r3

Thanks Thorsten! Problem solved. My Midibox is designed for SID6581, and it wasn't getting enough power. To get enough power for the filters to work, I had to use a 12V external power supply, not the 9V one I was using. This also increased the level of the soundoutput and reduced the noise ratio, so it's sounding very good! My next step would be to replace the PIC18F452 with the new PIC18F4685, and update to the latest SID v2 software, and possibly do the clock signal fix for my old MBHP v2 board if this turns out to be is crucial for the update. Your sysEx control panel software for the v2 looks like an amazing piece of software, I suspect it wont work with my MIDIbox SID V1.7303, so will maybe stick to JsynthLib for now until I've upgraded. Thanks again!!

So my filter caps are 470cf, with the the 471 'product' code on them.. Soldering these to together with the soldering points of the SID cap pins did not make a difference. The voltage regulator is a 7812 for my 6581. My SID board is an old MBHP v2 (2002) board. As my SID board is old, my conclusion for my next step would be to look into this (quote from ucapps.de) : "If you've built a module based on the _v2 layout, you need to solder an additional cable between the CLK input of the SID and Core::J7:SO/PIC Pin #17." ..hopefully this will do it. I will also get a voltage meter to measeure the voltage.

My filter caps have '471' written on them. Should I swap these out and replace with 470pf? The soldering points of the caps are not joined up to the joints of the SID properly, so if the 471s would be sufficient, I suspect maybe joining the soldering points up could solve it, so I would give that a go I think

Under the filter (FIL) menu on the Midibox, I've set mode (MOD) to any combination of L,B and H. Any setting with 'H' produces a tone, while any combination without 'H' mutes the sound. The cutoff and resonance values does not affect the sound at all under any of these settings. I've also set cc44 to 7, cc45 to 1, this does something to the sound, as I can hear it just while its seems to be switching values on cc44 and cc45 , but it does not seem to change the filter type on the midiBox, altough JsynthLib updates filter types on the midibox when selecting the filters in the software controller. The original Midibox os on this, was 2004 1.7, so it was build quite some time ago

Thanks Thorsten, I've managed to route the oscillators through the filters, both using midiCC, the JsynthLib java application, which btw is a great software MIDI controller for the MidiBox SID, and also manually on the MidiBox LCD. This just mutes the sound. The logical conclusion would be that the filters are broken on my SID, but having tried it on quite a few SIDs, including new old stock, of which one SID from the same stock are working fine with filters inside a C64 with Cynchart, makes me think that the problem might be inside my MidiBox. I would get the lates PIC18F4685 microcontroller and latest SID 2.0 app installed eventually, but not sure this would solve it.

The SID V1.7303 document about Available Controllers says that cc46 / cc47 should work with v1.7303, so don't actually know if upgrading the PIC would help. Not an nameized sell out, just someone passing on their unfinished work in good will. Hope anyway the forum can help, as it's hard to know where to start looking for a newbie like myself

Thanks Cimo, If I update my Midibox with a new PIC18F4685 from SmashTV, and install the new SID v2 app, do you think this would be sufficient, or would more components need to be replaced? Thanks!

I've aquired an unfinihsed Midibox SID, came with Midibox 2004 os 1.7, but have updated to 1.9 and updated with recend SID software using MIOSstudio. It is responding to MIDI CC messages, however midi CC46 and 47 for cutoff and resonance is not responding. Changing cutoff / resonance on the SID LCD panel itself does not affect the sound either. I have tried with multiple SID chips, so have ruled out broken filters on the SID. Could this be some error in the original design, or is there any way to check this / troubleshoot ? sid_box_.JPG