Retroaktiv PG-800 MINI Instruction Manual

RETROAKTIv
PG-800 MINI
CONTROLLER FOR ROLAND JX-8P, SUPER JX & MKS-70
Installation Manual & User Guide
2017 Retroaktiv LLC, all rights reserved.

CONTENTS
GETTING STARTED 3
FEATURES 4
PCB BUILD NOTES 5
INTERNAL INSTALLATIONS 6
ENCLOSURE ASSEMBLY 13
ASSEMBLING CONNECTOR CORD 15
PARTS LIST LINKS 16
BILL OF MATERIALS 17

GETTING STARTED
Thank you for purchasing a PG-800 Mini controller. This product allows for
hands-on programming of the Roland JX-8P, Super JX, and MKS-70 synthesizers.
The PG-800 Mini is available as a stand-alone desktop unit that conects to the
JX via a cord, or it can be mounted directly inside of the instrument itself. (JX-8P
and Super JX models only) The PG-800 Mini was designed to take advantage of
the blank panel space in the JX-8P and Super JX, where it fits easily into the upper
right corner of the synth.
This product was based on a project by Bas at Poesboes.com entitled “Fiing
your PG-800 with a new processor”. His aicle can be viewed at this URL: hps://
tinyurl.com/yc87fns2 This project would not have been possible without Bas and
we appreciate his generousity and technical assistance. The firmware in the PG-
800 Mini is different from the firmware available from Bas. Be aware of this if you
ever need to flash the firmware in your unit. Firmware updates can be found at
the PG-800 Mini product page at www.RetroaktivSynthesizers.com.
Many versions of the original JX firmware do not respond correctly to the WRITE
command from the PG-800. By default, the WRITE buon on the PG-800 Mini will
act as a SCRATCH PROG and RANDOM PROG generator. To disable this function and
allow the WRITE buon to send WRITE commands to the synth, hold down MANUAL
while powering up.
To begin using the programmer (Desktop unit), simply plug the 6-pin DIN cable
into the PG-800 Mini and the synth. If you have a PG-800 Mini installed in your JX,
the programmer stas up as soon as the synth is powered on.
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RETROAKTIv PG-800 MINI CONTROLLER FOR JX-8P, SUPER JX AND MKS-70 SYNTHESIZERS

FEATURES
The PG-800 Mini allows for easy, hands-on programming of Roland JX-8P,
Super JX, and MKS-70 synthesizers. While incorporating all of the features of the
original PG-800, the PG-800 Mini adds some useful new features.
• Random Program Generator - Holding the WRITE buon
for .8 seconds will generate a random sound.
• Scratch Program - Tapping the WRITE buon once (for less
than .8 seconds) will generate a basic program, which serves as a useful
staing point when creating a new sound.
• Manual - Tapping the MANUAL buon once will transmit the panel
positions of all 44 controls to the synthesizer.
• Copy/Paste - To copy the state of the PG-800 Mini’s controls
without actually transmiing them to the instrument, hold MANUAL for
.8 seconds or more. Once the copy has been made, holding the MANUAL
buon will transmit the stored panel state to the synth. Once pasted,
the memory will be cleared, and holding MANUAL will act as the copy
function once again.
• Disable PG-800 Mini - Holding WRITE and MANUAL down together
for 1 second will disable transmissions from the PG-800. This is useful if
using the JX in a peormance. Once in disable mode, tapping manual
will return the PG-800 Mini to its normal state. Any controls that were
moved while transmission was disabled will be updated upon enabling
transmission.
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RETROAKTIv PG-800 MINI CONTROLLER FOR JX-8P, SUPER JX AND MKS-70 SYNTHESIZERS
• WRITE MODE- Holding the MANUAL buon down on power-up will
disable RANDOM/SCRATCH generators and WRITE buon will transmit the
“WRITE” message to the JX. Whether this function works correctly on a
JX will depend on JX firmware. WRITE MODE is off by default.

PCB BUILD NOTES
The PG-800 Mini is available as a DIY bare PCB kit, as well as a fully
assembled “internal” unit. This section is for people building their own units and
installing units into the chassis of a JX-8P or JX-10P.
Construction of the circuit board is simple, but following these steps will make the
process go as smoothly as possible.
• Begin by installing components on the boom side of the PCB.
Take care when installing the small components underneath
the processor. Do not get solder into the through-hole pads
where the processor mounts to the top-side of the board. Do
not install the DIN jack, buons, or pots yet. C9 should be
omied. It is only used as a provision in which more filtering is
needed on the ADC.
• Now build the power supply on the top side of the board. Take
care that the solder joint on C42 does not make contact with
the large regulator fin on U18. The + side of the polarized caps
is indicated with a bold black line or a black dot.
• J1 is an ISP jack, and can be populated with any .1” breakaway
pins. This jack is only used if you need to flash the firmware.
• Use a socket for the main Atmel processor.
• Make sure that all pots are straight before soldering them into
your PCB. If they aren’t straight, they will not be able to fit
through the front panel.
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RETROAKTIv PG-800 MINI CONTROLLER FOR JX-8P, SUPER JX AND MKS-70 SYNTHESIZERS

INTERNAL INSTALLATION
1Begin by cuing out the drill template around the outside edge. The template
shows the front panel, as well as where the PCB will be. Each pot and switch centerpoint
is marked with a black circle. These holes should be .25” in diameter. There are 6
mounting holes indicated by a crosshairs paern. These holes should be .125” in
diameter. Position the template on the synth so that the PG-800 Mini PCB sits directly
to the right of the JX front panel PCB as shown below. The two should not touch. When
the drill template is in position, tape it down and use a center punch to mark the hole
locations. BE SURE THAT YOU HAVE PCB CLEARANCE BEFORE YOU DRILL!
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RETROAKTIv PG-800 MINI CONTROLLER FOR JX-8P, SUPER JX AND MKS-70 SYNTHESIZERS
FIGURE 1 - PG-800 MINI installed in a Super JX

2Now that the drill template is in position, 50 holes must be drilled. There are two
ways of doing this. The recommended (hard way) to do this is to remove the top half of
the JX from its base by unscrewing the 4 hinges that aach the two halves of the synth.
This requires that the main boards be unscrewed, so that the hinge screws can be
accessed. Disconnect any wires aaching the top and boom halves of the synth. Now
the top half of the synth can be placed on a drill press or other drilling jig (stabilizing
the chassis is of key impoance when drilling.). A drill press will generally yield the best
results (fewer burrs, cleaner cut) than using a hand drill. The holes will be cleanest if
there is something solid like scrap wood etc. under the suace you are drilling on.
The second way of doing this is by using a hand drill and carefully drilling all of the holes
by hand. Obviously drilling into the power supply board or leaving any metal shavings in
the synth is to be avoided. Always vacuum out the synth if there are any bits of metal
le aer drilling.
3Deburr all holes, especially on the top suace of the synth. Burrs on the top
suace will show up as bumps under the graphic overlay, which is unsightly. When
deburred, test fit the PCB through the holes to be sure of clearances and widen any
holes where the pots are chafing the front panel. When you are happy with the fit,
carefully stick down the graphic overlay. Be sure that it is straight, and that all of the
holes align, especially the 6 mounting holes.
4When the overlay is placed, use the screws and spacers to create 6 standoffs as
shown in the figure below. These standoffs are what the PG-800 Mini will mount to. This
must be done with the graphic overlay applied to the panel. Inse the black screws
(through the front panel facing side) into the 6 small mounting holes in the panel. From
the underside of the front panel, screw these into the threaded standoffs included with
the kit. Do this for all 6 mounting holes.
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RETROAKTIv PG-800 MINI CONTROLLER FOR JX-8P, SUPER JX AND MKS-70 SYNTHESIZERS

Figure 3 - Standoffs for mounting PCB
Figure 4 - Mounting PCB to panel
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RETROAKTIv PG-800 MINI CONTROLLER FOR JX-8P, SUPER JX AND MKS-70 SYNTHESIZERS

5Use the remaining 6 screws to secure the PCB to the panel as shown in Figure 4.
6Try closing the lid of the JX. Be sure that the PCB is not too close to the
transformer or the power supply heat sinks. Some Super JX synths have a taller heat
sink. The heat sink can be trimmed or reshaped at the top to allow for a bit more
clearance. This isn’t necessary, but it serves as insurance that the boom of the PG-800
Mini can’t make contact with the heat sink if the lid is able to open and close. Trimming
or bending the heat sink should only be done in a Super JX, and only if necessary. In
all installations, it is recommended that you use cardboard to shield any metal suace
(such as the transformer, transformer leads, or heat sinks) directly below the PG-800
Mini. Use a square of cardboad, then cut squares out of the corners, which will allow
the cardboard to be folded into a 3, 4, or 5 sided cube. Secure this in place over the PSU,
exposed transformer leads, etc. Cable ties or tape can be used to hold the protective
barrier in place.
Figure 5 - Protecting from shos
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RETROAKTIv PG-800 MINI CONTROLLER FOR JX-8P, SUPER JX AND MKS-70 SYNTHESIZERS

Figure 6 - Super JX with heat sink modified. (L shape bent into fin, and rear fin trimmed by
10mm)
7When you have secured the PCB to the panel and ensured a good fit, with plenty
of clearance, use the 5-pin multi-conductor wire and connect the 5 wires from the
PG-800 Mini to the JX as shown in the wiring diagrams. The 5 connections on the PG-
800 are indicated on the top side of the PCB where the DIN jack terminates. These 5
connections must be connected to the Jack PCB on the Super JX, and the Main PCB on
the JX-8P. The recommended spot to solder to is directly below the DIN jack on the JX.
Be sure that your pin orientation is correct when you solder. (Don’t solder the wires in
the mirror image where pin 1 is actually pin 6, etc.) Use figures 8, 9, and 16 to locate the
correct pins to solder to. The diagram shown in figure 16 shows the pin numbering of
the female DIN jack from the front. Remember that the numbering will mirror that if
looking at the male DIN cable from the rear. Verify this before soldering anything. If the
wiring is mirrored, it will likely destroy the PG-800 Mini. Mirroring would cause +15V from
the JX to be routed to the PG-800’s ground and destroy the Atmega processor. Triple
check your connections.
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RETROAKTIv PG-800 MINI CONTROLLER FOR JX-8P, SUPER JX AND MKS-70 SYNTHESIZERS