Debug Echo Base

[soggybag]

I built two Echo Bases using the MusicPCB PCB. The first worked first fine. The second passes a signal but doesn't have any delay. Everything seems to be working up to the PT2399. I get sound going into pin 15. But no audio at any of the other pins.

I'm guessing that either audio is not going into the delay, so nothing is coming out, or the delay is not functioning or the delay time is so short it is not having any effect.

[soggybag]

Experimenting on the working Echo base, I get audio in at pin 15 and delay audio at pin 14. The non working Echo base shows 5V at pin and 2.5 V at pin 6 which seems right.

[electrosonic]

I am troubleshooting the exact same problem on my build.  I have traced the audio into pin 16 and out pin 15.

The next step is to check the switching of the 4066 chip. ie the status of pin 12 and see if audio is going into pin 10 and out of pin 11.

MerlinB has added some additional notes to the original pt2399 data sheet  here...

http://valvewizard.co.uk/PT2399_Data_Notes.pdf

Worth reading to get a better idea how this is supposed to work.

Andrew.

[soggybag]

Thanks for the reply. I feel like audio going in at pin 15 should appear as an echo at pin 14 if I understand the function of the PT2399 correctly.

I had built one of these and worked fine, so the second build I soldered everything instead of using a socket. It's very difficult to remove a 16 pin DIP. Otherwise I would try a new chip and see if the chip is the problem.