no sound from SID

MIDIbox SID
1

so, i’m not sure what’s wrong at this point.

my core checks out good in MS.

i ran the MBSID interconnect test and everything checked good.

i loaded SID main, then SID_6581_without_cs, but then nothing…

i blew my c64 PSU, so i can’t check the SID chip with the C64 (i don’t have any games anyway).

i’m not sure if i have the audio hooked up correctly though. right now my core is powered by a 9V PSU, and the SID is powered by 2*9V batteries. i’ve hooked the audio out to SID J3, and only got some pops as i made the connections. then i tried sid J3:1 and core J2:2 and got nothing (like in http://www.ucapps.de/mbhp/mbhp_sid_c64_psu.pdf). then i tried sid j3:1 to sid gnd, still no noise what so ever. not even a buzz.

the only thing i haven’t tried yet is stuff it with my back up sid, but i want to make sure that i have my connections right before i do that.

am i uploading my apps in the right order, and how do i connect my audio out with this setup (or a set up using one wal-wart PSU)?

thank you.

edit: i stuffed the module with the backup SID and still got just about nothing. the only difference this time is that i would get a low buzz if i touched the chip or the caps. the audio out was hooked to J3:1&2.

once i had the buzz, i tried using the keyboard interface in MS, but got no real noise.

2

Since everything seems to be fine at the digital side, it could be a problem at the output amplifier stage around T1 - check the soldering joints, check that the transistor is mounted correctly (the direction does matter)

Best Regards, Thorsten.

3

hmm.

i’m using smash’s boards, and from what i can tell, everything is on there correctly.

i went ahead a rebuilt the entire audio out/in section and still got nothing.

here are some pics of that section:

(part side) http://i2.photobucket.com/albums/y17/iamlark/C64/SIDpics015.jpg

(solder side) http://i2.photobucket.com/albums/y17/iamlark/C64/SIDpics016.jpg

i can’t see anything wrong, but maybe i’m missing something…

i checked the voltage on from SID IC:28 to 14 and it’s reading at 12.3v. would that be enough to blow the chip?

if not, what would be the next step? new module or new chip?

4

12.3V is within the allowed voltage range

I just got the idea that something else could cause such a problem: the oscillator. The SID won’t generate any sound so long no clock is running.

Is your module stuffed with an integrated oscillator? Then check the connections around there (it’s impossible to measure the frequency without a scope). You could also try to clock the SID from the PIC like described at the MBHP_SID page — note that the oscillator has to be removed in this case

Best Regards, Thorsten.

5

ah, great idea.

i’m using smash’s board that included the 1.000MHZ oscillator. it is possible that this guy could have been damaged by heat?

i’m going to try running the clock off the core module and see what happens here.

just so i have this straight i wire it from core j7:3 to the sid clock input (pin 6), correct? do i need to wire anything else?

6

just so i have this straight i wire it from core j7:3 to the sid clock input (pin 6), correct? do i need to wire anything else?

No that’s all. Just don’t forget to remove the oscillator.

Raphael

7

TK!

you we’re right!! it’s works!!

honestly, i jumped when sound came out. it’s the most beautiful thing ever.

thank you for all your hard work on this and the other projects! i still have a few bugs to work out (note sounds after it is played) and the CS design, but THANK YOU!!