Hello,
I'm back from the first listening test of my dac.
It is mainly based on Doede's DAC, it uses a 12V battery, TL431 supplies for the CS8412 and a Mosfet regulator for the DAC itself.
I have 4 chips in parallel, Rload is calculated using Doede's document.
Vdac is 7.5V (actually I was planning to experiment a little but unfortunately I forgot my tester so...
maybe next time).
The source was a cheap DVD player, connected optically with a Arcam AVR200 and to my DAC with coaxial cable, so we could switch between the 2 converters.
With great surprise we (me and my friend, the owner of the Arcam) could hardly tell the difference between the Arcam and my DAC, they sounded a bit different but frankly I can't say which was better.
The only "clear" differences were the voice, more forward with the Arcam, and the image, a bit narrower with my DAC (maybe too much).
Considering that I still have to play to get the best permformance out of the DAC this seems a good result to me!
Next session I'll bring the tester(!) and my CD931 (hoping that in the meanwhile the crystal from Elso has already arrived), and will try to get the best out of these chippies...
Cheers
Andrea
I'm back from the first listening test of my dac.
It is mainly based on Doede's DAC, it uses a 12V battery, TL431 supplies for the CS8412 and a Mosfet regulator for the DAC itself.
I have 4 chips in parallel, Rload is calculated using Doede's document.
Vdac is 7.5V (actually I was planning to experiment a little but unfortunately I forgot my tester so...
maybe next time).The source was a cheap DVD player, connected optically with a Arcam AVR200 and to my DAC with coaxial cable, so we could switch between the 2 converters.
With great surprise we (me and my friend, the owner of the Arcam) could hardly tell the difference between the Arcam and my DAC, they sounded a bit different but frankly I can't say which was better.
The only "clear" differences were the voice, more forward with the Arcam, and the image, a bit narrower with my DAC (maybe too much).
Considering that I still have to play to get the best permformance out of the DAC this seems a good result to me!
Next session I'll bring the tester(!) and my CD931 (hoping that in the meanwhile the crystal from Elso has already arrived), and will try to get the best out of these chippies...
Cheers
Andrea
The DAC has no clock onboard, I made a provision for asynchronous reclocking but haven't completed it yet, partly because I was told that is better to improve the jitter at the source (changing the clock of the CD) than curing it in the DAC.
But as soon as I have a few time I think I'll try the ASR as well.
I only used 4 DAC chips for now but there's no real motivation.
I intended to experiment, I have 10 of them but before putting 8 in a row I wanted to see if my cooling arrangement was OK (BTW it works well, pics to come), so I went for 4.
But, as usual, so many variables and so few time
Cheers
Andrea
But as soon as I have a few time I think I'll try the ASR as well.
I only used 4 DAC chips for now but there's no real motivation.
I intended to experiment, I have 10 of them but before putting 8 in a row I wanted to see if my cooling arrangement was OK (BTW it works well, pics to come), so I went for 4.
But, as usual, so many variables and so few time
Cheers
Andrea
For the pics... first I have to borrow a digital camera.
For the temp... the datasheet only specifies 250 mW of dissipable power but this value, as well as the thermal resistance (100 °K/W) are quoted without cooling arrangements, so don't give good info on a safe temperature.
As a rule of thumb the chips shouldn't be too hot to touch.
Cheers
Andrea
For the temp... the datasheet only specifies 250 mW of dissipable power but this value, as well as the thermal resistance (100 °K/W) are quoted without cooling arrangements, so don't give good info on a safe temperature.
As a rule of thumb the chips shouldn't be too hot to touch.
Cheers
Andrea
Last one for now, showing the dac tower and the cooling arrangement. It is mathe with aluminium pieces cut to size. The blak thing that you can see near the chips is neoprene, an elastic polymer that holds the Alu pieces pressed to the chips.
This works well for me.
To take this pic I removed the 74VHC74 mounted on a homebrew SOIC to SIL adapter and intended for asynchronous reclocking (not implemented yet).
Cheers
Andrea
This works well for me.
To take this pic I removed the 74VHC74 mounted on a homebrew SOIC to SIL adapter and intended for asynchronous reclocking (not implemented yet).
Cheers
Andrea
Attachments
a picture is worth a million words...
thanks for the shots Andrea!
That battery looks like a UPS one, isn't it? Same as me... I had it already...
I've been doing inventory today, and I have some doubts that maybe you can check as you have a working circuit.
Main thing is resistor ratings. Must I assume that for the battery checker circuit 500mW trimmers are ok? or should they be higher rating? What abot the rest? will 500mW suffice? What about the rest?
what kind of chips are you going to use for the reclocking?
thanks for the shots Andrea!
That battery looks like a UPS one, isn't it? Same as me... I had it already...
I've been doing inventory today, and I have some doubts that maybe you can check as you have a working circuit.
Main thing is resistor ratings. Must I assume that for the battery checker circuit 500mW trimmers are ok? or should they be higher rating? What abot the rest? will 500mW suffice? What about the rest?
what kind of chips are you going to use for the reclocking?
No, I use my very own battery monitor 
, you can find it easily as I posted the circuit on the forum.
It is powered by the charger or, when it is missing, by the battery and, besides showing the state of the battery, detaches it when its voltage is too low and puts it into charge.
Cheers
Andrea
, you can find it easily as I posted the circuit on the forum.It is powered by the charger or, when it is missing, by the battery and, besides showing the state of the battery, detaches it when its voltage is too low and puts it into charge.
Cheers
Andrea
TDA1543-Doede DAC
Completed this DAC as per Doedes website with a few mods (see below).
Still a bunch of wires, but it works, and so does the reclocking using 11.xxx MHz can from Guido Tent.
Impressions:
This is a remarkably good DAC for the money and effort. In fcat, I have compared with a Theta Data Basic II and if the Theta scores 100, the 1543 scores 90! The Theta has more "drive" and bass resolution, and a bit better seperation in the mids. Highs are also more refined. I think that a good mains PS may be worth investigating for the 1543.
Setup-As per http://www.dddac.de
Mods: CS8412 FILT pin mod, PS pins bypassed with 100nF ceramic caps. Fan cooled.
Regards
Ryan
Completed this DAC as per Doedes website with a few mods (see below).
Still a bunch of wires, but it works, and so does the reclocking using 11.xxx MHz can from Guido Tent.
Impressions:
This is a remarkably good DAC for the money and effort. In fcat, I have compared with a Theta Data Basic II and if the Theta scores 100, the 1543 scores 90! The Theta has more "drive" and bass resolution, and a bit better seperation in the mids. Highs are also more refined. I think that a good mains PS may be worth investigating for the 1543.
Setup-As per http://www.dddac.de
Mods: CS8412 FILT pin mod, PS pins bypassed with 100nF ceramic caps. Fan cooled.
Regards
Ryan
The revenge of the DAC
After a first listening test where the dac was judged a little worse than the converter of the Arcam I came back to my friend's house with a renewed DAC, my modder's kit (tester and screwdriver) and a bottle of Genepy
The supply of the TDA1543s has changed, because I realized the mosfet-based one taken from the Convertus was supply-dependent and had too much dropout (I use a battery!). So I switched to a LT1085 with Ref pin bypassed and 150 uF on the output for stability.
The first test
(blind) with the "normal" dac (7.5Vcc ,Rload is 2k//820, about 580 ohm for 4 chips) confirmed the impressions of the first listening session, image less focused and a little flat soundstage. Not knowing which DAC was playing we had the same impressions and preferred the Arcam.
After that I raised the voltage to 8.5V, adjusted Rref and inserted the asynchronous reclocker (running at 80 MHz).
We weren't expecting a big change and were talking when someone pressed the "play" button... we immediately stopped talking and turned towards the speakers..the music was so sweet! Taking the Arcam as a reference if before it ranked 90/100 now it was 120/100!!
Can't describe exactly in English, for the Italian-speaking guys there is a word that best describes the sound I heard:
"emozionante"
Cheers
Andrea
After a first listening test where the dac was judged a little worse than the converter of the Arcam I came back to my friend's house with a renewed DAC, my modder's kit (tester and screwdriver
) and a bottle of Genepy The supply of the TDA1543s has changed, because I realized the mosfet-based one taken from the Convertus was supply-dependent and had too much dropout (I use a battery!). So I switched to a LT1085 with Ref pin bypassed and 150 uF on the output for stability.
The first test
(blind) with the "normal" dac (7.5Vcc ,Rload is 2k//820, about 580 ohm for 4 chips) confirmed the impressions of the first listening session, image less focused and a little flat soundstage. Not knowing which DAC was playing we had the same impressions and preferred the Arcam.After that I raised the voltage to 8.5V, adjusted Rref and inserted the asynchronous reclocker (running at 80 MHz).
We weren't expecting a big change and were talking when someone pressed the "play" button... we immediately stopped talking and turned towards the speakers..the music was so sweet! Taking the Arcam as a reference if before it ranked 90/100 now it was 120/100!!
Can't describe exactly in English, for the Italian-speaking guys there is a word that best describes the sound I heard:
"emozionante"
Cheers
Andrea
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