TK.

Today I did the first experiments with a CEM3378 filter, which some of the germans purchased in a collection order from synthtech.com A top view of the workbench: Right side: A AOUT_LC module based on the schematics from Karl Dalen. It mainly consists of 2 * 74HC595 and not less than 36*10k resistors to realize a 12bit DAC, which controls the Cutoff frequency. The final version I'm planning will consist of 48*10k resistors for an 12bit DAC (CutOff) and 4bit DAC (Resonance) (I guess that the resolution is enough, especially because I have to build 4 of them ;-) In addition this module has an OP-Amp to control the gain and offset of the output CV - for the filter it turned out that this is a very important feature Bottom: the CEM3378 circuit (based on the datasheet) + a +/- 5V voltage regulator. Both, the filter and the AOUT_LC circuit are powered with this low biased voltage. In addition, the CEM3378 needs +12V Left side: ok, my beloved MBSID And here the first demo - MBSID in TB303 mode, controlled via MIDI (internal sequencer not used) - filter/envelope parameters tweaked in realtime http://www.ucapps.de/mp3/midibox_sid/mbsid_demo11.mp3 IMHO the filter sounds very good, especially on filter sweeps it can be noticed that the volume doesn't get lower even when resonance is close to self-oscillation. During the first tests I also noticed, that key-tracking is a must for such a filter. Therefore I implemented it into the firmware (CC#6) - now I have to find a way to store this value, because the SysEx data structure is completely allocated :-/ Best Regards, Thorsten.

Search in the forum for "interconnection_test" and "interconnection test", there are a lot of hints within the appr. articles, how to debug the SID module Best Regards, Thorsten.

I just noticed that you are using the wrong JSynthLib version, please use this one: http://www.midibox.org/jsynthlib/JSynthLib-0.20.0_midibox_mod1.jar.zip Best Regards, Thorsten.

Wenn Du den Parameter dort aenderst, muss er auch an anderen Stellen geaendert werden. Welche das genau sind, kann ich Dir nicht so ohne weiteres sagen, zumal in Deinem Fall ja auch der LFO Depth3 Parameter (CC#74) umgelegt werden muesste (ich habe so etwas der einfachheit halber nie vorgesehen, und Du bist der erste, der danach fragt) Vielleicht ist es sicherer, den eingehenden CC einfach in der Empfangsroutine zu konvertieren. Oeffne mal sid_midi.inc, suche nach SID_MIDI_CC und fuege folgendes ein: SID_MIDI_CC SET_BSR SID_BASE ;; convert CC#74->CC#46 movlw 74 IFNEQ MIOS_PARAMETER2, ACCESS, rgoto SID_MIDI_CC_Not74 SID_MIDI_CC_74 movlw 46 movwf MIOS_PARAMETER2 SID_MIDI_CC_Not74 [/code] Gruss, Thorsten.

I can only say that 1.5 sounds correct (my first comment about 5.0 was wrong) It should work with this version, don't know why you cannot start JSynthLib - time to ask a java expert, maybe Meeshka can help (for the case that he doesn't read this article, just write him a PM) Best Regards, Thorsten.

I would suggest to edit the C version instead, it's easier to understand (I rewrote the whole application especially for guys like you who want to customize the display) - see http://www.ucapps.de/mios/midibox_lc_v2_0_alpha1.zip open "lc_lcd.c", search for "LC_LCD_DisplayPageSet", read the comments Best Regards, Thorsten.

yes, it's a SID specific problem, that the cutoff parameter is not linear yes, it compensates the non-linearity by re-using the exponent table which is also used to map the oscillator frequency. This works well for the upper frequency range, but not so well for the lower range. But the envelope trick can be used if sweeps within this range are desired. And again: another possibility is the use of the TB303 option, which reduces the cutoff to the lower range, so that you won't notice stepiness anymore in the range you are mainly using for these types of sound yes, especially the resonance doesn't really work the 8580 filter is definitely better for TB303-like sounds, the 6581 is better for soft sounds, I will make this clear in the TB303 tutorial Ok, again a complete statement to avoid any confusion: Yes, if no modulation source is assigned to the filter, and if the TB303 option is not enabled, you can sweep the cutoff over the whole range with CC#46 - sometimes it sounds steppy because of the 7bit resolution of this CC, but this can be fixed by using modulation sources for fine control. Most samples of the Prophet64 side are made with the 8580, when you are activating the TB303 SE option you can realize very similar sounds, because it changes the way how the filter is controled Best Regards, Thorsten.

Which java version are you using? It should be 5.0 or higher Best Regards, Thorsten.

The envelope trick I described above was the solution to avoid the stepiness, please try it out to understand what I mean. Don't forget to set CBM8580_FILTER_SWITCH to 1 (in main.asm) when you are using the 8580, or just upload the prepared *_8580_*.syx/*_8580_*.hex file, where this is already done. Of course, it also works with LFOs. By default, you can reach the max cutoff value with the cutoff CC, there is no additional headroom for modulation sources. The modulation sources just give you the possibility to finetune the cutoff when the ENV/LFO depth is low. Reg. your 6581: I guess that this is a bad chip, the behaviour cannot be improved by software or hardware modifications. Or you don't know yet, that the 8580 filter has a different (much better) characteristic compared to 6581 Therefore I didn't give you a comment to this problem - this has been discussed several times, and it's not clear to me if you've read these postings or not Best Regards, Thorsten.

Kurzinfo: Ich habe nun vier CEMs und eine Woche Urlaub (*juhu*) - in den naechsten Tagen werde ich die Low-Cost AOUT Version mit den CEMs testen und dokumentieren. Das MBHP_AOUT_LC Modul wird dann von MBSID/MBFM und MBSEQ unterstuetzt Das MBHP_AOUT Modul ist zur Ansteuerung natuerlich ebenfalls geeignet, wenn man die Spannungsteiler an den OPs so waehlt, dass die Ausgangsspannung maximal 5V betraegt - oder die OPs mit +/- 5V versorgt Gruss, Thorsten.

Hallo, sid_cc_table.inc und sid_sysex_table.inc sind fuer solche Aenderungen nicht gedacht, da es in cs_* noch weitere Referenzen auf diese CC-Nummer gibt. Ich wuerde empfehlen, den Controller extern im Sequenzer oder MIDI Controller zu mappen Gruss, Thorsten.

The PIC18F452 doesn't provide enough flash memory to combine the MB64 application with C functions Best Regards, Thorsten.

The original LC has a 2x55 display, all display modes are trying to compensate the lack of availability of such a special display by placing the characters within a 2x80 screen Best Regards, Thorsten.

Thats easy - just modify the sent value in the following way: addlw 0x40 andlw 0x7f Best Regards, Thorsten.

Thats a good question - I would say that this is a bug, the bargraph should reach 100% once the maximum value is reached. I cannot tell you a specific function which is responsible for this error, I can only say that this something which needs to be fixed Best Regards, Thorsten.

Not only NOTES, but any MIDI event Best Regards, Thorsten.

I cannot tell you where to by the MAX525 in Australia, but concerning the SysEx mapping: just use any MIDI event which you don't like to use --- if AOUT is required, hook the SysEx handler to Pitch Bend, or Aftertouch, or ... Best Regards, Thorsten.

There are too many references to the CC number in different tables, and also within the code. Therefore I cannot recomment to change anything with this table. Just do the mapping externally in your sequencer or MIDI controller Best Regards, Thorsten.

The secret behind Prophet64 is, that it only provides a reduced parameter set, which is required to produce a TB303-like sound... and nothing else. Therefore it might seem that sounds are possible which were not possible before, but this is not true! You just only need to get a feeling about the mighty MBSID engine ;-) In general the filter behaviour is device specific. Note that this is an analog circuit, depending on the revision number and the age of the SID it sounds different. Fine control: you could assign one or two envelopes to the filter, set depth to +30 or so, then use cutoff as "coarse controller", and the "sustain" as "fine controller". Play some short notes and modify the "delay" parameter - do you hear the difference? :) However, once you select the tb303 algorithm in the v1.7303beta9 version, you will notice a reduced, but fine controlable cutoff range. Thats one of the main differences. Then load one of the TB303 examples from the patches/ directory into JSynthLib, check especially the envelope settings, they are giving you a lot of hints, what is important for TB303-like sounds. As mentioned many times before, I will write a detailed TB303 tutorial! Just give me some days to realize the new CEM filter circuit as an additional demonstration which powerful sounds are possible with external extensions Best Regards, Thorsten.

I'm sorry for the forum downtime, it was caused by a php script incompatibility. I wasn't able to find an internet cafe with complete access (e.g. slogin) during my holidays, therefore the delay... I upgraded the forum software to the latest version, now it seems to run again. I'm off for just another travel in the next days. Once I'm back, I will setup a server and forum maintenance team (the appr. people who are in my mind will get a mail next week) Best Regards, Thorsten.

Hi *, I'm off for the next three weeks due to diverse travels. Please keep the forum clean during this time! :-) Best Regards, Thorsten.

Der Wavetable Sequenzer bietet mehrere Moeglichkeiten. So kann man damit nicht nur Notensequenzen oder Arpeggios realisieren, sondern auch perkussive Klaenge. Zugegebenermassen ist das Editieren am Control Panel ist nicht besonders komfortabel, mit dem JSynthLib Editor kommt man wesentlich einfacher voran - am besten schaust Du Dir mal die WT Patches aus der Default Library an, und vielleicht auch die midibox_sid_tb303.patchlib im patches/ Verzeichnis der v1.7303 release. Hier habe ich vor, nochmal ein detailiertes HowTo zu schreiben, doch mir fehlt momentan einfach die Zeit... :-/ Mehr Infos zu Wavetables gibt es uebrigens auch im Wiki: http://www.avishowtech.com/midibox/wiki/index.php/MIDIboxSIDFAQ#QA11 Kann ich mir auf Anhieb nicht erklaeren. Die MIDI Engine filtert die eingehenden MIDI Events so aus, dass nur die des eingestellten MIDI Kanals durchgelassen werden. Insofern koennen Drums auf Kanal 10 den Synth nicht stoeren. Vielleicht sendet Dein Sequenzer Daten, die er gar nicht senden soll? Gruss, Thorsten. P.S.: naechste Antwort fruehestens in drei Wochen...

This is the MIDIbox SID made by Rio. Note the special panel design - he just re-used the keyboard PCB of his canibalized C64 :)

Armin secretly built all the MIDIboxes of the last years and now presented me the results - well done! :-) MIDIbox 16 + PSU MIDIbox CV MIDIbox FM + CV MIDIbox SID MIDIbox SEQ

Im OSC Menue gibt es keinen Pos/CC Eintrag, welches Menue meinst Du genau? Der Super-Poly Mode, in dem man Polyphon ueber mehrere SIDs spielen kann, gehoert nach wie vor zu den "planned features" - d.h., irgendwann wird er mal kommen Gruss, Thorsten.