MIDIbox FM utilizies the Yamaha YMF262 sound chip (also known as OPL3) for generating the famous FM sounds known from Soundblaster (compatible) soundcards of the early 90s. In addition to the OPL3 specific features (6 four-operator voices, 5 percussion instruments) some software implemented modulation sources have been added to allow more expressive and very experimental sound creations.
A single operator provides:
8 different waveforms
an adjustable output level with 6-bit resolution which affects the output amplitude (carrier) or the modulation index (modulator)
a frequency multiplier with 4-bit resolution
a simple envelope generator (ADSR), each parameter with 4-bit resolution. Sustain phase can be omitted
each BankStick can store 128 sound patches, 16 drumsets and 32 ensembles.
up to 8 BankSticks can be connected
8 optional CV outputs which can be assigned to the LFOs and EG5s for controlling analog filters, VCAs, effects, etc...
MIDIbox FM Demo Samples
Most of these samples don't reflect the typical OPL3 sound, but should demonstrate the possibilites of the MIDIbox FM in conjunction with external Fx gear.
The very first demo song. 4 voices are playing an E-Piano like sound, the morphed arpeggio sequence is played live with the MIDIbox SEQ. From 0:00-0:32 you will hear the raw sound output of the OPL3, at 0:34 it has been enriched with a chorus and delay effect.
The second demo song was recorded after the FM drums were working. The background noise will disappear once the LM314 OPA has been replaced by a high quality TL074
This is a collection of some nice sounds and tunes which have been created during development of the sound engine, mostly to test functions like portamento, envelopes and LFOs
A FM drum groove with an external echo effect. Sound parameters are tweaked during the drums are playing to demonstrate some possible variations
The 16 MIDIbox FM drumset presets
Some random patches which have been created with the mk_fm_random.pl script - they demonstrate the possibilities of the mighty MIDIbox FM sound engine. The stereo effects are realized by playing the same patch with four instruments. If the wavetable sequencer or the LFOs are in freerunning mode, the output of each instrument sounds (very) different. The outputs are routed to separate audio channels, which are placed at different panorama positions in the stereo sum. An external delay effect has also been added to improve the results.
This demo demonstrates the possibilities of the AOUT module - an external Moog filter (Schematic from Rick Jansen) has been added and is controlled from one of the eight CV outputs. Since I only own one filter, the different sounds have been recorded one after another via overdub. The song stops at 1:29 (no download error) Are you able to realize the same sounds with a common FM synth? ;-)
A demo which uses MIDIbox FM + 4 MBHP_AOUT_LC modules + 4 CEM3378 filters - my current setup. See also this forum article.
MIDIbox FM can be extended successively from a simple synth module without LCD and control elements to a complete rack (or desktop) unit with control surface.
Sounds can be played once the MBHP_OPL3 module has been connected to the MBHP_CORE. All parameters can be edited with the SysEx editor in realtime from a Windows/Mac/Linux computer. A BankStick is highly recommended, otherwise only one patch, one ensemble and one drumset can be stored in the internal memory. Wavetables can only be stored in BankSticks. Note also that up to eight BankSticks can be connected - the large storage is especially useful if fast access to the preset banks is desired. Each BankStick can store 128 Soundpatches, 16 Drumsets and 32 Ensembles.
The next extension step is the use of one 2x40 LCD + eight softbuttons + one ESC button + one CFG button + four Instr/OP select buttons + 10 LEDs + one data dial (rotary encoder) - this enables you to edit all sound parameters directly on the device. One MBHP_DINX4 module and one MBHP_DOUTX4 module is required to interface these parts to the core.
The last extension step is the use of four V-Pots + the 6+4 buttons and 6*4 LEDs of the selection matrix. No additional DINX4 or DOUTX4 module is required for this extension.
Please read also the MIDIbox FM Manual which discusses the details of the user interface!
Below a list of the complete "MIDIbox FM" - costs can be reduced by choosing cheaper buttons, a cheaper case/panel and by organizing collective orders in the MIDIbox Forum!
This project is a DIY project licensed under TAPR NCL. A commercial release is neither planned, nor allowed! But the license allows you to build and sell up to 10 units per year (e.g. to friends) as long as the given constraints of the license are not violated.