socrates

So I acquired all the parts for my MB6582 years ago. Very slowly I assembled the base plate and then got into some problems during the checks I believe. Now after years of collecting dust I want to finish it off and get that awesome sound out of it . So this thread will probably be a debug/build/progress but also at some times a cry for help thread :P. So lets get to it. This is how I found it. Directly did the testing described in the MB6582 build guide. No Shorts between GND and Voltages SID's pin 25 are all connected to 5V and all pin 14 to GND Core's pin 11 are all connected to 5V and all pin 12 to GND 6N138 is connected to 5V and GND And now the trouble starts: On the 74HCxxx all pin 8 got to GND so that is good. But there are 3 problems on the pin 16 to 5v though. Looking at the picture you would already have guessed it, they are at U3_SID1, U4_SID2 and U23. So it is time to heat up the soldering iron and resolder those pins I guess. Comments are welcome and hope show you more progress soon.

I got it today. The red one looks nice!

got them already yesterday! Superb!

Nice I will follow this.

lost posts: lylehaze Posted 28 October 2009 - 16:24 If you're happy with the circuit, I hope you'll share it That works, but leaves you without pan/balance control. I used "Schmartboards" successfully to prototype the circuit. They worked very well. My desire for less stages is about sound quality more than core count.. I don't know of any quality problems with multiple stages, but I have never tried, either. The software is a bit over-commented.. some find that annoying, but it is the lesser of two evils. Put simply, incoming MIDI messages that affect the mix are stored in a big array, and any channels that may change as a result are flagged for re-calculation. Then the "math" part processes each flagged channel, combining volume, expression, master volume, pan/balance, effects levels, and effects flags into a single gain setting for each PGA gate. Finally, after all calculations are current with the MIDI data table, the gain settings are written out as a big block to the PGA chips. Of course there are other minor routines.. save and restore bank settings, display channel names and gain settings, responding to MIDI requests for the current state of the MIDI table. After explaining all that.. consider this: instead of a 3 band EQ followed by a single gain control.. how about adding to the end of the "math" part above by taking the final gain result for a given channel, then multiplying it by each of "Bass" "Mid" and "Treble" levels for that channel.. NOW you'll have achieved the same as if you had a separate level control after the EQ, but you'll have used one less PGA channel to do it. Those three PGA channels give you all the control after the EQ, but you'll have used one less PGA channel to do it. Those three PGA channels give you all the control you asked for.. but with less hardware.. And less hardware usually means better sound quality. I'm not sure I'm explaining myself properly.. I'll try a different way.. Please see the attached crude graphics.. (http://midibox.org/forums/index.php? app=core&module=attach&section=attach&attach_rel_module=post&attach_id=5571) (http://midibox.org/forums/index.php? app=core&module=attach&section=attach&attach_rel_module=post&attach_id=5572) You're using six gates, but each signal is only being "processed" ONCE.. You still have ALL the controls you had before, but a shorter signal path. The software will combine volume, expression, balance, master volume, and EQ settings into six levels, for those six PGA Level controls. You also get the (probably not useful) option of having a separate EQ settings for left and right. One last thing.. if you went to a 4 band EQ, there would be one PGA chip for each audio channel, much easier to divide up as you build.. (though I think the software could handle it either way) I have written enough for now.. I'd love to see some discussion on this when I get back from work tonight. LyleHaze

Lost posts: freddy Posted 28 October 2009 - 12:34 No problem at all, everyone has other things to do. Just keep your job! Meanwhile I managed to build 8-channel 3-band Butterworth filter to feed each channel to a single PGA. I'll connect the three per-band outputs together (hoping there are no big time differences between the bands, using an osciloscope there is a difference but it seems to be the same for all bands) and employ the 4th PGA input to be used for per-channel master gain control. I've received 4 PGAs yesterday, expecting another 5 free TI samples arriving today, waiting for a SOIC ZIF socket to test everything (two channels for start) on a breadboard or vectorboard. I'd like to make output section configurable therefore would like to build a patch-panel to mix individual channels to resulting output buses, I need to test this as well since I'm unsure how many outputs can drive how many inputs. I'm still unsure how many PGAs will be needed for 4 buses (2x L, 2x R) with individual per-channel pan control. If there would be no pan one PGA (4 inputs would suffice). I didn't peek into sources yet so I don't know how was your pan implemented (whether two opposite-bound channels to lower left while raising right and vice-versa), but I'd say there is a better solution for sure. Hm, there is no problem for employing several cores to drive multiple stages for this design if necessary, so singlestage is not a strict requirement. MIDIbox 28-10-09 21:16 http://midibox.org/forums/index.php?app=forums&module=forums&section=printtopic&client=printer&f=39&t=6776 Pagina 57 van 58 way they wish.. (more on that later)

Just amazing :o How much did the case cost and where have you fabricate it?

nice

Very nice box! But where did you got those knobs from?

I got them also (germany)

How is work going? I have installed the demo for live api and must say that is really impressiv what it can do. But now I don't know where to start for my own application...

You can also build a woodencase ;) but with cnc/laser live is made easyer :P

ableton just annpouced this at the Namm 09: http://www.ableton.com/extend

hmm this is interesting, I'll follow this project. ;)