Hiface 24/192k USB to spdif converter

[jkeny]

I'm listening to this through HD650 headphones directly connected to the ESS DAC's outputs, no caps, etc needed (the ESS DAC outputs 2V rms with no voltage bias). Everything sounds wonderful right through the frequency range - very much like we heard on the QUAD ESL 989 speakers last night. The datasheet recommends a load >5Kohm but is not complaining with the HD650's impedance of 300ohm.

The vol in foobar cannot be turned up full as it's painful but I can't help think that digital vol control is not the best idea in the world (it doesn't seem to have any detrimental effect here, maybe because the system operates in 24bit mode even on 16bit material?).

But my idea to kill two birds is to put a nice LDR vol control (fixed 27kohm R + shunt LDR) on the Vouts of the DAC bringing the DAC within it's comfort zone & dispensing with digital vol control.

Shane, I don't know the Caiman so I can't answer you

Edit: BTW, the HiFace & ESS DAC both handle 24/192

[lovejoy]

Hi Shane,
I haven't taken the mods to my HiFace as far as jkeny has - I'm just supplying a clean +5V via a modded USB cable to save modifying the case of the HiFace. I am feeding a Beresford DAC and the vast majority of my material is 16/44.1 standard Red Book.

I can tell you that even with my less elaborate mods, they are most definitely worth it. The standard HiFace is a good piece of kit and I bought one evaluating it without any mods against the optical output of my Mac, but just applying a clean +5V takes it into another league altogether.

I would bet that jkeny's mods take that a fair bit further again, which makes me sorely tempted with them. The problem is, at the moment I am enjoying the sound too much to contemplate parting with the HiFace for any amount of time ;-).

[UV101]

but just applying a clean +5V takes it into another league altogether.

Didn't someone famous once say 'when listening to music, you are really listening to the power supply'?

If they didn't, i'm saying it now

[jkeny]

Hi Shane,
I haven't taken the mods to my HiFace as far as jkeny has - I'm just supplying a clean +5V via a modded USB cable to save modifying the case of the HiFace. I am feeding a Beresford DAC and the vast majority of my material is 16/44.1 standard Red Book.

I can tell you that even with my less elaborate mods, they are most definitely worth it. The standard HiFace is a good piece of kit and I bought one evaluating it without any mods against the optical output of my Mac, but just applying a clean +5V takes it into another league altogether.

I would bet that jkeny's mods take that a fair bit further again, which makes me sorely tempted with them. The problem is, at the moment I am enjoying the sound too much to contemplate parting with the HiFace for any amount of time ;-).

Yes, your bet is a guaranteed winner

There are 3 areas that the ps is critically important - the clock supply (3.3V), Xilinx IO supply(3.3V) & DIT IO supply(5V) - all these handle the clock signal. Changing the 5V supply, gives a cleaner feed to the on-board switching regs which supplies the 3.3V & directly supplies 5V to the DIT. I have fed 3.3V directly & independently to the clock & Xilinx IO & then tapped off I2S & it sounds incredible because the on-board clocks are low-jitter custom made MEC clocks (I checked with Marco & the specs are good) & all they needed was a clean supply to shine.

On another front, I'm amazed at the ES9022 DAC's performance as a headphone driver - this thing seems to only begin to show any audible distortion at <100ohm load impedance

[jkeny]

A brief write-up on a listening session from a local audio meet http://www.tirnahifi.org/forum/viewtopic.php?p=318#p318

[jkeny]

i have boxed up the modded Hiface - here's some preliminary pics of it:
Boxed unit contains 2 batteries, modded Hiface & connectors specified below. It's about the same dimensions as an iPhone but thicker
Front shows USB in connector
Back shows BNC out, On/Off switch, socket for charger

[jkeny]

I've set up a basic web-site for this:
Home (Hiface Mods)

[jkeny]

Latest review of my modified Hiface http://www.head-fi.org/forums/f7/rev...hiface-483900/
Abstract

jkeny described the sound of the modified Hiface as similar to that of expensive analog and I couldn’t agree more: his modified Hiface make the other converters sound broken.

Personally, I have already asked jkeny if I could send him my stock Hiface to have a similar mod done to it.

[jkeny]

I now have a version of the modified Hiface for feeding I2S to Buffalo or AckoDAC digital inputs see here: DAC Options (Hiface USB Transport Modifications & Ancillaries)

[jkeny]

I've just had a report back from someone who bought a battery from me to test it against highly regarded commercially available & freely available regs & the battery is noticeably better.

He's running these regs on the AVCC of a Sabre DAC (we all know these are sensitive to PS quality). They are operated form a heavily filtered supply which is fed from a 1KVA isolation transformer - so a serious PS.

He said the change to battery was clearly better & noticeable within seconds but also became more obvious with extended listening.