Sunday, 22 May 2016

Korg PS 3100 - Temperament Adjust

The Temperament Adjustment allows you to tune the synth to different scales.

In the manual, it's described as a 12 note Temperament Adjust
Eg: Mean tone system, the Hepatonal Scale & the Just intonation scale.

In the Western world, we are used to the "Well Tempered Scale"

Saturday, 21 May 2016

Korg PS 3100 - Signal Generator - Oscillators

The signal generator (SG) is Korg speak for the oscillators.
The different waveforms are TRI, SAW etc.

PWM, Frequency adjust... fine & coarse.

Immediately below the SG section we have the modulation section.

For this to be active push the right orange switch to "on".
Notice the reverse switch on the left.
This section allows you to route MG1 (LFO) , the GEG (General Envelope Generator) or some external modulation source to the SGs.
So you can frequency modulate. :-)

Friday, 20 May 2016

Korg PS 3100 - Dynamic Low Pass Filter

The Low Pass Filter.
You have your standard controls ... Cut off frequency (Fc) & peak resonance (Q).
Remember that the PS 3100 has a independent filter for every key.
The Peak resonance (Q) knob adjusts the degree of emphasis at the cut off point, determined by the Fc knob

Below this is the KBD Filter balance & expand.
They allow you to adjust how the filter behaves along the span of the keyboard.

The KBD Filter Balance adjusts the Fc of each of the key's independent filters over a rising or falling slope corresponding to the scale of the keyboard.

The EXPAND knob adjusts the degree to which the Fc is varied by the envelope signal formed by the EM section (to the right).

Below the filter section is a modulation section.
You need to push the orange switch to "on" for this section to be active.
There are controls for the MG1, GEG & external CV modulation signals.
The MG 1  & GEG knobs adjust the depth of modulation.

 It's very similar to the mod section of the Signal Generators.

Korg PS 3200 - 11. GEG - General Envelope Generator

The GEG is a 3 stage envelope generator: Delay-Attack - Release.
 There is also a Auto switch -- when on, the envelope will automatically loop.
The 5 bottom jacks consist of 3 outputs & two trigger inputs.

There is also an input for control of VCA 1 .... which is part of the TSM

There are 2 types of triggers you can use:
a. Keyboard Trigger (KBD TRIG)
b. Momentary switch  (M.SW)..... a foot switch..... triggers the beginning of an operation.

Notice the 3 different envelopes.
a. -5V to 0V
b. +5V to 0V
c. 0V to +5V

Thursday, 19 May 2016

Buchla 208 build pics - Version 2

Some pics taken during the build of this wonderful module.
I'd say it took about 40 hours to put this together. It's more difficult than the TTSH (ARP 2600 clone).
I just finished it last night and couldn't believe that it worked first time.
So excited !!! I just had to post some pics.
 These are pics of the motherboard.

There are 12 daughter boards which plug into the main motherboard.

The cards are very tight to plug in.

One of the main difficulties was sourcing rare components from all over the world.

The partly populated front panel.

The original Buchla used plastic slider pots (above module). For this new version, I've substituted modern metal pots.

Almost finished.

The LEDs are a bit tricky to install.

You can buy the PCBs for this project from "The Electric Music Store". is another very useful site - awesome build notes.

Wednesday, 18 May 2016

Song View - Basic

The Mute & Launch button is also the solo.

To Solo.
1. Press the Left/right knob + Mute button
2. The button should turn blue.


To add another track, just press an empty track.


To change section colours.
1. Shift
2. Press the Audition button. (you will see the colours change).

Tuesday, 17 May 2016

Crystal Oscillators

You will often find these used with microprocessors & microcontrollers.

Its an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a precise frequency.
They are a type of linear oscillator made of quartz.

This is a 16 Hz quartz crystal. It uses a HC-49/S package.

This is also a 16Mhz crystal . The package is a HC49/U

These oscillators are not to be confused with your usual analog VCOs.
The crystal oscillator to provides a fixed frequency. They often are the clock for a microprocessor, UART, etc. 

Through Hole Crystal (THD)Package types vary.
They include HC49, HC50, UM, AT26, AT39


 Model                         Frequency Range Mode of operation

HC49/US                     3.0 MHz ~ 54.0 MHz Fundamental 36.0 MHz ~ 150.0 MHz 3rd-overtone


HC-49/S package.

UM-1 UM-5 UM-4    8.0 MHz ~ 70.0 MHz Fundamental 35.0 MHz ~ 200.0 MHz 3rd-overtone
This is a UM-1 low pass filter

A UM-5

AT26                            6.0 MHz ~ 27.0 MHz Fundamental
The AT packages are cylindrical in shape.

THey of course also come in SMD packages.

This is a ABLS7M2-12.288MHZ-D-2Y-T - 
Crystal, 12.288 MHz, SMD,
7mm x 4.1mm, 30 ppm, 18 pF, 20 ppm, ABLS7M2 Series

KORG PS 3100 - GEG - General Envelope Generator

This has 5  KBD Trigger Selects.
The knob setting determines the number of keys you must press in order for a trigger signal
to be sent to the GEG.

It's a second modulation source for the SGs.

The GEG is a 3 stage envelope generator: Delay-Attack - Release.
Similar to the GEG in the PS 3200

There is also a Auto switch -- when on, the envelope will automatically loop.

There is a switch that connects the GEG to VCA 1

Monday, 16 May 2016

kORG PS 3200 - preset sounds

These sounds are a good starting point if you are trying to learn how to program the PS 3200
They are from the manual.
The sound quality is just ok ....from a mobile phone, but  you should get an idea.

Steam Pipe Organ

Echo... one of my fav patches


Saturday, 14 May 2016

Korg PS 3200 - 14. Volume outs (D vol,P vol,F vol).

The PS 3200 has 3 outputs
1. Direct output
2. Headphone output
3. Final output.

The direct out is the signal formed by the SG, filter, the EM (VCA & Envelope Generator)
& the Balance Mixer
It is not effected by the equaliser, the amplitude modulator, the ensemble, VCA 1 & VCA 2 etc.
 The headphone out and Final Out are effected by the equaliser, the amplitude modulator, the ensemble, etc

Many people complain about the lack of a resonator in the PS-3200.
There are quite a few manufacturers who have attempted to reproduce this circuit.
I have purchased a MAM RS3 Resonator.
I think the best place to park this is from the direct output of the PS 3200.

Friday, 13 May 2016

Modded DJ decks

What to do with your old CDJ decks.???
If you're like me, you probably have lots of old CDJs lying around in the garage.
As technology moves on, the old decks become yesterdays gear that nobody wants.

This is a awesome idea. Time I got a 3D printer.
This is a modded Nexus 2000. It's fully functional.

 It's a beautiful job. Such attention to detail.

And Chewbacca loves it too.

As do the rest of the crew on the Millenium Falcon.
They can't wait to get their decks modded.

Korg PS 3200 - 12. Voltage Processors -VPs

The Korg PS & MS synthesizers generally work in the range of -5V to +5V
This Korg standardization, is good to remember, as it allows for precise control of synth operations.
You will see on the PS series of synths, voltage ranges printed on the various inputs & outputs.

This is where the VPs come in handy. There are two VPs in the PS 3200.

The Voltage Processors allow you to take an external voltage in the -5V to +5V range , and change it's range & phase. These are essential to safely connect external modules (even from other Korg gear).
The PS series were not designed to use external sequencers, for example. So if connecting something such as a SQ-10 or SQ-1, its safer to use these processors.

Needless to say, it's always a good idea to know what voltages your gear is outputting, before you plug it into your PS 3200. Buy an oscilloscope to check peak - peak voltages.

If nothing is plugged into a VP, the output will be +4.5V
You can use this as a fixed voltage source.

If you plug a changing voltage into the input, then you can limit the upper  & lower ranges of this voltage when it exits the VP. This input voltage must be in the -5V to +5V range
The PS-3040 is another potential source of CV. It's designed for the PS 3200.
Sadly I don't have a PS-3040 foot controller.  -- It uses the DIN connector.

VP-1 can also be used it as a VCA control.
Notice the orange switch that connects to VCA-2.
One last thing to note is a second switch which connects & disconnects the two VPs.
When the switch is to the left, a CV inputted into VP1 will exit from both VPs.
When the switch is to the right (as in the photo), any inputted CVs will exit from their same VPs only.

If you are thinking of using external gear with the PS 3200, a  Korg MS 20 is good place to start.
Keep in mind this block diagram:
Outputs from the MS-20 mini
Keyboard CV out: 0~+8V
Keyboard Trigger out : +5V to GND
Signal output (mono 1/8" mini phone jack, 2Vp-p output impedance 3.5k Ω)
EG 1 (normal): -5V to 0V
EG 1 (reverse) : +5V to 0V
EG 2 envelope signal reverse output (+5V - 0V) 
MG Triangle out (Positive Sawtooth - Triangle - Negative Sawtooth) : +2.5 to -2.5 (5VPP)
MG Rectangle (Wide Pulse - Square - Narrow Pulse) : 0 to +5V
Mod/control wheel output: -5V~0V~+5V
Push Button:+5V to GND
Pink Noise output : 5Vpp
White Noise output: 5Vpp
S/H output : 5Vpp
Modulation VCA: Signal output (-5V - +5V)

MS 20 mini ESP
CV Out (0 - +8.4V)
ENV Out (0 - +5V)
Trig Out (+5V-->GND)

Re: the SQ-1 sequencer:
Sequencers in general, give voltages to variable oscillators, telling them what pitches to play.
The Korg PS 3200 doesn't have a direct pitch CV input.
The manual warns you not to connect anything other than PS series gear.
However, if you must....
a) littleBits OUT jack (mini monaural phone jack)... 5V ???

    CV OUT: output level 1V, 2V, 5V, 8V [Hz/V]
    GATE OUT: output level 10V

c)  IN - SYNC - OUT jacks:
     SYNC IN: maximum input level 20V,
     SYNC OUT: output level 5V

My PS-3200 has a Kenton Midi to CV kit installed.
It works great, as it by-passes all the CV/gate stuff.

Moog CP-251
This CV processor is very useful to attenuate external voltages.
Used in conjunction with a scope, it's a very safe way to use external gear.