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MDAC first listen (part VI)

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fred sonnen said:
??
did you mean that a tuner is made by software?
did you forget the cinch or xlr output?
Click to expand...

The tuner uses an ADC on the IF strip + DSP, it achieves pretty much state of the art RF performance.

Its a spin-off from an earlier project we worked on, it costs very little to add to the BDAC so we did... I suspect its performance will surprise a lot of people, It Uses the BDAC's DAC stage for Audio. Basically for free, so why not...

The BDAC has both RCA & XLR outputs.

John
 
JohnW said:
I've spent about 3 months developing the BDAC's PSU, Audio & Clock circuits. These circuits are based upon topologys we have been using within our lab over the past years...

Based upon simulations results and experiences from the past - the latest circuit topologys should bring a leap in SQ...

HOWEVER:-

The BDAC uses the budget DAC's from ESS where we cannot bypass its internal "Fast" Digital filter... However we can Pre-Process the input Data with DSP, and we are hopefull to reduce the impact of the ESS's poor sounding internal filter.

We are also using two DAC's IC's in Dual Diff, this has in the past resulted in a significant leap in audio quality over single substrate DAC's - maybe due to internal Clock modulation between channels?

On cost grounds we are also forced to use Bipolar transistors in the input Diff stages of the analogue stages in place of the MDAC's JFET's - however I've optimised the circuit topology for Bipolars and the latest CROSSII uses MOSFET's in its output stage...

The BDAC clock also has 20dB to 40dB lower clock phase noise at LF advantage over the MDAC..

With so many advances over the MDAC, and some handicaps - it will be interesting to "hear" the final results..

John
Click to expand...

Fair enough. I guess I was more concentrated on the use of a more lowly DAC chip

I'd be really interested in what your 'statement' design would be like :)
(although I do like the value for money of your recent offerings)
 
Attempted update to 0.96 firmware failed ...

I've just, at long last, attempted updating to 0.96 from 0.90, using a Windows 7 64bit desktop. Closed down all software in sight. Connected MDAC, which was recognised. Ran MDAC updater. Command line window announced 0.96 update, and MDAC recognised ... and then "Cannot acquire handle." And that's it.

Any ideas, please?
 
Clerenlas said:
Attempted update to 0.96 firmware failed ...

I've just, at long last, attempted updating to 0.96 from 0.90, using a Windows 7 64bit desktop. Closed down all software in sight. Connected MDAC, which was recognised. Ran MDAC updater. Command line window announced 0.96 update, and MDAC recognised ... and then "Cannot acquire handle." And that's it.

Any ideas, please?
Click to expand...

I've forwarded you post to Dominik and will await his reply.
 
JemHayward said:
I use a EMU 404 USB DAC/ADC as a standalone ADC - I use a custom linear PSU, and connect to the MDAC via optical, and although I hate to say it, feeding my Naim prefix through the EMU to digitise it to 24/96 and then using the MDAC to change it back to analogue, which seems a pretty daft thing to do, has resulted in the best sound I've ever had from vinyl.
Click to expand...

Interesting Jem! Do you still get all that vinly sound or does it come across as a digital source?
 
JohnW said:
The BDAC has an AV Bypass so you could connect a Phono Pre that has an output level control - we could make one with Creek..

John
Click to expand...

John do you fancy making a simple switch and attenuator? 1 XLR input, 1 RCA input and 1 XLR output. Let the XLR input bypass fully balanced. RCA with a balance converter and volume controlled?
 
Sebbyp said:
John do you fancy making a simple switch and attenuator? 1 XLR input, 1 RCA input and 1 XLR output. Let the XLR input bypass fully balanced. RCA with a balance converter and volume controlled?
Click to expand...

MPAX with additional full range attenuator option!
 
JohnW said:
Why not Squeezebox Touch?

John
Click to expand...

I already have the Marantz and the macmini.....

I found this app on the appstore, which works well with the marantz (better then marantz own app) ...

8 Player

works for any DLNA player.... for $5 .. I'll use it now.... I like the airplay functionality of the Marantz for 'quick sessions' ...
 
bigmarcelo said:
I already have the Marantz and the macmini.....

I found this app on the appstore, which works well with the marantz (better then marantz own app) ...

8 Player

works for any DLNA player.... for $5 .. I'll use it now.... I like the airplay functionality of the Marantz for 'quick sessions' ...
Click to expand...

User friendliness is an issue with many streamers.
I can only echo John's suggestion. I've been using Squeezeboxes since 2005. Recently I tried Sonos but that player was boxed again after a month usage. The Squeezebox system beats everything out here in terms of users experience. The SB Touch / M-DAC combo works like a charm and can compete with many expensive streamers (due to the sound quality of the M-DAC). Highly recommended!
You could always sell your Marantz.
 
Sebbyp said:
John do you fancy making a simple switch and attenuator? 1 XLR input, 1 RCA input and 1 XLR output. Let the XLR input bypass fully balanced. RCA with a balance converter and volume controlled?
Click to expand...

Converting Single-ended to balanced without transformers requires active circuity, this starts to complicate the unit - also you should activity buffer the output of any attenuation to drive cables and power amplifiers correctly.

Might as well design the MPAX...
 
JTC said:
(just kidding)

So, am I on the list or not, Mr John?
Click to expand...

Hi JTC,

The pre-order list is variable - we are getting so many pre-orders now that will will increase our initial production batch(s) - something I did not want to do in case we discover issues once the first batch has been shipped.

But we are gaining more experience with the design platform, and gaining more confidence with the design - even at this early stage.

So don't worry, I'll insure you get a MPAX / MAMP's if your still interested when they are finally launched :)

I can say the casework looks really cute,

John
 
Hi John,

Was wondering if my PM got through to you , or are you still clearing the back log?

Regarding the BDAC, can both XLR and RCA outputs be used simultaneously?

i'm also curious about the differences between BDAC and MDAC, performance-wise. The BDAC's ess 9023 is capable of 112 DNR theoretically, and comparing this to the 133 DNR of the 9018, how will the 9023 perform better? Of course DNR and on-paper specs aren't the be all end all, but technically the 9023's a lower spec chip, ain't it? If you could put in the same improvements for the BDAC, into a new 9018-based DAC, would the 9018 DAC be better? I'm guessing that would be reserved for the statement lakewest stuff? :D

You also mentioned that the BDAC's clock phase noise performance is better than the MDAC. Forgive me if i'm mistaken, i thought the higher quality clocks tend to be more expensive and am wondering how you achieved that since the BDAC's a much cheaper product. That's quite impressive indeed!
 
liszt said:
You also mentioned that the BDAC's clock phase noise performance is better than the MDAC. Forgive me if i'm mistaken, i thought the higher quality clocks tend to be more expensive and am wondering how you achieved that since the BDAC's a much cheaper product. That's quite impressive indeed!
Click to expand...

I agree, quite an improvement.

I assume the performance improvement is a result of lowering the noise of the power supply for the clock circuit, or improving upon the oscillator circuit if it's a discrete (overtone, 70-110 MHz ?) design.

Any chance John, a capable DIY would be able to get the same improvement on his own MDAC, maybe by means of an upgrade kit with instructions ?
 
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