Re: Cheap Surround sound buffer/level shifter
Posted: Tue Aug 25, 2020 4:28 pm
Finally on order...
This feels a little like giving birth... I ordered 10 pc proto run (minimum), and a stencil so I can screen on solder paste...
The row of pots across the top are input trims between digital surround decoder and gain stage. I incorporated 1.5x gain from the wiper, doubled with unity gain inversion for total gain of 3x.. This will allow my 1V decoder output to drive Hypex amps to full scale (they need 2.5V AC).
The round puppies across the bottom are old school LEDs in case the SMD LEDs are hard to see...
The 6 green LEDs are one lit at a time for loudest channel.. the 7th red LED is for about 3dB below amp full scale for any channel (this could actually be an improvement patent to my old Peavey FLS patent).
I can not imagine doing another project using this old tired PCB software (eagle version 4.03)... It still indicates about 250 warnings on the schematic engineering rules check.
The PCB design rules check only poots out about 50 warnings related to the SMD LED footprint. Life it too short to be warning free....
JR
PS: I am really looking forward to getting full output from my hypex class D amps. Since this last decoder upgrade I am hearing new improved surround effects from old movies even at -8dB FS.
This feels a little like giving birth... I ordered 10 pc proto run (minimum), and a stencil so I can screen on solder paste...
The row of pots across the top are input trims between digital surround decoder and gain stage. I incorporated 1.5x gain from the wiper, doubled with unity gain inversion for total gain of 3x.. This will allow my 1V decoder output to drive Hypex amps to full scale (they need 2.5V AC).
The round puppies across the bottom are old school LEDs in case the SMD LEDs are hard to see...
The 6 green LEDs are one lit at a time for loudest channel.. the 7th red LED is for about 3dB below amp full scale for any channel (this could actually be an improvement patent to my old Peavey FLS patent).
I can not imagine doing another project using this old tired PCB software (eagle version 4.03)... It still indicates about 250 warnings on the schematic engineering rules check.
The PCB design rules check only poots out about 50 warnings related to the SMD LED footprint. Life it too short to be warning free....
JR
PS: I am really looking forward to getting full output from my hypex class D amps. Since this last decoder upgrade I am hearing new improved surround effects from old movies even at -8dB FS.