PEACOCK MIDISID User manual

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https://peacockmedia.software/midisid"
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Introduction 3
Powering MIDISID 3
Inputs, outputs and controls 4
Sockets 4
Controls 4
Stereo output 6
Reset button 6
The three modes 7
General MIDI mode 7
Polyphonic mode 8
Monophonic mode 8
MIDI Control change messages (CC) 9
Voice mapping 10
General MIDI mode 10
Polyphonic mode 10
Monophonic mode 10
Playing a .mid file and getting the most out of it 11
Preset instruments 12
Advanced SID settings 12
Ring modulation 12
Muting voice 3 13
The SwinSID Nano b 14
Other SID replacements or real SIDs? 14
Updating the firmware 15
Dismantling MIDISID 15
Troubleshooting 16
Appendices 17
Appendix A 17
The menu 17
Appendix B 18
Bring your own box 18
Appendix C 19
The list of General MIDI instruments 19
Appendix D 22
General MIDI Percussion (Channel 10) 22
Appendix E 23
MT-32 Instrument list 23
Appendix F 26
Control Change (CC) codes and values 26
Appendix G 28
Version control 28
Appendix Z 29
Planned features 29
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!"#$%&'()%"*
Thank you for your interest in MIDISID. As its name suggests, it contains two modern SID
replacements and responds to MIDI.
I have long dreamed of multiple SIDs in a small device which can be driven by any MIDI input, or
play a .mid file, and have multiple rotational controls for the SID's parameters - ADSR, filter PWM
and so on.
The SID is the "Sound Interface Device" originally designed for the 1982 Commodore 64 home
computer. It has a distinctive sound and was clearly designed to stand alone as a 'synthesizer on a
chip'.
If you don't know or care for the history of the C64 or SID, then MIDISID is a MIDI-based 6-
oscillator synthesizer with a choice of 4 waveforms (plus combinations) per voice, ADSR envelope
per voice, one filter with resonance control per chip, modulations such as PWM, filter sweeps,
vibrato and advanced features such as waveform sync and ring modulation.
If you don't find the information you're looking for in this manual, I'll be very glad to discuss any
aspect. Find the contact form or register for email updates at https://peacockmedia.software/
midisid/
~ Shiela
+%,-$."/*0!1!2!1*
Power MIDISID with 9vDC via the barrel socket using a 5/2.1mm barrel jack. This needs to be
centre-negative as per the symbol above which may be marked on your supply. MIDISID will draw
around 100mA when fitted with two SwinSIDs, so make sure that your supply can safely deliver at
least that.
A lot of guitar pedals use this type of supply, so if you need to shop for a power supply then a
search for "guitar pedal power supply" may be a good starting point.
!
A 9v battery with the supplied battery clip -> barrel plug adaptor will work. (Rechargeable is good.)
This will get you started quickly and may be useful in situations where you aren't close to a mains
supply or don't have enough sockets. That may not be ideal for regular long-term use because
battery life is relatively short (your mileage may vary, but a typical 175mAH battery may last just
under 2 hours of continuous use) and the audio output will become noisier as the battery is used
and the voltage falls.
Because of possible ground-level differences, please connect the audio and MIDI cables first, and
the power last.
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Sockets
MIDISID has four sockets at the rear (right-left):
•a barrel jack which will take a 9v centre-negative power supply. See Powering MIDISID
•a standard MIDI 5-pin DIN for midi in. Currently MIDISID only accepts MIDI via the good old-
fashioned 5-pin DIN. If your keyboard or other device uses midi over bluetooth or USB then use
a suitable adaptor. Generally with 5-pin DINs, the 'out' of one thing connects to the 'in' of another.
•a 3.5mm stereo jack socket for audio out.
•a micro USB. Used only for updating the firmware. (see Updating the firmware.) Does not
receive or send MIDI over USB. Don’t try to power the unit via the micro USB
Controls
It has four controls. These are rotary encoders with push buttons.
They aren’t labelled but if we imagine them named A - D:
A is the main navigation control. Turn left and right to scroll through a menu.
Push A to select, but note that at the deepest level of any menu (for example, selecting an
instrument) simply scrolling through the options is enough, no need to push A.
B is the secondary navigation control. It will scroll through longer menus faster. For example It’ll
scroll up or down through the list of instruments 8 at a time, which has the effect of moving from
one group of instruments to the next. (128 instruments, arranged in groups of eight, see Appendix
C). It acts as a 'coarse' control when adjusting tuning in cents.
Push B for ‘up’ or 'back'
C can sometimes be a 'supercoarse' control. For example when tuning, A will move one cent at a
time, B 8 cents and C a whole octave at a time.
Button D (when you are in Monophonic or Polyphonic mode) will invoke the save/load menu. You
can choose to save your current settings to one of 16 slots, or load previously-saved settings from
one of those slots.
See Appendix B for the full navigation menu"
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Rotary controls and context
A
B
C
D
A D S R
Attack
Decay
Sustain
Release
PW / PWM
Pulse Width
Modulation speed
Modulation depth
toggle Reset
Filter
Filter type
Cutoff frequency
Resonance
Sweep
Off / time
Cutoff freq. start
Cutoff freq. end
Vib
Delay
Vibrato speed
Vibrato depth
Tuning
Fine, +/- 1 cent
Coarse, +/- 8 cents
+/- 1 octave
Ring/sync
toggles ring/sync
toggle mute voice 3
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Stereo output
The two-SID version of MIDISID has a stereo output jack, which can give the illusion of stereo but
there's no mixing or panning. The 3 voices from one SID go to one channel and the 3 from the
other go to the other channel. (The voices on each chip are mixed within the SID). Depending on
the mode and voices used, this can sound pleasing, or odd, or sound as if all of the sound is
coming from one side. If you want to mix to mono, use a stereo-mono adaptor in the jack or mix
down to mono after recording.
If you're composing your own music, you can make an instrument appear on one side or the other
by putting it on channel 1-3 or 4-6 (or 4-5 if you're also using channel 10, which will be mapped to
voice 6)
Reset button
The reset button is on the bottom board, towards the front and to the right of centre.
(Early MIDISIDs left the button unpopulated, if this the case, a button was included with your
MIDISID. The button should snap into place and snap out again very easily and make good
connection while it's in place.)
It doesn't perform a hardware reset of the SIDs, but when the microcontroller is reset, the Pico sets
all SID registers to zero and then applies the default patch to the voices. If a harder reset is
required, cycle the power.!
The main reason for including a reset button is so that you can update the firmware. The Pico's
boot mode button is very difficult to access without dismantling the MIDISID. (See Updating the
firmware.)"
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General MIDI mode
Any MIDI player should allow you to choose the output. To connect your computer to MIDISID you
can use a USB MIDI interface or an audio interface that has traditional MIDI sockets.
MIDISID should render a midi file as well as possible within the limitations of the SID. In practice
some files will work better than others. Files that only use fewer channels and fewer notes at a time
per channel are more likely to sound best. For more complex files, you can edit the files in a DAW
to improve the results. There are now many examples of MIDISID playing .mid files at the Youtube
channel https://www.youtube.com/@MIDI_IN
For more details, see Playing a .mid file and getting the most out of it!
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Polyphonic mode
Plug in a keyboard or other controller, switch to polyphonic mode and play with 6-voice polyphony.
Select from 128 preset sounds or access the SID's settings (wave, ADSR, PWM, filter). Use the
preset instruments or play with the settings to create your own.
Monophonic mode
Plug in a keyboard or other controller and switch to monophonic mode to play complex or full
sounds that combine all of the voices and settings on a chip. Use the preset instruments or play
with the settings to create your own.
Using any of the modes, you can use a DAW to send MIDI to MIDISID and then capture the
resulting audio. Logic Pro calls this an "External MIDI Instrument", Ableton an "External Instrument
Device". Check tutorials for your particular DAW.
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MIDISID currently responds to:
•pitch bend messages (0xE0-0xEF) (full range of control is one tone either way)
•program change messages (0xC0-0xCF)
•mod wheel messages (0xB0-0xBF (CC) 01) Using the menu (Monophonic or Polyphonic >
Parameters > Modwheel) you can set whether this controls vibrato strength, filter cutoff or pulse
width (obviously the latter will only have an effect if square wave is being used.)
•Pitch bend sensitivity (RPN 0, MSB - semitones)
•Control Change (CC) messages (0xB0-0xBF followed by the control number and the appropriate
value listed in Appendix F)
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General MIDI mode
Each MIDI channel is assigned to voice. So on a 2-SID MIDISID, channels 1-6 are mapped to
voices 1-6.
One special case - if a note is detected on channel 10 (traditionally percussion). Then channel 10
is assigned to voice 6, with channels 1-5 mapped to voices 1-5. This mapping persists until the
next power-on.
The default patch for a voice is a piano sound, but a MIDI 'program change' message will change
the patch for that channel / voice. MIDISID will handle the program change messages 0-127 (or
sometimes given as 1-128. See Appendix C.
Patches will persist on the channel until another program change message is received, the mode is
changed or MIDISID is reset.
You can use this to your advantage and get more sounds in your music by using multiple program
changes within a track. Obviously only one part can be played at a time, but this allows you to put
multiple instruments on a single channel / voice as long as they don't play at the same time.
.mid files usually contain one instrument per channel, with program change messages at the start.
If you're composing your own music, or if you open an existing .mid in a DAW, then it's easy to
change these program change messages or add more wherever you like.
Obviously after powering-on or resetting you may have to make sure that you play a track or .mid
file from the start so that MIDISID receives the program change message for each channel.
Polyphonic mode
The same patch is applied to all voices on all chips. A note is played using a single voice. Any note
on any channel is assigned to the next free voice. If all voices are in use, then the note can't be
played
Monophonic mode
A patch uses all three voices on all chips. All are triggered by a note, giving (with 2 SIDs) a stereo
output with 3 voices heard on both channels. Because 6 voices are heard but unlikely to be in
sync, the sound will be rich and full. (the sync setting changes this.) This chorus effect can be
enhanced by adjusting the tuning of each voice very slightly. Some patches, eg Honky Tonk, use
this for effect.
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