MDAC first listen (part XVIII)

[jirij]

As an A.08 long-timer, I can quite clearly recognize the difference - made me realize how my MDAC sounded right after purchase - rather bass-light, but clean. And I once again prefer OS over OTXD (it was the other way around on A.08). Right after trying out the new firmware, a thread called "mdac in, bass out" flew through my head.
Not that it's a bad thing, the soundstage is certainly wider and perhaps there's more "control", I also happen to own "bass light" AKG K702 headphones, so I guess I get what I deserve.

Overall - it's a welcome change, because it's a change. I was really getting tired of my favorite tracks sounding always the same.
Also, I have a feeling that this kind of music taste will be more ideal for MIMP with Monitor Audio Bronze BX2 as some find them too bassy.

And I'm not really a bass-centric kind of guy.

Dominik, thanks for the effort.

Also, I'd like to add one strange thing.

On songs with a significant beat (to be exact - "Now Or Never" by "Outasight" for example, some poor quality but still usable sample available on youtube), the A.90 appears to shift the beat a few milliseconds behind, causing the song to sound "slow". I have an arcam rpac here, which doesn't seem to have that characteristic and MDAC with A.08 had the same flavor.
Was anything done about the pre/post ringing? Could some elimination of pre-ringing lead to this kind of artifact (and reveal an "incorrectly" done mix)?

No blind testing done so far, but "it's somewhat slow" was one of the first things that "hit" me.

Tested with both AKG K702 and AKG K240 MKII (headphones). OS/OTXD filters don't appear to change that behavior.

edit: maybe it's just a different bass characteristic that confused me and not a timing issue of a wider band, though you're welcome to do any measurements

edit2: after listening to more higher quality instrumental tracks, the extra soundstage does wonders and if there's ever a "should we go A.08 or 0.90 way, sound-wise" decision, I'd add a humble +1 for 0.90 as this seems to be a style specific to MDAC and therefore gives it a personality

 

[Sonic_D]

Welcome

What CD player are you using as a transport? - sounds like its not Bit accurate!

John

Thanks for the response. Apologies should have said, it is a Cambridge Audio 740C. I thought that might be the answer, will try burning again or finding something to compare with I guess. It still sounds great, but not quite as good as the USB. Although I recognise without the clock sync the CD will not be jitter free like the USB.

 

[Elviz]

I downloaded the new firmware and i think it is just great! Especially the Optimal Spectrum filter seems to get my attention much more than before. I think it has more depth than before. It used to sound a bit more flat. Now it is a very good option against the OT filters. These are just my first observations...

Very nice release. Thank you Dom and John!

 

[flognuts]

+1 for the A0.9.

 

[JohnW]

I have a bit of a strange situation going on here that is not exclusive to version A.90, which I think I know the cause of, but will mention here for your perusal. Don't hate me, but I am an optimal spectrum fan. I personally find it the most dynamic, and yes it is bright, but aged 25, I am able to enjoy that higher frequency response ;-) Anyway, the issue I am having is almost certainly not the fault of the M-DAC but certain selections on the M-DAC appear to totally eradicate the problem that I am having. Essentially, the issue that I am having is only replicated when the optimal spectrum filter is in use with the appropriate nominal frequency sample rate and bit depth input matched to the music that I am listening to (exclusively through USB). The problem I am experiencing is sharp clicking noises of varying intensity and duration during playback through my Quad 77 integrated amplifier, usually when the bass of a track kicks in. If I change any of the above conditions, i.e. the filter/macbook bit depth+sample rate output/or even slide the digital volume (effectively altering the bit depth) this issue is non existent. Actually, if I take out the Quad77 out of the equation and just use my headphones, there is no issue. So as far as I see it, the amplifier is at at fault, but why? Just to add, this issue is only replicated with a certain number of tracks as well. My only guess is that certain transient peaks seem to play havoc with the amplifier. If I increase the amplification on the Quad77, this also seems to alleviate the problem too, I.e. as far as I see it, the clicks are of a fixed amplitude when the symptoms are presented. I know that with the appropriate remote control for the device, one can change the input sensitivity on the Quad77 and I'm hoping this is the solution but I cannot test that since I do not have access to such a remote unfortunately. If this isn't the solution, I have to admit that I am quite clueless here.

Harry,

This is certainly an odd issue - one I'd certainly like to understand - if only out of interest as to understand what's happening!

Couple of things spring to mind – maybe the amplifier’s input stage is being overdriven by the MDAC’s output level – or maybe Hi-Levels of Low or even High frequency energy is upsetting the amps input stage…

Have you tried with the MDAC set to -1dB, (I'm presuming you are using the amplifiers level control)?

If reducing the MDAC’s output level resolves the issue then it’s the input stage of the amplifier unable to cope with the MDAC’s output level (its about 2.3Vrms “Peak”)…

 

[lapkwan]

I'll confirm with Dominik - maybe he's trying to test us all!!!

*I often Ask Dominik "double blind test me" - unknown to me he would swap the filter names etc - Then I'm greatfull to find I'm not going crazy or imagining things...

The forum here flares suddenly with the coming of the new fw A.09, natural enough. I haven't tried the new fw yet but I feel I cannot agree with John more that blind test and blind comparison are actually required, at least for all responsible guys who want to post their comparison results in this forum. For the sake of pursuing something really good for us, I strongly recommend blind test (or make it blind in your own way) for all of you please!

 

[JohnW]

Thanks for the response. Apologies should have said, it is a Cambridge Audio 740C. I thought that might be the answer, will try burning again or finding something to compare with I guess. It still sounds great, but not quite as good as the USB. Although I recognise without the clock sync the CD will not be jitter free like the USB.

Ebays your friend for really cheap CD players you can use as a decent transport these days

 

[DANOFDANGER]

After most of the day to compare this is how i feel.

A.09 has these quality's
Tight+louder bass
Vocal expressions more noticeable and comforting
cymbal and shaker a-like sounds more clear and less harsh

But after extensive listening i found myself finding a flaw which i cant put my finger towards, only thing i can try and label it with would be some sort of smearing which is affecting my listening comfort and is actually causing some heavy fatigue. When switching back and forth it becomes more noticeable and find myself more relaxed and comfortable with original 0.90.

Update.
I might have narrowed down the smearing to the optimal transient filters, i dunno what it but OS seems to be much different which i dont think it should.

Update 2. I think the OT filters are broken lol, the mids are really woolied and sounds like the source of the smearing. Just seems to big of a difference between OT and OS, i used to enjoy OT in all previous firmwares.

 

[fusion5]

Thanks for the response. Apologies should have said, it is a Cambridge Audio 740C. I thought that might be the answer, will try burning again or finding something to compare with I guess. It still sounds great, but not quite as good as the USB. Although I recognise without the clock sync the CD will not be jitter free like the USB.

Have you tried disabling the upsampling on the 740C?

 

[sq225917]

You can't disable the asrc on the 740, though its spdif out will be very clean you may not like how asrc sounds

 

[finesensations]

Hi All

Changed from vA.05/OT DD to vA.09/OT DD last night and mainly listened to TV and some 'Later' recordings.

Now listening to radio (LBC).

First impressions:

Sibilance more noticeable and sometimes on the edge of being acceptable.

Overall sounds a little lighter/thinner.

Bass lighter.

Need to play louder (+3dB ish) to get an acceptable sound balance.

I'll try some music I know well and update later.

 

[JTC]

Could it be that the sibilance was always there and you're just hearing it more clearly? I find TV can be a touch sibilant (via optical into MDAC) which I put down to a slight emphasis on the HF to make it easier to hear people talking. Just an idea.

 

[lapkwan]

What's sibilance?

 

[finesensations]

Could it be that the sibilance was always there and you're just hearing it more clearly? I find TV can be a touch sibilant (via optical into MDAC) which I put down to a slight emphasis on the HF to make it easier to hear people talking. Just an idea.

Using A.05, sibilance was there in differing amounts but was handled well in that it didn't sound overblown, but sounded natural, and didn't draw it to my attention.

Just tried A.09/OT DD with some Dave Brubeck,via Grooveshark, and from memory it does sound a little thinner and instruments have less body and sound more 'toy-like'.

In a different system it could sound different/better but atm in my system it doesn't sound as good overall as A.05/OT DD.

 

[sq225917]

sibilance- over emphasis of 'S' sounds in singing.

 

[WAD62]

Just tried A.09/OT DD with some Dave Brubeck,via Grooveshark, and from memory it does sound a little thinner and instruments have less body and sound more 'toy-like'.

In a different system it could sound different/better but atm in my system it doesn't sound as good overall as A.05/OT DD.

I'm on A.05 (however OT XD) for the same reasons as you, I prefer the extra weight/body...looks like I'll be sticking with it, although I will give A.09 an audition over the weekend.

 

[finesensations]

I'm on A.05 (however OT XD) for the same reasons as you, I prefer the extra weight/body...looks like I'll be sticking with it, although I will give A.09 an audition over the weekend.

Will be interested to hear how you get on with A.09 as, atm, I appear to be alone in preferring A.05.

 

[JohnW]

You can't disable the asrc on the 740, though its spdif out will be very clean you may not like how asrc sounds

Not good the SRC cannot be disabled...

BTW your MDAC arrived this morning

 

[JohnW]

Does the phase invert function actually do anything in this release (ISTR it was introduced as an experimental means of comparing something to do with software-related sonic changes)?

I ask because toggling it seems not to change the sound in the slightest in this release.

Well you can trust your ears - but now you have confirmed to yourself the effects of LIM (Logic Induced Modulation). LIM modulates the internal Clocktree and thus crosses the Digital to Analogue domain. LIM is basically PSU related Die modulation.

On earlier versions the DATA was inverted before the Digital filters (thus the Digital filter logic which forms a significant area of the DAC die (You need to consider there are 8 individual Digital filters) process the data "Inverted") - while on the latest release the Data is flipped directly at the DAC Array output "elements".

The Human ear is incredibly sensitive - the differences are not measurable directly on the audio output with standard test (apart from the Phase Inversion) and yet they are audible - this is what makes HiFi design so challenging.

John

 

[sq225917]

Not good the SRC cannot be disabled...

BTW your MDAC arrived this morning

Thanks John let me know how much I owe you for return postage once it's ready to ship. let me know if you need any more of those op-amps as well.