Tír Na HiFi

jkeny wrote:but the real heart of the devices is a Xilinx chip - in the case of the Musiland, it's a Xilinx FPGA & the HiFace, it's a Xilinx CPLD.

Hi jkeny,
Very interesing work.
Just out of curiosity, is is possible to change the hardware internals of the FPGA's by redoing the RTL, synthesis, etc etc? Perhaps access to that sort of stuff is prohibited by the device.

Dave

DaveF wrote:

jkeny wrote:but the real heart of the devices is a Xilinx chip - in the case of the Musiland, it's a Xilinx FPGA & the HiFace, it's a Xilinx CPLD.

Hi jkeny,
Very interesing work.
Just out of curiosity, is is possible to change the hardware internals of the FPGA's by redoing the RTL, synthesis, etc etc? Perhaps access to that sort of stuff is prohibited by the device.

Dave

Sorry Dave, I don't know what RTL,etc is? BUT the asynch USB drivers are proprietary & no source is available. I presume you could use JTAG to read or write to the FPGA? Are you experienced in this sort of area?

jkeny wrote:

DaveF wrote:

jkeny wrote:but the real heart of the devices is a Xilinx chip - in the case of the Musiland, it's a Xilinx FPGA & the HiFace, it's a Xilinx CPLD.

Hi jkeny,
Very interesing work.
Just out of curiosity, is is possible to change the hardware internals of the FPGA's by redoing the RTL, synthesis, etc etc? Perhaps access to that sort of stuff is prohibited by the device.

Dave

Sorry Dave, I don't know what RTL,etc is? BUT the asynch USB drivers are proprietary & no source is available. I presume you could use JTAG to read or write to the FPGA? Are you experienced in this sort of area?

RTL is a special coding language used to describe how a synchronous or asynchronous digital circuit operates. Most digital design starts off this way.
You could use Jtag to access certain areas of the FPGA but I'd say it would be just basic register access, however as regards altering the internal digital cicuitry, you'd need the vendors tools and licensing. I've used FPGA's plenty of times in my work.

Oh meant to say John, I can see the linked pics here at home no prob. Couldn't see them in work, miust have just been network crap in work. We OK here anyway so no need for me to repost them I think....


Fran

John what sort of mods are you doing with the Squeezebox? Maybe it's time I dissembled mine :)

DavidMc wrote:John what sort of mods are you doing with the Squeezebox? Maybe it's time I dissembled mine :)

I'm modding the SB Receiver (one half of the Duet product). First off, let me say this sounds pretty good straight out of the box so I'm hoping for great things from it. The planned mods at the moment consist of:
- tapping the I2S signal & feeding it to a different DAC (ESS DAC) - this is done already
- removing the noisy 3.3V switching regulators & replacing with a direct 3.3V feed from battery.
- feeding the 11.289MHz clock (or an external clock) directly to the Xilinx CPLD

There may be others that I discover but these are the areas I'm interested in. If I was interested in improving SPDIF output I would do some other mods but I'm using I2S. If you need any help give me a shout.

I've done the second mod to this Squeezebox receiver
- removing the noisy 3.3V switching regulators & replacing with a direct 3.3V feed from battery.

No great leap in sound so I'm hoping the clean low jitter clock will bring it to the level of the HiFace's finessed sound.

jkeny wrote:I've done the second mod to this Squeezebox receiver
- removing the noisy 3.3V switching regulators & replacing with a direct 3.3V feed from battery.

No great leap in sound so I'm hoping the clean low jitter clock will bring it to the level of the HiFace's finessed sound.

just out of interest....

(I think my transport/dac may be about to commit hara-kiri...!!)

what files are you playing....??

I am thinking of heading the hd route as I am going to upgrade my pc soon, so I'll have a spare which I can use as a server and then airport to the rest of the house....

so something like a hiface + beresford dac could be a good budget route (how do they compare to the wee chinese usb dac/amp do-hickeys....

jaybee wrote:

jkeny wrote:I've done the second mod to this Squeezebox receiver
- removing the noisy 3.3V switching regulators & replacing with a direct 3.3V feed from battery.

No great leap in sound so I'm hoping the clean low jitter clock will bring it to the level of the HiFace's finessed sound.

just out of interest....

(I think my transport/dac may be about to commit hari/kari...!!)

what files are you playing....??

Do you mean 16/44 or 24/192? I'm doing all my sonic evaluation using 16/44 WAv files on PC - Herbie Hancock, The Joni Letters to be exact. A great test of low level retrieval of a DAC & some beautiful songs & sax playing! I have some 24/96, 24/88, 24/176 & 24/192 files which I have played about with but well recorded 16/44 is as good as the 24/192 I have.

I am thinking of heading the hd route as I am going to upgrade my pc soon, so I'll have a spare which I can use as a server and then airport to the rest of the house....

so something like a hiface + beresford dac could be a good budget route (how do they compare to the wee chinese usb dac/amp do-hickeys....

The HiFace is a great kit stock BUT modded it is stupendous! I'll have to give Fran a listen soon and see what he thinks (You know modders bias is even stronger than owners bias :)).
I'm keeping the HiFace, might sell the Musiland (Chinese 24/192 excellent do-hickey), haven't decided on this one yet BUT I didn't want a PC in the listening room so am trying the Squeezebox Receiver - it has great potential :)

so does the 24/192 work like dvd upscaling to 1080....

I'd be using apple lossless as a format... or at least I have been....

spent about three days putting the mammy-in-law's cd collection onto the ipod we got for christmas!!! tiresome! so I don't know that I could face into re sampling all of my own.....