MDAC First Listen (part 00110100)

[kosmonova]

"Welcome" to PFM with our first post

The MDAC USB is an "Input device" so it does not provide power to the external devices.

Thanks for your reply John and compliments for the great product! I have been a happy Mdac owner since 2013, using it with a Squeezebox Duet. I am looking for a different streamer and the chromecast is actually not that bad (and very user friendly). Unfortunately it only has Spdif out and it's output has been measured as quite jittery.

 

[JohnW]

We are just working on an internal "streaming" solution for the MDAC2 which is "jitter free" by being clock-lock to the DAC's Master Clock.

 

[JohnW]

jirij,

We just ordered an RPi3 for you and the CM1 modules ahead of the MDAC2 Stage2 PCB

Jarek can drop off the RPI3 to you end of the week when he returns to Brno.

 

[JohnW]

I might just stick with MDAC2 if FDAC does not have direct CD playing capability and if the Audiolab CDT is clock-locked to the MDAC....

http://www.superfi.co.uk/p-16323-au...anthid=33169&gclid=CP_Q1rjLltECFUHGGwod52oIJA


John, would you recommend this? The visual match and the possibility of using just one remote makes it tempting. If it is indeed clock-locked it is a no-brainer.

GBP400 for a CD drive is alot of money - you could purchase many replacement slot loaders for the FDAC if they where ever needed.

 

[Steven Toy]

GBP400 for a CD drive is alot of money - you could purchase many replacement slot loaders for the FDAC if they where ever needed.

I would trade in my Rega Apollo.

In any case, I think the M-CDT has been discontinued as I can't find a seller anywhere.

 

[jirij]

I would trade in my Rega Apollo.

In any case, I think the M-CDT has been discontinued as I can't find a seller anywhere.

Don't forget that FDAC will also have that SPDIF RAM-based buffer (was it 3-4 seconds?), so if you don't need audio synced with some video, you could use that and get rid of PLL, no clock-lock needed. It's not a perfect solution (as in - the clocks might drift over super long sessions / songs), but it's still good.

 

[adamdea]

Yes unfortunately Audiolab did not add an external clock input on the MCDT - a missed opportunity

Is there anything in its design which differentiates it from an ordinary CD player with the dac taken out?

 

[highfi]

John whatever happened to that cd mechanism that you had designed for use in another manufacturer's player (a car slot loader I recall)? If I remember correctly you intended to use it in FDAC.

 

[misterdog]

He put it back in Renata's car...

 

[JohnW]

Is there anything in its design which differentiates it from an ordinary CD player with the dac taken out?

Well:-

1. No Display

2. Matches the MDAC

3. Not Clock-Locked

I've not seen inside a unit but I doubt it even has a clean clock reclocking the SPDIF output - with this clock then fed back to the CD servo chipset - apart from matching the MDAC I don't see its advantages.

 

[JohnW]

John whatever happened to that cd mechanism that you had designed for use in another manufacturer's player (a car slot loader I recall)? If I remember correctly you intended to use it in FDAC.

It used in the Creek CD player we designed - but its expensive and I dont trust its long term availability.

Its also very tall - and only CD. with the Sata drive bay on FDAC we can have a CD / DVD / Blueray reader / recorder...

Apparently a few drives can even read certain SACD disks.. but not sure how that would work with Linux...

 

[jirij]

Its also very tall - and only CD. with the Sata drive bay on FDAC we can have a CD / DVD / Blueray reader / recorder...

Also DVD-RAM, which is a block device exactly like a HDD (you can read/write files freely), has several error-checking layers and supposedly long durability (designed for archival purposes) and can be read/written on any recent (~8 years) optical drive, so you can easily copy files on it from a PC. Ideal for those wanting physical CD-like media with the convenience of HDDs.

Apparently a few drives can even read certain SACD disks.. but not sure how that would work with Linux...

I've never seen such drives. There was some Vaio laptop advertised with SACD playback, but IIRC it was something like DSF files on a DVD.

As far as I know, one could read the SACD metadata with a custom drive firmware, so any programmable drive should be able to do it assuming somebody writes the seeking/reading software for it as the decoding key is (again, AFAIK) stored between some tracks or in track imperfections (read errors) or something.

Personally, I don't think there's benefit in ripping SACDs as the vast majority was probably mastered in PCM. Could be worth it if the masters are better than regular redbook CD ones, though.

edit: The HDCP master key has been cracked in ~2010 (won't post link here, just in case), so all you need now is the encrypted 1bit stream from the disk and you can software-decode it. Also, it's not only PS3 that can do it.

 

[cstanpfm]

Well:-

1. No Display

2. Matches the MDAC

3. Not Clock-Locked

I've not seen inside a unit but I doubt it even has a clean clock reclocking the SPDIF output - with this clock then fed back to the CD servo chipset - apart from matching the MDAC I don't see its advantages.

Hi John, below is the internals of the CDT from the web.

 

[Rune]

It is almost 2017 I can not believe that I just read that some of you want to be able to burn CD/DVD from your FDAC
Now files is transferred/backed up to the Cloud, USB drive and NAS.
Why because 8GB DVD or even 25Gb that a Bluray can hold is is just not enough when you have a TB of music.

And then why from the FDAC when it is much easier from the UI of a computer.

It is fine to be able to play CDs, but that is it.

 

[EIffel]

Wow, this thread is moving fast! I'm wondering how JohnW can keep up, let alone progress the project and have (a bit of) a normal life!

I must say that I like the latest developments, and the move towards a modular approach on the PSU and optional RPi/streamer/display controller board, for instance, as well as the use of the CM3 for better software support. This should help as the 'finish line' is approaching.

I'm still in for the VFET/FDAC combination, but having a basic MDAC2 as a first installment (with the ability to add features over time and ultimately to convert it to a slave unit in a FDAC like case) will keep me entertained come Munich. I "still have" my MDAC Toy L3 to listen to when I'm not reading this thread ;-)

Now for my questions/suggestions?
- Some of us paid for 'salvaged' MDACs. Would it be possible to use these units as donors for the MDAC2?
- I think we need a wiki to keep track of all the hardware options being contemplated for the various devices, their specs, costs (dev+boards) and sequencing, as this is getting quite complex, despite the elegant modular approach (the AV bypass and ability to 'upgrade' the chassis of the MDAC2 to something similar to the FDAC are examples of options which I value but which get lost in some discussions... and I won't talk about the VFET variants such as the IV bridge )

 

[Ian M]

It is almost 2017 I can not believe that I just read that some of you want to be able to burn CD/DVD from your FDAC
Now files is transferred/backed up to the Cloud, USB drive and NAS.
Why because 8GB DVD or even 25Gb that a Bluray can hold is is just not enough when you have a TB of music.

And then why from the FDAC when it is much easier from the UI of a computer.

It is fine to be able to play CDs, but that is it.

I haven't played a CD for about 2 years. Things are moving on and since we will probably not be seeing an FDAC before 2018, I certainly don't want a CD drive in it and don't want to see a slot where one might go.

 

[Jason_PFM]

It is almost 2017 I can not believe that I just read that some of you want to be able to burn CD/DVD from your FDAC
Now files is transferred/backed up to the Cloud, USB drive and NAS.
Why because 8GB DVD or even 25Gb that a Bluray can hold is is just not enough when you have a TB of music.

And then why from the FDAC when it is much easier from the UI of a computer.

It is fine to be able to play CDs, but that is it.

+1

12 TB NAS, with 6 TB of music, lots of hi-res.
Never going back to disks again


I feel like a tremendous amount of time is wasted on trying to integrate boards, streamers, OS'es.
While there have been many external WORKING solutions for years !
No wonder there's nothing released after +3 years.

Apple remote on iPhone;
https://www.dropbox.com/s/n7pnlb11cnm1b5x/Playing.jpg?dl=0

 

[Rune]

I haven't played a CD for about 2 years. Things are moving on and since we will probably not be seeing an FDAC before 2018, I certainly don't want a CD drive in it and don't want to see a slot where one might go.

It is hardly a deal breaker and remember that there are many that only trust physical medias

All my CDs are ripped and stored on my NAS and last time I burned something to a disc was at least five years ago.

+1
I feel like a tremendous amount of time is wasted on trying to integrate boards, streamers, OS'es.

I disagree.
The merger of DAC and streamer is the future. It is a natural progression.

 

[misterdog]

. I certainly don't want a CD drive in it and don't want to see a slot where one might go.

So to some the inclusion of a CD drive is a deal breaker.

Yet to some (possibly less than 5) not having a CD drive is a deal breaker.

The joy of design by committee.

 

[jirij]

I guess the CD drive, if anything, highlights that FDAC is/was meant to be a sort of universal toolbox. Because IMHO ripping can be much better done on PC where the software can ie. download album cover from the Internet, upload the result to one's cloud drive or whatnot, whereas FDAC will have presumably limited ripping features. Similarly, the 9.5mm/12.7mm drive is somewhat "brittle" and harder to use than a top-loader where you just place the CD without effort, so it's presumably not targeted at people who play 20 CDs a day. So what's the point?
Well, if you have a fully streaming based setup and a friend comes along with "hey, play this CD" and you got rid of all computers with a CD drive a decade ago, ... or if you just ADC'd a live recording and want to distribute a copy of it at the venue, you can burn a few raw recordings, without needing a computer.

Granted, those are "corner cases" for some, but so is the HDD/SSD inside the FDAC (you can always have a NAS with better features, RAID, etc.), the streamer module (you can always tape an ARM board of your choice to the back), AV bypass (you could make an external box with a relay hooked up to the 12V trigger), DSP (separate clock locked box would be more flexible / upgradeable), etc.

The point is that even if I dislike the "one box" approach as it, by design, will always be "worse" than single-job components connected together (look at those printer/scanner/fax/etc. multifunction devices), I respect the designer's choice and as long as the DAC portion of it is top notch, I don't care too much.

I'll still do my best to help the project(s) as I presume others have use cases for some of the features, but I doubt I'll use them personally day-to-day. Wanting a single box with exact features tailored specifically to my needs would be a bit selfish, wouldn't it?