A guitarist playing a grey Circle Guitar, the wheel leaving a trail of cyan light

Two modes, four ways to control it.

Player mode

White light

The guitar’s own controls drive the wheel.

Standalone

MIDI mode

Amber light

The wheel follows MIDI from your pedalboard, controller or DAW, and every control sends MIDI to external devices.

Pedalboard
Morningstar MC Pro
MIDI controller
Tested with BeatStep Pro. Others yet to be tested.
DAW

To change modes, hold the encoder down while you switch the guitar on.

For sonic explorers

The hexaphonic pickup makes the six strings six independent voices. From subtle augmentation to complex multichannel sound design, the guitar can behave like a six-part ensemble, shaped by both hands and the precise control of the strumming wheel.

The controls

Player modeMIDI mode

The white Circle Guitar from the front, with its main controls labelled

EncoderPlayer mode: Press: start and stop. Turn: speedMIDI mode: Press: D1 (note 38). Turn: CC3
Home buttonPlayer mode: One turn to Home, at the last-set speedMIDI mode: Wheel home. C#1, velocity 127
Button 1Player mode: 1× speedMIDI mode: B2
Button 2Player mode: 2× speedMIDI mode: A#2
Button 3Player mode: 3× speedMIDI mode: A2
Button 4Player mode: 4× speedMIDI mode: G#2
Button 5Player mode: 5× speedMIDI mode: G2
Button 6Player mode: 6× speedMIDI mode: F#2
Pot 1Player mode: CC14, 0–127MIDI mode: CC14, 0–127
Pot 2Player mode: CC15, 0–127MIDI mode: CC15, 0–127

Build

Body: solid alder
Neck: maple, titanium-reinforced, 25.5″ / 650 mm
Fretboard: sustainably sourced ebony
Frets: Jescar 47104
Nut: Graph Tech
Bridge: Gotoh FX6
Machineheads: Gotoh SGL510Z
Strings: D’Addario
Pickup: Cycfi Nu Multi 6 hexaphonic
Outputs: mono and multichannel out
Breakout: Cycfi Nexus-GK (Cycfi Research product page, opens in a new tab), one output per string
Wheel: 16 pick positions, removable in two halves with the strings on
Picks: 16 magnetic Magpicks with interchangeable soft, medium and hard nylon picks, for different picking strengths

Full control reference

Position control

On startup, the wheel rotates until pick position 1 reaches the Home position.

There are 64 discrete stop positions mapped to 64 MIDI keys, known as Positional Notes.

Pressing a Positional Note spins the wheel. Releasing it stops the wheel, placing your selected note in the Home position.

Whole positions, 1 to 16, with their notes
Ticks mark quarter steps

E8 stops the wheel.

Using a single Positional Note will result in at least one full rotation.

To stop in under one full rotation, release and press another note before the wheel passes the new selected position.

Sequencing a series of short notes together can create continuous rotation, strums, swing or intermittent rhythmic bursts.

Every fourth note is a whole position: C3 is 1, E3 is 2, G#3 is 3, and so on to C8, 16.

Full table, every note

Note no.	Note	Destination
60	C3	1
61	C#3	1.25
62	D3	1.5
63	D#3	1.75
64	E3	2
65	F3	2.25
66	F#3	2.5
67	G3	2.75
68	G#3	3
69	A3	3.25
70	A#3	3.5
71	B3	3.75
72	C4	4
73	C#4	4.25
74	D4	4.5
75	D#4	4.75
76	E4	5
77	F4	5.25
78	F#4	5.5
79	G4	5.75
80	G#4	6
81	A4	6.25
82	A#4	6.5
83	B4	6.75
84	C5	7
85	C#5	7.25
86	D5	7.5
87	D#5	7.75
88	E5	8
89	F5	8.25
90	F#5	8.5
91	G5	8.75
92	G#5	9
93	A5	9.25
94	A#5	9.5
95	B5	9.75
96	C6	10
97	C#6	10.25
98	D6	10.5
99	D#6	10.75
100	E6	11
101	F6	11.25
102	F#6	11.5
103	G6	11.75
104	G#6	12
105	A6	12.25
106	A#6	12.5
107	B6	12.75
108	C7	13
109	C#7	13.25
110	D7	13.5
111	D#7	13.75
112	E7	14
113	F7	14.25
114	F#7	14.5
115	G7	14.75
116	G#7	15
117	A7	15.25
118	A#7	15.5
119	B7	15.75
120	C8	16
121	C#8	16.25
122	D8	16.5
123	D#8	16.75
124	E8	STOP

Speed control

Note velocity governs rotational rate in revolutions per bar (RPB).

In MIDI mode, with the wheel locked to the bar by MIDI clock, revolutions per bar is how many full turns the wheel makes in one bar of music, at the current tempo.

Speed control, played: velocity, the wheel, one bar of MIDI, and the CC74 envelope

Velocity

16Velocity gives 2RPB

60 RPM

Note held

The maximum rotation speed is 300 RPM, so the available range of RPB is dictated by the BPM.

MIDI editor: one bar, Positional Note C3

Drag the end of the note back to shorten it. At note-off the wheel stops at its next home, then starts when the note plays again.

CC74 envelope (velocity 1)

Velocity 1 on a Positional Note switches to CC74 speed control: an envelope drives the wheel’s speed, using the chart’s 2–127 values.

This allows an expression pedal on the Morningstar MC Pro to control the speed, an LFO to create a speed-change loop, or MPE MIDI to draw speed ramps tied to a Positional Note.

Click or tap to add a point, drag to move it, double-click or double-tap to remove it.

Tempo, BPM

BPM governs tempo.

The chart below shows the RPB value corresponding to each MIDI velocity.

Full table, velocity 0 to 127

Velocity	Function
0	Does nothing
1	CC74 SPEED CONTROL
2	0.25 RPB
3	0.375 RPB
4	0.5 RPB
5	0.625 RPB
6	0.75 RPB
7	0.875 RPB
8	1 RPB
9	1.125 RPB
10	1.25 RPB
11	1.375 RPB
12	1.5 RPB
13	1.625 RPB
14	1.75 RPB
15	1.875 RPB
16	2 RPB
17	2.125 RPB
18	2.25 RPB
19	2.375 RPB
20	2.5 RPB
21	2.625 RPB
22	2.75 RPB
23	2.875 RPB
24	3 RPB
25	3.125 RPB
26	3.25 RPB
27	3.375 RPB
28	3.5 RPB
29	3.625 RPB
30	3.75 RPB
31	3.875 RPB
32	4 RPB
33	4.125 RPB
34	4.25 RPB
35	4.375 RPB
36	4.5 RPB
37	4.625 RPB
38	4.75 RPB
39	4.875 RPB
40	5 RPB
41	5.125 RPB
42	5.25 RPB
43	5.375 RPB
44	5.5 RPB
45	5.625 RPB
46	5.75 RPB
47	5.875 RPB
48	6 RPB
49	6.125 RPB
50	6.25 RPB
51	6.375 RPB
52	6.5 RPB
53	6.625 RPB
54	6.75 RPB
55	6.875 RPB
56	7 RPB
57	7.125 RPB
58	7.25 RPB
59	7.375 RPB
60	7.5 RPB
61	7.625 RPB
62	7.75 RPB
63	7.875 RPB
64	8 RPB
65	8.125 RPB
66	8.25 RPB
67	8.375 RPB
68	8.5 RPB
69	8.625 RPB
70	8.75 RPB
71	8.875 RPB
72	9 RPB
73	9.125 RPB
74	9.25 RPB
75	9.375 RPB
76	9.5 RPB
77	9.625 RPB
78	9.75 RPB
79	9.875 RPB
80	10 RPB
81	10.125 RPB
82	10.25 RPB
83	10.375 RPB
84	10.5 RPB
85	10.625 RPB
86	10.75 RPB
87	10.875 RPB
88	11 RPB
89	11.125 RPB
90	11.25 RPB
91	11.375 RPB
92	11.5 RPB
93	11.625 RPB
94	11.75 RPB
95	11.875 RPB
96	12 RPB
97	12.125 RPB
98	12.25 RPB
99	12.375 RPB
100	12.5 RPB
101	12.625 RPB
102	12.75 RPB
103	12.875 RPB
104	13 RPB
105	13.125 RPB
106	13.25 RPB
107	13.375 RPB
108	13.5 RPB
109	13.625 RPB
110	13.75 RPB
111	13.875 RPB
112	14 RPB
113	14.125 RPB
114	14.25 RPB
115	14.375 RPB
116	14.5 RPB
117	14.625 RPB
118	14.75 RPB
119	14.875 RPB
120	15 RPB
121	15.125 RPB
122	15.25 RPB
123	15.375 RPB
124	15.5 RPB
125	15.625 RPB
126	15.75 RPB
127	15.875 RPB

Each control, by mode

Control	Player mode	MIDI mode
Indicator light	White	Amber
MIDI mappable	Pots 1 and 2 only	Every control
Encoder press	Starts and stops the wheel in a continuous spin	Sends MIDI Out D1 (note 38)
Encoder turn	Sets the speed. The default is 4×, the same as button 4	Sends CC3, range 0–127
Home button	Each tap turns the wheel once at the last-set speed and stops pick position 1 at the Home position. Tap again while it turns to keep it turning; taps don’t add up. Press the encoder to return to a continuous spin.	Sends the wheel back to the Home position. Sends MIDI Out C#1, velocity 127.
Button 1	1× speed	MIDI Out B2
Button 2	2× speed	MIDI Out A#2
Button 3	3× speed	MIDI Out A2
Button 4	4× speed	MIDI Out G#2
Button 5	5× speed	MIDI Out G2
Button 6	6× speed	MIDI Out F#2
Pot 1	MIDI Out CC14, range 0–127	MIDI Out CC14, range 0–127
Pot 2	MIDI Out CC15, range 0–127	MIDI Out CC15, range 0–127

Player mode

Indicator light	White
MIDI mappable	Pots 1 and 2 only
Encoder press	Starts and stops the wheel in a continuous spin
Encoder turn	Sets the speed. The default is 4×, the same as button 4
Home button	Each tap turns the wheel once at the last-set speed and stops pick position 1 at the Home position. Tap again while it turns to keep it turning; taps don’t add up. Press the encoder to return to a continuous spin.
Button 1	1× speed
Button 2	2× speed
Button 3	3× speed
Button 4	4× speed
Button 5	5× speed
Button 6	6× speed
Pot 1	MIDI Out CC14, range 0–127
Pot 2	MIDI Out CC15, range 0–127

MIDI mode

Indicator light	Amber
MIDI mappable	Every control
Encoder press	Sends MIDI Out D1 (note 38)
Encoder turn	Sends CC3, range 0–127
Home button	Sends the wheel back to the Home position. Sends MIDI Out C#1, velocity 127.
Button 1	MIDI Out B2
Button 2	MIDI Out A#2
Button 3	MIDI Out A2
Button 4	MIDI Out G#2
Button 5	MIDI Out G2
Button 6	MIDI Out F#2
Pot 1	MIDI Out CC14, range 0–127
Pot 2	MIDI Out CC15, range 0–127

The light also shows blue when a MIDI note is received and green when MIDI clock is received.

Defaults

MIDI In: Channel 2
MIDI Out: Channel 1
Full wheel control: MPE MIDI set to Multi-Channel, with First and Last Note Channels set to Channel 2

Two modes, four ways to control it.

Player mode

MIDI mode

For sonic explorers

The controls

Build

Full control reference

Position control

Speed control

Each control, by mode

Player mode

MIDI mode

Defaults

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