moogah

First post updated. Should have one of these in hand soon.

+1 8)

And so begins my plans for werld domination! mua-ha-ha! Possibly, keep watching this thread and we can talk about it once I have an actually finished unit assembled and have verified the CAD. I'm about halfway finished with creating a sub-panel assembly which will hold the LCD's, MB modules and pad-per-hole for the buttons. I'm working on placing cutouts for wiring at the moment... funfun.. Hopefully when I'm done I'll have a Wilba-esq "flat" sequencer.

Bravo! Looks very nice 8) Shame there aren't more of them! I've been trying to get in touch with a silkscreener to finish my case for almost a month now :(

Here is where I'm at with the other half of my MOTM controllers (the other piece being the standard MBCV for connecting to a DAW). I'm going to use E-Switch 5500 Series switches since I've got about half a carton left from the first couple batches of MB808's and I'll use standard pad-per-hole to hold the buttons (the encoders will be attached directly to the panel). I'm going to try using a switched encoder for the Menu button. Currently this layout is missing a few labels and the neccessary mounting holes for the perfboard, I'm thinking about creating a subpanel in FPE to mount everything to so there are fewer screws on the front panel. EDIT: Almost done now, but I'm not ready to order this just yet. I'm going to wait until I have my MBCV module in hand (which is using some of the same ideas) so that I can see how well some of this will work before spending money on this layout. I'd also like to find some alternatives for the subpanel. FPE only works with aluminum and I'd really rather find a place which can work with steel for the subpanel. This would allow me to try out some ideas to simplify how everything stacks together. Also, the subpanel alone costs 70$ right now (!!) due to having countersunk screw holes on the reverse side.... quite the luxury! ;) MBSEQ_MOTM_Subpanel.JPG MBSEQ_MOTM_WithSubpanel.JPG MBSEQ_MOTM_Subpanel.JPG MBSEQ_MOTM_WithSubpanel.JPG

Yah, that's some sexy case! I think I'll take one 8)

First post updated. All that is left now is to consider using counter sunk screws to mount the LCD, and also if there needs to be another set of mounting holes to help mounting the vero board which will hold the buttons and DINX1 circuit. I need to rummage through my bins tonight and see if I have some peices which match the dimensions of the LCD and therefore can re-use some mounting holes by stacking the vero and LCD boards...

First post updated: I found some problems with the spacing of the mounting screws so I've removed the attached .fpd until they are correct (I've also found that a standard MOTM panel is just a little bit smaller than 3.5 inches.) @W: thanks! that's what I needed! @Sebo: Blue! Looks really nice 8) How are those Yusynth VCO's? I've got a stuffed PCB for one here, but haven't gotten around to making a panel for it yet..

For me that decision would depend on what I wanted to use it for.. I wouldn't put the jacks on the back in the first place, that's my preference. But if I was primarily using it to control monosynths and the like I'd keep the jacks in CV/Gate pairs as it will help keep your cabling nice and neat. For a modular it's less predictable how things will be patched and I have a premium on keeping similar items grouped together, hence the grouping of the CV and Gate jacks

Thanks TK, will make those corrections tonight 8)

Just about finished this panel last night and would like some feedback from anybody who is used to working with MOTM format and FPE. In particular, suggestions on better and cheaper fonts would be appreciated! EDIT: Up to version 8 now, many little details have changed. There is now a subpanel for mounting the LCD and Pad-Per-Hole, but it is not likely big enough to hold the remaining MB modules so another 90 degree bracket will probably be needed to complete a build. I've switched the cutouts to the E-Switch 5500 series since I don't have the marquardt's in hand and I'll want to build this ASAP. I'll be ordering these files today. The subpanel posted here is expensive! The reason is mostly due to having countersunk holes on the reverse side which adds 10$ alone. For those who arn't rich I'd recommend just removing the countersinks entirely on the subpanel. There is also a 2mm recess added to the backside of the frontpanel which is meant to let the display sit inside the panel a little bit. I did this for two reasons, one that I think it will look a little nicer (MOTM panels are quite thick) and the second is that it gives a little bit of room to work with when trying to find the right size standoffs and spacers. MBCV_MOTM_v8.JPG MBCV-MotmPanel_v8.zip MBCV_MOTM_v8.JPG MBCV-MotmPanel_v8.zip

Where is cimo?? ;) He was talking about this very idea a while back! +1 to the star trek comment too 8)

To elaborate on what flexi says: if I reach waaaaaaay back to music school, I remember the top number being commonly called the "beat" and the bottom being called the "meter".. but I also sorta remember that there really is no official designator for them!

I don't own any line 6 gear, so I'm just guessing here... Check the manual for a MIDI implementation chart, if your lucky you'll find that all the parameters are mapped to MIDI controllers. It would then be possible to create a "remote control" from something similar to the MB64 and then add some code to store the parameters in patches. .. and, I think you could adapt the SEQ application to do the same thing, plus sequencing..

Yes, it will take some thought and effort to make it work.. but it's probably worth it :D SubContractor: stop by chat sometime if you want to pick my brain, but you probably don't want to start with a whole 9090, I think it would be reasonable to tackle one instrument at a time, possibly end up with a "lite" version which still gets quite a bit done!

This was part of the original idea for the MB808, a long long time ago. To make a long story short, this really just isn't possible* You will need to use a combination of digipots, voltage controlled resistors (CA3080's) and vactrol's to cover all the parameters that need to be modified.. and that is drastically understating the amount of engineering and prototyping that will be involved... I would estimate that you'd nearly double the amount of PCB involved with a 9090, before adding the standard MBHP modules. Assuming you *do* find a suitable way to get all the parameters under voltage or digital control you will need to have quite a few AOUT channels running to control the VCRs and vactrols. If you get all that done, you will probably be just in time for the new core module to provide you with enough sequencer tracks to actually sequence the parameters... All in all, this would be one of the most difficult projects I've seen around here.. *of course everything is possible, somehow..

Neat little part.. might have to try a few out :)

That combination of switches looks very nice Sasha! I've passed over those switches @ mouser a few times in the past because the catalog drawing looked very similar to some cheap-o switches, but I think I'll have to buy a set of them now :)

Even just knowing what the problems are is quite useful to me at this stage (all I really know is that I don't know much at all!), and working out solutions is something I'm pretty good at.. so don't hesitate to share what you know! So it sounds like I'm going to need some DSP filters to properly handle aliasing, I can google those up and get some research done. My big concern at the moment is, if we're going to be working with blocks of sample data then I think we're going to end up having to deal with "windowing functions" in order to provide a smooth output. Another possible approach is the adapt some granular synthesis techniques, which (beyond providing us with a very cool form of synthesis to work with) may greatly simplify some common operations.

8) Careful or you'll get recruited! I *do* like the sound of lofi sampling, but I don't really see the wisdom in starting out creating an under spec'd sampling engine. Ideally we should be able to code up something that can operate across the full range of fidelity so people can decide for themselves what they want. Same goes for intentionally leaving in aliasing and artifacts, I think the goal right now should be to create an engine that meets a proper specification for a sampler, once we've done that I think it will be very easy to know where modifications can be made to "degenerate" performance :)

16 bit audio needs about 700kbits/s if I've done my math right, which would mean that 8mbits/s should be more than enough to feed multiple channels of audio actually. I guess a simple .wav file player will be the first step and a .wav mixer the second 8)

Oh! Very exciting! I can see that I'll need one of these new cores now too :) Does the thought of connecting the STM directly to a "memory unit" and doing all the processing on the core itself raise any red flags TK? I gravitate towards the dsPIC's only because I assume there may be too much overhead in processing sample data from memory to the I/O to handle interface code at the same time... but that is just a guess! The next hurdle as I see it would be what kind of memory, which I know very little about... I'd like to be able to use standard PC memory sticks because it seems like a simple solution (everybody else does it...) but I've got no idea if doing that even makes sense (is SD fast enough to use as RAM?)... can you offer any tips on what would be involved in connecting a memory controller to the STM? I'll be googling in the meantime :) At a high level I would think that synth code is a great starting point, but instead of mathematically generating the audio data to send to the I2S port we would need to have another callback function which will let the application know that new sample data has been loaded from memory. Ideally this process would allow us true random access of the RAM @44.1Khz (shouldn't be a problem?) for each new sample at the output and the STM will be responsible for knowing what samples are in memory, where they start and end, which samples are currently cued for playback and where their current playback position is... and if all that works then I could work on adding pitch and amplitude envelopes and LFOs. If all that worked like it should it would be nice to find that the memory bandwidth allowed us to retrieve more than one sample worth of data per refresh cycle so that layered sounds can be created.. and of course we'd then want to be creating dynamic voices and patches instead of simple static playback configurations... and if that's not enough feature creep for a single post consider that with all these SSM filter chips running around I would bet that more than a few people would like to have dedicated outputs for each "voice" :D Have I overshot what the STM core is capable of doing yet? Edit: I just discovered the programmers lounge, I'm sure many questions are already answered in there somewhere.

I dug around a bit and I've made a nice little discovery! It appears that microchip is selling a "turnkey" dsPIC development board for only 60$ It has onboard programming/debugging, 24bit audio I/O with mic and line level amplification (!) and 4 megs of ram all connected to MPLAB via USB :) I don't think I can resist this ;)

Very interesting! And that guy is (somewhat) local to me as well. I'll have to look into this! After building my 9090 I realized how "simple" it would be to create a basic lo-fi sampler using R2R ladders. I hadn't yet thought up a lightweight way to load and store samples yet tho, so the best designs we could do would be like the early 80's sampler based drum machines where the sounds are permanent, but you can modify the playback parameters and add filtering. With the new core module in the works I have to wonder if we've opened up some potential tho.. I think I read that TK wants to include SD memory support, which will provide us with a way to store sample data... but many questions follow: - what kind of RAM chips are available and affordable? - would it be best to use dedicated DSP chips like the dsPIC to handle the sample processing and I/O (many of these are inexpensive and have onboard ADC and DACS which make them quite attractive.. but nearly all are SMT only). There would likely be some expertise needed to write up all the DSP routines we'd need. In any case this person seems to have come up with a nice simple design which is probably quite capable, I'll be watching this closely!

Stryd pretty much explained what you are dealing with. The *right* way to do it is the intuitive way, even though the caps are in parallel you should think of each one being a separate filtering stage and place them one after another. However, with this design I don't think you'd be able to measure a difference between those two layouts. I would spend my time perfecting the layout so that all your traces are on one side and the ground plane can occupy the other (this will help with hum as well). It can certainly be done with the amount of space you have. Also, as you have it now those two regulators will pretty much be touching each other. I would re-locate them to the "sides" of the PCB (this will give you *much* more room for various heatsinks).