Looking for TAS5100

[thomaseliot]

Hi Marek,

Equibit is a patented technology by Toccata Denmark, licensed to Texas Instruments that bought Toccata some years ago.

Equibit is a whole digital amp with no feedback, that is that power stage input is a digital stream and output is another digital stream directly connected to speakers: no signal "goes back" to the amp to say what's happening in the real world (speaker).

This also means that power supply variations are reflected entirely to speakers. So PS must be very well regulated and precise, in the order of less than 50mV tolerance.

In a digital amp there is no way to implement an analogue pot. Your solution with TAS3004 is a DSP volume control: it performs mathematical transforms of pcm to modify amplitude of resulting sine waves. Is the same volume control of PC sound cards.

Unfortunately with this method you get much lower resolution of sound, at normal moderated sound levels.

So TI recommends to control the amp volume with a variable power supply: Tact millennium amp (that uses Equibit) use this technique.

Have you a picture of 5010+5100 board?

Ciao

Thomas

[Markus2006]

Fast Freddy,

What I need from TAS5261 is that it: "supports Pulse-Width Modulation (PWM) Frame Rates of 192 kHz to 384 kHz". Hopefully, this will allow for connecting it to TAS5010.

Marek

[Markus2006]

Thomas,

Thanks for explanations. Now I understand the issue with variable power supply. Such a power supply is not used in case of my amp. Can you point me to TI recomendations regarding this? There could be some application shown.
I don't have pictures of my boards but here: http://www.ep.com.pl/archiwum/07-2006.jpg
you can see how the preamp looks like (at the bottom of the picture). The power amp looks similar (just without LCD).
And here you could actually download the article (first item on the PDF list):
http://www.ep.com.pl/?strona=archiwum.php&r=2006&m=7
but it requires some access code, which you can get by sending a SMS - I never used it and I don't know whether it will work from Italy.
Not long ago there was a reference to similar method on this forum.
It was a thread about EEEngine. Its it what you are talking about?
EEEngine
and more information from Yamaha:
http://www.yamahaproaudio.com/topics..._eeengine.html

Marek

[thomaseliot]

Look this post:

http://www.diyaudio.com/forums/showt...70#post1043870

The reference variable power supply from TI is here:

http://focus.ti.com/lit/an/slea038/slea038.pdf

There is an evaluation board from TI with TAS5518+TAS5261 (TAS5518 is the 8 channel version of your 5010):

http://focus.ti.com/docs/toolsw/fold...5261k2evm.html

Here you'll find complete documentation, user guide and gerber files for the board.

I got some TAS5518 from TI, if you are interested.

[Markus2006]

It looks like power supply is very important for TAS5261. But the evaluation board does not contain one. The power supply seems to be to complex for me at the moment.
Do I understand correctly that TI used TAS5518 with 8 channels and TAS5261 with just two outputs on the evaluation board? What happend to the other 6 channels ?

Marek

[thomaseliot]

The evaluation board for 8 channels is here:

http://focus.ti.com/docs/toolsw/fold...5152k8evm.html



in the two ch one, six channels are unused.

Yes, ps is complex enough. It must be a very stable SMPS.

[Markus2006]

I'm not sure about the term "stable". It seems to me that the required voltage is calculated based on current power module requirements (either by TAS5518 or dedicated microprocessor), and the output SMPS voltage is changed accordingly. So the voltage changes. I have to read posts by Kim (it's a pitty that he has no time to check this thread - he may be the guy who has TAS5100 ).

Marek

[BWRX]

Originally posted by thomaseliot
I'm in with a group buy for TAS5261 TI Equibit power stage. But it has analogue input. Could your input stage be compatible with TAS5261?

The board I made has two chips, the TPA2001D1 and the TAS5261. The TPA2001D1 accepts an analog input and will output the PWM signals to control the TAS5261 output stage. Any 0-3.3V PWM signal can be used to control the TAS5261.

Originally posted by Markus2006
Of course, I hope that TAS5010 can be connected to TAS5261 - I have to read the datasheets.

Of course it can. As I said in the TAS5261 thread, I have supplied PWM inputs on the board to jumper in external PWM signals - the same PWM signals your TAS5010 would send to the now obsolete TAS5100.

[thomaseliot]

Hi Brian

what do you think about Marek's TAS5010?

When finished with your 5261 board we could try this and build our TACT millennium digital amp.