I’ve got and old version Sid completed somewhat a Year ago. Could troubleshoot everything easly myself thanks to the Applications and this Forum. Great! Only just before I wanted to upgrade to V2 my audio signal dissapeared and left a Hum (the type when something isn’t properly grounded)to irritate my ears:(
I did run the 1 Khz App again, but ofcourse no result. Checked the sid Interconection, wich has probabely nothing to do with it, but wanted to try the new version anyway –> possitive results, nice work Thorsten!. But now I’m really stuck.
One thing to notice is that played around with an other DIY-Synth (A Benjolin) and plugged it differents out (Saw/Puls/Filter etc) out in Sid’s IN and OUT (I know this doesn’t make sense, but I didn’t mark IN and OUT on the back of the sid…)
One of the sids’s gets a bit hot, although the voltage of my psu ok (5.2V)
Does someone have an idea if I could have damaged something this way, or if not some other hint?..or maybe just a link to the topic I didn’t see with the same problem?
You need to check the other supply to the SID… i.e. at pin 28, and where it’s connected to the 9V or 12V (depending on SID type).
You can try a different test to narrow down what the problem might be:
take out the SIDs from both modules
bridge pins 8 and 27 with a 1K resistor
run the testtone app
This will generate a 1kHz square wave tone (same as the testtone app makes with the SID) by toggling pin 8 at 1kHz, which is thus connected to the audio buffer circuit at pin 27 (the SID’s audio out pin). Pin 8 is connected to SID:J2:SO so this is another test if this connection to the PIC is working.
Ok did run the testtone app without the 8580 an 1k res. between Pins 8-27. got a nice 1 khz tone! Also tested the Voltage between 28 and 14 –> 9 Volts exact.
One thing I found out was that I had switched the + and - on the Audio jack sockets from the beginning (so Tip was - and Sleeve was +) Funny that I could play with it for about a year without problems, although Hum decrease now when hearing the testone.
I’m afraid that plugging the other DIY synth has seriously damage something because of the switched + and -. I have some 6581’s so I will change them and try. I’ll keep an update.
