Saturday, 19 September 2020

How to Program a Roland TR-808 - Quick start guide

Roland TR 808 - Quick Start

The 808 is a pretty basic machine that isn't too complicated to program, though it has a few odd quirks that are good to know. Before, you write any new patterns, it's important to clear the old ones.

How to clear old patterns 

1. Turn on with the top left power switch
2. Turn the MODE knob all the way to the left, to "Pattern Clear".
3. Choose which memory location you wish to erase by pressing one of the
    16 step buttons.
4. The "Basic Variation" switch needs to be in the AB position.
5. Press the Red "Pattern Clear" Button

yOU will see the AB LEDs flash really fast



How to program a simple pattern (1st Part rhythms)

1. Clear any existing patterns (See above)
2. Turn the MODE knob to the "first part"
3. The LED should be blinking in time with the tempo.
    (If it's not blinking, check the sync switch at the back of the 808.
     It should be set to internal sync)
4. set the Basic variation to A. The A LED will light up.
5. Hit START.
   The LED should be running across the 16 steps
6. Set the scale (I mostly use the 3rd row which is 4/4 time)
 7. Use the "instrument select" rotary switch to choose your instrument.

8. Program your beats by pressing the step buttons (step mode) or the TAP button
   (Tap mode)

9. If you flick the Basic variation to B you can program the steps 17 to 32.
   The B LED will light up. (Keep the MODE Knob on "first Part")
   Setting the variation to A/B will play steps 1 to 32.


I generally use pre-scale 3 which is a standard 4/4.
If you want to go double time, use pre-scale 4


How to Play existing patterns

Now that you have programmed lots of patterns, this is how you play them back. You can jump from one pattern to another.

1. Turn on with the top left power switch
2. Turn the MODE knob all the way to the left, to "MANUAL PLAY".
3. Choose which rhythm you wish to play by pressing one of the
    16 step buttons.
4. You will notice that the LED above the step button will flash.
5. The "Basic Variation" switch has 3 modes (A, B, and A/B) which gives you a total of 32 sixteen step patterns.
5a. Set the Basic variation to A. The A LED will flash.
6. Adjust tempo
7. Press the START/STOP Button

8. If you set the variation to B, steps 17 to 32 will play.
    Setting the variation to A/B will play steps 1 to 32.

9. Pressing a new step button will tell the 808 to play the rhythm stored in that memory slot.

aLWAYS check the sync switch at the back 
The 808 in this pic is the master, and is sending DinSync (clock info) to a TB 303.


The Second Part

I don't use this very often, but it's good to know what it does.
The 808 allows you to program a total of 32 different patterns (16x2). 
Each memory has a 1st & second part that can be used for even more rhythm patterns.   

This second part is used to allow for rhythms other than 16 or 32 steps.
Use it if want 12 steps, or 18 or 24 steps. 
It allows you add the difference that you are missing from the first part to the second part.
For example, if you want to make a 24 step pattern, you can make the 1st part 16 steps long and
the second part, 8 steps long. Or you can make the 1st and second part 12 steps.

Below is an example of how to use the second part. 
This is how you add a second part to an existing 1st part.
1. Program your 1st part rhythm as shown above.
2. While it it playing turn the program knob to "second part".
3.  Hold the red button down & press the last step you wish the 2nd part to have.
    eg to add an extra 8 steps to your existing 16 step pattern, press the 
    8th step button. You now have a 24 step pattern.
4. When you that step button you will instantly hear the tempo 
    of your existing pattern change (it's slower).
5. Add your extra beats as above.
6. While the drum is playing you can add new sounds to each part 
    by switching the program knob between the two parts

   If the mode selector is on the 2nd part, then the LEDs will indicate
   the 2nd part only.
   If the mode selector is on the 1st part, then the LEDs will indicate 
   the 1st part only.

7. Press the START/STOP button when programming is finished.

How to program two 12 step patterns

 ie 12 steps in part A & 12 in part B

1. Choose a free Memory slot (steps 1 - 16)
2. Set mode to Pattern Clear. (set Basic Variation to A/B). 
    Clear patterns as above.
3. Set the Basic variation to A. The A LED will flash.
4. Set Mode to 1st Part Pattern Write
5. Press Start. 
    (The sequencer must be running for this to work).
6. set PreScale to 4

7. Press CLEAR  + step 12
    You can add some drum beats if you wish for the 1st part, or leave it empty for now.
8. Set Mode to 2nd Part Pattern Write
   (the LEDs for each step will go off)
9. Press CLEAR + STEP12

9a. Program some drumbeats for the second part.
   You have now set up a 24 step pattern and the flow of LEDs will change from the 1st part
   to the second part. (Note, the number of steps in the 1st & second parts don't need to be the same).
10. Set the mode selector to Part 1 to program new beats or exit that part if there are existing beats present.
    Likewise for part 2

   If the mode selector is on the 2nd part, then the LEDs will indicate the 2nd part only.
   If the mode selector is on the 1st part, then the LEDs will indicate the 1st part only.
11. Press the START/STOP button when programming is finished.

After you have done all this put the 808 into pattern play mode.
Now you can jump between  patterns in real time.


I/F Variation Switch

I/F Variation = Intro or Fill-in Variation A or B
This performs the same function as the BASIC VARIATION switch, except it is only used for INTROs and FILL INs and relates to the last four white STEP buttons.
Intros and fill ins are additional rhythms separate from your basic rhythms. You add an intro at the beginning of your main rhythm, and a fill-ins between different basic rhythms.






The step buttons 1 to 16 are divided into two groups:
a) BASIC RHYTHMS (buttons numbered 1 to 12)
   (white buttons numbered 1 to 4)






Drum-fills will play automatically. This is based on the 'AUTOFILL-IN' knob selection.
The AutoFill-In knob can be set to 16, 12, 8, 4 and 2.
The selected "White Pattern" will automatically play every 16 or 8 or 4 measures etc
If the AUTOFILL-IN is set to 'Manual ' then the 'TAP" button will function as a 'FILL-IN' trigger... but only while the unit is playing.

You can turn the Intro/fill function on and off by pressing the TAP button.
When you first turn the mode to "play" you will see two LEDs lit:
a) One from the 1 -12 group  (flashing LED)
b) one from the 1 - 4 group (solid LED)
Pressing the start button will play the rhythm as standard.
If you press the TAP button first, the 1-4 LED will start to flash.
Now press the START button and the selected intro rhythm will play before the basic rhythm.
To disable this function just press the TAP button again, and the LED will stop flashing.


Setting the Pre-Scale.

Pre scale is the number of steps for each beat.
The prescale must always be chosen to match the minimum division of the note to be used in the rhythm pattern.
Matching the pre-scale on each of the recorded rhythms is really important. Though the switch may not change, each track can still run at different tempos. This was the case when I bought this drum second hand, all those years ago... I couldn't understand why each rhythm played at a different speed.

If you are playing a pattern and decide to change the pres-cale switch, don't forget to also press the red Pres-cale button.
 Example 1
To program a rhythm in 3/4 time.... uses a 12 step measure and the number 3 Pre Scale.

1. STOP the Rhythm
3. Press a BASIC rhythm button (1 to 12)
    The LED should light up but not flash.
4. Set the Basic Variation switch to A
5. Press CLEAR button
7. press START/STOP button
8. Set the Pre Scale selector switch to #3
9. Hold the CLEAR button down & press switch 12 at the same time.
10. Release the CLEAR button
 You have just set a 12 step pattern using a #3 Pre Scale.

Example 2: (basic 4/4 beat)
Create a 16 step pattern using the #3 pre scale 

1. Clear the memory as above (in A/B mode)
2. Set variation to A
4. press START button
5. Set the Pre Scale selector switch to #3
6. Hold the CLEAR button down & press switch 16 at the same time.
7. Release the CLEAR button

Example 3.
You can change the time signature of existing rhythms without erasing them.
1. STOP the Rhythm
2. Select a BASIC rhythm button (1 to 12) to edit
    The LED should light up but not flash.
3. Set the Basic Variation switch to A
5. press START button
    Your rhythm will play.
6. Set the Pre Scale selector switch to #3 (for example)
7. Hold the CLEAR button down & press switch one of the step switches (1 - 16)
   at the same time.
8. Release the CLEAR button


Composing the Rhythm Track

Play/Compose/Track Clear

There is memory for 12 Rhythm Tracks .
It's labeled in orange and uses the instrument select dial.

This is how we sequence a entire performance.
It's done live.
1. STOP the Rhythm pattern.
2. Set the MODE to COMPOSE
3. You will see a Step LED flash. 
4. Set the instrument select to #1
    (to compose in bank 1)
6. Set both variation switches to A
7. Press START. 
    While in this mode every change of rhythm 
    patterns will be memorized.
8. Play your desired patterns in whatever order you wish.
9. Press STOP
    The exact time you press STOP is critical .... it must be exactly when the measure ends.
10. Set the MODE to PLAY to listen to your performance.
Each of the 12 tracks will memorize up to 64 measures.
These can be used separately or together for a max of 768 measures (12x64)


It's important to note that both Variation switches are "play" function only.
The 808 doesn't memorise the setting of either switch.
When the drum plays rhythm #5, you can control if part A, part B or part AB is finally played.
I think this is a pretty neat performance feature.
+ TR 808 Drum links
           + Repairing a Roland TR-808 - Part 1 - Opening the Machine           
           + Roland Drum Machine Timeline

Friday, 18 September 2020

ARP 2500 - The 1027 sequencer

The ARP 1027 sequencer

It's the 50th anniversary of this magical synth. So I'm exploing the different modules. A sequencer is one of the essential components of any modular synthesizer. The ARP 2500 is no exception

Also called the Clocked Sequential Control Module, this is essentially three 10 step sequencers, though you can set it to be any number of steps (between 2-10) you wish.
If you wish to get more than 10 steps, use a sequential switch.

It's quite a large module occupying 2 units.
There are 3 rows of pots providing three sets of CVs  for each step.
The sequencer has an internal clock so can step along automatically.
When run fast at switching rates in the audio spectrum, the 1027 can generate sound in the form of very complex wave forms.

The 3 voltage outputs are labeled A, B, & C.

The Clock
The illuminated ON & OFF switches can start & stop the clock and thus the sequencer.
Set the switch to "Trig" .
You can also start & stop the clock with external pulses that are imputed to the ON & OFF inputs.

The pot labeled "Pulse Repetition Frequency" controls the speed of the internal clock.
It can be run at very low or high frequencies. ... between
20 pulses/minute to 400 pulses/second.
The clock speed can also be controlled with an external CV via the "VC trig" input.

The sequencer produces a 10V gate pulse every time it makes a step.
The pulse width can be varied between 5% to 95%.
The width can be adjusted either manually or with a control voltage.

VC Width & VC Freq.
Apply control voltages here to have external control.
The Clock Out is also a source of 10V pulses,
You can use this to clock external gear.

Pulses applied to the ON or OFF inputs will start & stop the clock.

Input Sensitivity :  "ON", "OFF", inputs are +8 volts.
                            VC Width & VC Freq inputs are 0-10 volts 

If the clock is turned off, you can manually step and reset the sequencer with the pink Step/reset buttons.
You may also do the same thing with external CV .... 10V pulses applied to the "S" and "R" inputs.
If you are trying to clock the sequencer from an external source such as another sequencer
plug 10V pulses into the "S" input.

Finally, notice the ten "POSITION GATES" outputs.
A 10V pulse is outputted at each ... corresponds to the current step the sequencer is on.
If you wish to change the 10 step sequence to 8, connect the 9th gate out into the "R" input.
If you wished the sequencer to count to 5, and then reset, connect the 6th gate to R.

View this post on Instagram

#arp2500 #mixsequencer #arp #synthesizer

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To skip a step, connect the position gate output(s) to the "S".
The sequencer will then skip those positions.

There are cable jacks at the back of the 1027 module to connect with other modules such as:
1028 - Sequencer slave
1026 - Preset Voltage
1050 - Sequential mixer


Electrical Specifications
Output Impedances : 1Kohm all outputs
Output Position Gates : 0 to +10V.
Input Impedances : 100Kohms minimum , all inputs
Input Sensitivity : "S", "R", "ON", "OFF", inputs are +8 volts
                           VC Width & VC Freq inputs are 0-10 volts
Pulse repetition frequency (without external control):
                         20 pulses/minute to 400 pulses/second.
 Power requirements: +15 V @ 150ma, regulated to +/-0.1%
                                 -15 V @ 75ma, regulated to +/-0.1%
                                 +12 to 15V @ 100ma, unregulated for the lamps.

Wednesday, 16 September 2020

Erica Synths Syntrx - battle patch

 Jam with a Erica Synths Syntrx


View this post on Instagram

#battlepatch #syntrx #ericasynths

A post shared by jono (@dj_jondent) on


Sounds great. We tried to copy a patch from my AKS synthi.
They sounded very similar.


Thanks to Paul and Dee


Ancillary Justice, Ancillary Mercy & Ancillary Sword - Ann Leckie

I just finished reading the Imperial Radch Trilogy. Highly recommended. 

The first book, Ancillary Justice won the Hugo, the Nebula, the BSFA, the Arthur C Clarke and the Locus awards. I don't think any Science Fiction novel has won as many awards.
It's definitely not your basic level Sci-Fi.
The series is made up of 3 books: Ancillary Justice, followed by Ancillary Sword and Ancillary Mercy.

A friend of mine is going to start reading this and I though a brief summary would help her.

The beginning of Ancillary Justice is very confusing and it's possible this will discourage many readers.
But if you can get your head through the first 2 chapters you will probably love this series.

Ann Leckie explores AI (Artificial Intelligence) quite a bit. The main character is an AI. She is a ship, a soldier, a human, and a computer ... all in one.
The opening chapters don't explain this and I had to read quite a bit till I was able to process this info.
I was questioning human intelligence and asking myself whether AI is less important.
Are they in fact of equal value?
Should we be afraid of AI?
Maybe in the future AI can be see as a partner to human intelligence. 
Is artificial intelligence part of our evolution? 

The true first editions are all soft cover / paperbacks.

This is I understand the first hardcover version.

There was a Limited lettered edition which sold for $250 USD
(Lettered: 52 signed copies, bound in leather, housed in a custom traycase and sold out pre-publication)
There was also a Limited edition  version that had a price of $50USD
(Each volume is signed by the author and numbered out of 500)

Burton, MI, Subterranean Press, 2015


  ................ don't read past this if you are worried about spoiling the story

The story is set thousands of years in the future.
The names of the three books, Justice, Mercy & Sword are also the names of the 3 classes
of space warships that feature in the Radch universe.
Ancillaries are the solders which "man" these warships.
"Man" is probably not the right word to use as most of the characters are gender neutral.
and the main character calls everyone she, regardless of whether they are male or female... but that's another story.
Each warship has its own compliment of hundreds to thousands of Ancillary troops
(the number of solders depends on the type of warship).
These troops are essentially captured enemy human solders from past battles who's minds and identity are wiped and reprogrammed with the ship's AI (artificial intelligence). You can think of each ship and it's ancillary troops as one and the same sentient beings. To top it off, the AI's have emotions.

The main character "Breq" also goes by the names One Esk 19, and Justice of Toren.
She is an ancilliary.
She is the last remaining fragment of the AI of the troopcarrier "Justice of Toren". This AI is trapped in a ancillary human body when the mother warship is destroyed.
The first book covers the events of how she takes revenge on the person who destroyed her warship
(Anaander Mianaai).
It's really her quest for justice, so the name of the book is apt.

Human's are present in this universe, and they live in harmony with AI's.  Actually the human ruler is evil, and the AI's are on the side of good. The suggestion is that artificial consciousness is not to be feared and is as relevant as human consciousness. AI may even come to the rescue of humanity.

Breq struggles to reconcile this as her humanity starts to reassert itself. She is after all an AI inside a human body.

The portrayal of gender is also fascinating since the main characters are essentially computers that don't see the need, nor understand gender. The novel makes the case that gender is irrelevant. It's interesting that to the computers, the default gender is female.

The concept of Justice is of course explored and I think found to be quite fluid and abstract.

The main conflict starts when the ruler Anaander Mianaai has a fight with herself.
This sounds confusing, until you realize what the ruler is.
Anaander Mianaai has been cloning herself for the last 3000 years. So she never dies and can in effect
rule forever. To make matters more interesting, she clones herself thousands of times, so a clone of her can be on every planet and station of significance. Some of these clones develop new personalities (as you'd expect over thousands of years) and set up a rival govt.

The story is basically one of two beings disagreeing about the nature of Justice.
Thinkers from Plato to Shakesphere have asked this very question.

Sci Fi Links

Asimov's (Isaac) Foundation
+ Asimov  - I, Robot -  - novels & Magazines
+ Dune - The Chronological order of the novels
+ Dune Universe Timeline

+ Hugo Awards Best Sci Fi novels of the 1950's
+ Hugo Awards Best sci fi novels of the 1960's
+ Hugo Awards Best Sci Fi novels of the 1970's
+ Hugo Awards Best Sci Fi Novels of the 1980's
+ Hugo Awards Best Sci Fi novels of the 1990's
+ Hugo awards Best sci fi novel of the 2000's (2000 - 2009)
+ Hugo Awards Best Sci Fi novels for the decade 2010-2019

+ Nebula Best Sci Fi Novel awards 1960s
+ Star Wars 
+ vorkoisgan saga reading order - Lois McMaster Bujold

These are the hard cover versions

+ Subterranean Press

Wednesday, 9 September 2020

Happy 909 Day

Happy 909 day.
I love this machine almost as much as my 808.

As if inventing the TR 808 wasn't enough. Initially, the 808 was a flop so Roland thought they had better try something new. Little did they know that the 808 was simply way ahead of everyone else and in time would be viewed as a work of art.

So Roland followed with the TR 909. Their second classic.
Probably the engineers thought the public wanted a drum machine to sound like a real drum.

Unlike the 808 which was a pure analog machine, the 909 used samples for some of its sounds.
The 909 also has midi :-)

+ TR 909 Drum
        + Roland TR 909 Programming Tutorial - getting started
        + Roland TR 909 - How to Program
        + Roland Tr 909 - Drum Mapping & Midi triggering

Friday, 4 September 2020

Roland Tr 808 repair - Part 2 - replacing the switches

How to open up the TR-808 .....continued from the last post:
Repairing a Roland TR-808 - Part 1

Now that you have opened up the beast you'll need to unplug the board from its various connectors.

 You can just make out 4 of them here.
The connectors are 40 years old & probably brittle ... take care.

The other 2 are tucked at the rear ... They plug into the PCB connecting the inputs & outputs.

Next you need to separate the main PCB from the front panel.
It's held in place with the remaining screws (11) & the nuts/washers for the pots & rotary switches.

(Mine was missing lots of nuts/washers.... I reckon they would have been once present).

These screws circled in green are the ones that are left
Remove the central screw last, and the PCB should just pop out.

If you look at the PCB carefully, you can see it's actually two boards joined just right to the last of 5 central switches

The Main board apart from housing things like the cPU & RAM, also has some of the voice circuits:
Snare, Claps, Maracas, Hi Tom/Conga, Mid Tom/Conga, Lo Tom/Conga, Bass Drum, Claves/Rimshot.

The Voicing Board has the circuits for the Cowbell, Cymbal, Open Hat, Closed Hat,
Mixer, & master Volume.

Now it's time to remove the step switch board

That volume pot (extreme right) is definitely not original.
I'll replace it one day! At the moment, it's working fine ... I prefer to let sleeping dogs lie
 iT'S held in place with 7 screws. They sit on standoffs.

Careful you don't break the ribbon cable
The FFC - flat flexible cable.

Admire those ICs

The 4011 is a 2 input NAND gate.
The 4051 is a multiplexer -- a digitally controlled switch

The 4 ICs on the top (D444C) are the memory.
I think they are 4K SRAM chips ???

This D650C is the CPU. It's the brain of the 808
You can also find a similar CPU the TR 606 (the 606 uses a D650C 128)
They are super rare . It's a 4 bit microcontroller
The UPD650C-085 is a special custom Roland (version 0.85) chip. It manages 11 analog channels with individual gain mix.
The voice board generates 16 analog percussions which 8 of them are circuit-shared.

The felt shades help to keep dust out.
There were originally shades on the toggle switches, rotary switches and all the pots I think ,
but mine are mostly gone ;-(
Next time I open this I must remember to put new ones in.

Notice The JRC 4558 (Japan Radio Corporation) in the bottom of the pic -- they are dual Op-amps.
These are everywhere on this board

The HD 14584 B  is a Hex Schmitt trigger

The AN6912 is a quad comparator

4013B - Dual type D flip/flop
4001 - Quad 2 input NOR gate
14584BP - Hex Schmitt trigger

The new board is on top.
Its a Technology Transplant board.

 The colours, esp the white buttons are slightly different.
Maybe the passing of time has faded  the white switches

Screw in your new step board & reassemble the machine

The PCB should slot into the front panel.

Plug the connectors.

That green cable is the ground.

hOPEFULLY  it works

Roland Links

+TB 303
       + Intro & Setting up
       + Pattern write
       + Track Write

+ TR 707 Drum
          + Roland Tr 707 - Drum Mapping & Midi triggering
           + Roland Tr 707 Drum - Basic programming
           + Pioneer Squid - Midi Mapping a Roland TR 707

+ TR 808 Drum
           + Repairing a Roland TR-808 - Part 1 - Opening the Machine

+ TR 909 Drum
        + Roland TR 909 Programming Tutorial - getting started
        + Roland TR 909 - How to Program
        + Roland Tr 909 - Drum Mapping & Midi triggering

+ SE-02 (Studio Electronics / Roland)
       + Transposing sequences with the keyboard 
       + Filter/Amp envelope

Wednesday, 2 September 2020

Synthrotek - LPG build notes

These are my build notes for the Synthrotek Dual LPG.
It's  a eurorack format module

 I'm not afilliated with Synthrotek.
These are my personal notes to help me trouble shoot any probs should they arise during the build.

Toggle Switches Sub-Miniature DPDT switch on-on pc thru-hole

data sheet


I like to install the toggle switches and jacks  on the panel PCB first as these are the tallest components.

Make sure you next solder the connecting headers (before the slider pots as one is under the pot.


I'm using the synthrotek supplied vactrols

The vactrols that we recommend (that sound the best to us) are: Xvive VTL5C4, VTL5C9 and NSL-7053 (our equivalent found here)
You can even get wild and have a different kind of vactrol in each channel!
Mouser Part #
V1 Single #1, V1 Single #2, V2 Single #1, V2 Single #2
Choose between VTL5C4, VTL5C9 or Synthrotek tested vactrols

official page
+ Build Notes
+ Manual