Thursday, August 2, 2007


Now DAC output stage is a "simple" SRPP. It sounds nice, but.... it can be made better. After lots of investigation I decided to go Aikido way. It is really great design and very flexsible. I might try Moskido as well.

I've removed digital PSU out of DAC and mounted new PSU. Now everyhing is nice and clean. No bruuum and background noise. Great!

SLA battery chager (UC3906) prototype works. I plan to built 4 on them on a board and put SLAs in nice separate chassis. I will use RCA conectors (standard and thay have good connections).


Monday, July 30, 2007

Coupling caps

After quite some investigation I will most likely go for Mundorf Silver/Oil. Possible candidaces are: Audience Auricap and Audio Note Copper Foil (Silver Foil are way too expensive). Since I have WIMA MKP at home, I will try these as well (for fun - they should be very transparent and thin).

Value is determined by C = 1/(2*pi*R*f), where f is a roll-off frequency. Coupling cap forms a high-pass filter with resistor and impedance of the next stage (power amplifier). I recommend values 470nF and larger.