We have got a few requests to custom make DAC for a few customers locally, and have been researching on how to make a better output stage for I/V conversion for DAC chips with current output, especially differential types.
We've tried many types, such as Op-amp, discrete, passive resistor, and transformer based. So far passive resistor and transformer based are our favorite. Both these give the most natural and organic sound.
We've done some Googling, and we found that we're not alone! A few very famous modders (Lampizator) and custom builders (Andrea, and etc) have been promoting DAC output stage with resistors and transformers!
It just so happen that we do have some ready made input transformers made previously for preamp input coupling / isolation use. It can be used perfectly as DAC output stage.
|DAC input transformer|
- Permalloy EI core, with a small % of Z11 for voicing / sound tuning
- Core size: EI 35
- Size: 66mm x 3mm x 33mm H
- Signal level: 3 Vrms @ 20Hz
- 20Hz -0.1dB to 100kHz -1dB
- DAC output, CD output, Op-amp preamp output, signal coupling (input transformer, output transformer), output inversion use
- Price: U$150 / pair
- Limited quantity only, left over from mass production for a high volume manufacturer
- 5：1， 10：1 versions may be available, please email