++)
SPDIF Input direct or SRC controlled. ***)
i2s Output. +++)
2ch USB/SPDIF converter only. +)
This needs a special case.
SPDIF output will be ultra low jitter, similar to the original Phasure NOS1.
Can be combined with i2s Output (see above).
Digital loopback for 2 channels (max 32/384). (x)
Use to your imagination.
8 channel 24/384 operation. +++) ****)
The interface is ready for this, the output stages of the D/A part are not at this time.
The software development comprises in-driver XOver functions.
4, 6 or 8 channel operation is user selectable.
Immune to playback software on the SQ department. (x)
At last ...

The following is about hardware add-ons coming on a separate user-installable circuit board, which will be available in August 2011 :

DSD-128 (or -64) Input. **)
Notice that this is about Direct DSD (not converted to PCM) and that at this moment XXHighEnd can not play Direct DSD yet. Other players can though.
24/192 2ch A/D conversion (recording).
Full system Noise Analysis. ***)
This includes (later) upgradeable Driver software.
Needs XXHighEnd and will also allow for the special XXHighEnd Analysis software (measure *any* difference in cables, software, etc. etc.).
Additional 2ch Oversampling (!) 24/192 D/A converter.

Specifications of the PCM D/A section in short :

All measurements at the end of a 2m cheap interlink, done with a dScopeIII digital analyser :

Frequency response 1 Hz to 384000 KHz (768KHz sample rate). Flat within 0.19dBr in the audio band (DC not sustainable).
Input of 16 or 32 bits for all Sample Rates (24 bit input is converted to 32 bits).
Input Sample Rates (Hz) : 22050*, 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000, 705600*, 768000* all auto-select without glitches*.
* Under control of XXHighEnd only.
Output Sample Rates always equal the Input Sample Rates, but notice that in software (PC, XXHighEnd) each native “file” Input Rate can be upsampled to each accepted higher Output Rate (like 96000 to 384000 or 44100 to 176400 etc.) and next is output to the DAC. Output bit depth is 24 - or 16 bits when Input bit depth is 16 bits.
100% Filterless Non Oversampling design, using 8 x PCM1704U-K Burr Brown (Texas Instruments) multibit 24 bit D/A converter chips. Filtering for Redbook material to be applied in software (officially provided by XXHighEnd through Arc Prediction which supports all modes), or not using filtering at all (like for HiRes), at own choice.
Output level for Single Ended Mode (RCA) is 1.5VRMS (-3dBFS relative to normal Full Scale). Output level for Differential Mode (XLR) is 2.7VRMS (+3dBFS relative to normal Full Scale).
Output Impedance is 33 Ohm. It is the explicit advise to use the NOS1 without pre-amp and without analogue volume control for optimum results (long interlinks can be driven).
The Clock section consists of separate 44100 Hz and 48000 Hz base oscillators. The provided oscillators carry an overall jitter of better than 0.5ps and phase noise of better than 120dBc/Hz at 100Hz and better than 108dBc/Hz at 50Hz.
The net jitter should equal the fed jitter (of 0.5ps; there's nothing in the path from the oscillators to the D/A chips).
All terminals are official Neutrik.
Requirements PC : USB 2.0 interface.
MAC : USB 2.0 interface.
Allowed USB cable length is ~~6 meters / 20'~~ 7 meters / 23'.
USB is powered by an internal dedicated linear power supply.
Output terminals are provided for Single Ended (SE, RCA) as well as Differential (Balanced, XLR) by standard. No switches are in the signal path and no transformers are involved.
S/N ratio in-(audio)band is at –132dBFS at full scale (-0dBFS) differential (XLR) output.
Out of band (from off 31000Hz and up to 96000Hz which is the measureable limit) this is better than –144dB, and at the limit of the analyser operating at 24 bit and 192KHz.
For SE (RCA) output at –6dbFS (the maximum for the 1.5VRMS output) the noise is at –140dBFS or 134dB down. Here, the noise from off 31000Hz and up is at –144dBFS or 138dB down.
Mains related products for SE measure 17uVRMS at –121dBFS (measured at 50Hz mains). Notice this will be because of the pickup of noise of poor interlinks. Better interlinks will show better than 7 uVRMS at –128dBFS.
Mains related products for Differential measure 2.2uVRMS at –139dBFS (measured with 50Hz mains).
SE (RCA) output measures in(-audio)band Unweighed 0.0018% THD+N at 16 or 24 bit input and an 1KHz test signal with a sample rate of 44100Hz and Arc Prediction filtered into 176400Hz.
The THD+N from Differential (XLR) is beter than 0.0015% which is under the typicle specs of the D/A chips.
Notice : This is measured at 24/192KHz sample rate because of analyser limits. But, the NOS1 USB is made for 24/768000(705600) input, which implies a theoretical factor of 4 better. Taking the Non Oversampling principle into account, it will be fair to calculate the 1KHz testsignal's THD to 0.00045% for RCA and to 0.000375% for XLR. This also counts for THD+N because the extrapolated result will still be above the noise floor.
Further non-extrapolated results from 24/192000 measurement :
The same 1KHz test signal measured unweighed over the total analyser’s useable range (0 – 96000Hz) shows a THD+N of better than 0.0035% (XLR).
A-Weighed this is better than 0.0013% and C-Weighed better than 0.0009%.
In-band A-Weighed is better than 0.0012%, C-Weighed better than 0.0009% again.
All measurements have been done at the end of 2m interlinks, the input impedance of the analyser set to 100K. This gives the real honest figures going directly into your power amplifier.
In addition to the above, all in-band harmonics stay under –110dB, and out of band residuals at an equal distance to the sample rate of the test tone can be seen at –95dB (like for a 44100 base sample rate and 1000Hz test tone, at 43100 and 45100). When extrapolated from the 24/192000 measurements to the 24/706500 real life playback practice, the figures will be -122dB and -107dB respectively.
Channel separation RCA : Better than 125dB.
Channel Separation XLR : Better than 130dB.
Suitable for 110-130V or 220-240V.
Watch out : Units with a Serial Number of 10001 u/i 10200 will be internally wired for 110-130V or 220-240V on your indication at ordering. It will need the change of this wireing to make the unit suitable for that other mains. Please take good notice of this when taking (or selling) the unit to country with this other mains;
The re-wireing will take 5 minutes to change, but you may not be able to do it yourself. Units with Serial Numbers of 10201 and up will contain a user-switchable power inlet. And careful : The currently used power inlet looks to be switchable as well, but it really is not !! It will only indicate the target mains on the outside, and while this by itself is user-switchable this should not be done in any occasion, without changing the inernal wireing accordingly !
Double secured with 500mA (1000 for 110V) fuses (non “audiophile” for hot and cold); The second fuse is not a spare, but actually used.
No mains filter of any kind is applied.
Full color touch display which can be switched off. (Touch) Functionalities vary per XXHighEnd version.
Dimensions (L x W x H): 43.5 x 43.5 x 8 cm = ~ 17.4 x 17.4 x 3.2 "
Weight ~10.4 kg = ~22.9 lbs.
No audio feet provided !

Pricing

Price of the new NOS1 USB in standard blue colour powdercoat (see below picture) 2ch RCA+XLR Out : 3320 euro ex vat and shipping.
Price of Upgrade from the original NOS1 to NOS1 USB : 335 euro ex vat and shipping.

Price of any car paint (two component) colour (provide a colour code please) : 160 euro.
Price of powdercoat black (picture at the top) : ~~depending on the amount which can be done at the same time, between 125-175 euro.~~ 70 euro. Edit September 23 2011 : We have let done a batch of 25 for the time being allowing this price now. We name it Saturn Black and it is a soft-feeling beautiful finish with small spikes of metallic.

Notice that the first batch of NOS1 DACs do not contain the DC Offset Control and real time Meters; it is adviced to have your NOS1 upgraded to that for 140 euro, when you upgrade anyway.

Price of further extensions on request (because of the efficiency in the various combinations).
Email requests or questions may be sent to sales a@t phasure.com; please denote "NOS1 USB" as part of the title.

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