The ultimate TDA1543 DAC layout??

[Peter Daniel]

I was working recently on a compact layout for TDA1543 DAC and I came with this configuration. To simplify I2S connection TDA chip supposed to be on a bottom layer. I was almost completely satisfied with this solution, when suddenly an idea struck my head

I got reminded about all those fancy ground plane talk, minimizing inductance and capacitance, and of course 3D layout techniques used in Connosseur preamps.

So I decided to break the envelope of 2 dimentional assembly plane and get more adventurous.

[Peter Daniel]

So here's what I came with. IMO, this is the best TDA1543 DAC I've built so far.

[Peter Daniel]

I started with attaching copper foil to the top of CS8412 chip (thinner grade from Alpha core inductors using double sided adhesive tape). I attached later TDA1543 chip on top with BCK an FSYNK lines directly aligned on both chips. This leave the DATA line only slightly longer , but still as short as it gets.

All the regualtors (AN800x) ae attached directly to chip pins, their ground pins directly to copper plane. All bypass electrolytics are attache directly to chip pins (BG N 4.7 mostly)

The other chip visible in a pic is the input buffer (from Kusunoki DAC3). I used Vishay S102 to terminate the input.

[Taco]

Very nice, you're a true artist .

what are those transistors next to the recieverchip powersupply-pins?

hmm while typing this reply you posted the explaination. the regulators are those transistor looking things.

[Peter Daniel]

All connections are as short as possible. I decided to use 12V battery to power the whole thing with 4 separate regulators. I will later try 2 batteries (separate for DAC and receiver). The sound is really good and comparing to AC power it seems to be more realxed and smooth, but the difference is not that big. Initially I had 2200/16 BG cap to prefilter DAC regualtor, but it seems that the sound is better with out that cap.

[Peter Daniel]

In some other thread, there was a discussion about ceramic bypass caps. Well, that DAC was initially built without them, as I wanted to check out their influence. Comparing what I remembered from the sound of my other DACs (having those caps) the sound seemed to be dry and not liquid enough, lacking a bit of sparkle. After adding ceramic bypasses, it improved. I don't know what other guys are using, but the caps I favour are 15n X7R 0612 and 330n X7R 0612 from DK. They are pretty expensive and have soldering tabs on longer side, being even more suitable for bypass purposes. I solder tham directly to the chip pins, stack on each other, the smaller one being closer to the chip.

Here's the link to excellent article by Pete Goudreu discussing triplets bypassing http://groups.google.com/groups?selm...&output=gplain

[Peter Daniel]

Here's a pic showing my deditaction in installing ceramic caps on regulators feed lines (soldered directly to copper plane and wire)

[Peter Daniel]

Some people complain about CS8412 and spdif interface, yet this DAC, when used with CD Pro2 connected with Kimber Iluminations D-60, BNC termianted cable, sounds much better than my modified battery driven Marantz CD-94 (I2S direct) with non oversampling mod, Tent clock, synchronous reclocking and active, discreet output stage. I will be modifying Marantz again (soon)

The Marantz still posses traces of digital haze, while this setup is free from any digital artifacts.

[Bricolo]

As always, Peter, a true piece of art

[zygibajt]

Very,very good Peter!

I like it a lot!
Do you have any drawn schematics? Maybe I will try TDA1543 again.
Is the output stage and I-V passive (I think it is)?

Have you compared CD 94 and CD-PRO as a transport only.
CD 94 is equipped with CDM 1.I guess it should be better than CD-PRO.


Bartek