2ch Mediacenter DAC?

[dnilsson]

Hi,

I'm about to add another mediacenter to my home, the current multichannel equipment will be moving to a dedicated moviearea in the basement and I will replace it with a smaller 2 channel setup in the livingroom for listening to music.

The speakers I've selected for this new 2ch setup are the "Dynavoice Challenger M-65", see http://www.dynavoice-av.com/index.php3?pageid=2 and I will be building a DX HRII Amp for this. I suppose calling this a "value" setup would be appropriate. Audio will most likely be played back by MythAudio since the rest of my mediacenter equipment is already on MythTV. Maybe some other audioplayer but still on Linux.

The mediacenter computer probably has a low-end soundcard (haven't tried it yet but I assume so). So I'd like to add an external soundcard/DAC running off the Linux mediacenter computer. My hope was to be able to drive the DX HRII Amp directly from the soundcard, ie no separate pre-emp with volumecontrol.

With this background set, I'll get to the point of my question. Looking at the range of DACs available it seems that a DAC like for example the DDDAC1543 MK2 would fit quite nicely. In this case I could for example put this DAC in the same enclosure that hosts the DX HRII amp and have a nice 2 enclosure solution (computer + all-in-one DAC/Amp). This however requires that I can use the mixer functionality in the PCM2707 DAC over USB, an option which is only available when not using an external TDA1543 DAC. If I were to add the TDA1543 DAC I would have no volume control at all (bad idea...)!

So, the options that I see are either

1) Go with a simple PCM2707 DAC, use the internal volume control in the PCM2707 and be done with it. This makes me wonder, will the PCM2707 be the weakest link of my system? As I pointed out earlier, this is not a high-end solution so I don't need to go crazy with the DAC solution either.

2) Add the TDA1543 to the PCM2707 and somehow figure out how to add a volume control. I have investigated this some and it seems that I would have to add for example another USB device which implements the control endpoint of the audio spec and talks to an external volume controller over lets say SPI. I guess an AVR microcontroller could do this task. Anyone know of any such projects? Would it be worth the effort compared to alternative 1) above?

3) Other options?

[dublin78]

Just put a potentiometer or stepped attenuator (volume knob) between DAC and amp?

[dnilsson]

Hi,

Well yes, that is certainly an option... But not being able to control the volume with a remote seems like a big drawback though. I guess one could argue that a separate remote just for controlling the volume could be used as well, but this seems like a hazzle as well (that is what I have today, one remote for the mediacenter and one for the amplifier).

Call me picky or whatever, but I'd really like to be able to control the whole mediacenter from one remote. That means that the volume control needs to be controlled from the computer running the MythTV frontend. I thought using the mixer functionality of the USB audio standard is the "best" option but maybe there are other option?