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probably the last problem i bump into!


ytsestef

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here goes:

I use the stereo setup, but the system does not seem to be able to control the two sids seperately, i.e.: i use the drum engine, for example, and when i set an instrument in osc1,2 or 3 both sids are producing sound. when i set an instrument in osc4,5 or 6 no sound is produced at all... Do I have to configure something? Am I missing something? I have connected the SO of the one MBSID module to J14 of the CORE module as described in the OPSU pdf. PLZ HELP!!!

edit: oh, and in the SID menu, under "mon" there is a circle, not an asterisk  :-\

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yes, they are connected into a stereo input of a behringer line mixer. you can be sure that i am not listening to one SID because one of them has a somewhat different filter frequency response and i can clearly hear a difference between L and R channel when playing back C64 tunes (SIDplayer mode). It is a control issue.

Question: If the wire that connects J14 of the CORE with SO of the Right SID is not making good contact would it still play the same as the Left SID or would it be silent???

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Question: If the wire that connects J14 of the CORE with SO of the Right SID is not making good contact would it still play the same as the Left SID or would it be silent???

In such a case, it wouldn't play any sound at all.

The CS# line is triggered whenever a SID register should be changed.

No CS# connection -> no register change

CS# lines connected to the same output pin of the PIC -> each SID will get the same register changes

You mentioned, that with the modified testtone application the volume level is lower.

It would be lower, if the audio outputs of both MBHP_SID modules are merged (-> mono), and one SID doesn't play anymore - like in the modified testtone application.

Your issue is really strange, I don't have an explanation for this (yet)

From where did you get the PCBs? Or is the circuit built on a prototyping board?

And just to ensure: did you already check the power supply voltages (0V/5V) at each 74HC595 and the SID? Just to ensure, that they are supplied correctly. If this wouldn't be the case, and if they would get their power from somewhere else (e.g. from the data lines), a lot of strange things could happen ;)

Best Regards, Thorsten.

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It would be lower, if the audio outputs of both MBHP_SID modules are merged (-> mono).

I'm pretty sure that this is not the case. Trust me, I am an experienced sound engineer, I am just relatively poor in electronics and software. I am sure that what I hear is two channels, aka stereo. I even told you I can distinguish small differences in sound characteristics between the two SIDs. The two line outputs are definately seperate, and from what I know there is no such thing like audio exchange between SIDs possible in MBSID.

***Also, when I say lower in level, I mean _LOWER_. Like -40dBFS RMS in my audio interface whereas using the other application (the one that is not modified) I used to get -6dBFS RMS.

From where did you get the PCBs? Or is the circuit built on a prototyping board?

I use smashTV's PCBs.

And just to ensure: did you already check the power supply voltages (0V/5V) at each 74HC595 and the SID? Just to ensure, that they are supplied correctly. If this wouldn't be the case, and if they would get their power from somewhere else (e.g. from the data lines), a lot of strange things could happen ;)

Best Regards, Thorsten.

I have measured every voltage many times and everything is fine. In addition to that, when connecting one sid at a time (mono mode) everything is working perfect.

Thanks again for your time!  :D

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It's really a riddle...

Just to get some more hints: could you please do some continuity checks with your multimeter (if it has a "beeper" for such checks, it would be perfect).

For such a check, the SID chips and the PIC should be removed from the sockets (not required for the other chips).

Don't check on the J15/J10, but put the probers directly into the empty socket holes.

- check that the continuity between PIC Pin RD4 and (Right-)SID Pin CS#

- thereafter the continuity between PIC Pin RC5 and (Left-)SID Pin CS#

Thereafter check that there is no continuity between:

   - PIC Pin RD4 and ground (Vs)

   - PIC Pin RD4 and +5V (Vd)

   - PIC Pin RC5 and ground (Vs)

   - PIC Pin RC5 and +5V (Vd)

   - PIC Pin RD4 and RD4

   - SID Pin CS#and ground (Vs) (check on both SIDs)

   - SID Pin CS# and +5V (Vd) (check on both SIDs)

   - Between the two SID Pin CS#

This test should ensure:

   - that the CS# line is connected correctly (no open wire)

   - that there are no shorts between PIC and SID Pins against each other or Ground/+5V

Best Regards, Thorsten.

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