A nice dac to complement the Aleph-X.

[vit]

Is it possible to use the D1 output stage with a pair of pcm1794 running i mono mode?
The pcm1794 is a stereo dac with differential current output (–7.8 mA p-p)
pcm1794

[audiodesign]

Someone could sell me some PCM1704 and DF1704 ?

A. Ciuffoli
www.audiodesignguide.com

[hifimaker]

Digikey has a big selection:

http://www.digikey.com/scripts/DkSea...S&Cat=32899746

-David

[tiefbassuebertr]

Originally Posted by Nelson Pass

What is interesting about the D1 I/V (besides it being the
only part of the circuit I participated in) is that it simply
cascodes the output of the DAC, the output being a current
source looking for a virtual ground. Thus, it contributes
almost no noise or distortion, and is unbelievably immune
to high frequency (RF) modulation and has no feedback
(just for sex appeal).

Why didn't anybody think of this before? Hell if I know.
It is an obvious thing in retrospect, but nobody seems to
have picked up on it. I blame the educational system for
cranking out "digital only" design engineers.

This question I also ask myself. Even by the successor of PCM63P/1702, the PCM1704 I don't find in commercial products like DENON such an I/U stage.
Only still integrated OP-AMP solutions I know.
In this case this URL's are of interest:
http://members.chello.nl/~m.heijlige...alogue/IV.html
http://www.dddac.de/pcm63/DAC_I-V_Resistor.htm
also the AES paper
"Current-steering transimpedance amplifiers for high-resolution
digital-to-analogue converters" (M.O.J. Hawksford)

BTW - what I must consider, if I want to combine your IV topology with the PCM1704 ??

[samoloko]

Originally Posted by pquadrat

This is the PCB.
The project was more a "proof of concept" and a test if I can get it running, not to be the ultimate DIY DAC. But i tried to use most information and tips I found, except about special oscillator circuits. Just one thing at a time

Short description: optical receiver TORX176, receiver TI DIR1703 switchable between coax and optical input, next step is the Analog Devices AD1896A Sample rate converter to upsample to 96kHz. It feeds the TI DF1706 digital filter to drive four PCM1704 DACs for balanced output. I/U Conversion is PASS D1.
Voltage regulation for digital part (3.3V, +- 5V) is on board, +-30V for output stage has to be supplied. I use one of my ONO power supply boards, which gives a nice regulated +-30V.
There are two errors in the layout. one trace between the two rectifier bridges has to be cut, and I forgot to place the output caps of the D1 stage. But otherwise it seems to work nice, and it sounds fine.
-Peter

would anyone post schematic ?