Hi there, I have a slightly modified Lite Audio DAC60 with non-working digital selectors. While poking around in the DAC I have probably connected the display ribbon cable the wrong way (or something) and sent some voltages astray.
The display is mounted on a separate assembly with momentary switches and a HEF 4094BP register chip. The assembly is hooked up through a ribbon cable to 4 transistors on the main board, leading to an AT89C51 microcontroller. All the microcontroller does is control a switching relay for Coax/Toslink and it displays sampling frequency (which still works).
I am not really comfortable with the microcontroller stuff so any help with troubleshooting is welcome. Of course, it doesn't help that I can't find a good schematic. There is a rough one here (AT89C51, big chip in the middle):
Lite Audio Dac 60 Schematic
And the digital input circuitry (minus the microcontroller) can be found here:
http://www.audiodesignguide.com/DAC/dac_ah_circuit_new.JPG
1. I have measured the voltages on the transistors and they all measure the same (ok?)
2. Tried substituting an exact replacement for the HEF4094BP.
3. Any chance I could have fried something on the microcontroller?
The display is mounted on a separate assembly with momentary switches and a HEF 4094BP register chip. The assembly is hooked up through a ribbon cable to 4 transistors on the main board, leading to an AT89C51 microcontroller. All the microcontroller does is control a switching relay for Coax/Toslink and it displays sampling frequency (which still works).
I am not really comfortable with the microcontroller stuff so any help with troubleshooting is welcome. Of course, it doesn't help that I can't find a good schematic. There is a rough one here (AT89C51, big chip in the middle):
Lite Audio Dac 60 Schematic
And the digital input circuitry (minus the microcontroller) can be found here:
http://www.audiodesignguide.com/DAC/dac_ah_circuit_new.JPG
1. I have measured the voltages on the transistors and they all measure the same (ok?)
2. Tried substituting an exact replacement for the HEF4094BP.
3. Any chance I could have fried something on the microcontroller?
Just to add, if there is any Lite DAC owners here feel free to send me a PM. Would be very interested in discussing possible mods.
PCM63 DAC mods
DAC60 is the same as older DAC50 (DAC chip is different, PCM1704 instead of PCM63).
DAC60 is the same as older DAC50 (DAC chip is different, PCM1704 instead of PCM63).
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