WMD Synchrodyne Expand Enhanced Control User Guide
- June 1, 2024
- WMD
Table of Contents
WMD Synchrodyne Expand Enhanced Control
Specifications
- Core: 4 pole (-24dB/octave) Switched Capacitor Filter circuit
- Output: 2 pole output for mellower filter sound, self-oscillates at high resonances
- VCO Frequency Range: .02Hz to 400kHz
Product Usage Instructions
Synchrodyne Overview:
The Synchrodyne is a modular system composed of various modules to create a
flexible and stable Switched Capacitor filter. It comprises three main parts:
the VCO, filter circuit, and modulation inputs.
VCO and Signal Processing
- VCO Controls: Use the Fine knob to tune the oscillator within its frequency range. The VCO tracks at least 5 octaves using the V/Oct Input for pitch control.
- Sync Input: Provides a rising edge sawtooth reset/sync input without affecting the slope of the sawtooth wave.
- FM Inputs: Utilize the Lin 1K and lb:p 1K inputs for linear and exponential frequency modulation to the VCO respectively. Adjust the blue trim-pot on the back for input signal levels.
Filter and Resonance Control
- Resonance Knob: Directly controls the resonance of the Switched Capacitor Filter. Adjust using the Reeonuce Eno’b knob.
- Resonance Modulation: Apply frequency modulation to the primary Resonance knob using the Reeonuce CV Xnpu.t and Attenuate% input for animated filter resonance.
Output Modes
The LovePue / BandP&H / BipPaee ToaVle selector determines the output mode of
both the 2-Pole and 1-Pole outputs. Thank you for purchasing the WMD
Synchrodyne. We hope you its sound and features. The Synchrodyne multitude of
modules put together to create a flexible and stable Switched Capacitor
filter. It consists of three main parts.
VCO
The Synchrodyne’s VCO is a traditional Sawtooth Core. Its frequency range is ~.02Hz to 400kHz.
- IV/Oct Input – Calibrated input for pitch control. They do not affect the slope of the sawtooth.
- Coarse & Fine Knobs – Coarse to tune the oscillator within approximately 1/3 octave range.
- Exp FM – This input jack and bipolar attenuator provide exponential FM to the VCO. This input is DC coupled.
- Lin FM – This input jack and bipolar attenuator provide Linear FM to the VCO. This input can be DC or AC coupled. A jumper on the back enables DC coupling when a shift is caused by the bipolar attenuator’s voltage.
- Saw Output – The Sawtooth output is available here. Its level is approximately +-4.5 volts.
- Pulse Output – This output presents the rectangle wave necessary for driving the PLL. It is not a 50% duty cycle square, but approximately 30%/70% as that provided the best performance for driving PLL.
Warranty and Other Information
The Synchrodyne is 14 HP. Current consumption is 60mA for the +12 rail; and 50mA for the -12 rail. The majority of the audio circuitry runs at +-5 volts and uses high-speed rail-to-rail opamps. The depth from the back of the panel is roughly 40mm with connectors. Synchrodyne is reverse polarity protected. The Synchrodyne is RoHS and CE compliant. The Synchrodyne is warranted for 12 months after purchase. But please contact us if you ever have problems. We will take care of you.
Phase Locked Loop (PLL)
The PLL takes the rectangle wave from the VCO and drives the filter.
CLK Input
Rev 1.09-1.13. VCO Pulse is normaled here. Plug in an external clock to
control the PLL. Rev 1.14 – Logical OR input to Filter with the PLL. Allows
for formant sounds (two simultaneous filter frequencies). Rev 1.15 – Switch on
back to go between Logical OR and classic CLK Input mode.
Multiply & Divide Switch Knobs
These rotary switches adjust the frequency of the clock multiplier & divider
inside the PLL. Adjust these to set the frequency ratio. Higher multiplication
factors cause the PLL to react especially at low input frequencies.
Phase Delta Output
This output represented by symbols is the result of the multiplication factor
It produces some self-PWM as the PLL stabilizes and will equal the input clock
frequency if the PLL is locked. This output provides an interesting self-
modulating audio or clock
PLL Output
This is the output of the PLL stage. It is the input frequency multiplied and
divided by the set ratios.
Track Speed Knob
This controls the reaction speed of the PLL in trying to with changes to
the input Causing the reaction to reply faster than the rack causing the PLL
to respond faster than the frequency. Overtracking produces a frequency output
and low bursts of high and low-frequency output.
Damping Knob
This control reduces the rate of fluctuation while over-tracking, damping the
over-tracking and increasing stability. More damping will be needed as higher
ratios of Frequency Influence tape ca cata This control This control acts
directly with the Track Speed and Damping controls in stabilizing the
frequency of the PLL. Use a voltage source to modulate the PLL signal. Very
complex modulations are possible by using Influence with the internal VCO and
other controls.
Influence Input and Knob
This control directly with the track speed and Damping controls in stabilizing
the frequency of the PLL. Use a voltage source to modulate the PLL signal.
Very complex modulations are possible by using Influence with the internal
VCO and other r controls.
Filter
The core of the Synchrodyne is a 4-pole (-24dB/octave) Switched Capacitor
Filter circuit. The 2-pole output is tapped and provides a mellower filter
sound. The Synchrodyne will self-oscillate at high resonances on both outputs,
however, it is more prominent on the 4-Pole output. The Switched Capacitor
Filter topology has a few interesting features. It is a sampled data
construct, so, at low cutoff frequencies, the filter will produce aliasing
noise, similar to the sample rate reduction on the Geiger Counter. This
topology is also very stable and accurate, allowing for predictable cutoff
frequencies to be selected. Across its entire range (.02 Hz to 16kHz) the
filter will remain within +-0.2% of where it should be.
In Jack – Insert signal to be filtered here.
VCA CV Input and Knob – When there is no input to the VCA CV Jack, the knob
acts as an attenuator for the input signal. Plugging into the VCA CV jack
causes the knob to act as an attenuator for the CV signal controlling the
input VCA. Fold Toggle – Flipping this up causes the input VCA to drive a
four-stage wavefolder. The output of the wave folder then goes to the filter.
The level of the input signal going into the filter from the wave folder is
adjustable with the blue trim pot on the back of the Synchrodyne. This will be
broken out to the expansion.
Resonance Knob – Directly Controls the resonance of the Switched Capacitor Filter. Resonance CV Input and Attenuator – This input will add to the primary Resonance knob through the attenuator. Use for animating the Filter’s resonance. 100:1 – 50:1 Ratio Toggle – This controls the filter core’s frequency ratio. There is one octave of difference between the two frequencies, the settings. At low 50:1 the ratio will produce more aliasing/sampling distortion.
LowPass / BandPass / HighPass Toggle – Selects the output mode of both the 2-pole and 4-pole outputs. Filter Outputs – Jacks for the 2 Pole (-12dB/Oct) and 4 Pole (-24dB/Oct) are available. Please note that they are 180 degrees out of phase from each other. Additionally, a single-stage wave- told output is available for both the 2-pole and 4-pole outputs. The wave- folded outputs provide another level of sonic depth to experiment with.
Warranty and Other Information The Synchrodyne is 14 HP. Synchrodyne Current consumption is 60mA for the +12 rail; and 50mA for the -12 rail. multiply POLL The majority of the audio circuitry runs at +-5 volts 10009,512*56 and uses a high-speed rail-to-rail opamp. The depth from the back of the panel is roughly 40mm with connectors.
Filter
Synchrodyne is reversed polarity protected. The Synchrodyne is RoS and CE
compliant.
Bean Cl
The Synchrodyne is warranted for 12 months after purchase. But please contact
us if you ever have problems. We will take care of you.
Revision 1.09 (2012)
The Synchrodyne is calibrated at the factory and calibration should not be necessary. The PLL Expansion Header is not connected. For connecting expansions, remove jumpers and connect the red stripe of the 14pin cable towards the asterisk (). indicates factory calibrated.
Revision 1.13 (2016)
The Synchrodyne is calibrated at the factory and calibration should not be
necessary. For connecting expansions, remove jumpers and connect the red
stripe of the 14-pin cable towards the asterisk.
- Power Header, Red Stripe down.
- The PLL Expansion Header is not connected.
- Wave Folder Level Trim.*
- Audio Expansion Header
- The bottom set of pins must be jumpered if expansion is not connected.
- Wavefolder Bias trim.
- Expand normal switch the Expand module.
- Linear FM AC/DC Switch.
- 1V/Octave Trim.
- Saw Wave Offset.
- The output level is centred.
The Synchrodyne is calibrated at the factory and calibration should not be necessary. For connecting expansions, remove jumpers and connect the red stripe of 14-pin cables towards the asterisk. For rev 1.15, 14-pin expand cables do not need to have a cutout pin. indicates factory calibrated.
- Power Header, Red Stripe down.
- PLL Expansion Header The top two sets of pins must be jumpered if expansion is not connected.
- Wave Folder Level Trim.*
- Audio Expansion Header. The bottom set of pins must be jumpered if expansion is not connected.
- Wavefolder Bias trim.*
- Expand the normal switch Set to NORM for no expansion. Set to EXPAND for use with the Expand module.
- Linear FM AC/DC Switch.
- 1V/Octave Trim.
- Saw Wave Offset.
- PWM Trim. Set so that at maximum VCO frequency, Pulse Output level is centred about oV.
- CLK IN jack setting: Set to CLK IN to bypass the VCO when you patch into CLK IN.
- Set to CLK OR to have the CLK IN jack logical OR to PLL going to the filter. CLK OR lets you do formant filtering with just the Synchrodyne.
FAQs
Q: What is the frequency range of the VCO?
A: The VCO frequency range is from .02Hz to 400kHz.
Q: How does the Filter self-oscillate?
A: The Filter will self-oscillate at high resonances on both outputs, with
more prominence on the 4 Pole output.
Q: How stable is the Switched Capacitor Filter topology?
A: The topology is very stable and accurate, allowing for predictable cutoff
frequencies to be selected within +-0.2% of the desired range.