Seems this is similar to that Pro3a:
[url=http://www.head-fi.org/content/type/61/id/1440506/]
Compare others:
Pro3a:
U8:
U12:
Audio Breeze:
HYDRA Z:
I dont see same oscilators(gold pieces)
On the Pro3a types
Ok so to bring you up to speed - this was covered some 50-60 pages ago. There are different Crystal clocks for the retiming of the audio signal. The gold colored ones and really the relabeled silver ones in the Gustard - are OEM rebrands of the JYEC TXCO (temperture controlled crystal osc). These are better then the old standard XO Fox type clocks. The best TXCO clock (IMO) is made by Crystek and they have various models - the Hydra and Tanly use the CCHD-957. Very close and in some ways better clocks from Japan are produced by NDK with again various models the NZ2520SD being the best. Modders like Alex have modded the U12 and MX-U8 using these NDK clocks, as posted previously here (and see Alex's Melidous MX-U8 Thread).
These clocks for audio purposes are measured in many ways - one of the most common specs given is for 'Phase Noise'. Back many, many pages I gave the links to some engineering white papers discussing the various types of digital jitter and noises. It also goes into the technical limits of test equipment to measure phase noise at low frequencies. Another is freq stability (the TXCO beat the older XO here) with var in the +/- 1ppm range (excellent!)
http://www.silabs.com/Support%20Documents/TechnicalDocs/Clock-Division-WP.pdf
The clocks in the U12, MX-U8 and the Audio Breeze are all the JYEC type OEM with phase noise at
1kHz of -125dB and 10kHz -128dB
The NDK NZ2520SD TXCO
1kHz -153dB and at 10kHz -158dB
The Crystek CCHD957 (45.1584Mhz):
1kHz -153dB and at 10kHz -163dB
Now remember dB is a log function - so each -3dB is 10x better. So we are talking orders of magnitude better phase noise with these better clocks.
Now the DIYinHK board you show is a different one.
That board is for i2s output and is designed to piggyback off a DACs 3.3VDC ps. The DIXO Pro 3a is spdif only - both coax and optical. It's a plug and go set-up with the ultra low noise regulator on board.
It'll take a 5VDC feed - and I have had huge success feeding my Hydra Z with this Li Ion 16,000mHa battery (even the dynamics improved - bass added another 1/2 octave lower!). So like the 5VD fed Hydra the DXIO would be able to use this battery as well. I do have two different TeraDak linear power supplies coming - one with an R-core transformer and very heavy power filtering and linear regulation. To use in comparison.
http://www.ebay.com/itm/331547668930?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (2amps - 3.6 amps peak! This sucker has juice) $24 - not bad.
Here are the specs for the DIXO Pro 3a
Feature:
1) Newest XMOS chip and uses 48MHz oscillator to asynchronous reclock usb audio data to SPDIF line, old XMOS uses only 13Mhz oscillator, over 4x better jitter rejection theoretically.
2) C0G AC coupling capacitor (All SPDIF output equipment requires AC coupling capacitor to avoid the isolated transformer saturated by DC bias component, if no grey color(C0G) capacitor is found in the PCB, that SPDIF equipment can be considered as low end)
3) Ultra low phase noise NDK NZ2520SD oscillator, thin film resistor and Murata isolated transformer (Be care the very common China made Pulse transformer in many 192khz SPDIF equipment is only capable of maximum 7Mbps(i.e. 96khz) according to the official datasheet.) Components are sourced from NDK and digikey directly (guarantee no fake product from China)
4) 1.0uVrms Ultralow noise linear power regulator (use of decade old LM317/1117 regulator is kidding for audiophile)
5) Solid ground plane (a must for high speed digital circuit)
6) No Via in active circuit (via inductance always create jitter problem)
7) Compact size 25mmx 59mm x 63mm
8) PCB can be USB powered or auto switch to external power 5-6V when connected(Please notes over-voltage can damage the component immediately, any modification void item warranty) External power socket has LED shows which power supply is in use. The external power socket uses the most common plugs size 5.5 mm (0.22 in) in outside diameter.
One note:
The NDK ad on DIYinHK incorrectly states the NDK has "For easier comparsion(
lower is better
), we overlay the two phase noise graph at the same scale, under 25khz(human listenable range) nz2520sd(red line) is better, over 25khz(human unlistenable range) crystek 957 is better."
Unfortunately it seems these 'engineers' can't read a log scale. The crossover in phase noise is at 2500Hz not 25000Hz. 2500Hz is definitely IN the human range of hearing. Ugg!
