Best way to mod expensive dac or cd players


2010-11-18 9:12 am
Use very high speed and powerful op amp for the i/v converters for Iout dac's while using their feedback resistors as a combination of a high value resistor(hundred of kohms) in parallel with 1...10k potentiometer in series with a minimum resistor load for that op-amp and this arangement will work as a volume Potentiometer.Of course there won't be any muting position because of that series you will have a minimum audible volume :) You'll be telling your friends that's a special "feature" of you DAC ;)

Have no worries about the SNR due to lower value resistor ! 1K or 100ohms is the same sh..t from a noise perspective with modern a DAC!
That's all you need,nothing else.No image filter, no nothing...maybe just a simple first order RC filter at the output if it's used as a line output.
You could be using OPA2132 +both op-amps in lm6172 paralleled on one channel output as in Technics(Sandman) circuits while using the feedback resistor as Volume Pot and i can equally drive headphones or line output.
You could easily have this arrangement with opa2132 and a THS6012 or TPA6120 (Technics(sl-p900,sl-p990,sl-p777)-Sandman or inverted topology in Burr Brown Best of both worlds App note ) .
Used with headphones there's no need for ultrasonic filter, the headphones will take it.Used with high speed power amplifiers, the speakers will filter out all the ultrasonic content naturally IF PRESENT!
Don't follow audio "guru" telling you countless useless methods of spending your money for nothing!
It Works!
Last edited: