MDAC First Listen (part 00101011)

[JohnW]

Having sections in a copper lined Al CNC milled chassis to provide RF-Screening/Isolation much like the Detox may be a further improvement for the FDAC.....this type of design advantage could outweigh the extra production cost?....especially for the enormous number of screws this may require.

It certainly would, and I could use the Base as the heatsink for the output devices and PSU - which reduces the mechanical parts required and helps improve dissipation. Heat is radiated directly into the chassis rather then needing to rely on radiation from internal heatsinks with increases the internal operation temperature.

Last night I start to look at ways of reformatting the existing MDAC2 design around a milled base / possibly complete Chassis. The Base could be milled, and the "Covers" could be an optional cost extra cost for those wanting the very best

The Detox 'rats nest' looks scary....can't imagine what the FDAC 'rats nest' will look like....you may need to issue an R18 warning before issuing that .

The FDAC Analogue stage is a fully discrete SMD design - I've spent a couple of years designing it via Computer simulations - then direct to PCB and it worked first time

Here the original MDAC2 PCB being tested on the TDR to confirm the PCB characteristic impedance (critical for the PECL base clock distribution).

https://dl.dropboxusercontent.com/u/86116171/MDAC2 TDR.jpg

https://dl.dropboxusercontent.com/u/86116171/MDAC2 TDR 2.jpg

You can see the TDR sampling head connected to the MDAC2 PCB via Semi rigid Coax Cables - these cables are very expansive and supplied as matched pairs for this differential TDR application.

Note the ESD connection caps sitting on top of the sampling head - the Sampling head is very sensitive to static discharge, any voltage over +/- 2.5V will damage the head - the heads costed new about US$20,000 so it makes for a bad day if you damage one... still at least you don't have to tell the "Boss" :-

https://dl.dropboxusercontent.com/u/86116171/Sorry Boss.jpg

The MDAC2 Analogue PCB during testing:-

https://dl.dropboxusercontent.com/u/86116171/IMG_7261.JPG

https://dl.dropboxusercontent.com/u/86116171/MDAC2 PCB.JPG

 

[JohnW]

Price for the 2x Detox prototype bareboards is GBP220 in China bareboard PCB prototypes are supplied free by the manufacturer.

Anyway ordered and the PCB are being processed....

 

[tesox]

Hello erverbody / Hello John !
I'm a proud M-DAC owner for years and have followed this thread for the same period.
The M-DAC is the only piece of equipment that stayed in my setup all the time,
because I love it from every aspect (exept the poor quality of the remote's surface).

I listen to headphones only and as time goes by I stepped up to high-end headphones.
Along with my latest purchase (Audeze LCD-3 and auralic Taurus MKII) I realised that
there is still room for improvement and I replaced the M-DAC with an Audiobyte Black Dragon.
This DAC is really great (better) but lacks a little bit in punch and lowest level frequency
response like i'm used to from my M-DAC. I hope now that the F-DAC will keep all the
good things from the M-DAC output stage and just betters the "weak" areas.

Ok, I'll keep it short now.

I just want to know if there is a place left for me
to jump in the "F-DAC @ cost - line" by now.
(Sorry for my bad english I'm from germany)

 

[JohnW]

Recently I've been under much pressure concerning the FDAC project with PFM sponsors understandably concerned about slipping delivery schedules.

To express the development cycle I propose that we release an FDAC "Lite" based on the simplified Detox Milled Chassis concept.

The FDAC Lite is a small format simplifed version of the FDAC using the core Analogue / Dual ESS9018 DAC sections of the FWC FDAC but without its advanced DSP / FPGA features. The FDAC Lite would be a production precursor to the FWC FDAC and like the Detox we would benefit from the production line experience in manufacturing a simpler product.

As to timescales the FDAC Lite is the FDAC Analogue / DAC stages "Copy and Pasted" with an added USB interface and a pair of Optical / Coax SPDIF inputs - nothing more. The idea is to try and have the prototype completed before the New year - So production can begin in ASAP in the New Year (We will be effected by the Chinese New Year).

https://dl.dropboxusercontent.com/u/86116171/FDAC Versions 01.jpg

Development funding the same as the FWC FDAC as its basically the FDAC platform - but "Unit At Cost" will be cheaper, say around GBP150 to GBP250 Max + local Vat and shipping. This brings it price range with the original MDAC territory but for a much more advanced design.

Without the FPGA and advanced clock features it will not be a sonic competitor to the FWC FDAC - but as far as I'm concerned significantly better then products like the Mirus. I expect you will get 80% to 90% of Sonic performance of the FWC FDAC versions.

The proposed design route is to continue working on the FWC FDAC Analogue / DAC sections once they are completed then "Copy and Paste onto a smaller PCB adding the USB input (this is a couple of weeks process) and then send to manufacture. This also allows me to gain production & user experience (sonically) of the heart of FWC FDAC and gives us a fully working platform to fine tune the Vishay Bulk foil resistors etc.

I need to design the USB input for the FWC FDAC so ultimately no extra time is required due to designing the USB interface ahead of schedule for the FDAC Lite but with the added advantage we can have a smaller "Shoe Box sized" DAC with the heart of the FWC FDAC expressed into production.

Please give me your thoughts and study the FDAC series feature list.....

At the moment I'm working on the FWC FDAC analogue stages redesign.

 

[adamdea]

Recently I've been under much pressure concerning the FDAC project with PFM sponsors understandably concerned about slipping delivery schedules.

To express the development cycle I propose that we release an FDAC "Lite" based on the simplified Detox Milled Chassis concept.

The FDAC Lite is a small format simplifed version of the FDAC using the core Analogue / Dual ESS9018 DAC sections of the FWC FDAC but without its advanced DSP / FPGA features. The FDAC Lite would be a production precursor to the FWC FDAC and like the Detox we would benefit from the production line experience in manufacturing a simpler product.

As to timescales the FDAC Lite is the FDAC Analogue / DAC stages "Copy and Pasted" with an added USB interface and a pair of Optical / Coax SPDIF inputs - nothing more. The idea is to try and have the prototype completed before the New year - So production can begin in ASAP in the New Year (We will be effected by the Chinese New Year).

https://dl.dropboxusercontent.com/u/86116171/FDAC Versions 01.jpg

Development funding the same as the FWC FDAC as its basically the FDAC platform - but "Unit At Cost" will be cheaper, say around GBP150 to GBP250 Max + local Vat and shipping. This brings it price range with the original MDAC territory but for a much more advanced design.

Without the FPGA and advanced clock features it will not be a sonic competitor to the FWC FDAC - but as far as I'm concerned significantly better then products like the Mirus. I expect you will get 80% to 90% of Sonic performance of the FWC FDAC versions.

The proposed design route is to continue working on the FWC FDAC Analogue / DAC sections once they are completed then "Copy and Paste onto a smaller PCB adding the USB input (this is a couple of weeks process) and then send to manufacture. This also allows me to gain production & user experience (sonically) of the heart of FWC FDAC and gives us a fully working platform to fine tune the Vishay Bulk foil resistors etc.

I need to design the USB input for the FWC FDAC so ultimately no extra time is lost by designing the USB interface ahead of schedule for the FDAC Lite but with the added advantage we can have a smaller "Shoe Box sized" DAC with the heart of the FWC FDAC expressed into production.

Please give me your thoughts and study the FDAC series feature list.....

At the moment I'm working on the FWC FDAC analogue stages redesign.

Sorry I'm not following. Are you suggesting a new third thing which is neither the upgrade board for the Mdac. orginally proposed nor a new complete FWC dac but a new something or other dac in a new chassis?

 

[fusion5]

I think I could live with reduced feature set in my second system (on my desk). I'll give it some more thought later today.

 

[tesox]

Hi John,

I'll keep it short now. (#543)

I just want to know if there is a place left for me
to jump in the "FWC FDAC @ cost - line" by now.
(Sorry for my bad english I'm from germany)

 

[mattgbell]

Sorry I'm not following. Are you suggesting a new third thing which is neither the upgrade board for the Mdac. orginally proposed nor a new complete FWC dac but a new something or other dac in a new chassis?

That's certainly what it sounds like.

I'll be holding out for the FWC FDAC with all the trimmings.

 

[JohnW]

Sorry I'm not following. Are you suggesting a new third thing which is neither the upgrade board for the Mdac. orginally proposed nor a new complete FWC dac but a new something or other dac in a new chassis?

To much was sacrificed to squeeze the FDAC design into the original MDAC Chassis.

The proposed idea is once the FDAC Analogue PCB has been completed to "Copy and Paste" the design onto a PCB with a USB input + a pair of SPDIF inputs.

Devoid of the FDAC FWC Advance features (FPGA / DSP / Advanced Clock / Touch Screen / Digital expanse slot) Basically a "Lite" version of the FDAC it can be sent into production ahead of the FWC version for those who are nervous to wait for the FWC FDAC.

The "Lite" Version would be a "Copy and Paste" of the FWC FDAC Analogue / DAC stages so would have 80% to 90% of its sonic benefits - but cheaper and in a smaller footprint chassis - something alone the lines of the Detox CNC Chassis but larger.

In your case I think you would miss the FPGA / DSP advanced features so its not a unit for you... but then it is cheaper (the "At Cost" Build).

 

[fusion5]

John,

I'm not sure if I want to reduce my second (non slave) FWC FDAC to a FDAC lite unit as it would allow me to use slaves in my second system aswell (at a later date).

Would it be possible to get an additional FDAC lite? I could also fund one of the prototype units and a full complement of bulk foils (maximum number) to allow you search for one or two reasonable resistor configurations.

Michael

 

[JohnW]

That's certainly what it sounds like.

I'll be holding out for the FWC FDAC with all the trimmings.

I understand - I made the proposal for three reasons:-

1. Simpler design so less potential issues during production - a case of the production line learning to walk before running just like the with the Detox, the FWC FDAC would then be a "natural" progression from the FDAC Lite.

2. I'm under a lot of stress recently from certain PFM members who wish to leave the project as they "see" little progress - the FDAC Lite is a rapid route to realising a significant upgrade to the MDAC based upon all the development work on the FWC FDAC.

3. Its the heart of the FDAC design allowing us to gain experience from its performance and a fully working platform to try the Vishay Bulk foil resistors and tune the design.

I'm working on the FDAC Analogue stage - any talk of the FDAC Lite has no impact the FDAC time-scales apart from time spent posting here.

If FDAC Lite happens then its a "Copy and Paste" of the FDAC board obviously once its been completed. So the FDAC Analogue PCB comes first and once its completed we decide:-

A. Spend a couple of weeks to add a very simple Digital stage (USB port + SPDIF input) and send it to production as the FDAC Lite (I have to design an isolated USB input for the FWC verison anyway).

B. No FDAC Lite, just start working on the FDAC FWC Digital PCB with the time-scales involved.

 

[JohnW]

John,

I'm not sure if I want to reduce my second (non slave) FWC FDAC to a FDAC lite unit as it would allow me to use slaves in my second system aswell (at a later date).

Would it be possible to get an additional FDAC lite? I could also fund one of the prototype units and a full complement of bulk foils (maximum number) to allow you search for one or two reasonable resistor configurations.

Michael

If its deemed a sound idea to proceeded with the FDAC Lite then Yes

 

[JohnW]

Hi John,

I'll keep it short now. (#543)

I just want to know if there is a place left for me
to jump in the "FWC FDAC @ cost - line" by now.
(Sorry for my bad english I'm from germany)

Yes, we have spaces open(ed) on the FWC FDAC project and would happily welcome you to join the project

 

[fred sonnen]

Hallo John

From my point of view the lite will delays the FW FDAC quite some month.
* You have to develop the PCB, case, ectr.
* You have to organize producing, shipping, ectr.
* You will have to answer and discuss o lot of questions with / from customers.
* ectr.
perhaps there is a market for the lite. but please after the release of the FW FDAC....

 

[tesox]

Yes, we have spaces open(ed) on the FWC FDAC project

Hi John,

thank you for the good news.
I've done the payment.

I think the final options like color and features will be clarified
when the production date is foreseeable?

Stephan

 

[JohnW]

Hi John,

thank you for the good news.
I've done the payment.

I think the final options like color and features will be clarified
when the production date is foreseeable?

Stephan

Stephan,

Thank you - Welcome to the project.

The production will be split into 3 stages (Thus allowing you to spread the "At Cost" payments):-

1. Analogue PCB January / Feb 2016 2016 (Subject to Chinese New Year disruptions)

2. FWC chassis January / Feb 2016 (Subject to Chinese New Year disruptions)

3. Digital PCB Late April 2016 (Once completed the units can be shipped).

Hopefully this will be OK or we can reverse your Payment?

 

[JohnW]

Hallo John

From my point of view the lite will delays the FW FDAC quite some month.
* You have to develop the PCB, case, ectr.
* You have to organize producing, shipping, ectr.
* You will have to answer and discuss o lot of questions with / from customers.
* ectr.
perhaps there is a market for the lite. but please after the release of the FW FDAC....

Apart from the Copy and Paste PCB design from the FWC FDAC, the idea would be to offload the balance to Dominik in China so I can return to the FWC ASAP.

 

[fred sonnen]

Apart from the Copy and Paste PCB design from the FWC FDAC, the idea would be to offload the balance to Dominik in China so I can return to the FWC ASAP.

Are you sure regards past and copy.
It's you, JohnW. Was there ever a simple solution for you?
;-)

 

[AndyU]

Any chance of balanced XLR outputs on the lite? And would there be a remote control?

 

[tesox]

Stephan,

Thank you - Welcome to the project.

The production will be split into 3 stages (Thus allowing you to spread the "At Cost" payments):-

1. Analogue PCB January / Feb 2016 2016 (Subject to Chinese New Year disruptions)

2. FWC chassis January / Feb 2016 (Subject to Chinese New Year disruptions)

3. Digital PCB Late April 2016 (Once completed the units can be shipped).

Hopefully this will be OK or we can reverse your Payment?

This is absolutely ok John!
I'm in no hurry. I just want a final product wich is as good as possible.
I'm happy to be part of the project now.