TDA1541a S2

[Peter Daniel]

I would be definitely interested. If you want all the bells and wistles, maybe two board designs would be beter. One more conventional and simple (yet with enough features, but single chip) the other one, fully loaded.

[Bricolo]

Since everyone wants different features, why not designing a multi pcb dac?

In example, one for the PS, one for the dac itself, one for the output stage.

A modular system that works with plugins: if you want to add ASR, just remove the wires between the reciever board and the dac board, and put the ASR board between them


Would this work, or would the interconnections/wires/various bords degrade the signal quality?

[deandob]

A multiboard DAC is the way to go for a modular approach.

I have noticed with DIY & tweaking hifi that certain tweaks and settings work better for certain music & recordings, and worse for others. I'm thinking that if a DAC is built with lots of features that can be switched in and out, then you are able to adjust the sound to best suit the source material without having to resort to a soldering iron.

With the features documented above, there would be quite a number of possible combinations allowing you to experiment to your hearts content. The digital tweaks would be easy to switch in and out, the analogue tweaks (eg. select different filter or output buffer) would need to be well implemented to ensure the switch does not affect the quality. It wont be as simple as just switching in/out these features due to interaction & compatibility reasons (eg. sinc filter & decima upsampling) but with some care it should work.

Regards,
Dean

[guido]

Covering part of the requirements:

http://www.diyvideo.com/forums/showt...172#post102172


Anyway, i'm looking at transformers at the moment. 1:15 could do the job with two tda's balanced. Then i can put the transformer over the the normal and inverted output and i don't have DC over it (the one i'm looking at can't handle DC)

Now testing with some crappy transformers, but not enough gain and bandwith. PCB is installed into a cd650 (it's alive again) but, just for now, using the player powersupply. That will be the next thing after the output (and i finally get some sound..)

Greetings,
Guido

[deandob]

Guido,

Interesting idea splitting the i2s signal into L and R for separate D/A conversion.

Have you compared your implementation with 2 x TDA1541 DACs in parallel? Common concensus here seems to be that putting the TDA in parallel gives more body to the sound (I have not checked this yet).

Using a transformer for output is definately a good option for output.

Regards,
Dean

[Coulomb]

A balanced Parallel TDA1541 DAC would need 4 x TDA1541?

Anthony

[deandob]

4 x TDA1541 for balanced outputs?

Maybe, but not for the price of 4 x TDA1541A S2!! There are several ways of approaching a balanced output with only 1 DAC chip, use of a transformer, balanced discrete output, balanced buffer output (eg. DRV134) or logically inverting the i2s input on a separate DAC chip (I would need to research this one further).

Personally I'd parallel the DACs and use an output stage that supports both balanced and unbalanced.

Regards,
Dean

[Zodiac]

IMHO a modular approach would be best. This is the route I have taken with my DAC. The receiver, reclock, dac, output and power supplies are all on separate boards. This way I don't have to redo everything when tweaking one of the modules. This approach has been especially useful for the output stage, as I have a few different ones on the go that I am evaluating / tweaking. I imagine there is probably a (very) slight loss of quality due to interconnecting wires, but then I think this is balanced by better isolation between noisy parts (receiver) and sensitive parts (output stage)

[jonclancy]

..I'm up for this one, too!!



Jon

[guido]

Originally posted by deandob
Guido,

Interesting idea splitting the i2s signal into L and R for separate D/A conversion.

Have you compared your implementation with 2 x TDA1541 DACs in parallel? Common concensus here seems to be that putting the TDA in parallel gives more body to the sound (I have not checked this yet).

Using a transformer for output is definately a good option for output.

Regards,
Dean

Dean,

Did not try this yet, there is a jumper on the pcb to choose equal or balanced output. However, balanced should be better, since it blockes common mode signals. E.g. PS noise.

Also going to look into DEM reclocking someday, maybe this is also an option for your project. But remember, the more stuff people want in it, the less chance that something will be realised...

GuidoB