Pro-ject DAC Box DS DAC

Stepping into the Pro-ject room in the Venetian I spied an entire wall of little boxes--literally dozens of them. Norbert Schmied, from the company's US representatives, Sumiko, handily pointed me toward the DACs and Streamers.

New to CES this year is the company's DAC Box DS in a small compact package and retailing for $549. Features include 24/192 SPDIF, Toslink and async USB as well as PCM-1792 Burr-Brown DAC and 2 filter options.

labjr's picture

Their web site says it uses the PCM-1792 DAC. Doesn't say if it will handle Native DSD.

JasonVSerinus's picture

I don't believe Jon's blog implies that this DAC handles DSD.

labjr's picture

I wasn't thinking the blog implied that it did. Just wondering if native DSD is gonna be possible with this?

There are so many companies making DACs now. It wouldn't be a bad idea to include native DSD decoding as an added feature, whenever possible.

Jon Iverson's picture


parzab's picture


If objectively to speak, to design, the software driver and digital part of the DAC I have no claims.
But after "Pro-Ject DAC Box DS" purchase, I long time it wasn't happy with sound quality.  The sound of a DAC corresponded to average Chinese boombox, instead of HighEnd to equipment.

The study of the diagram of analog part of a DAC showed that developers stupidly copied the diagram from datasheet of PCM1792.
Nominals of details are given in datasheet for theoretical demonstration and don't consider real optimum operation modes of operational amplifiers (OA) for the maximum sound quality.

It was necessary to make some modifications:
1. I replaced OA NJM2068 (JRC) on AD823A are much more better;
2. I replaced nominals of details round the operational amplifiers -
     a). replaced resistors in I/V-converter from 750 Ohms on 470 Ohm;
     b). replaced resistors from I/V to the buffer from 560 Ohms on 6,8 kOhm;
     c). replaced buffer negative feedback resistors from 270 Ohms on 6,2кОм and
     OA AD823 began to work in the stable mode Kg=0,912 (almost=1);
     d). replaced capacitors in Low-Pass filter from 2700pF on 220pF.

3. On an output of a DAC I added the T-shaped filter from cable radio aimings with a cutoff frequency is set: f = 331,6kHz. (R7,R8 = 24 Ohm, C9 = 10 nF).

As a result of these modifications sound quality improved very strongly and acquired level of elementary HighEnd.

The diagram of modifications for downloading: