Anyone like to comment on this NOS DAC

[Chris V]

I hope this is OK to ask this here?

I am going to audition a NOS DAC which will hopefully improve on my SHEK D2 in my system. Would anyone like to comment on the 'quality' of the design and components.

In particular Peter, would one expect it to work best with XXHighEnd with the valve re-clocking option turned on or off.


NOS (Non oversampling –zero digital domain filtering) design

Based on 1x TDA1543 – one of the most analogue sounding DAC chips ever directly connected to CS8412 SP/DIF receiver

Active I/U conversion via a special transistor with a shortest signal path directly connected to the tube grid - unlike other TDA1543 based DACs on the market our DAC is excellent at reproduction of low level musical information

ECC88/6N6P tube output stage

Tube based re-clocking option (can be switched off by a jumper)

Shunt voltage regulators everywhere (much smoother and more analogue sounding)

We only use fine selected audio components such as Allen Bradley resistors, Philips BC, Nichicon Muse, Panasonic Pureism, Kendeil capacitors, Telefunken diodes, PIO output capacitors

The PCB has no mask on the bottom side and all conductive traces are covered with gold and a special varnish for a for a more open and detailed sound

Mains input wiring as well as SPDIF and analogue out is wired in pure silver

Silver plated RCA connectors

[CoenP]

This was something like my diy dac in 2000, terribly old school.

I also have the ifi nano idsd for headphone purposes but connected it the other day to my main rig. Big surprise: excellent sound and fun. You can trick this one into pseudo NOS by feeding it a high sampling rate from xxhe like 384khz. Then the xx arc pred filter dominates over the internal one and that is audible in a positive sense.

This dac is dirt cheap and does the works for music lovers, portable too if you have other plans. Only nuisance is that quality listening needs to be done over the battery, but its life is sufficient for more than one evening of listening.

No, it does not live up to the phasure dac, but what do you expect really...

Regards, Coen

P.s. Very good sound is also attainable on the mac with audirvana+(Upsampling)

[Chris V]

Thanks Coen 

[PeterSt]

Oops ... I wanted to start out the previous post with this :

No Chris, no problem at all with asking about other DACs. The only thing what might happen is that my personal comments seem not valid because Phasure has such a product herself. This latter is obviously true, but the former sure is not (well, I hope !!).

I need to purchase a lot of stuff myself and I guess I am reading more reviews and spec sheets etc. than many of you together. I look through my special glasses and "verdict". Mostly this is about consistency (I mentioned the word in my previous post) and how you can tell that people BS to begin with (be commercial) or lie or don't know. Some times it is a "sport" and not easy to not make mistakes.

What, by all means, should NOT come from this, is that people stop proposing things (like DACs) like you just did, Chris - because it could perceivedbly be "dumn" from the proposer, or something. Not so at all of course.
So what I just did is genuinely sprouted my thinking when I read such a thing and this includes that it tells nothing about the sound (not in this case). Maybe one thing about the sound : since the 1543 is 16 bits only, it can not do (take) any upsampling (formally needs one additional bit per (2x) upsampling step). So might you go for the Arc Prediction filtering in XXHighEnd - it's a no-go.

Peter

[PeterSt]

It took me 1 minute to find it.
Quite some more to find out who or what the seller is. And THAT alone would make me the most suspicious.

http://www.clar(removethis)tes.co.uk/about
Edit : I added the "(removethis)" so Google won't index this. Meaning : It is fine that someone (me) publishes an objective judgement but it is less nice when quotes from persons can be associated with those persons - especially when the general idea is - or could become a negative one. See and follow the (by now new) posts below.
That is your seller. Hum.

Maybe they got hold of a pallet of DACs but ... I don't know.

Now tell me - If you would be a respectful UK company, would you sell on ebay Hong Kong ?
http://www.ebay.com.hk/itm/SW1X-Audio-Design-DAC-01-NOS-TDA1543-ECC88-6N6P-Tube-Note-300B-2A3-amp-/181910924043?hash=item2a5abc6b0b:g:~6EAAOSwo6lWKhT6

Now what's crucial here :
This is brandnew (from the Ebay UK page), right ?
Of course it is brand new. But as the text is old, see the picture below for what's in there. Indeed that's from my old Telefunken TV they probably tore down for this.
Or maybe it was the 2nd WW Philips radio - I forgot.

Still it can sound good.

Peter

[Chris V]

It took me 1 minute to find it.
Quite some more to find out who or what the seller is. And THAT alone would make me the most suspicious.

http://www.clartes.co.uk/about
That is your seller. Hum.

Maybe they got hold of a pallet of DACs but ... I don't know.

Now tell me - If you would be a respectful UK company, would you sell on ebay Hong Kong ?
http://www.ebay.com.hk/itm/SW1X-Audio-Design-DAC-01-NOS-TDA1543-ECC88-6N6P-Tube-Note-300B-2A3-amp-/181910924043?hash=item2a5abc6b0b:g:~6EAAOSwo6lWKhT6

Now what's crucial here :
This is brandnew (from the Ebay UK page), right ?
Of course it is brand new. But as the text is old, see the picture below for what's in there. Indeed that's from my old Telefunken TV they probably tore down for this.
Or maybe it was the 2nd WW Philips radio - I forgot.

Still it can sound good.

Peter

Good detective work Peter 

I only stopped from putting the name on here as I didn't want to be seen as advertising someone else's products.

It has all the hallmarks of a re-badged Chinese product, but the guy lives local to me so I will go and have a listen.

Indeed I might just ask for a tour around the English factory.

[Chris V]

Here is a bit of correspondence I had with the seller. Does this man sound like he knows what he is talking about or is it more BS?

Me

"As my music source I am using computer software that does all the upsampling before it sends out the data. It is capable of outputting data at 32bit/768Khz.

In terms of ultimate SQ how will your NOS DAC be handling a 32bit/768Khz signal?

Please keep the response simple as I am taking advice from the people who generate the software and am not skilled at all this technical stuff."

 
Seller

"I can see where you coming from. A resolution is only one aspect of a good sound. Higher resolution does not guarantee a good sound anyway, when there are so many other factors just deteriorate the sound beyond comprehension. Many years ago I also thought that the higher the resolution the better it is, until I realised that the potential of 16 bit Red Book (CD) format was far from being fulfilled. Wait until you hear a properly designed 16 bit NOS R2R DAC that can resolve as good or better than a 32 bit Delta Sigma DAC.

Speaking of resolution, the highest resolution of an mass produced R2R DAC chip known to me is 24 bit (which requires digital filtering) and a NOS capable R2R DAC chip is 20 bit.

R2R means resistor network based chip architecture, the most accurate and most expensive DAC chip to design and to produce. Only the R2R chips can provide a true resolution in its original sense. If you have a R2R DAC chip with 16 bits resolution and low noise capacitors around, most likely you will come close to the specified resolution.

On the other hand, all modern 24 and 32 bit DAC chips of Delta Sigma type are <1 bit noise shaping by design, i.e. produce noise and that clean up the signal with a demodulator, which supposed to be 24/32bit. These modern chips do not really resolve the claimed accuracy and are quite forgiving with low quality components and all of them require filtering by design.

On top of that, what is the benefit of upsampling to 32 bit if the maximum resolution of digital SP/DIF signal is 20/24 bit and the recording itself is 16 bit only?

The 32 bit upsampled signal is re-formated to 24 bit SP/DIF, where 12 bits are lost. When a signal arrives at a SP/DIF receiver chip of a DAC, the last 8 bits of 24 bit get truncated to the resolution of the DAC chip e.g. 16 bit. It is like taking a low resolution picture and zooming it in, then adding additional bits to make the curse looking squares appear smoother and then zooming it out again. In other words, there is no value added with upsampling. In my expreience, the upsampled signal cannot and does not sound better relative to the original 16 bit.

I hope that everything I wrote makes sense"



 

[CoenP]

I played for some time with the cheapest philips CD player of early 90s which I bought for 5 euro at the second hand store. This one had the TDA1543 and I managed t lift some processor pins to disable the digital filter and put it in NOS (1x) mode.

Though it was NOT the last word in resolution the CD player was a lot of fun to listen to and had great tone. Actually it was generally accepted that the TDA1543 has a maximum of 12 bits resolution which is more than enough for todays over compressed pop albums, but not for high end listening and certainly not enough for through-dac-digital volume control.

I was surprised to learn that the Doede Douma Dac (DDD dac) is still alive and kicking today. Here resolution is enhanced by averaging many (multiples of eight) TDA1543 dacs. In a classic setup with analog volume control and tubed amplifiers this DAC probably sounds very nice since real 16 bits of resolution will surpass the capabilities of the other components and its remaining distortion is likely pleasant to the ear. Please note that the tube is needed to conceal or ameliorate the rough distortions that NOS (1X OS) exhibits.

Yet technology moved on in 20+ years and really I think there is no comparison with my IFI nano iDSD, which can sound like a true high resolution DAC and is super versatile and super cheap. It supports all current formats without external conversion like you would have to do with a 16/44.1k NOS DAC. It really is able to let you familiarize with the potential of PC/computer based audio.

Of course there are similar offerings as the nano iDSD to consider and as a starter in this field I think this amount of money will be well spend to jump on the learning curve and decide later if this suffices or that you wish for something else.

regards, Coen

[PeterSt]

Hi Coen,

I was surprised to learn that the Doede Douma Dac (DDD dac) is still alive and kicking today. Here resolution is enhanced by averaging many (multiples of eight) TDA1543 dacs.

I know you are not saying that the resolution becomes higher of it. But for understandings :

What happens with that is that the stack of same D/A chips get more linear because they-are-not-so inherently (actually they are not so much the same ).

How this is useful to a better sound or distortion of if you like "resolution" ?
Well, see next post (that severeness can't be overcome by any means), because I don't see it.
Yes, more current output ... (easier I/V and IIRC the DDD does this passiveley).

Regards,
Peter

[PeterSt]

My initial impression :

If I write him an email he could buy one of my DACs.

Read :
His response seems to be genuine.

Try to see this in the context of the so many persons/companies who put up large stories about why 96KHz is sufficient (while of course their DAC can't do more). This includes very well known and respected "names". Still it is "BS" so to speak, to not offer more. Thus, what those persons / companies should do instead, is explicitly telling about the negatives of e.g. 192KHz; why it would be devistating. THEN I'd buy the 96KHz storie(s).
But of course this is difficult, so you don't see that happening (but see next post as well).


Chris, it is all rather complicated. So something to really learn again :

We both know that you and me are from the BD-Design Forum era where I started out with XXHighEnd. Say this was over a year earlier than this forum emerged (2007). I started to implement upsampling;
I tried many 3rd means of it myself (like Rabbit stuff from Foobar) and in the end - as I recall it - ended up with something which was at least not worse than doing nothing (so just NOS). But really helpful ?
No.
At that stage, my stories would have been - and were if you ask me - the same as your Seller just put up to you.
But hey, this was 9 or 10 years ago and a few things changed;

I created Arc Prediction which was actually my own promise to the NOS1 being in deveplopment because I refused to make a ringing filter (that would kill the NOS virtues) and against all odds I even succeeded with that. From there more started to do this explicitly, and while Coen mentioned Audirvana, that would indeed be one ho got the idea (Damien (Demian ?) from Audirvana even implemented the "always even" upsampling for me).
Much much more has been going on and the whole idea of in-DAC doing things (or do nothing) started to shift towards the PC. Ask "Miska" from HQPlayer and see how actually (only) two guys on this globe understand the principles (he thinks the very same as I do, although he is the DSD guy).

What am I saying ?
Well, that it is VERY EASY to miss out on this all because one forgets to read a couple of forum posts and a similar couple of years (or is not into that at all).

Back to your seller ...
BS ?
Not as I read it from that text.
Old fashioned (if I am allowed to see it like that) ... sure.

Tell him that the digital filter (in or outside of the DAC) makes the sound. And not his Telefunken GPS-towers in there.
And how he sells D/A converters while he should be doing energy stuff (IIRC - I already forgot).

Still it can sound good.
Nah ... it can't. LOL.

Look below. I coincidentally needed that this morning for something else. It is a 10KHz test signal and genuine NOS.
If one likes that, one likes distortion. It is from this topic/post :
World's best measuring NOS DAC : Phasure NOS1 (it is a large topic so let it rattle until it downloaded all the pictures - it is Reply #130 in there).
The first picture (the orange one - the same as you see below) is a NOS DAC without filtering (remember, filtering = upsampling !)
The second picture looks quite 99% the same, but it is from a DAC which is now used as NOS and thus no filtering again.
The third picture is that same latter DAC and but now 4x Upsampling with a nice filter is applied (I don't know any more what filter that was at that time).
All you need to do is envision that the first picture (also shown below) can not be improved upon because the DAC is not capable of a higher sampling rate and/or does not supply the necessary number of bits to do that.

You know what ?
Squeeze a 20Hz tone through your system. What do you hear ?
Well, if it is 40Hz capable, you will hear 40Hz. That is a similar distortion as you see below but easy to proove because you can hear it so easily.
(with the notice that 20Hz should be inaudible to you)
Disclaimer before I'm aimed at : People owning the Orelo MKII speaker of course will hear nothing ineed.

Yup.

Peter

[PeterSt]

Help ...

I am laughing myself, now I see this picture pop up in this post.
My story is nice and valid, but please notice that the "harmonics" you see are a bit outside of the audio band. That happens with a 10KHz base tone ... (which I thus coincidentally ran into this morning).

Anyway, still the idea is clear hopefully.

Peter

Edit / PS : But you can compare the distortion figures (the 10% you see) because they are calculated from the in-band response only). For that, dive into the link I gave, where you see that the same signal can end up to be 0.004% but which can not be justified by these plots (so you need to believe me).

[CoenP]

Hi Coen,

I was surprised to learn that the Doede Douma Dac (DDD dac) is still alive and kicking today. Here resolution is enhanced by averaging many (multiples of eight) TDA1543 dacs.

I know you are not saying that the resolution becomes higher of it. But for understandings :

What happens with that is that the stack of same D/A chips get more linear because they-are-not-so inherently (actually they are not so much the same ).

How this is useful to a better sound or distortion of if you like "resolution" ?
Well, see next post (that severeness can't be overcome by any means), because I don't see it.
Yes, more current output ... (easier I/V and IIRC the DDD does this passiveley).

I think we say the same.
Bit linearity is enhanced by paralleling (or Dynamic Element Matching if you want to keep the current small) from 11 to 15-16 bits, but even perfectly linear you still have to deal with the gross distortions that NOS 1x (16/44.1k in) implies.

By NOS, both Peter and I mean that the DAC does not filter digitally but the PC does that for you. Now you can apply a filter to the bare music data that sounds and measures well and feed it to the DAC WITHOUT additional in-DAC processing.
Please note that the bitrate to the DAC needs to be high to overcome the distortions and that's the job of the digital filter. As a bonus extra signal bits can be calculated (ie 24 bits) to mimic the signal closer.

So: signal processing in the PC and the DAC adding NOTHING to it at a HIGH BITRATE (i.e. 192KHz or higher). Iow preferably you need a very bit-linear NOS DAC that works on these high frequencies. Unfortunately these do not exist with an old fashioned SPDIF interface (nor do the sources) and you need USB or something else. Note that the IFI doc works up to 384kHz (not completely NOS) and the NOS1a up to 768KHz.

nuf said,
regards, Coen

[Chris V]

Ok that makes sense, but the job of the firewire in my system is to carry the signal from XXHE to the Fireface 400 which is an external sound card and is much better than the internal computer sound card.

If I fed a good NOS DAC with a USB signal from the computer I seemed to have omitted the Fireface 400, so what is being used as a sound card 

[CoenP]

Ok that makes sense, but the job of the firewire in my system is to carry the signal from XXHE to the Fireface 400 which is an external sound card and is much better than the internal computer sound card.

If I fed a good NOS DAC with a USB signal from the computer I seemed to have omitted the Fireface 400, so what is being used as a sound card 

Eh?

Usb is not a signal, it is a cable system to transfer data on a short distance and a simple way to connect devices to your pc. Only the initiated know the electrical and pc stuff that makes this possible. All pcs have usb ports, the digital music signal is transferred via the usb system to the Dac which also has an Usb port. There are different flavours of usb operation, i guess all modern DAC use the same mode today, anyway all will work. Several years ago people called these dacs 'Usb dacs'.

Regards, Coen

P.s. A sound card is a big DAC albeit not/never Non Over Sampling, whats your point really?

[Chris V]

Coen, thanks for baring with me, perhaps I have got this wrong all along

When I started with computer music, first option was to let the computer play using its own sound card (sounded rubbish).

Then XXHE came along and the advice I took in (perhaps wrongly) was that the internal sound card would hold back the sound quality and to switch to an external sound card attached by a firewire. This was and still is the Fireface 400 which is used solely as a sound card and the internal DAC is not used as this is not very good.

Signal from the Fireface 400 is taken via a single digital cable to the DAC.

This is how it is currently wired and plays very nicely. My assumption therefore was that somewhere in the system a quality sound card was required. Is this all nonsense?