Cheap "USB DAC" M-Audio Transit + Marantz CD60

[lucpes]

Cheap "USB DAC" M-Audio Transit + Marantz CD60

Ok, I have the parts to start with (got the cdp for nothing with cold solder joints on the regs), but not much experience with delicate digital stuff, will report as I progress through.

M-audio transit in the attachment

The marantz has TDA1541A and SAA7220 so it should be pretty straightforward.

Could you please give me your ideas? Mine are remove the DAC from the transit, remove link to 7220 on the CDP, connect I2s lines with a short ribbon cable, make sure the ground is same on the transit and the CDP.

So from the place of the AK4584 tap the following:

Audio Serial Input - SDTI
Audio Serial IO Clock - BICK
Channel Clock - LRCK

to the corresponding pins of TDA1541A

bit clock input - BCK
WS - word select
Data Left - DATA

So LRCK -> BCK
BICK -> WS
SDTI -> DATA

is this ok?

edit: oops, could someone please move this to digital

[lucpes]

Basicly what I'm asking if I got the correspondance bewteen the I2s pins of the AK4584 and the I2s pins of TDA1541A right.

[lucpes]

Another variant which I think is correct:

Serial must be data (SDTI goes to DATA)
Serial Clock must be bit clock input (BICK goes to BCK)
LRCK goes to WS.

[lucpes]

Originally posted by lucpes
Another variant which I think is correct:

Serial must be data (SDTI goes to DATA)
Serial Clock must be bit clock input (BICK goes to BCK)
LRCK goes to WS.

Well, got it all figured out Sound is unbelievable compared to the actual cd playing or the soundcard itself.

Well, in I2s mode the TAS1020A puts out:

CSYNC->LRCK (WS)
CSLK->SCLK (BCK)
CDAT0->SDOUT1 (DATA)

These go to pins 1 2 3 of TDA1541

Remove the small smd resistors to the DAC and the 3.3 V regulator to disable the rest of the card. It's very easy to figure out which goes where if you read the datasheet for TAS1020 I2s mode 1.

Anybody knows of a way to temporarily disable the 7220? I kinda don't need it anymore

[lucpes]

note: 3.3 regulator is the small device marked 7633 not the first reg...

[soundcheck]

I'll start to tweak my M-Audio transit soon.

Did you apply any further tweaks?

Powersupply? The 5V USB must be a total mess.
Clock? I would like to run at least two switchable low jitter clocks one for
24/44.1 and one for 24/96 feeding a TAS5706..

From what I learned with my PCM27Ox a dedicated PS is key, best would
be full galvanically isolation.

Perhaps my Opticis USB 1.1 ( with teddy-reg regulated 5V on the receiver side supplying 5V for the PCM2707 via USB power ) solution might work.

Cheers

[FibCouple]

Originally posted by lucpes



Well, got it all figured out Sound is unbelievable compared to the actual cd playing or the soundcard itself.

Anybody knows of a way to temporarily disable the 7220? I kinda don't need it anymore

Hi Lucpes

Congratulations on getting that working to your satisfaction. Are you using 1020B in asynchronous mode?

For SAA7220, you can simply pull the power supply plug to your digital board or remove the chip itself if it is on an adaptor I guess.

Originally posted by soundcheck
I'll start to tweak my M-Audio transit soon.

Did you apply any further tweaks?

Powersupply? The 5V USB must be a total mess.
Clock? I would like to run at least two switchable low jitter clocks one for
24/44.1 and one for 24/96 feeding a TAS5706..

From what I learned with my PCM27Ox a dedicated PS is key, best would
be full galvanically isolation.

Perhaps my Opticis USB 1.1 ( with teddy-reg regulated 5V on the receiver side supplying 5V for the PCM2707 via USB power ) solution might work.

Cheers

Hi Soundcheck

Here are some threads from DiyHiFi.org where TAS chip in transit has been discussed & modded. Hope these help.

http://www.diyhifi.org/forums/viewtopic.php?t=958

http://www.head-fi.org/forums/f6/96-...b-chip-223478/

http://diyhifi.org/forums/viewtopic....st=0&sk=t&sd=a

The power supply will definitely help. Although, reading there using external clocks is not as straightforward.

I am also using PCM2707 in isochronous-adaptive mode but wonder if 1020B in isochronous-asynchronous will give even better quality as now the data delivery from computer will be slaved to the
external clock.

Another product called three-two also uses the 1020B with external clocks in asynchronous mode although it is more expensive than m-audio transit to wreck to get the i2s out. :-)

http://threetwo.cooper-street.com/

Please share with us how things develop for you.

Regards

Fib

[soundcheck]

Interesting. Until now I was just aware that Wavelength Audio -Gorgon Rankin is running in async mode.
AFAIK - if I recall it right he is selling his code to OEMs.

Empirical Audio is using the M-Audio as base for I2S outputs and putting in a Superclock4 afaik.

I'll followup your links.

My problem with the 2707 is that you're tight to 16bits and 48khz max. and beside that it generates awful lot of jitter.

THX

[FibCouple]

It looks like cooperstreet have just shut production of three-two dacs.

Is Steve Nugent of Empirical audio running his off ramp i2s as asynchronous? It will be intersting if a superclock can be inserted for TAS1020B.

Regards

Fib

[Mazuki]

hey lucpes,

after the USB input mod, do you have to hit "play" on the CDP in order for the DAC to work, or is it always functioning?