MDAC first listen (part VII)

[Krisposs12]

You should really find the root cause of the "Buffer Flushing" are you using Apple hardware?

Could be software or hardware settings - others have reported success by enabling USB 3.0 mode in Bios... odd, but who knows what changes at the firmware level...

John

Thanks John. Am using a PC with Windows 7 64-bit. I do have USB 3.0 enabled (some of my drives use it) - not sure what's causing the buffer flushing but will investigate further.

Do you think once that's sorted I should reflash the M-DAC with the 0.99 firmware? I would have thought if everything seems to be working that the flash went OK...

Thanks
Krisposs

 

[JohnW]

Thanks John. Am using a PC with Windows 7 64-bit. I do have USB 3.0 enabled (some of my drives use it) - not sure what's causing the buffer flushing but will investigate further.

Do you think once that's sorted I should reflash the M-DAC with the 0.99 firmware? I would have thought if everything seems to be working that the flash went OK...

Thanks
Krisposs

No need to reflash - if the MDAC is functional then the software update is OK...

John

 

[jonstatt]

I just got left channel crackle with the latest 0.99 unfortunately.

I was doing a bitperfect test with a Sonos on COAX1 (which worked and passed), and then after I dropped out of the test mode, the crackle was there.

 

[JohnW]

Hi Ben,

I'll talk with Dominik - we can fix the AC3 bypass mode (Digital output).

John

 

[desp_erado]

Hi Ben,

I'll talk with Dominik - we can fix the AC3 bypass mode (Digital output).

John

Thanks John.

It's weird as the PS3 (also optical) is fine passing AC3 through the MDAC and the Virgin box used to work fine before 0.99.

If you need any extra information from me, let me know.

At the moment, this minor inconvenience is completely obscured by the nice change to the SQ 0.99 brought!

Ben

 

[Krisposs12]

No need to reflash - if the MDAC is functional then the software update is OK...

John

Thanks for your help again John. I think the increased sibilance might have been in my head, I listened to the same sources through my Asus Xonar STX and noticed the same "increase" in sibilance. But since my coaxial digital output comes straight through the STX into the M-DAC and passes the bitperfect test it can't be a genuine issue. Of course, it could just be my headphones sounding a little brighter than they did this morning, but it seems to be a red herring overall.

I also switched to a different USB port when investigating the buffer issue with USB sound (I was using 2.0 before and am now using 3.0) - so far no issues so hopefully that problem's solved.

Also tried switching the Polarity setting from its default of "non-inverted" to "inverted" but cannot tell any difference - what might you expect here anyway?

Best regards,
Krisposs

 

[JohnW]

Thanks for your help again John. I think the increased sibilance might have been in my head, I listened to the same sources through my Asus Xonar STX and noticed the same "increase" in sibilance. But since my coaxial digital output comes straight through the STX into the M-DAC and passes the bitperfect test it can't be a genuine issue. Of course, it could just be my headphones sounding a little brighter than they did this morning, but it seems to be a red herring overall.

Give time for the MDAC to run-in... From cold and new it can sound hard and less organic until it "Warms Up" and the Organic Caps??? bed in...

I also switched to a different USB port when investigating the buffer issue with USB sound (I was using 2.0 before and am now using 3.0) - so far no issues so hopefully that problem's solved.

Good - the second time that I've heard USB3.0 compatible port / Mode has solved the issue...

Also tried switching the Polarity setting from its default of "non-inverted" to "inverted" but cannot tell any difference - what might you expect here anyway?

Best regards,
Krisposs

No I'd hope not, but second order effects (differences in Data processing patterns) might have changed the sound. The Phase Inverts feature was requested by a PFM owner... so we added it, even though I do not believe there will be a difference in SQ due to the system "phase" - although second order effects could be possible.

John

 

[Krisposs12]

Give time for the MDAC to run-in... From cold and new it can sound hard and less organic until it "Warms Up" and the Organic Caps??? bed in...



Good - the second time that I've heard USB3.0 compatible port / Mode has solved the issue...



No I'd hope, but second order effects (differences in Data processing patterns) might have changed the sound. The Phase Inverts feature was requested by a PFM owner... so we added it, even though I do not believe there will be a difference in SQ due to the system "phase" - although second order effects could be possible.

John

Interesting... thanks for the explanation.

My M-DAC will be getting a lot of use so should run in nicely before long!

Best regards,
Krisposs

 

[gh0st]

Hi JohnW,

Could I trouble you to clear a few PM spaces? I'm upto a certain point with my PSU build and I've got a couple of Qs

Cheers /dom

 

[JTC]

Really impressed with 0.99. "Apostrophe" never sounded so master-tape like - I honestly could hear things I'd only ever heard through cans. Really impressive. I wonder how much more is left to be 'eeked' out of the source though...

 

[arthur]

Hi Authur,

What Software version or you using? Press the Knob during power-up...

You only need to change inputs and back to solve the issue (No need to reset).

We believe the latest V0.99 solves the issue (No Feedback yet to the contrary...),

John

Hi John. Mine is virgin fresh from out of the box.

I'm loath to mess with software as it frightens me just less than a heart attack

I'll do all the upgrading stuff with the Lakewest release. With my eyes closed and a candle lit and touching wood and stuff

Still looking forward to the Mpax. Saved enough now. Woohoo!

 

[AndrewR]

Thanks for your help again John. I think the increased sibilance might have been in my head, I listened to the same sources through my Asus Xonar STX and noticed the same "increase" in sibilance. But since my coaxial digital output comes straight through the STX into the M-DAC and passes the bitperfect test it can't be a genuine issue. Of course, it could just be my headphones sounding a little brighter than they did this morning, but it seems to be a red herring overall.

I also switched to a different USB port when investigating the buffer issue with USB sound (I was using 2.0 before and am now using 3.0) - so far no issues so hopefully that problem's solved.

Also tried switching the Polarity setting from its default of "non-inverted" to "inverted" but cannot tell any difference - what might you expect here anyway?

Best regards,
Krisposs

You may find that USB is better than the soundcard. I had been using an XONAR D2 coaxial output and then used async USB and the difference was very noticable.

Andrew

 

[Dominik]

Hi John,

I've noticed one small thing that may/may not have anything to do with the new firmware, but it was working before. I use the MDAC to handle all digital signals and run a SPDIF coax cable from it to the surround processor. However, on my optically connected Vigin box, HD channels, when the sound is AC3 and the MDAC displays "Encoded bitstream", I get no sound at all. When I switch to a SD channel which is straight stereo, it passes that through fine. I've tred fiddling with the jitter corrrection settings (medium is best to avoid dropouts on this input), but no difference.

My PS3 is on the other optical input and that works fine though and the MDAC is passing through the bitstream.

Any ideas?

Ben

Hi Ben,

It seems your Virgin box flags the S/PDIF as invalid and in turn your M-DAC zeroes the data in the frame. You are right, this behavior changed since the shipping version v0.90. Please run the update bellow which will ignore the validity flag in S/PDIF and pass everything through unadulterated:

http://db.tt/G7qcFuVt

Dominik

 

[desp_erado]

Hi Ben,

It seems your Virgin box flags the S/PDIF as invalid and in turn your M-DAC zeroes the data in the frame. You are right, this behavior changed since the shipping version v0.90. Please run the update bellow which will ignore the validity flag in S/PDIF and pass everything through unadulterated:

http://db.tt/G7qcFuVt

Dominik

Hi Dominik,

That worked a treat, many thanks!

Will future versions have this e.g. the Lakewest builds (is it safe to include it?) or will you be able to have it as an option?

Once again, many thanks for the very speedy resolve!

Cheers,

Ben

 

[JohnW]

I just got left channel crackle with the latest 0.99 unfortunately.

I was doing a bitperfect test with a Sonos on COAX1 (which worked and passed), and then after I dropped out of the test mode, the crackle was there.

The only good news you can tell me is that the crackle started directly after the Bit perfect test?

If this is so, then that's great as the "ESS Left Channel Locking" counter-measures are turned off during Bit Perfect testing due to MCU overhead limitations...

John

 

[JohnW]

Hi John. Mine is virgin fresh from out of the box.

I'm loath to mess with software as it frightens me just less than a heart attack

I'll do all the upgrading stuff with the Lakewest release. With my eyes closed and a candle lit and touching wood and stuff

Still looking forward to the Mpax. Saved enough now. Woohoo!

Dont forget for full protection you also need to stand in a circle with a cross in the middle

 

[JohnW]

Really impressed with 0.99. "Apostrophe" never sounded so master-tape like - I honestly could hear things I'd only ever heard through cans. Really impressive. I wonder how much more is left to be 'eeked' out of the source though...

I suspect quite a bit more

BDAC BDAC BDAC.... MPAX MPAX MPAX...

Your falling into the HiFi trap

But interestingly you also confirm my suspicious that 0.99 sounds better?

John

 

[JohnW]

John, when the MPAX+"MDAC tuning" option is available, would it be possible to also lower the output level (balanced) of the DAC?

Yes, the MPAX will have a 12dB, 24dB, 36dB stepped attenuator controlled directly by the MDAC.

The attenuator section is then buffered facilitating a low impedance drive to the power amplifiers - this extra buffering stage is optional (via the MDAC Menu).

John

 

[jonstatt]

The only good news you can tell me is that the crackle started directly after the Bit perfect test?

If this is so, then that's great as the "ESS Left Channel Locking" counter-measures are turned off during Bit Perfect testing due to MCU overhead limitations...

John

It was indeed directly after the bit perfect test. I haven't heard it at any other time yet.

 

[jonstatt]

But interestingly you also confirm my suspicious that 0.99 sounds better?

John

The problem is, you said you thought it sounded better, so now it maybe a mass hysteria that we have all convinced ourselves it sounds better. When it comes to audio you can never downplay too much the relevance of psychoacoustics including the influence of others and simply things like your own mood at the time. Unfortunately there is no easy A/B comparison possible unless we had two MDACs with different firmware.