I'd like to start building the Audio DAC 2000 that was published in Elektor 1999 (11 -12) and 2000 (1).
Only problem I see is the GAL that is used in the schematic.
It was a part that had to be ordered through Elektor services but that was 19 years ago, so I haven't found any reference off it.
Is there someone who can tell me if there is a possiblitit to buy that GAL or the program that resides within it.
I know it is a long shot.
Only problem I see is the GAL that is used in the schematic.
It was a part that had to be ordered through Elektor services but that was 19 years ago, so I haven't found any reference off it.
Is there someone who can tell me if there is a possiblitit to buy that GAL or the program that resides within it.
I know it is a long shot.
Why to use such an obstacle?
The magic of this DAC is nothing more as the PCM1704 feeded from digital filter DF1704.
Years proven practice:
- avoid DF1704 (if you need a digital filter, go with PMD100 or PMD200) or do that pure NOS
- avoid active output analog filter (instead of that use passive)
- make a better board (with a solid GND)
- use a modern converter USB/I2S (there is a lot on the forum, I have a good experience with jlsounds, it supports direct conversion for PCM1704)
- power supplies composed of LM317 / 337 could be better
The magic of this DAC is nothing more as the PCM1704 feeded from digital filter DF1704.
Years proven practice:
- avoid DF1704 (if you need a digital filter, go with PMD100 or PMD200) or do that pure NOS
- avoid active output analog filter (instead of that use passive)
- make a better board (with a solid GND)
- use a modern converter USB/I2S (there is a lot on the forum, I have a good experience with jlsounds, it supports direct conversion for PCM1704)
- power supplies composed of LM317 / 337 could be better
Tailgunner, you must have a specific reason to want to build an ancient device. Please note that there are better and more recent easily available devices to be found/built. These also sound better than that DAC 2000.
As miro1360 pointed out, avoid DF1704. PCM1704 meanwhile has a TDA like reputation which makes it an expensive chip. It is good but it is not holy. Besides that implementation is a key parameter. Recent development has given us excellent voltage regulators which are way better than those used in 1999 for instance.
I don't agree with avoiding active output stages. These can be designed quite well but passive output stages have the bonus of simplicity.
As miro1360 pointed out, avoid DF1704. PCM1704 meanwhile has a TDA like reputation which makes it an expensive chip. It is good but it is not holy. Besides that implementation is a key parameter. Recent development has given us excellent voltage regulators which are way better than those used in 1999 for instance.
I don't agree with avoiding active output stages. These can be designed quite well but passive output stages have the bonus of simplicity.
I thought that DAC was the very best. What is the reason for this high distortion.
Don't be lured to a modern delta-sigma DAC only because of parameters, it starts and ends there. The high price of the chip PCM1704 has a reason (avoid ebay sources). It sounds really great, but you must follow the principles we have written above. I do not recommend the active post filter because, the myth says about a proper design, everyone has their best, so which one won the battle? Stay with the pure passive filter or no filter at all and try NOS connection. Use an active I/V stage (here you can leave a room for experimentation, start with active I/V based on ADA4898-1 (or similiar alternative, avoid ebay sources) as the reference and later you can try different DIY discrete designs and compare them between). Power supplies from LM317/337 with an accurate reference.
There are delta sigma DAC chips (ESS Sabre comes to mind) that sound good. If we all would think like that no new technique would be better than the old one it replaced 
LM317/337 for instance are now really old news when LT3045/3094 etc are around. These are better by a large margin. I am sure some audiophile will say that LM317/337 sound better
For some reason many audio guys keep using parts they already knew 30 years ago. My advice is to try new stuff and find out if you like it. A passive output stage is nice but more expensive if it uses transformers.
Tailgunner, you can look out for a DAC with Wolfson receiver for SPDIF and a well known USB asynchronous receiver if you need that. Make sure the design uses more modern LDO ultra low noise regs. There are many cheap designs that can give quite good results. I would also search for a design that can play 24 bit/192 kHz and maybe even DSD. It will make the device a bit more future proof and you will be able to compare high res recordings with plain 16 bit/44.1 kHz ones. There are many threads here about DACs so I won't create another one.
Some will laugh but I recently acquired a Denon PMA60 Full Digital Amplifier and I am quite fond of it. It is a DSD capable amplifier that is digital till the power stage so a DAC and amp in one. A powerDAC so to speak. It sounds better than my Gainclone for instance.... Agreed, it is not DIY and it is not for analog sources but it is cheaper than building a good DAC and amp No output stage to worry about too.
LM317/337 for instance are now really old news when LT3045/3094 etc are around. These are better by a large margin. I am sure some audiophile will say that LM317/337 sound better
For some reason many audio guys keep using parts they already knew 30 years ago. My advice is to try new stuff and find out if you like it. A passive output stage is nice but more expensive if it uses transformers.
Tailgunner, you can look out for a DAC with Wolfson receiver for SPDIF and a well known USB asynchronous receiver if you need that. Make sure the design uses more modern LDO ultra low noise regs. There are many cheap designs that can give quite good results. I would also search for a design that can play 24 bit/192 kHz and maybe even DSD. It will make the device a bit more future proof and you will be able to compare high res recordings with plain 16 bit/44.1 kHz ones. There are many threads here about DACs so I won't create another one.
Some will laugh but I recently acquired a Denon PMA60 Full Digital Amplifier and I am quite fond of it. It is a DSD capable amplifier that is digital till the power stage so a DAC and amp in one. A powerDAC so to speak. It sounds better than my Gainclone for instance.... Agreed, it is not DIY and it is not for analog sources but it is cheaper than building a good DAC and amp
No output stage to worry about too.
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It is not so easy to make a proper connection of the delta-sigma DAC for the inexperienced, for experienced engineers it is sometimes a hard nut. For that it is quite easy to build R-2R and get an amazing result.
I have nothing against LT3045/xxxx and alternatives. I posted LM317 as a pure analog and a proven good PS for PCM1704 ... The LM317 will not be sufficient for delta-sigma.
Denon PMA-60 is the proof that THD parameter up to 1% is irrelevant for ears, or certainly not a sound quality reference.
I have nothing against LT3045/xxxx and alternatives. I posted LM317 as a pure analog and a proven good PS for PCM1704
... The LM317 will not be sufficient for delta-sigma.Denon PMA-60 is the proof that THD parameter up to 1% is irrelevant for ears, or certainly not a sound quality reference.
PMA60 has 0.07% THD at 25W @ 8 Ohm....
Output power 8 Ohm (20 Hz - 20 kHz, T.H.D. 0.07%)
25W (1kHz)
Output power 4 Ohm (1 kHz, T.H.D. 0.7%)
50 W
One must be a rather hardcore listener to be able to listen at 25W sound level. Anyway, tailgunner you might listen to this amp in a shop. Maybe you will like it, maybe you don't. I stopped using DACs as I jumped on the FDA bandwagon. I like the simplicity of FDA and I don't have analog sources anyway. No expensive potentiometers and relays anymore as stuff is handled in the digital domain. Of course it is not ideal as feedback is a design challenge but it has a lot of positive features. It is spacial and relaxed, let's say it is musical.
Output power 8 Ohm (20 Hz - 20 kHz, T.H.D. 0.07%)
25W (1kHz)
Output power 4 Ohm (1 kHz, T.H.D. 0.7%)
50 W
One must be a rather hardcore listener to be able to listen at 25W sound level. Anyway, tailgunner you might listen to this amp in a shop. Maybe you will like it, maybe you don't. I stopped using DACs as I jumped on the FDA bandwagon. I like the simplicity of FDA and I don't have analog sources anyway. No expensive potentiometers and relays anymore as stuff is handled in the digital domain. Of course it is not ideal as feedback is a design challenge but it has a lot of positive features. It is spacial and relaxed, let's say it is musical.
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THD is tricky, the function has any constant growth ... you have to look at the whole chart (PMA-60 THD chart not found) ...
... it brings the idea to consider SPL in different speakers (in a living room, 1W on stereo speakers with SPL 88 have a similiar loudness as 0.35W on another speakers with SPL 93 ... THD will be different at the same listening level)
TDA8950
... it brings the idea to consider SPL in different speakers (in a living room, 1W on stereo speakers with SPL 88 have a similiar loudness as 0.35W on another speakers with SPL 93 ... THD will be different at the same listening level)
TDA8950
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I can recommend to look at one of my R-2R discrete DACs, can be viewed as a modern PCM1704 replacement. The newest and best is the dam19x1, it's easy to use and flexible, the main thread is here:
dam1941 - Next Gen Discrete R-2R Sign Magnitude 24 bit 384 Khz DAC module
dam1941 - Next Gen Discrete R-2R Sign Magnitude 24 bit 384 Khz DAC module
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