rich said:
ne0shell can i use the gamma2 DAC with headphones that dont require amplification and powered speakers? i.e.
ALC889a -> optical -> gamma2 -> analogue phono output
i presume you cant use both at the same time, so some type of splitter is needed.
The Gamma DAC can drive a wide range of headphones by itself, including high impedance ones. The build plan calls for changing a pair of capacitors for a set of audiophile caps that maintain full frequency and eliminate a low freq roll off the standard caps cause.
I'm using the tube preamp in line with the DAC just to warm up the sound on my jazz and classical audio files, otherwise the DAC by itself works just fine. You can split the signal for a headphones plus powered speaker arrangement.
The gamma can be configured to take a USB input (bypassing the mobo audio stage completely), a SPD/IF input (fed from the ALC chip) or all the above. By using the USB input I can ignore making the ALC audio chip work in future upgrades since I probably won't use it at all. I plan to build a digital switch to flip between my Hack, xbox and DVR.
The gamma itself has an input switch and volume pot on it. I could connect the USB, optical from xbox and coaxial from the DVR all direct to the DAC and use the built in switch to select my inputs.
It has digital inputs, digital outputs, 2 headphone outputs and 1 set of RCA analog outputs. The volume knob is an add on not shown in the photos posted. The DAC is full pass and convert - in other words you can connect any digital input and use any digital or analog output. You can use the USB input and run optical or coaxial outputs, RCA analog and headphone outs all at the same time or vice versa.