The slicer is the same for both oscillators. The only difference is in the power supply, the Clapp uses the on-board TWTMC-D&D regs (Demian design) while the Driscoll uses my TWRPS-pp micro (push-pull series regulator).
Components of the DAC are:
- Aune HDMI to I2S receiver
- Ian's Fifo buffer with single clock reclocker board
- TWTMC-D Driscoll OCXO + TWTMC D&D + TWRPS-pp micro (6V and 3V3) to feed Ian's staff
- Ian's I2S to PCM
- TWRPS-pp (6V) as power supply for Ian's stuff
- Red Baron with TDA1541A in simultaneous mode offset binary (EC-design)
- Salas shunt power supply for Red Baron (-15V, -5V, +5V, +3V3)
- Rhopoint wirewoud as I to V resistors
- Broskie AIKIDO with 4 6N23P
Since about two years I use the PCM1792 in a PCM-DAC as well as in a DSD-DAC with my clock of course. (Look at my website) It needs no reclocking in the PCM-DAC. They beat every DAC I could find in Eindhoven....
Herbert.
Hmmm....interesting....same slicer, and presumably good PSU.
well, finally we're getting an audible proof that the overtone xtals in a
low impedance circuit have better objective performance, what I did not believe in.
My, this is a massive DAC.
Well, I am glad to hear about the good results.
I spent quite a few hours with different DAC chips in the late 90's and strangely, I always
found myself defining the lowly, old, inferior, almost 16 bit, TDA1541A as the most natural DAC
chip (but with oversampling, not NOS)....strange.
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A side note on NOS, vs OS dacs:
The NOS dacs, regardless of the DAC chip used - always sounded extremely blurred and unatural to me, along
with many delta sigma DACs that always sounded (more or less) hard and fuzzy (but never blurred and weired like NOS dacs)
I dont know....Delta Sigma Conversion theoretically has many advantages to PCM but....
The winner in my ears was always TDA1541A, with AD1856 98% equal to TDA chip - but only in OS mode.
In NOS mode, AD1856 was ”less bad”.
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Herbert, What is the Rx chip in your design?
The late 90's is quite a long time ago, long before the PCM1792 came on the market....
NOS is nonsence. Be aware that I use a SW digital filter on an FPGA which is very much better than the HW digital filters!
Herbert.
I have to confess Herbert....I have never tried the PCM1792, and I've
heard sooo many good things about them.
and delta-sigmas are much much better now.
As mentioned earlier, they are theoretically better, at least in the y-domain....But as in anything
else in electronics HW, it is more about the implementation I guess...
knowing you, I think your filter sounds very interesting.....but since the it is implemented in FPGA... I guess it is not SW based??
Sorry.... I don't know anything about PCM1792...or your set-up, other than it sounds very interesting...I didn't think they needed os.
I would like to know more about your setup if you don't mind sharing a little bit.
heard sooo many good things about them.
and delta-sigmas are much much better now.
As mentioned earlier, they are theoretically better, at least in the y-domain....But as in anything
else in electronics HW, it is more about the implementation I guess...
knowing you, I think your filter sounds very interesting.....but since the it is implemented in FPGA... I guess it is not SW based??
Sorry.... I don't know anything about PCM1792...or your set-up, other than it sounds very interesting...I didn't think they needed os.
I would like to know more about your setup if you don't mind sharing a little bit.
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The DAC in the above image uses the TDA1541A in NOS mode, it sound extremely natural and detailed, not blurred or confused. As you said several time often the result depends on the implementation.
I also own a Naim Audio CD 3 (TDA1541A single crown with SAA digital filter). It sounds very good as it comes from the factory, but after I removed the SAA it sounds better.
I also had the opportunity to listen to the AMR CD-77 (Thorsten Loesch TDA1541A NOS design), well it's the best DAC I ever heard.
I don't like Delta-Sigma DAC, for me they are unnatural and often harsh, they are "noise generator", since R2R dac are "music generator". They came out of the market because their production is very expensive, not because Delta-Sigma are better sounding. The PCM1704, recently out of production, the last R2R dac on the market, was sold for about 70 Eur, since a SIGMA Delta costs a fraction. I believe there is a reason for this, and the reason is very simple: R2R dac are too expensive, while the market asks for "lighting toys", not for device to play music. Ask yourself why MSB sells a R2R dac instead of a Delta Sigma, much simpler to implement since it only needs a good clock, while a R2R dac requires a very expensive selection of very expensive resistors.
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NOS multibit DACs looses -3db at 20KHz when fed with RedBook files. But it's possible to equalize preamps output to compensate for that.
OR it's possible to perform oversampling/upsampling/filtering with PCs and dedicated softwares (Phasure's XXhighend Player or Signalist's HQPlayer) and then feed NOS R2R DACs.
I believe this is the right path to best possible sound. Altough not simple, nor cheap, it can lead to unbeatable results.
I totally agree with Andrea: only R2R dacs for music! All the rest is only made to get industrials richer :-(
OR it's possible to perform oversampling/upsampling/filtering with PCs and dedicated softwares (Phasure's XXhighend Player or Signalist's HQPlayer) and then feed NOS R2R DACs.
I believe this is the right path to best possible sound. Altough not simple, nor cheap, it can lead to unbeatable results.
I totally agree with Andrea: only R2R dacs for music! All the rest is only made to get industrials richer :-(
Thank you Andrea & Fralippo for your information and updates.
Yes, I also did that.
Buying every cd player with TDA1541A and modifying them.
Many TDA1541 and AD1856 DAC kits from Ebay and so on (like many of you Im sure).
One of the first things I did was to make them NOS.
I COMPLETELY respect your opinion, but to me NOS has always sounded really bad and "strange".
The NOS sound always appear very "doubled" with some instruments appearing aggressively disharmonized, blurry and "wide" within the soundstage.
Almost feeling like two different people were playing the same instrument.
The soundstage is percieved as strangely blurry and unnatural.
The best result I got was with TDA1541A and DF1700 which sounded magical.
What is the reason for this?
I was reading a report many years ago where an engineer had reported similar findings to mine. It got me very curious.
Since that time (10 years ago) I have accidentally met 5 people (without searching for them) who did agree with me.
It is my understanding that it might be a neurological difference or an anomaly in some humans where their auditory system is extremely sensitive to "double tones" that are not harmonically related.
I am not joking with you, NOS dacs sound really bad to me. So much so that I can't listen to them more than a cpl of minutes.
I agree with Andrea on CD77. It was a MARVELOUS player. It also had the possiblity to switch to OS with different filters settings, making it very flexible.
I would like to inform you (without going into details) that the reason big companies are investing in Delta Sigma Conversion is not purely financial.
Theoretically SDC is superior to PCM.
R2R DACS might be less sensitive to jitter and need not the highish clock.rates necessary in bitstream-modulators.
But as I wrote above:
According to my humble opinion, the best sounding DAC to this date 2016 - when properly designed is still TDA1541A, with AD1856 following closely.
I did once listen to MBS dac in a shop and it didnt have a chance against TDA1541A. I was not particularly impressed. But it might have been something else in the chain.
In OS mode and properly designed, the sound of TDA1541A is EXTREMELY natural and "analogue" with almost no harshness what so ever.
It will not have the precision of say ESS Sabre DACs, but ESS Dacs will never have the ease, effortlessness and the sweet rendition of TDA1541A.
Yes, I also did that.
Buying every cd player with TDA1541A and modifying them.
Many TDA1541 and AD1856 DAC kits from Ebay and so on (like many of you Im sure).
One of the first things I did was to make them NOS.
I COMPLETELY respect your opinion, but to me NOS has always sounded really bad and "strange".
The NOS sound always appear very "doubled" with some instruments appearing aggressively disharmonized, blurry and "wide" within the soundstage.
Almost feeling like two different people were playing the same instrument.
The soundstage is percieved as strangely blurry and unnatural.
The best result I got was with TDA1541A and DF1700 which sounded magical.
What is the reason for this?
I was reading a report many years ago where an engineer had reported similar findings to mine. It got me very curious.
Since that time (10 years ago) I have accidentally met 5 people (without searching for them) who did agree with me.
It is my understanding that it might be a neurological difference or an anomaly in some humans where their auditory system is extremely sensitive to "double tones" that are not harmonically related.
I am not joking with you, NOS dacs sound really bad to me. So much so that I can't listen to them more than a cpl of minutes.
I agree with Andrea on CD77. It was a MARVELOUS player. It also had the possiblity to switch to OS with different filters settings, making it very flexible.
I would like to inform you (without going into details) that the reason big companies are investing in Delta Sigma Conversion is not purely financial.
Theoretically SDC is superior to PCM.
R2R DACS might be less sensitive to jitter and need not the highish clock.rates necessary in bitstream-modulators.
But as I wrote above:
According to my humble opinion, the best sounding DAC to this date 2016 - when properly designed is still TDA1541A, with AD1856 following closely.
I did once listen to MBS dac in a shop and it didnt have a chance against TDA1541A. I was not particularly impressed. But it might have been something else in the chain.
In OS mode and properly designed, the sound of TDA1541A is EXTREMELY natural and "analogue" with almost no harshness what so ever.
It will not have the precision of say ESS Sabre DACs, but ESS Dacs will never have the ease, effortlessness and the sweet rendition of TDA1541A.
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Alexiss, were you aware of the falling frequency response when oversampler ic is removed from the chain? -3b at 20KHz and almost -1db at 1KHz is something you can immediately hear! That HAS to be corrected. That's the problem and reason of unpleasant results you experienced IMHO.
Furthermore I can add that most of the time the power supplies regulators found on cd players and/or oriental boards aren't of good enough quality. You'd replace them all. Both feeding dacs and output op-amps. Also it'd be a very good idea to cut-out filtering and second op-amp stage...
p.s. try a PMD100 digital filter in place of the DF1700 ;-)
Furthermore I can add that most of the time the power supplies regulators found on cd players and/or oriental boards aren't of good enough quality. You'd replace them all. Both feeding dacs and output op-amps. Also it'd be a very good idea to cut-out filtering and second op-amp stage...
p.s. try a PMD100 digital filter in place of the DF1700 ;-)
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Oh yes, I was very aware of that. Please see the comments above:
I did not complain about lack of detail due to treble roll-off.
This is only one of the problems with NOS design as there will be increasingly fewer number
of samples as the signal frequency approaches half Nyqvist frequency and so the signal power drops due to longer holds than samples.
You can "improve" this (not cure it) simply in the analog domain or in the digital domain.
Oh yes, I tried them all;
op amps,
no op amps,
pure resistors,
transistors: singletons, multiples, VFB, IFB, No FB
Transistors,
tubes,
bipolars,
fets,
hybrids,
opamps in configurations you've never seen...yes all.
The same goes with the PSUs...tried all of em:
IC,
discrete,
LDO,
linear,
switch,
passive,
through-hole passive,
smd,
tube rectifiers,
silicon rectifiers,
transistor-based rectifiers,
selenium rectifiers,
fast recovery rectifiers
germanium rectifiers
Soft switching rectifiers
Current pulse,
voltage pulse ....all.
They wont cure the fundamental NOS deficiency. But again: I fully respect your opinion and your ears.
At the end of the day, thats what counts....
PS:
Tried it with PMD100 AND PMD200. PREFERRED DF1700 (not DF1704).
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At this moment I'm very busy at work, and I also have to finish building the audio system of my friends.
As soon as I will find a little free time I try the revision, maybe a couple of weeks.
But TDA1541 have primitive DEM = mismatch shaping which have some similar characteristics to ΣΔ ?
No, not 'mismatch shaping' (which is indeed what S-D DACs do) rather mismatch minimization. In other words TDA1541 DEM attacks the source of the problem, differing bit weights, whereas S-D DACs accept the mismatch and do their best to ensure its audibly concealed vis-a-vis THD+N measurements.
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