Pushing the limits of TDA1543 NOS DAC

[northernsky]

Originally Posted by uncle_leon

It is still possible to DIY one - the schematics are available, and the updated version is actually simpler than original. I can help with alternate parts choices (what to use instead of Black Gates etc.).

Hi,

I am also one of the DIYers who recently asked Peter for a DAC kit unlikely sold out.

I was able to built Peter's chipamp kit, but it was fundamental Peter's thread on gainclone instructions for beginners. Can you address me to a similar thread?

Thank you

Renato

[uncle_leon]

Originally Posted by Destroyer OS.

If I understand this new build it is just under the premise that better power is the only thing the 1543 needs... Then some DC coupling output, correct?

Is the improved power about regulation, or noise rejection? I haven't been under the impression that power regulation improves sound as much as noise rejection, yet.

I cannot comment on the regulation vs noise issue, but I do know that Peter and Bobken went to great lengths optimising passive components in their latest DACs. By optimising I mean choosing the best sounding value, as well as choosing the best sounding brand/type, in each position.

Originally Posted by northernsky

Hi,

I am also one of the DIYers who recently asked Peter for a DAC kit unlikely sold out.

I was able to built Peter's chipamp kit, but it was fundamental Peter's thread on gainclone instructions for beginners. Can you address me to a similar thread?

Thank you

Renato

I'm afraid the NOS DAC is a bit more complex than a Gainclone... I mean it is simple for a DAC, especially if you use IC regulators, but there are still things to consider, like managing digital/analogue grounds, shielding, input isolation etc.
I mean, you could just solder it together on a protoboard as per Peter's schematic, and it would likely work fine - all I'm saying is that the range of trouble you could potentially run into is much broader than with a Gainclone... So I do not think there is a thread with instructions for beginners because without the kit, it is not really a project for beginners...

[northernsky]

Originally Posted by uncle_leon

I'm afraid the NOS DAC is a bit more complex than a Gainclone... I mean it is simple for a DAC, especially if you use IC regulators, but there are still things to consider, like managing digital/analogue grounds, shielding, input isolation etc.
I mean, you could just solder it together on a protoboard as per Peter's schematic, and it would likely work fine - all I'm saying is that the range of trouble you could potentially run into is much broader than with a Gainclone... So I do not think there is a thread with instructions for beginners because without the kit, it is not really a project for beginners...

Thank you Uncle Leon. Let's wait, may be Peter changes idea and prepares a new batch of kits.

Renato

[SomekPoland]

Hi guys, great thread BTW. I'm thinking of connecting TDA1543 to my TE7022 USB-I2S converter. Do i need to change something? There are following pins at the converter: MCLK, LRCK, DATA, SCLK. How should i connect it to TDA input? DATA-DATA, MCLK-BCK and what with the other two?

[marconi118]

I am planning to use the balanced version (with 2 1543) to drive a balanced circlotron amp
Do I need matched 1543? how to match them?
Any advice on coupling caps / non coupling caps and volume control on a full balanced system?

[abraxalito]

This is probably extreme heresy but I haven't yet found X7R ceramics to be a limitation on sound quality when used as couplers, so long as they're over-sized to mitigate against the voltage coefficient. Currently I have 6 paralleled 4u7 6.3V in 0603 size as output couplers for my DAC.

[uncle_leon]

Originally Posted by northernsky

Thank you Uncle Leon. Let's wait, may be Peter changes idea and prepares a new batch of kits.

Renato

Here is the most basic NOS DAC circuit that you can attempt to build, that will still work (and likely sound reasonably good too). I took Peter's "classic" schematic and edited it to simplify it. I also incorporated some of the recent updates into it. Have a look and see if this is something you would feel confident attempting.

This simplified DAC should actually sound better than original - with the following reservations:
- the original NOS DAC used very high quality passive components (Black Gate, Riken, Caddock), some of which are no longer available.
- the IC regulators that Peter liked are also no longer produced, and somewhat hard to obtain, which means you may have to resort to LM78xx-type regulators (which will likely sound worse). Where simplicity is not that important, one could go with any of the new low-noise regulators, or buy/make a "super regulator" (such as the Bobken reg discussed here earlier).
- using different regulators could mean that the optimal values for their output caps are now different.
- your shielding arrangements, and wire routing choices will have some impact on the sound, and may sound a bit worse than Peter's PCB (although it may sound better too).
- the classic DAC uses a ferrite bead at the input if the regulator U3. I prefer the sound without it, but some people like it. It does (theoretically) make sense to install it if you use a single trafo, because it will limit "spreading the contaminations" in the power supply.

One could probably go even further with the simplification, and feed the regulators from the same PSU, but I think that would be going a bit too far in terms of sound quality compromise, and it would not simplify things that much (if you know how to build one diode bridge, then you certainly know how to build another).

[northernsky]

Originally Posted by uncle_leon

Here is the most basic NOS DAC...

Thank you! Now I know how to spend Christmas holidays... at least studying the diagrams. I'll try.

Renato

[Peter Daniel]

This post shows the most cost effective way to convert my original DAC into recently updated version. For even simpler approach, discreet regulators on receiver chip could be also omitted: Pushing the limits of TDA1543 NOS DAC

[marcus1]

Thanks Peter - just to clarify; do you mean that VD+, VA+ and M1 on the CS8412 chip can be fed by a single AN8005 regulator rather than two?

Originally Posted by Peter Daniel

This post shows the most cost effective way to convert my original DAC into recently updated version. For even simpler approach, discreet regulators on receiver chip could be also omitted: Pushing the limits of TDA1543 NOS DAC