Hi Andrea & I hope you are fine.
I started playing around with DACs in the late 80's. The only thing available back then being Phillips TDA15..'s and a few BB's.
Later on (early 90's) came the 1-bit chips and "revolutionized" the industry. Phillips own TDA1547 was absolutely terrible. My objective observations are in sync with your findings.
I even did some experiments with SABRE dacs (2010 - onward) and although they measure really well indeed and require very few parts (big +), the sonics was uninspiring.
IMHO, the best DA chips are the ones not available anymore.
I would rank TDA1541a = PCM1704 = AD1865 as the best. With the PCM1704 having the best measured performance. However - one DAC chip really changed my mind about 1-bit chips:
In the early 90's, a Swedish engineer designed a magnificent DAC based on a CS4328 single ended DAC.
The sound from this DAC was nothing short of astonishing. It was quickly grabbed and produced by Forsell Mediphone, and in combo with their Air Reference transport, there was (and still is) nothing like it for 16/44,1. It's a shame really that not many people heard this stuff. I know - because I own one.
I later found out that Jonathan Valin of Stereophile and even Mr. Levinson himself had the Air Reference combo as their reference front ends.
There was an updated version of the Forsell dac launched by the designer himself, but it too worked best with the Forsell Transport (I own that too).
I am writing this to tell those with 1-bit dacs not to lose hope. That implementation appears to be more important than the type of DAC chips, since even 1-bit dacs can sound fantastic, specially with the wonderful oscillators Andrea is producing.
The older 1-bit chips appear to sound better than the latest, newest ones since they contain so much less circuitry inside. The AKM chips are also truly wonderful sounding devices.
Good luck.
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... yes, I happened to do all the CAD work for that DAC 
Here is a picture of my unit...
and a fair amount of auditioning - many late nights past by...
Also many visits to dr. Forsell - he had fantastic sound using modified Beveridge SW2 and own take on corner bass lines. WOW!
//
(but no credit for me re: layout or design...)
Here is a picture of my unit...
and a fair amount of auditioning - many late nights past by...
Also many visits to dr. Forsell - he had fantastic sound using modified Beveridge SW2 and own take on corner bass lines. WOW!
//
(but no credit for me re: layout or design...)
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Yes, it only sounded the best together with the Forsell Air Transport.
With other transports, it didn't sound optimal.
At Taiwan Audio Show back in 1994, they had a set up with Forsell Air Reference front-end (Dac+Transport) and Audio Note preamps and amps.
It was the best sound on that show, better than vinyl.
Everyone who came into the room didn't leave.
NOS Dacs sound very nice, but compared to the best Delta-Sigma dacs, they seem to loose precision, air and finesse.
But I love TDA1541 and PCM1704 and PCM63.
PCM1702 is almost identical to PCM63, but it is not a very good sounding dac.
Best wishes
With other transports, it didn't sound optimal.
At Taiwan Audio Show back in 1994, they had a set up with Forsell Air Reference front-end (Dac+Transport) and Audio Note preamps and amps.
It was the best sound on that show, better than vinyl.
Everyone who came into the room didn't leave.
NOS Dacs sound very nice, but compared to the best Delta-Sigma dacs, they seem to loose precision, air and finesse.
But I love TDA1541 and PCM1704 and PCM63.
PCM1702 is almost identical to PCM63, but it is not a very good sounding dac.
Best wishes
Sorry Andrea for being off the topic
Well, I always thought AD1862 sounded a little "bright" to my ears.
I would say I'd prefer AD1865 as it sounds more like TDA1541a.
However IMHO TDA1541A sounds smoother and rounder than Analog Device DAC chips.
I would love to try one of your 5.6 MHz oscillators driving the Phillips chip diectly in NOS mode.
I think the result might be spectacular.
Best wishes
Well, I always thought AD1862 sounded a little "bright" to my ears.
I would say I'd prefer AD1865 as it sounds more like TDA1541a.
However IMHO TDA1541A sounds smoother and rounder than Analog Device DAC chips.
I would love to try one of your 5.6 MHz oscillators driving the Phillips chip diectly in NOS mode.
I think the result might be spectacular.
Best wishes
Another fan of TDA1541a
Another fan of the TDA1541a here. Definitely pairs well with Andrea's current GB SC cut at 45MHz. I look forward to trying it directly with the new 5MHz WTMC. I have run the same 1541a DAC driven by a FOX clock on the WaveIO, then the NDK on BBB/S03, the NDK on FIFOPi, the NDK SDA on FIFOPi and now Andrea's WTMC. Each clock upgrade I questioned if we would hit the point of diminishing return on the TDA1541a. The SDA was a clear upgrade, and WTMC was a game change. I expect the 5MHz WTMC will be the ultimate 1541a. There may be better DAC's out there, but this combo serves me well.
Another fan of the TDA1541a here. Definitely pairs well with Andrea's current GB SC cut at 45MHz. I look forward to trying it directly with the new 5MHz WTMC. I have run the same 1541a DAC driven by a FOX clock on the WaveIO, then the NDK on BBB/S03, the NDK on FIFOPi, the NDK SDA on FIFOPi and now Andrea's WTMC. Each clock upgrade I questioned if we would hit the point of diminishing return on the TDA1541a. The SDA was a clear upgrade, and WTMC was a game change. I expect the 5MHz WTMC will be the ultimate 1541a. There may be better DAC's out there, but this combo serves me well.
Very interesting read....
I would love to know more about your setup and your experiences when you upgrade to Andrea's 5MHz oscillator.
Thanks Alexiss
This has been a fun, rewarding journey.
If interested, you can see my review of Andrea's clock and implementation tips/experience at post #1843. https://www.diyaudio.com/forums/dig...itter-crystal-oscillator-185.html#post5887494
The DAC/Streamer build notes are in a blog Reference Music Server Finally Making Music - diyAudio
I will document sound impressions after the next clock upgrade.
This has been a fun, rewarding journey.
If interested, you can see my review of Andrea's clock and implementation tips/experience at post #1843. https://www.diyaudio.com/forums/dig...itter-crystal-oscillator-185.html#post5887494
The DAC/Streamer build notes are in a blog Reference Music Server Finally Making Music - diyAudio
I will document sound impressions after the next clock upgrade.
Well, I held the mouse at least...
all the credit for the design goes to, at the time, Peter Bremen. //
That Forsell duo is indeed extraordinary well engineered as well as sounds nothing like any dac I have heard. It's very lifelike, really solid and transparent.
The way the power supply layout is done is next to nothing I have ever come across.
The only bad thing is the open/close mechanism, which can, partly, fail. It's replacable though.
A big thank you for pointing out the do's and dont's regarding the clocks and 1 bit dac's. This saves money and time, and possibly frustration;-)
My apologies again to Andrea for not writing directly on topic.
Yes, you are right. The Forsell DAC was truly incredible.
I think the transport was by another design team and I know nothing about it.
The only thing I know is that Forsell Air DAC and transport together made heavenly music.
There were many circuit ideas in Forsell DAC which were quite unique and I haven't seen anything like it commercially ever since, specially the circuit board design and the power supply.
I will try to implement an Andrea - clock in the Forsell soon.
Yes, you are right. The Forsell DAC was truly incredible.
I think the transport was by another design team and I know nothing about it.
The only thing I know is that Forsell Air DAC and transport together made heavenly music.
There were many circuit ideas in Forsell DAC which were quite unique and I haven't seen anything like it commercially ever since, specially the circuit board design and the power supply.
I will try to implement an Andrea - clock in the Forsell soon.
Andrea,
rediscovered your master clock thread few days ago.
I`m really very impressed about your continually envolving work, over years, with fantastic results. Thanks a lot for your efforts!
Still running Crystek clocks, I questioned myself several times about their influence on the sound, together with (after reading your last posts, I`m nearly afraid to say) Sabre DACs in Non-Microwave-Mode
Last year, I did a comparison between these chips with a studio clock regeneration system of very low jitter, down to subsonic frequencies.
The sound improved definitively, especially in the bass region, but also over the rest of the audio spectrum.
So I would really like to implement your clocks in my and a friends system.
Just added the parts to the groupbuy list...
rediscovered your master clock thread few days ago.
I`m really very impressed about your continually envolving work, over years, with fantastic results. Thanks a lot for your efforts!
Still running Crystek clocks, I questioned myself several times about their influence on the sound, together with (after reading your last posts, I`m nearly afraid to say) Sabre DACs in Non-Microwave-Mode
Last year, I did a comparison between these chips with a studio clock regeneration system of very low jitter, down to subsonic frequencies.
The sound improved definitively, especially in the bass region, but also over the rest of the audio spectrum.
So I would really like to implement your clocks in my and a friends system.
Just added the parts to the groupbuy list...
"Sabre DAC in non-microwave mode" is great!
Joking aside I don't really like the sound of the delta-sigma DACs, maybe I haven't heard the right implementation yet, but I found them a bit harsh, especially human voices seem to lose consistency.
In other words, I found the multibit DACs more natural.
However, I believe that a good master clock is an advantage for all types of DACs because the digital to analog conversion is time based and therefore the short term stability is crucial.
Maybe delta-sigma DACS pay for the need for high conversion frequencies, where the phase noise of the oscillators is worse.
In any case stay as low as possible.
Joking aside I don't really like the sound of the delta-sigma DACs, maybe I haven't heard the right implementation yet, but I found them a bit harsh, especially human voices seem to lose consistency.
In other words, I found the multibit DACs more natural.
However, I believe that a good master clock is an advantage for all types of DACs because the digital to analog conversion is time based and therefore the short term stability is crucial.
Maybe delta-sigma DACS pay for the need for high conversion frequencies, where the phase noise of the oscillators is worse.
In any case stay as low as possible.
RE: Forsell DAC. By sheer coincidence I just found a tube with 5 CS4328 and 2 CS8412's left over from the production of the Entec Number Cruncher. Its unsettling that that effort was 25 years ago. I may still have some PCB's left over. Most went to Bob Crump and John Curl for the short run of their version they built. I may need to fire it up again. Its an 18 bit chip so its limited re today's SOTA.
WRT CS4328, about the only characteristic that looks different, in a good way
to more modern DS DACs is the lack of noise floor modulation. 0dBFs and
-90dB noise floor look identical, albeit quite high so maybe there is some but
it's being swamped.
TCD
WRT Forsell Air transport, I've both worked on a few and listened to a few in very good systems. They are boat anchors and a pile of engineering junk.
From memory they didn't even re-clock the SPDIF data stream...??
A crazy attempt to address the jitter issue at the wrong end of the chain, ie; before it is encoded to SPDIF. Back in those days Hi End were really lagging
behind Pro WRT addressing jitter where it counts, at the DAC. Pro products were starting to implement some kind of secondary slower PLL after the
receivers (fast) PLL. Apogee (originally as owned by B Jackson) comes to mind with their C768 clock. Their old DA-1000 was re packaged and sold by
ML in the Cello product line. I think it was Dan Lavry (Lavry Engineering) that first introduced a FIFO system at the DAC end to really take care of jitter.
It's also worth noting that he was the first to implement a discrete weighted resistor ladder DAC many years ago.
TCD
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