Hk Dac Pcm 1704

[mfr]

I've removed the opamps and checked the output of the DACs and it's the same - distorsion.

I've bypassed the TTL input circuit, no change.

The distorsion is low when digital input volume is very low, otherwise 99% distorsion.

?? I'm checking the pcb for errors

Any ideas?

[mfr]

There is a difference on PCB compared to schematics regarding the DF1704:

It is wired as if MODE=software but no connections to most control pins:

pins 3,4,5,7,9,10,11,12,13,15,16,17,18,27 are floating

pins 19,20 are HIGH

I wonder what the default software registers are set at. I've checked the datasheet and no mention of defaults....

[Jocko Homo]

Look on page 9......your answers are there.

Anywa, I don't think that is your problem. You could always ground pin 9 just for grins: it should operate the same way.

Jocko

[mfr]

Here is the distorted sound:

dac_distorted MP3 (465K)

Here is what it should be:


dac_source_ref MP3 (465K)

I was wrong that the bass is distorted, seems ok.

Is this digital overload or analog????

[mfr]

I can't see the default settings of the registers on page 9...

I see a table with the software registers at page 10 \, but it is not indicated what are the defaults. When the IC is left floating, what is the setup?

[mfr]

I found the problem !

The CS8414 was not configured for I2S output. This was supposed to be wired on a small carrier board which mounts on the main PCB. Thanks for the help.

The DAC sounds very good. I can only compare to CI Audio VDA1 and optional VAC1 power supply. It sounds better, soundstage much wider and accurate, qualities that CI Audio had in the top range now are present in midrange and at lower freq (dynamics, etc).

[Jarno]

Hi mfr,

I saw the DAC is now fully operational. I had a look at the DIY club site and saw they also carry pcb's for tube preamps, looks pretty interesting, good prices too. But since I haven't heard of anyone else ordering there, I was wondering what your opinion is on doing business with them (I heard shipping from Asia can be a bit "erratic")?

Thanks,

Jarno.