[Karsten]

As a little comfort I can say that the price is not final yet. So far I only know the development cost, which has been quite substantial. When I know the real production cost, I may be able to adjust the price to SP owners.

The goal has been to develop the best possible and most versatile DAC, without really cutting any corners. So if things work out as expected, the DAC should be able to compete with the really expensive designs.

A small, but still nice feature I forgot to mention, is that it is possible to bypass the output DC blocking capacitor by moving a jumper. So if the poweramplifier (or preamp) already has a DC blocking capacitor, it is safe to bypass it at the DAC output. I have chosen not to use any servo loops, so a small amount of DC may be present at the output, however this still remains to be tested.

Regards,
Karsten

[bhobba]

Hi Karsten

As a little comfort I can say that the price is not final yet. So far I only know the development cost, which has been quite substantial. When I know the real production cost, I may be able to adjust the price to SP owners.

Yep.  This is cutting edge stuff - hence my comment about price.  After thinking about the matter I am looking at setting my system up in two stages.  Stage one using a Burson pre-amp and modded 740C.  Stage 2, once I get my super, will use more high end stuff.  For that your product will be high on the list - along with other high end stuff like the DAC Steve Nugent is developing.

Thanks
Bill

[Telstar]

Somebody on the Circles forum pointed me to this thread, thanks to him.

I have some questions for Karsten.

-First of all, it is a true 24 bit ladder?
-Will it accept high-res sample rates of: 24/96, 24/174.6 and 24/192?
-Will it use Anagram Q5 DSP upsampler? If not, what kind of oversampling is performed?
-What about PSU? Internal, external, battery?
-USB (to 12s i guess) or Firewire input?

I have heard of a custom made DAC from a Sonic2 evaluation board from a friend, with improved output stage, battery. in my setup is was very good, but not to cry for a miracle. Compared to my old Muse Model Two, feeded by my VRDS transport. I'm sure my amplifiation was the bottleneck, though.

Price if confirmed at 6k is on the high side. The competition is getting fierce.
Berkeley alpha dac is priced at under 5k and APL hifi should be 4k or 5k, with tube output (which i value very much). Orpheus Audio is releasing a new DAC as well based on Anagram Q5. No idea about price yet.

[Karsten]

Hi Telstar,

Thanks for the interest 

The DAC is based on the Anagram Sonic2 module. This link should give you all the basic answers you are looking for: http://www.anagramtech.com/digital-audio-portfolio/modules/sonic2/ You'll find links to both product brief and data sheet from here.

I'm however only using two AD1955 in stereo mode and summing the output. The reason for this is that I don't want to deal with electrical differences between individual chips. The only drawback to this approach is a slightly lower SNR, but improvements on other more significant parameters. The prototype is measuring THD+N at -117 dB, which is fully acceptable to me.

The PSU is a quite conventional (but well build) internal linear construction, which seems to serve it's purpose very well.

The USB is actually going via spdif internally, but it should not be an issue given the technology used. The I2S input is available through an experimental connector. If Firewire interface is desired it would of course be possible to use a Firewire to I2S or spdif adaptor.

This design will work as a reference class digital preamp as well, which should be taken into consideration when judging the price. But let's see I may be able to give a good introduction discount 


It is possible to modify the Sonic2 evaluation board to sound good, but it is native a "quick and dirty" implementation of the technology, so it is not an easy job to do right.

[Karsten]

The final prototype DAC boards are here, at last....... They are not bad at all.... 

[mcullinan]

Can you show us a snapshot of the board... so we can see what you are doing.
Thanks.
Mike

[Karsten]

Sure Mike, will do so as soon as I get a few minutes to spare...

[Karsten]

Here are some pictures:

[Karsten]

I can add that an expansion board will be available at some point which, among other features, will open the possibility for a server/client based ethernet solution.

Karsten

[mcullinan]

Awesome! I have no idea what Im looking at, but it looks like its organized really well. Plus you have good ears. What kind of sound have you arrived at with this board and what if any changes do you think need to be made.

On another note how does one decide what sounds good/not so good during the development phase. Do you compare your product vs already commercially available DACs? Does this board allow you to make changes while you are playing music or measuring things.

Thanks.
Mike

[Karsten]

Mike,

It is of course important to establish a baseline by evaluating as many different converters as possible, which i have done. The preprototype has been intensively modified over a very long period of time in order to make the right component choices etc., once this was done satisfactory these experiences could be merged into the real prototype.

I spoke to the designer who did the component level design today, he was actually quite surprised about how well it measures. When the measurements are held up against the Fourier transform, it actually measures a lot better than previously stated. This is clearly audible.

Karsten