D
Deleted User
Guest
Had too much time today and so I decided to cannibalize a braindead ME-70 I had already thrown into the junk box, because the 'customer service' at Roland prefers to p on users and charge 150 Euros plus shipping to reflash a faulty-by-factory firmware, which can not recover from a power outage that happens just while moving a potentiometer. Not again. I tracked down the Service Notes on the net, but no chance to reanimate the thing without reverse-engineering the firmware.
So I came to the idea of replacing a 11 year old ESC chip with a Tensy 4.0, which I guess would anyway dance circles around the oldie.
The board is better than one would expect:
AK4556VT codec (!)
nice preamp NJM2115V
nice power supply around a BD9850FVM
stereo headphone out with insert detection
stereo line out with mute circuit
6 detent pots and
19 smooth pots on muxes
1 analog foot pedal
4 footswitches
2 switch inputs
5 pushbuttons
14 LEDs and
2-digit-LED display on serial latches
I added some features:
Teensy 4.0 with USB, obviously
a MC34063A and stuff in app note config to provide 9V from USB and limit inrush/charge current to the board's many caps and filters
S-PDIF optical out
a 240x240 IPS with ST7789 over SPI, just because it is cool
two CD74HC4051 muxes to compensate missing inputs for Teensy 4.0
wires, more wires,
damping resistors (!) on all digital lines
glue to hold it all together
After the patchwire orgy, it just plays extremely well and now I have something to play on with Audio library.
More will follow, if you are interested.
My primary intention was to build a Teensy 4 stomp box pedal from scratch, but this is way cooler for now. The stomp box will follow once the software is complete.
View attachment 19817
View attachment 19818
View attachment 19819
View attachment 19820
So I came to the idea of replacing a 11 year old ESC chip with a Tensy 4.0, which I guess would anyway dance circles around the oldie.
The board is better than one would expect:
AK4556VT codec (!)
nice preamp NJM2115V
nice power supply around a BD9850FVM
stereo headphone out with insert detection
stereo line out with mute circuit
6 detent pots and
19 smooth pots on muxes
1 analog foot pedal
4 footswitches
2 switch inputs
5 pushbuttons
14 LEDs and
2-digit-LED display on serial latches
I added some features:
Teensy 4.0 with USB, obviously
a MC34063A and stuff in app note config to provide 9V from USB and limit inrush/charge current to the board's many caps and filters
S-PDIF optical out
a 240x240 IPS with ST7789 over SPI, just because it is cool
two CD74HC4051 muxes to compensate missing inputs for Teensy 4.0
wires, more wires,
damping resistors (!) on all digital lines
glue to hold it all together
After the patchwire orgy, it just plays extremely well and now I have something to play on with Audio library.
More will follow, if you are interested.
My primary intention was to build a Teensy 4 stomp box pedal from scratch, but this is way cooler for now. The stomp box will follow once the software is complete.
View attachment 19817
View attachment 19818
View attachment 19819
View attachment 19820