FS Chevron Audio Paradox NDF DAC

[Bourney]

For Sale Chevron Paradox two box NDF Dac.

I've owned one of these for around 10 years I reckon now.
I originally had an older model that developed a fault in 2019, it went back to Colin at Chevron and he offered to build a new one with the later spec including the matching coloured fascias and digital input display for a very reasonable price.
The same as in this review model.

https://www.tnt-audio.com/sorgenti/chevron_paradox_e.html

It is a very pure and uncongested sounding DAC with that midrange that comes with an NDF DAC.
It's built like a tank and has the off board power supply and interlinking cable. Make no mistake, its a top spec DAC designed and built by a well respected audio engineer.
Obviously difficult to value fully, I paid £500 for the old one second hand years ago. Think this is about 2 1/2 years old now and newer spec, so I guess I'll offer it up for the same.

£500 + postage

Located in Stoke of you'd like to hear it and collect.

I'll move to something like a modern Rega Saturn R with a digital input. I mostly listen to CD.

https://images2.imgbox.com/a7/f8/hWKOAkWy_o.jpg (https://imgbox.com/hWKOAkWy)

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https://images2.imgbox.com/59/d9/KxvkgRLl_o.jpg (https://imgbox.com/KxvkgRLl)

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https://images2.imgbox.com/e6/79/Q9nxulpo_o.jpg (https://imgbox.com/Q9nxulpo)

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[bumpy]

HI
I am not familiar with NDF. I've tried reading about it but got confused. :scratch: Is it another way to say no oversampling?
Thanks Chris

[Bourney]

I think so. Its no digital filtering I think.

[bumpy]

I think so. Its no digital filtering I think.

Thanks
Can anyone else contribute to the understanding?

[Bourney]

I've just read the tnt review in the link above and it mentions no oversampling. I guess that is NOS?

[Edward]

I have one of Colin's Paradox DACs. Love it. Wide open clean sound, massive amounts of detail, totally engaging and natural sounding. Steve, if you wish I can dig up Colin's technical implementation notes and post it here.

[Bourney]

That would be great, thank you Edward.

[Edward]

That would be great, thank you Edward.

Here you go - see below.

By the way Colin is now not building DACs but in a recent email said that if I had any problems with my DAC he would fix it. I guess the same would apply to the one you are selling Steve.

Anyway here are the technical notes. This was for my DAC so may differ from others (e.g. mine has XLR outputs) but the general notes apply to all of Colin's DACs (before he did his DDD versions).

________________________


The Paradox NDF16 DAC provides very high quality sound reproduction from a range of digital audio
sources. Its key features are :-


 No Digital Filtering is used which would otherwise degrade the time domain (impulse)
response. Essentially musical notes start and stop as recorded, digital filtering would soften
the decay and sometimes the attack of musical notes.


 16 multibit DAC chips are used operating in 8 times interpolation and differential mode. This
results in lower noise and distortion.


 Jitter on the SPDIF sources is well attenuated using a 2 stage attenuation design. This
ensures good sound quality from a wide range of digital sources.


 A computer can be used as the digital source via USB2. An asynchronous USB decoder is
used to ensure ultra low jitter. DAC is fully isolated from computer power supply & ground.


 The analogue stages work in Class A mode to ensure sound quality is not degraded and
Left/Right channels have separate regulated power supplies.


 Separate DC power supply isolates the DAC from RF & AF noise caused by mains. Multiple
transformers avoid internal ground loops and reduce electrical noise transfer between circuits.


 Maximum sample rate is 48 KHz via SPDIF inputs and 192KHz via USB2.

NDF16 DAC Comments:-


 The DAC chips operate with a maximum of 16 bit input resolution. 24 bit music will replay
but the 8 smallest data bits are ignored. In general I don't find HiRez music to sound better
than Redbook.


 The use of 16 DAC chips to give 8 times interpolation & differential audio output might be
thought to give an increase in resolution and sample rate, but this is not really the case.
The apparent increase in resolution & sample rate makes low pass filtering of the DAC
chips audio output easier. This filtering is done partly in the audio output stages and partly
by listeners ears. The real gain from operating 16 DAC chips in this way, is a reduction of
distortion & noise, in particular 2nd harmonic distortion is substantially reduced and
ultrasonic & RF noise is substantially reduced. Although 2nd harmonic distortion is
considered benign even desirable it does result in discordant intermodulation distortion.


 8 DAC chips receive the same data but at precisely delayed times, when mixed at the
output one step in the audio output become 8 smaller steps which are closer to the desired
analogue (stepless) signal. The other 8 DAC chips receive inverted data so a differential
audio output is generated . This is buffered to the XLR outputs. It is also summed with our
own design Opamp buitlt with discrete components and operating in class A.


 Because each DAC chip is still only receiving the inputted data (eg 16bit/44KHz) jitter
tolerance is not degraded by the 8 times interpolation, this is in contrast to most
oversampling or upsampling DAC’s or CD players where the digital data is multiplied up
and then presented to one DAC chip, this then has to operate at a much higher clock
frequency. A higher clock frequency makes the DAC chip less tolerant to jitter.


 Although jitter is well attenuated in the DAC, different sources are still likely to affect sound
quality. This can be caused by ‘bit imperfections’ in the data most likely to be from error
corrections made by the CD transport. A CD transport has to read CD data more or less in
real time and not all errors in data reading are corrected exactly. By contrast ripping a CD
to computer hard drive using a program such as ‘Exact Audio Copy’ allows the computer to
take as long as it needs to get the correct data, re-reading sections if need be. Also after
ripping you get a report on ripping accuracy so you know whether you have captured exact
data. For this reason even a modest netbook pc can give surprisingly good sound quality
via USB input on the DAC. As mentioned earlier not all USB DAC’s attenuate jitter
adequately but the Paradox NDF16 does

[bumpy]

Does anyone have the phone number for Colin at Chevron?

[Bourney]

Think he prefers contact by email initially.

[bumpy]

Think he prefers contact by email initially.

Shame. I have a few questions which are a bit complex and need interactive discussion. I really cant be bothered with e mail exchanges :(

[Edward]

Colin definitely prefers initial email contact. I have always found that he responds quickly to emails.

Bear in mind that Colin only started building dacs (and other stuff) after retiring from his previous full time work and that was some years ago.

[Bourney]

Colin definitely prefers initial email contact. I have always found that he responds quickly to emails.

Bear in mind that Colin only started building dacs (and other stuff) after retiring from his previous full time work and that was some years ago.
He called me after I had emailed him, but as you say, he works from home now so he definitely isnt in it to run a business and make lots of money.! . I found him to be an absolute gentleman, who was so interesting to listen to, who couldn't do enough for me when he really didn't have to.

[Edward]

He called me after I had emailed him, but as you say, he works from home now so he definitely isnt in it to run a business and make lots of money.! . I found him to be an absolute gentleman, who was so interesting to listen to, who couldn't do enough for me when he really didn't have to.

Indeed, same experience here.

I'm kicking myself for not originally ordering his DDDac implementation. By all accounts it was a world beater. We had it all priced up to my spec but then I got distracted. :doh: Sadly he no longer does new builds, but as I mentioned he is still available for repairs (so far not required).

[Bourney]

£450 tempt anyone?.