Make that Cheap and cheerful.
I spotted this little kit while surfing ebay and thought that it appeared to have a lot of potential if important erea's were given special attention.Since niether of my current DAC's have 192k capability this looked like a economical way to try the few high sampling downloads that I have stored on my PC at their full resolution.
The kit I purchased did not include the chassis,transformer ,connectors etc.
It came with a blank PC board with the exception of having the three SMT IC's already soldered (the DAC,DIR and logic).All the other parts to populate the board are included .For the price the parts are of decent quality but since they are standard hole through types they are much easier to find suitable higher quality substitudes,which ofcourse is what I did.Since board real estate is at a premium there is no room for exotic film caps etc.
I opted for Nichicon HE and UCC KME's for main filter caps.I used Panasonic FC's for local decoupling, bypassed by Panny stacked films. WIMA film's were used the PLL filter and BC polyprop's for the lowpass filter.I also substituded the LM78/79 regulators with the lower noise MC variants.Nothing exotic but definately a few notches above the stock parts.
The DAC circuit itself is as simple as it gets.There is no USB input or sample rate convertor ,instead input is via SPDIF into a Cirrus CS8416 DIR followed by an AKM4396 dac chip then to the low pass filter/output buffer.AKM is one of the biggest makers of DAC chips but these are mostly found in higher end soundcards.On paper atleast the AKM4396 is an excellent DAC and appears to be the equal of the dual differential 24/192k offerings from Cirrus and Burr Brown.
However it is my opinion that it is the analog section that can have an even greater influence on sound quality than the specific data converter used.The opamp included with the kit is the archaic 5532.Not the worst sounding device around but far from the last word in resolution.I find it on the soft slightly dark side sonically.I will be replacing it with a pair of discrete class A opamp's similar those marketed by Burson.
Also in an atempt to not adversly affect the signal - noise performance and preserve all those 24bit's of resolution I will be placing the little toroidal transformer in it's own separate chassis to prevent the possibility of any 60hz hum being coupled into the output.
I found a Hammond case with ideal dimensions for the PC board.