Roland SH-101 NOVAMOD Schematic

<<<NOVA-MOD>>>

FM Filter

VCF CV

LFO CLK

IN

IN

MODULATOR VCO SOURCE MIXER

LFO/CLK
RATE

TUNE

WAVEFORM RANGE

NORM LO HI

EXT AUDIO
IN

MOD PULSEWIDTH SUB OSC NOISE

LFO

MAN

ENV

EXT CLK
IN

VCF

FREQ RES ENV MOD KEYBD A

-1

-2

-2

CV GATE CV GATE

HOLDDC IN

IN

VCA ENVELOPE

GATE

Trig

ENV

LFO

GATE

PHONES OUTPUT

OUT

R

S

D

NOVA

POWER

VOLUME PORTAMENTO

PORTAMENTO

TRANSPOSE

BENDER

SEQUENCER ARPEGGIO LEGATO REST

PW SOURCE EXT AUDIO FM SOURCE AMOUNT

ROLAND

SH-101

Features:

• VCF FM: Amazing new sounds are now added through this feature. Six FM sources are

available.

• LFO Clock Input: Syncing the Arpeggiator and LFO to external drum modules and

sequencers is now possible. As well, interesting feedback loops can be created.

• PW Modulation Source Selection: Now you can choose a pulse width source. It is

independent from the LFO’s waveform setting. OSC sources are included.

• Pulse width to near 0%: Pulse width effects are now made more extreme and powerful.

• External Audio Input: The ability to do FM of the VCF by an external audio source or to

simply route a signal into the audio path is now provided. Don’t forget feedback loops!!

• VCF CV Input: Just plug in a foot pedal or a CV from a midi converter and your SH-101

will sing!

• LFO Rate Scalar: Ever hear a bell sound out of a 101? Try this on Hi!! Want a really slow

sweep...you got it too!

• 1/4” CV/Gate In/Out Jacks: Aren’t we all tired of those miniphono plugs? They should

only exist on walkmans.

NOVA-MOD Details:

Pulse width to near 0%

By closing the pulsewidth to a spike, new sounds can be attained by the SH-101. This “spike” wave source is very
useful for brightening a bass patch. (A bass patch, with only the sub Osc waveform assigned, can be brightened, but
not raised in pitch, by adding a little pulsewidth signal with a manual setting of less than 1% duty cycle.)
In another application, in which only full ramp waveform is assigned, manually raising and lowering the spike
waveform’s amplitude has been compared to sounding like a wavetable sweep.
As well, LFO modulation of the pulsewidth is made more dramatic because of the closer approach to 0%.

Pulsewidth Modulation Source Selection

A six-way rotary switch enables you to chose the pulsewidth modulation sources independently of the LFO’s waveform
setting. This modulation source makes many new and interesting sounds. A randomly modulated pulsewidth is
especially unique and pleasant.

The PW modulation sources are:
LFO Triangle
LFO Square
LFO Random
Sub Osc -1 Octave Square*
Sub Osc -2 Octave Pulse *
LFO Noise
* The Sub Osc Mod sources creates a unique bass enhancement because of their higher frequency and keytracking.
The result is a richer and deeper sound. As well, although there are only two sub Osc sources, changing the sub Osc
switch -1/-2/-2 results in even further modulation effects.

LFO Rate Scalar

A three-way toggle switch scales the overall range of the SH-101’s internal LFO Clk (the existing LFO rate slider still
functions normally). The scalar settings are Normal/Low/High.
In the Low setting, a cycle of 30 seconds can be attained. This is great for mild changes in “trance” type music.
In the High mode, up to 1200Hz can be used to create interesting cross-mod bell like sounds. Perfect for “industrial”
music and clanging metallic sounds. High mode works especially well when creating a synthetic kick drum patch or
short-wave radio sounds a la Kraftwerk’s Electric Cafe and Radioactivity albums respectively.

LFO Clock Input

A 1/4” jack allows the insertion of an external clock signal to drive the 101’s LFO. This injected signal triggers the LFO
but does not change it’s waveform. Buy applying a clock, LFO AND
source. This makes for very moving and groovy patterns with only a drum box and NOVA-MODed 101. A particularly
nice application is to modulate the VCF Cutoff with a Random LFO while playing the sequencer. Of course you can,
at the same time, inject a separate clock into the arpeggiator via the 101’s Ext. Clk In Jack. This will enable you to run
the arpeggiator and LFO at different speeds (hopefully related in some way).
As a bonus, audio can be injected to drive the LFO. A simple trick is to patch the headphone output into the Ext. LFO
Input. This feedback loop makes for sounds that can be mildly distorted to heavily distorted by simply adjusting the
VCF’s Mod amount. [No need for an external distortion processor!] This effect is great for slow sweeps with a
resonating filter setting. Very minimoog-ish.

External Audio Input

A 1/4” jack and toggle switch allows external audio to be injected. A rotary pot controls the amplitude of the injected
signal. It can be routed to one of two sources:

1. directly into the filter along with the OSC’s waveforms. External processing of audio through the VCF and ENV is
a typical feature on some synths however a separate trigger can be applied to fire the SH-101’s envelope.

2. into the VCF’s cutoff modulation point. (An external FM source)

VCF CV Input

An external CV can be applied to the 101 via this 1/4” jack. This feature is typical on a Juno-60, Jupiter 4 and Pro­One. A MIDI controller converted to a CV or an “expression” foot pedal are typically connected here.

arpeggiator are both synced to the external

VCF FM

VCF FM is the most powerful NOVA-MOD feature. It can be used in moderation to simply add brightness to a bass
patch with low frequencies (due to subtractive synthesis). Or it can be used to create powerful cross-mod sounds that
are difficult to explain...they must be heard. These sounds are somewhat aggressive, distorted, bell like but most
importantly, not attainable on a regular SH-101. These sounds are similar to those heard on a MiniMoog with its third
LFO assigned.
One example: Dial a patch with only a ramp waveform assigned but at the same time, modulate the VCF Cutoff with
the Pulsewidth. Manually change the pulsewidth to vary the FM effect. It is quite unique. You can then switch in Sub
Osc -2 Oct. Pulse as the FM source then adjust the -1oct/-2oct/-2oct switch to change the sound further. Finally swing
the Pulsewidth waveform as the FM source but switch from Manual to LFO modulation and then play with the PW
Mod’s waveform.

A rotary pot controls the amount of modulation. A six-way rotary switch selects the FM Source:
Pulse waveform
Ramp waveform

-1 Octave Sqr waveform*

-2 Octave Sqr waveform*

-2 Octave Pulse waveform*
Noise waveform
* As well, although there are only two Sub Osc Sources, the sub Osc switch -1/-2/-2 changes the sound, giving
even more variety.

ENV #2

A second Attack/Decay envelope. (To be developed). This is in the works but hopefully will be available soon.

1/4” CV/Gate In/Out Jacks

The existing 1/8” jacks are replaced by 1/4” jacks. Nothing special here except convenience.

NOVA-MOD Parts List

2 6 position Rotary Switches (Radio Shack units work fine but 3” long shafts must be cut. As well, pins must be
flattened to prevent interference with keyboard action, shims may be required to lower keyboard.)
Roland 4 position switches (pn 13119303 SRM1034-K15) may be used also but the switches must be
“adjusted” to swing 6 positions. The same clearance considerations must be made with respect to the key action
however these switches will accept the correct Roland knobs.

2 100K Rotary Pots. (Radio Shack units work fine but 3” long shafts must be cut. As well, pins must be
flattened to prevent interference with keyboard action, shims may be required to lower keyboard.)
Roland pots (pn 13219274 EVH-5XAP20A15) may be used. The same clearance considerations
must be made with respect to the key action however these pots will accept the correct Roland knobs.

1 DPDT Switched 1/4” jack.

2 1/4” Jacks with shorting contact

4 1/4” Jacks

1 SPDT toggle switch with center off position

1 4.7 uF 10V cap.

1 150K resistor

3 100k resistor

1 50k resistor

4 knobs (Roland PN 016H071)