MDAC First Listen (Part 00101010)

[Mikas]

Yes and the title "Are the Lights On or Off?" sums it up nicely how he see the world in black and white

Things tend to be that way in the digital world.


I believe it's easy to affect analogue paths, not so with digital ones. That doesn't mean that an interference signal travelling on a digital cable, can't enter the analogue domain further down the path.

Michael

 

[Rune]

Hello Misterdog

Are you running ESLs there with nc400!?

I went to a Colleagues home on Friday and listened to his LYNGDORF TDA system. I believe it is Hypex UcD amplification based (fully active) with open back dipolar midrange, complimented by 2 x 10" woofers in the corners of room.

The Image or Soundstage was the widest I have heard, assuming this dipolar setup is much like MartinLogan ESL. The level of high frequency detail was spectacular too, blows my current setup away....however the midrange I found a bit too neutral meaning the Vocals...could almost sound a little bit 'hollow', lacking some guts or 'chest' if that's how I can describe it.

With your nCore nc400 on ESL, do you find the Vocals lacking a bit of something, at all?

Many thanks

I don't think what you heard had anything to do with the nCores but more to do with how the designer wanted the speakers to sound.
Neutral to the warm side instead of in your face treble to the bright side.

 

[ti33er]

Thanks for your opinion. Interestingly I just had a reply on DIY Forum echoing a bit of what I heard the other day. Most things I've read on the Internet about people saying they didn't get on with Class D, seems to be what I heard on the LYNGDORF TDA System.

Does anyone live near West London with nc400 amplifiers here (had no response on DIY yet); except someone in Coventry from AVForums kindly offering a demo, but still a bit far away for the meantime

 

[Rune]

Thanks for your opinion. Interestingly I just had a reply on DIY Forum echoing a bit of what I heard the other day. Most things I've read on the Internet about people saying they didn't get on with Class D, seems to be what I heard on the LYNGDORF TDA System.

Does anyone live near West London with nc400 amplifiers here (had no response on DIY yet); except someone in Coventry from AVForums kindly offering a demo, but still a bit far away for the meantime

First remember that ncores are not the same as Hypex UcD they are a never design. All Class D does not sound the same.
You can't make a conclusion that Class D is not for you based on what other people on the internet says. You have to hear it with your own speakers and preferably at home.
You also have to take into account what else you can buy for a similar money.
I suspect that some of the people that says that Class D is not for them are spending way more on their amps than the nCores so not an apples to apples comparison.
I use nCores with Dali Epicon 8 which is a big speaker and they definetely sound better than the Cyrus X300 they replaced. But maybe with less demanding speakers it could have been the other way around.

 

[downtothebone]

At the moment there is nothing to buy.

Assuming you mean
http://mdac2.referata.com/wiki/Main_Page
then there is not much there which still applies except for the sign-up and subscription info. I don't think John has made a formal announcement that this, the MDAC-2, is dead, but everybody is assuming that.

Instead, there is what promises to be a far better state-of-the-art machine, the FDAC, a full-width module in it's own signature-style case, a limited edition, though there are rumours/suggestions about a (probably much later) commercialisation of this. The FDAC is the main project for John at the moment. Nearly all the list of subscribers on the Wiki are going along with this change to the project, so this is what their subscriptions are supporting now. John has posted an outline drawing of the case and various other details, but it's hard finding them.

I don't know how many places, if any, John still has open, but I am one of the few who want to drop out of the project, so if you are interested you could take over my subscription- pm me if this sounds interesting.

There are two other active projects. One is the DETOX, a USB signal cleaner which promises to be a big improvement on the very successful Regen from Uptone Audio in California. So far as I know there are no limits to numbers for this, and there is a subscription offer on the "MDAC-2" page. The other is a state-of-the-art amplifier, the VFET, but the list may be closed for that.

Hope this helps.

Bob

Thanks for the info Bob - appreciated. No need for me to keep up with this thread anymore then ...

 

[JohnW]

Yes, I meant Detox. I using battery for laptop and as Detox also will be used with laptop, it will be nice to avoid extra AC adaptor.
Or maybe FDAC can have a output socket to power Detox, if space allows it.

The Detox will be quite power hungry, I might consider a Battery PSU as a later option.

 

[JohnW]

some of us are pushing budgets here [FDAC plus VFET]

man maths goes so far

Currently even from the premium vendor the FDAC chassis is within budget - but we still need to consider the cost of the HQ PSU, Front panel, packaging + Remote handset etc.

 

[JohnW]

I spent this weekend "prototyping" the Detox Clock / Clocklock interface with the MDAC.

I must confess there where times I cursed myself for pursuing the ideal operation with the clocklock feature... but it appears I have it working well now .

A real lash up, but nice to have solved the design issue:-

https://dl.dropboxusercontent.com/u/86116171/Detox Clock Proto.JPG

Note the Optical input floating on the left of the PCB - connected to the MDAC's clock output.

I'll tidy the lab in the morning! :-

https://dl.dropboxusercontent.com/u/86116171/Detox Lab.JPG

Now I have a working clock circuit - the heart of the design, time to design the PCB

 

[iansr]

John
I hope in due course to come over to meet you and pick up my FDAC and / or VFET amps. With a lab like that it will be very disappointing if you don't have a mass of wild unkempt hair and mad staring eyes . . . . ;-)

 

[fusion5]

I'll tidy the lab in the morning!

Looks good to me...

Great news about the clock circuit!

 

[timola]

That poor disemboweled MDAC....Horror movie cave-lab!...I'd be frightened to visit.:

Dr Frankenstein creates a new masterpiece with time....it lives!...

Thanks for the update John.

 

[ChrisPa]

With a lab like that it will be very disappointing if you don't have a mass of wild unkempt hair and mad staring eyes . . . . ;-)

You're going to be disappointed then

 

[JohnW]

With a lab like that it will be very disappointing if you don't have a mass of wild unkempt hair and mad staring eyes . . . . ;-)

Unfortunately for poor Renata that pretty much sums me up at the moment, I've been so engrossed in work I've not shaved for the past week... but today's the day!

 

[JohnW]

Heres the results of the Detox USB Clock-Lock circuit in action:-

https://dl.dropboxusercontent.com/u/86116171/USB Non Locked Clocks.jpg

In the above scope shot you can see the 12MHz internal USB clock of the MDAC not synchronized to the upstream USB Host clock (the "Blue" trace area).

https://dl.dropboxusercontent.com/u/86116171/USB Locked Clocks.jpg

Above you can see the Detox's clock-lock interface in action - where the MDAC's internal 12MHz USB clock is cleanly locked to the 24MHz USB host clock (the USB hub IC in the Detox).

The USB Clock-lock option is one of the advanced features of the Detox - but has caused me much hair pulling here in Czech!!! now finally off to wash and shave and hopefully Renata will forgive me!

 

[BigDog]

...from What's Best Forum on REGEN and JITTERBUG with John's testing being presented in comments.

http://www.whatsbestforum.com/showt...t-Jitterbug-and-Uptone-Regen-USB-Conditioners

 

[adamdea]

...from What's Best Forum on REGEN and JITTERBUG with John's testing being presented in comments.

http://www.whatsbestforum.com/showt...t-Jitterbug-and-Uptone-Regen-USB-Conditioners

Interesting. I'm rather wary of Amir, but I agree with his point that what matters is what comes out of a dac.

 

[JohnW]

Scope Waveforms of 50cm and 1.5m Platic fibre optical links transmitting a 12MHz clock, (scopetimebase 1nS/DIV).

You can see that the longer 1.5m Optical cable has about twice to three times the Jitter of the shorter 50cm cable.

1.5 meter plastic optical TOSLINK cable:-

https://dl.dropboxusercontent.com/u/86116171/1.5m POF 12MHz.jpg

50cm plastic optical TOSLINK cable:-

https://dl.dropboxusercontent.com/u/86116171/50cm POF 12MHz.jpg

 

[BE718]

Interesting. I'm rather wary of Amir, but I agree with his point that what matters is what comes out of a dac.

It seems to correlate with my experience of the regen, and my basic measurements showed additional (albeit very low level) spuria also.

Anyhow I also very much agree with the critical point being what comes out of the dac. I await with great interest to Johns measurements of the audio clock being affected by the USB crap and cleaned up by the regen/detox - and how this translates into the audio out.

 

[Purité Audio]

Interesting. I'm rather wary of Amir, but I agree with his point that what matters is what comes out of a dac.

Why wary of Amir,he has a business ,and a tie in with Harman, but his background with Microsoft, he was around when they purchased Pacific Micro.
He appears to know his stuff.
Keith.

 

[adamdea]

Why wary of Amir,he has a business ,and a tie in with Harman, but his background with Microsoft, he was around when they purchased Pacific Micro.
He appears to know his stuff.
Keith.

Do you remember the hi rez abx thing. there was a long thread on whatsbest about it. Much argument on HA. I think he knows his stuff but...I'll stick with wary. But not dismissive.