strophlex

If you disconnect the power supply, but leave the power switch in the on state, then you get continuety between Switch:1 and Switch:2, right? I think the PSU part seems fine after all.

I can take the remaining 16.

Thanks! I'll have a look and consider...

Wow! This is insane! :thumbsup:

Thanks for the reply TK. I have considered adding a switch, but it would be nice to have it as a software setting that is saved with the patch. I am too spoiled with MBSID... To you think it is too hard for me to implement this feature? EDIT: And who am I? I am a proffesional programmer since five years but haven't done loads of assembly programming. Just a bit.

As you know, there is no filter in the MBFM original configuration, so there is no filter settings to forward. But there is generic AOUT settings to forward LFO and EG to AOUT and in this case filter cutoff and resonance. What I am thinking of here though is the on/off switching of the bypass relay in Seppomans SMM2044 module. If that is possible to control from the MBFM.

Thanks! This did the trick! I am just not good enough with FM yet, but this was a good lesson to learn.

Hi all I am thinking of building an MBFM with SSM2044 filter modules. As you probably know, the filers modules have a digital 5V bypass switch. Is it possible to control that from the MBFM software? There seems to be unused outputs on the DOUT module but I must be able to control them from software too and I guess adding menu items for this is not peace of cake...

Just to make sure, when you do the continuity checks, you have the PSU disconnected, right? Did you desolder the switch completely or just a bit? Don't do any more desoldering, I just want to know.

Thanks Imp. I will try that.

I will double check the other outputs and try the volume. The synth is not connected to a computer, so that rules out all sound card issues. Thanks.

Hello again. Don't desolder anything more. I think it will be possible to find the problem now. Be careful not to bend the pads and traces that have come loose. Check these with continuety mode on the multimeter. J3:5V - J3:GND Switch:1 - Switch:2 Switch:1 - J3:GND Switch:2 - J3:GND Which ones beep?

Thanks for the reply. I haven't managed to solve this. Thought it was just the way the chip worked since nobody had a solution. Did you listen to the audio samples? Is it the kind of artifacts you experienced.

Don't get me wrong. I don't know if it does. Did you try?

Too bad the pad came loose, but don't worry about that. Sounds like a short in the PSU part as you first expected. Might be a good idea to desolder some components there, but it is harder than desoldering the bridge. Especially the switch. Where do you live? What about the two pins of J3? Any beep?

Tip for desoldering: 1) Put the board in a vertical position using a heavy clamp (like those metal clamps used for wood work). 2) Grab one side of the component with fingers, pliers or tweezers. 3) Reheat the solder at the joint from the back side of the board. 4) When the solder has melted, gently pry that side of the component out. 5) Repeat for the other side of the component. The component is free from the board. 6) Reheat the solder again and use a solder sucker from the component side to clean the hole from solder. Sometimes it makes sense to add some fresh solder to be able to get this done. Do not heat too much or the glue holding the copper traces will melt and the traces leave the board -> trouble! Good luck!

Did you make these continuity measurements with the power brick disconnected? If not, do that. The transformer in the power brick is a wire and makes continuity beep. EDIT: Never mind this, the 5V is regulated so there should be no short inside the power supply. There seems to be some bridge between +5V and gnd. It could be anywhere. One thing to try is to remove the bridge at J73. That would make it possible to check if the 5V-gnd bridge is before or after J73.

I am pretty sure the AOUT channel for the VCA module is configured in unipolar mode plus it works fine when controlled from the CFG -> VOL menu. I don't think it is that module. It must be something in the software.

I guess you got nothing between ground and the bridge at J73. I guess you have to turn the board over and measure pin 1 and 2 of the switch. This will help you: http://www.mb6582.org/plans/MB-6582_Base_PCB_R2_Color.pdf

Argh... I cannot get this to work. Again, CFG -> VOL works perfectly. If i set an external filter (After SID but before VCA) in resonance I can adjust the volume with this setting, so I am 100% sure the VOL setting is forwarded via AOUT to the VCA. Then, in the modulation matrix, I assign one modulation source to VOL and set the depth param of both the EG/LFO and the modulation to 127. I doesn't matter if I use EG or LFO, same result. Only about 50% modulation range. Only half range if I use negative depth too. There must be some setting I am missing...

No idea about connecting two cores to the same aout_ng. I would guess the serial signals will be messed up.

You are right. But what about interaction between MBSID and MBCV. Is there a way of sending CC from MBSID?

It's all extremely crowded. Heatsink and cables makes it difficult to see anything, especially on the photos. All of it has been built a long time ago. Debugging and calibration has tested my patience though and it has been in the drawer several periods. The PSU was built using the schematic on the wiki. I also added a diode at each output to make sure current never flows in the wrong direction in the case of a failure. The MB6582 is powered by the same 12V DC that goes to the AOUT and SSM modules.

My expansion box described in the beginning of this thread was finally completed this winter. Here are pictures: http://midibox.org/forums/gallery/album/146-mb6582-expansion-box/

Late but here are pictures of the finished box. http://midibox.org/forums/gallery/album/146-mb6582-expansion-box/ I am 18 months late to answer, but if you have questions about this build, you are of course free to PM me.