I kinda had to know if it had random bits of point-to-point wiring inside.

Ayre is in Colorado, thought maybe Charles Hansen went Mikhail!

Pretty sure whatever disease Mikhail has is only transmitted sexually... so we can safely conclude that it won't make it past him.

Weird that they used solder mask on one and not on the other.

I dunno, it's hard to tell if there is a solder mask when FR4 isn't used, which seems likely here. I'm assuming stencils were used for the SMT stuff, so I'm betting there is some sort of solder resist layer.

Is the unmodded dac not passive i/v?

Is the unmodded dac not passive i/v?

By "unmodded" do you mean pre-production?

Production board looks great. Is that a fully discrete output stage? Nice!

By "unmodded" do you mean pre-production?

I meant the dac in the more recent pictures. Justin hypothesized the first pictures were of a "modded" unit so I just repeated that, shrug.

Damn I love me an FPGA.

I wish I could buy those PRP resistors

I wish I could buy those PRP resistors

Can't see anything out of the ordinary in the pic. What's so special about those PRPs?

1/8w from the looks of them which can't be bought anywhere.

I now want this DAC.

What DAC chip is it using? I think I can make out PCM1796?

Andrew if you have the unresized photos could you attach them to a new post? (IIRC there is no size limit to photo attachments)

Edited July 4, 200917 yr by deepak

It is the 1796. I'll post a link to the Flickr set with the full-size images when I get home.

Can't see anything out of the ordinary in the pic. What's so special about those PRPs?

They are the .1%, 25 PPM/C versions:

http://www.prpinc.com/pdf/Audio_PR9372_Series.pdf

"Available in small quantities"....perhaps a group buy is in order?

Here you go, Deepak.

This attachment thing is cake. How come I never bothered to learn to use it before?

Edited July 4, 200917 yr by Hopstretch

Thanks, can't wait to hear this too!

I now want this DAC.

Heh! You want all DACs.

A couple of pages ago he said he wasn't as interested anymore because it was USB input only.

I guess after she was stripped naked he fell in love again. Can't blame him.

he wasn't as interested anymore because it was USB input only.

... me neither...

I guess after she was stripped naked he fell in love again.

... ME TOO

At last a discrete, really balanced, output stage. If only she had SPDIF input... it's just me who likes she had more than one input to play with?

If this had just one more input (BNC please!), I would stop dreaming about the Berkeley and buy this... but based on the layout with the USB receiving circuitry on its own board, which I would assume sends I^2S to the main board............. well it probably isn't impossible to design a S/PDIF input board! switching boards to switch sources would be pretty tedious however. Monseigneur Hansen... are you listening?

Monseigneur Hansen... are you listening?

Suspect so. I emailed back and forth with Ayre a while ago asking if they were considering a universal player/DAC combo. The answer was no, but we will probably eventually have a high-end stand alone DAC, though it will cost a lot more than the QB-9.

A couple of recent tidbits on the QB-9 upgrade path from Charles Hansen. Just on the off-chance anyone else is interested.

The QB-9 is a modular design that has a separate input board for the USB receiver. The TAS1020B is limited to USB 1.1, which can only handle up to 192/19. Nobody uses that, so to reach 192/24 we will have to change to a new USB receiver. This will probably be available by the end of the year. Don't forget that 192 kHz requires Class 2 USB Audio (not the same as USB 2.0), which currently is only supported by OS X. The initial release of Windows 7 will not support Class 2, but MS will probably add it in a Service Pack after a year or two.

Anyway, Gordon (Rankin) is looking at various receiver chip options now. It will require many months of time to port the code over and then add the Audio Class 2.0 capability. (Instead of just "frames", Audio Class 2.0 allows "sub-frames" for greater data transfer rates.) Replacing the board will probably be 5% - 10% of the cost of the unit, with a grace period for recent purchasers.

So this information appears to imply for pc audio folks it is better to wait until 1Q 2010 or for me then it appears the Metric Halo/ Sonic Studios 302 may be the path to take for now.

I remember seeing a 24/192 USB recently...forget where, unfortunately...recent issue of Absolute Sound, which had a thing on USB DACs? Will look later.