+1 - It also means that I can abandon the idea of building a new PSU.
MDAC First Listen (part 00100001)
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+1 - It also means that I can abandon the idea of building a new PSU.
travelfotografe
pfm Member
Hi John, I understand that the rear panel is hard pressed for space. The original design (as on the wiki) was for a 4Way Female XLR balanced headphone connection:- 1 left +, 2 left -, 3 right +, 4 right -, (Shell Ground), which is sort of an unofficial standard used by many headphone amp manufacturers. I guess since you are going with a miniXLR, may as well use a 5-pin connector for a proper pin to be used for ground, and to revert to the standard where output is male XLR.
In case if space miraculously appears for any of the miniXLR to be upgraded to full-sized XLR, please consider the balanced headphone out.
Leon
fred sonnen
pfm Member
I can not judge this. John can it for sure. It's just struck me.
I like the idea of dropping Bluetooth from MDAC2 L2. I prefer as simple as possible DAC without any unnecessary and possible disruptive elements. The attenuator is a must though. That is why I am planning to go for L2 instead of L1.
JohnW
pfm member
Admittedly I know little abut Linux, but I would have thought that almost all embedded system operate with Linux - Flash Media just appears as a data storage device no different to HDD / SDD, the system cares little about the physical form of the Drive.
Again, its purely down to software - are you certain the Linux cannot support DIFF files (it would be very odd, as its just a basic file type).
A standalone CD solution would be a totally different design mechanically and electrically from a Streamer solution - for a CD solution we would use the Metal body Car Mech, while for the streamer we would use a "Laptop" type drive just to extract the data.
Yes indeed this is the case, however HDMI is part of the module - already pre licensed.
jamjar784
Heavy Up
John,
As the L4 design is to be repackaged could you please consider including the 20dB attenuation into the L1 design? Am I right to think the costs/features ATM are (for Toy/Fusion MDAC owners):-
- MDAC2 L1 £250-300 FPGA filters, dual ESS9018, RCA AV bypass, XLR headphones, Toy resistors, DSD/DXD (embedded PCM), galvanically isolated USB Audio Class 2 up to 32bit/768kHz
- MDAC2 L2 £400-450 L1 + DSP, bluetooth, 20dB attenuator, advanced clock, ASRC free SPDIF
- MDAC2 L3 £550-600 L2 + DSD/DXD ADC, preamp/RIAA EQ, USB wireless, word clock/video clock sync
- MDAC2 L4 £??? streamer
For MDAC owners with no previous upgrade + £300 development costs.
Did you mean bluetooth and wireless functions will be removed from L2 and L3 and be added to L4?
Many thanks
JohnW
pfm member
Leon,
Yes your totally correct on all points - personally I'd prefer the full size XLR just to make life easier - but really there is just no height clearance between the PCB layers to have connectors mounted above each other (on each board) - if space allows, I'm also considering mounting a separate shielding layer between the boards on the higher end versions - the full size XLR's pretty much butts against the above mounted digital PCB.I've placed the Analogue output XLR's at each end of the PCB - so that the digital board is mounted between them...
JohnW
pfm member
Tony,
I hope to use the transformer from the 8200MB's that's about all... the design will use DNM's 4 pole TCaps in the PSU section.
Yes, the design will include full OPS protection - it has too otherwise I'll have blown units returning back from all 4 corners of the world...
JohnW
pfm member
JamJar,
The analogue attenuator is costly on the BOM (extra relays, PP film Caps and Vishay Bulk foil resistors), its already going to be exceeding hard to meet the cost target for the L1 unit - and please also consider that I need to live, it costs time & money to develop these features - you can plainly see how much time I've spent developing this project
JohnW
pfm member
The Advanced clock option of the L2/L3 is also significant in SQ terms.
JohnW
pfm member
Agreed - it really doesn't matter how the DSD is package, so long as it remains bit accurate.
JohnW
pfm member
Just to be clear here - its ME who's first suggest that Bt / USB streaming might be dropped from L2 / L3 - only because they would be duplicated on the streamer - and having multiple 2.4GHz transmitters within the same confined area is not a good thing - No decision has yet been made - I like the idea of BT streaming / Wireless USB - if space allows (and cost come within budget).
Yes, I liked the idea of an integrated solution (single box) - but looking at the rear panel space and I'd have to remove almost all of the "standard" digital I/O's to mace space for the Streamers I/O ports that it would effectively cripple the DAC in "standard DAC mode".
The MDAC chassis is the limiting factor.
Also the streamer would have required a separated external PSU, this can be integrated into the streamers chassis.
Maybe at a later date we can combine both units into a single larger chassis, a little like Lego, owners could transpose there internal boards and PSU into this new Chassis.
fred sonnen
pfm Member
Are you saying you will offer a streamer / Cd- Transport (with a laptop type drive) and the MTRN (with Metal body Car Mech)?
Or is the MTRN dead with upcoming Streamer / Cd-Transport?
JohnW
pfm member
Ok, but Bluetooth is not, I suppose.
Bluetooth was there to add a rudimentary method of streaming to the MDAC2 in this modern world... it was never going to be HiFi! Now with the option of the streamer we can do the job correctly.
I still like the idea of the Wireless 44.1KHz USB (I'd rather have this option then the BT if one had to go) as the Wireless USB would be bit accurate (44.1Khz 16 bits) so at least it can be considered HiFi
JohnW
pfm member
MTRN would be dropped if we released the streamer - there would be little cost difference between them, each would extract the Data Bit perfect.
I'd rather spend our resources developing the chassis tooling on a streamer + optical drive then just a CD unit, the CD would have no advantages over the streamer.
fred sonnen
pfm Member
OK, I can understand you decision regarding MTRN <-> Streamer.
and the Streamer / CD-T is running with the MDAC2 master clock?
But what's about the "Metal body Car Mech" you seams to be proud of.
fred sonnen
pfm Member
;-)
I know what this "Metal body Car Mech" is for.
Because of that I asked if John will drop this high class mechanism for a cheap laptop mechanism?
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