Building the ultimate NOS DAC using TDA1541A

[maxlorenz]

Hi Bernhard,
Still the same mood?

It is obvious that, for the ethernal begginer that I am, and because of the high prices of enclosures + shipping expenses, I always calculate wrongly the sizes. That DAC began as a little DAC for humble purposes but, as it sounded so good, more and more tweaks were added, so it became too crowded. Maybe you read on my post that this DAC deserved more tweaks? I had to add: and a new case. Thanks for the advice.

Now, do you believe good quality passive units do make a difference in performance or sound?
Now my advice is try a "pure resistor" as -EC- has offered (generously, I have to add) here, in some significant position and then comment... 😉

Hi -EC-,
Thanks for the kind words. The difficult part was the "star" made from PCB material. I only had a big "cube" to cut it: around 1cm of radius.
The winding was relativelly easy. I will do some 50R for the output of the DIFFAMP and evaluate your honeycomb on a different task. 😎

Best regards,
M.

 

[tessier]

Hi ecdesign

The Direct Interpolation DAC could be done with a single DAC.

A multi-tapped delay line could accomplish the job. Without adding jitter. And you can weight and sum the outputs. I never implement this, so it's only theorical.

Any opinions or suggestions about that ?

Cheer

Paul

 

[maxlorenz]

Hi,
I have been trying to hear some noise induced from the near laying toroid but nothing...only crystal clear, richer than ever sound 😀

Maybe the honeycomb architecture is immune to induced noise from the strong magnetic field of my 12VA transformer??? 🙂

Now I have to find time to:
1) Build some 50R honeycomb for the output of the DIFFAMP.
2) Upgrade the PS of the Digital section and upgrade to superTeddyRegs.
3) Upgrade box.

😎

 

[rfbrw]

Hi,
only crystal clear, richer than ever sound 😀

This raises a wee small problem.Since every change is always a step forward, the highs are higher, the lows are lower and the mids are middling, by now, you should quite literally be bringing the musicians to life. Do you plan to share your good fortune or are you going to keep them all to yourself ?

 

[maxlorenz]

Hi dear rfbrw,
Long time no see 🙂 It is always a pleasure to read your posts...but I do not quite understand what do you mean...I only subscribed to what -EC- stated: that the I/V resistor is very significant in the sound quality of this DAC and that even high quality resistor are not as good as the "transparent" honeycomb DIY (comparatively cheap) one. What is the part that you do not understand???
Are you not able to listen differences in sound quality of passive (or active) devices?
Would you test the very basic -EC- DAC if I send you for free a pair of honeycomb resistors when the sacred wire arrives?
You would need a clean I2S signal that I assume should be really easy for you. 😉

Sincerely yours,
M.

 

[tessier]

Hi

Anybody do have a photo of a 10khz sine output on a oscilloscope from a DI4 direct interpolation dac ?

Thanx

Paul

 

[Bernhard]

It is obvious that, for the ethernal begginer that I am, and because of the high prices of enclosures + shipping expenses, I always calculate wrongly the sizes. That DAC began as a little DAC for humble purposes but, as it sounded so good, more and more tweaks were added, so it became too crowded. Maybe you read on my post that this DAC deserved more tweaks? I had to add: and a new case. Thanks for the advice.

Now, do you believe good quality passive units do make a difference in performance or sound?
Now my advice is try a "pure resistor" as -EC- has offered (generously, I have to add) here, in some significant position and then comment... 😉

What do you mean with "eternal beginner" ? You're here since 2003.

I use 4 x 7 Vishay RCK02 for passive I/V but will someday wind new Manganin resistors, which I have already used earlier.
No need for honeycombs because with Manganin the wire can be much shorter.
My tactic is to avoid the problem rather than to solve it.

 

[Bernhard]

Hi dear rfbrw,
Long time no see 🙂 It is always a pleasure to read your posts...but I do not quite understand what do you mean...I only subscribed to what -EC- stated: that the I/V resistor is very significant in the sound quality of this DAC and that even high quality resistor are not as good as the "transparent"

He for sure means that, from reading both your's and ec's claims about substantially improved sound quality after every tweak you do, one has the impression that:

The dead must have come to live again already !

Still I miss an analog filter which I know is an indispensible part of a non os DAC.

 

[Bernhard]

the highs are higher, the lows are lower and the mids are middling

I suggest resampling with a DSP in such a way that the audio band is spread, so that 20 Hz becomes 10 Hz and 20 kHz becomes 40 kHz, with 1 kHz in the middle staying untouched, output format 88,2 kHz.

 

[rfbrw]

2x OS ?

 

[Bernhard]

As a compromise

 

[rfbrw]

How about a PMD100 before all those nasty TDA's ?

 

[maxlorenz]

Hi dear Bernhard,

What do you mean with "eternal beginner" ? You're here since 2003./QUOTE]

I was hoping that this was self explanatory. I see you have some difficulties with language. It means simply that I recognize the fact that I will never achieve the level of master in this particular branch of the human knowledge. That allows me to have always an open mind 😉 and accept the fact that the world is full of intelligent people, some even smarter than myself...

Best wishes,
M.

 

[rfbrw]

Hi dear rfbrw,
Long time no see 🙂 It is always a pleasure to read your posts...but I do not quite understand what do you mean...I only subscribed to what -EC- stated: that the I/V resistor is very significant in the sound quality of this DAC and that even high quality resistor are not as good as the "transparent" honeycomb DIY (comparatively cheap) one. What is the part that you do not understand???
Are you not able to listen differences in sound quality of passive (or active) devices?

Don't like passive i/v, I have it in my old non-nos audionote. Always seems to me that the following stage is trying to make up for what has already been lost.

Would you test the very basic -EC- DAC if I send you for free a pair of honeycomb resistors when the sacred wire arrives?
You would need a clean I2S signal that I assume should be really easy for you. 😉

Sincerely yours,
M.

Thanks but no thanks. No TDA1541A's for me.

 

[maxlorenz]

OK. 🙂
That I can understand.

OS v/s NON-OS...
It is comparable to active/multiamplification speakers v/s "fullrange" speakers dilema.
I have active speakers on my main system nº1 and fulrangers on my sleeping room; each time I listen a good recording on the first one I say "this is it", only to find that the humble FR system is also charming, in a different way...

Active system:
Picasa Web Albums - mauricio

Fullrange:
Picasa Web Albums - mauricio
Picasa Web Albums - mauricio

Cheers,
M.

PS: maybe your old Audionote needs a little tweaking :-D

 

[rfbrw]

PS: maybe your old Audionote needs a little tweaking :-D

Been there. Went nos. Quickly went back to os.

 

[jean-paul]

Been there. Went nos. Quickly went back to os.

I think you would be surprised if you would take your DAC and compared it to John's. I visited him and heard some of his DAC's and they are very good (and built like a medical instrument).

maxlorenz: I would indeed move the transformer out of the vicinity of the DAC chips. It is simple: keep the supplies at the left side ( as seen from the front ), keep digital circuitry in the middle and you will have space for analog signal circuitry on the right side....

 

[hollowman]

I think you would be surprised if you would take your DAC and compared it to John's. I visited him and heard some of his DAC's and they are very good (and built like a medical instrument).

I'm a big proponent of OS but have heard some NOS systems that manage to get a few things right. It doesn't surprise me if the DAC project of this long thread sounds very good (and perhaps better than a lot of underdeveloped OS systems). There are a whole lot of variables at work that have nothing to do with digital design but get packaged (encapsulated) misleadingly under OS or NOS sound: e.g., superb output section, well-designed PS, excellent noise-reduction (EMI/RF) techniques, etc.

All this said and all else being equal, I do firmly believe that the orig. decision(s) to develop the mathematical concepts for digital filters for CD-DA, back in the mid-1980s, was truly necessary for improving CD sonics. In fact, the majority of the industry has adopted this since the late 1980s (ever since then, NOS is extremely rare, even in audiophile and, believe it or not, DIY circles). This is, perhaps, a different situation than Bitstream/MASH (which was done mostly for economic reasons: made DACs cheaper to incorporate into low-end gear) or even DSD (partially conceived by Sony/Philips for DRM) or Sigma-Delta design (economics again: make DAC design/production less $, not necessarily better sounding).

 

[maxlorenz]

Thanks Jean-Paul. As I said, I will rebuild and upgrade this DAC. In fact, I will upgrade all DACs with -EC's- honeycomb resistors, low noise voltage references and (CLCLC)n power supplies 😎 as time allows...

Rfbrw wrote:

Been there. Went nos. Quickly went back to os.

Yes, I imagine most would do this if the sonics are awful...but if one recognizes that certain atributes of music are present (while other are lost) in such a proportion that they produce a more than satisfactory musical experience, some gifted beings, like DDDAC and-EC- would try to solve the apparently "unavoidable" drawbacks of the approach to produce unique music reproducing machines. I think one has to applaud them for the effort.
I imagine Jean-Paul is not easily impressed, or subject of hypnosis 😀 so I would take his opinion as valuable. I have to say I have not heard John's DACs but only my versions of his DACs, as I always introduce tweakings to everything I build... 🙂 I can' t help it.

Cheers,
M.

PS: now listening Sam Cooke's "Night Beat"; vynil rip downloaded from avaxhome.ws

 

[rfbrw]

I don't doubt for a moment that they very good dacs but with all the optimisations, I would liken them to that technological marvel of the 1980's, the Porsche 959. Thing is, I always liked the brutal simplicity of the Ferrari F40.