Non Oversampling DAC-complementing CD-PRO

[Elso Kwak]

Originally posted by fedde
I just did an experiment again. I took my
old DAC and added a 7806CV and a switch. I can quickly switch between 5V and 6V now (3x1k). The second regulator is a 7805CT. BTW: does anybody know what the best 78xx's are !?

Hi Fedde,
The MC78T05 has better specs. It is a 3 Amp. regulator in a TO-220 package from Onsemi (formerly Motorola). Used in the digital supply of my Philips CD-650 I did not hear a improvement though

[jcarr]

I do find that the 78xx and 79xx regulators from various manufacturers measure somewhat differently. They also appear to possess distinctive sonic personalities. Sonically, rather than attempting to play audio cowboy and stating categorically that one is better or worse, I find it much more productive to match up the regulator to the circuit based on the sonic compatibility and total sonic results.

For example, on one previous occasion, blind testing revealed that a Motorola 78xx regulator (TO-220 package) sounded considerably less desireable for a specific application than any other 78xx regulator chosen for the test (including Toshiba, JRC, Mitsubishi, National Semiconductor models and so on). I believe that I ended up choosing a National Semiconductor regulator as sounding the most subjectively pleasing for this particular application. But for a different application, the most subjectively pleasing regulator could very well be different.

hth, jonathan carr

[jkeny]

I don't want to take this thread in another direction altogether but I tried to post a new thread and all I got was a message to do a search - any help?

Now that a number of people have purchased the CD PRO module maybe some of you can answer a number of questions I posted a long time back 04-06- 2002
http://www.diyaudio.com/forums/show...p?threadid=3022

about trying to mod a Marantz CD4000 (same as Phillips CD713, 723) into non oversampling mode by

- using computer linked to CD4000 running DSA software (available on Daisy laser site http://www.daisy-laser.com/download.../dsaprogram.zip) which should allow reading DSA commands from CD4000 and sending DSA commands to CD4000 thereby changing sampling mode to whatever is liked I2S, Sony 16 bit, Sony 18 bit and whatever oversampling is liked non, 2 times, 4 times. I tried this software and only partially succeeded in getting it to read data coming from CD4000 - couldn't write anything to CD4000. Has anybody since tried this software? Could be an interesting tool to test various modes and sampling rates provided DAC chip is capable of interfacing with these modes.

OR

- a second way of achieving the same objective (and possibly better permanent solution) was to buy the display module from Homeoptics which If I remember correctly has various jumper settings which allow the user to set modes and sampling rates ( am I correct here?). Only problem for me was Daisy (Nico) does not sell display module seperately, he will include extra display modules with CD Pro purchases and this may well be an avenue worth looking into if there is any interest.

I am launching this out there to see if it floats

[jkeny]

Sorry, maybe my information just posted is out of date? Do Homeoptics supply the same display module as is specified on Daisy-Laser site? http://www.daisy-laser.com/display_tn1.htm


If so then the user can control the mode and sampling rate by the use of jumpers on the display pcb as per the following:
http://www.daisy-laser.com/downloads...nslmk39901.pdf

I find this of interest in a number of ways for experimenting with easy selection of different modes I2S, EAIJ and different sample rates 1 times (non), 2 times and 4 times oversampling.

Anybody know about this?

John

[RichardJones]

Hey, is anyone going to answer my question to that resistor before the LM431's?

gggrrr...

[Peter Daniel]

This resistor has to be calculated according to current draw of the circuit, were voltage drop is a difference between pre regulated voltage and regulated voltage.

[Peter Daniel]

Originally posted by jkeny

- a second way of achieving the same objective (and possibly better permanent solution) was to buy the display module from Homeoptics which If I remember correctly has various jumper settings which allow the user to set modes and sampling rates ( am I correct here?). Only problem for me was Daisy (Nico) does not sell display module seperately, he will include extra display modules with CD Pro purchases and this may well be an avenue worth looking into if there is any interest.

I am launching this out there to see if it floats

I've built the display board but didn't see any jumpers to set sampling rates. Maybe it's done in a software?

[jkeny]

Peter,
that's a pity the Daisy-laser site has the following info http://www.daisy-laser.com/download...anslmk39901.pdf which specifies this way of working.

Have you tried to downlaod DSA comms software to communicate via PC with your CD and modify the modes/sampling rates this way? http://www.daisy-laser.com/download.../dsaprogram.zip)?

John

[Cobra2]

The display-unit for the "PRO" ( http://www.daisy-laser.nl/homeoptics/ ) is not the same as this: http://www.daisy-laser.com/display_tn1.htm.

And you will not be able to buy it as a private...
(or anything on the http://www.daisy-laser.nl site...)
exept the "kit" on these pages: http://www.daisy-laser.nl/homeoptics/

Arne K

[RichardJones]

So... If I use 6v batteries to power the CS8412, TDA1543 and 74VHC74..

and use LM431's on all power/gnd combo's... what value of that initial resistor should I use?

Should I use 2x 1K resistors across the LM431's like in the schematics?

Thanks!!!!

I'm slightly confused as the output voltage is dependent only on those 2 1K resistors according to the datasheets.. Not that initial series resistor.