When we think of vintage synthesizers names like Moog, Korg, Arp, Roland and Oberheim come to mind.  One name that seems to slip by is PAiA (pronounced Pie-ah).  I discovered PAiA in the mid 1970s while gathering information on various musical instruments.  With no Internet back then we had to write letters to manufacturers for information on their products.  Most manufacturers were happy to send out glossy catalogs of their products full of information.

I learned of PAiA through Larry Fast.  Larry was Peter Gabriel’s keyboardist for quite some time but also had his own band project called Synergy.  In this latter Larry fashioned sounds that were absolutely marvellous and new for the time.  My particular favourite album of his is called Cords.  Check it out if you have a chance.

Among Larry’s listed instruments on the album were those by a manufacturer called PAiA.  The information I found about them at the time indicated they made Do-It-Yourself kits for keyboards.  Their Strings and Things was of particular interest to me at the time as it seemed within my reach but that never ended up happening.

You’ve probably heard PAiA instruments before.  Do you know Peter Gabriel’s Games Without Frontiers?  The drum machine track is a PAiA drum machine.  The PAiA was actually the first programmable drum machine available.

So flash forward 40 years and modular synthesis is all en vogue again.  I thought the idea of building some modules would be cool and PAiA would be a great place to start.  Their 9700 modular features a MIDI to CV converter, a dual VCO, a VCF and a VCA.  Just what you need to get started.  In this thread I’m going to tell you about my build experience…

First, a little background

In the early ’80s I got my start building electronics working at a shop making clone 80 column cards and internal modems for Apple ][ computers.  We also made RS232 and Centronics parallel cables.  Back then you couldn’t just walk into Best Buy and purchase them off the shelf.  My teacher was a guy named DL.  He was tough and would throw away any half-assed work I’d do.  Our boss, Rod The Man, got pissed off if stuff got thrown out so I learned to solder well, quickly.

I ordered the 9700 kit from PAiA February.  It arrived within a few weeks, the delay mostly due to Customs.  The packaging of the kit was outstanding with each module packaged separately.  It is easy to keep the components organized and separate from one another.

I’m not going to review the modules themselves (yet) but rather the build process.  I’m a lightly experienced assembly guy and this is a very ambitious project.  I can solder pretty well but my skills beyond that are long from developed.  I used a multimeter before but that was 30 years ago.

I’m here to tell you how this build went for me.

The 9700

The 9700 MIDI2CV module is the starting point of the project.  Not only does this module convert signals from MIDI input devices to Control Voltages it supplies power to the entire rack of modules.  This build went very smoothly and the unit functioned perfectly when I was done.

Things I learned;

  • Do NOT let solder bleed over onto holes next-door.  It’s a nightmare!

IMG_3124 IMG_3126

One modification I made to the module involved the power adapter.  The unit comes with a 12 VDC wall adapter.  The documentation recommends cutting off the connector and then soldering the wires directly to the 9700 module.  This would mean dragging the wall-wart around everywhere, having to coil it up and make sure it wasn’t in the way.  All the while there would be tension on the connection points.

Instead I purchased a fifty cent female adapter and connected it to the board with two short lengths of wire (the red and black in the photo above).  When the board is in the FracRak I connect the adapter to one of the pre-drilled holes and the unit now has a removable power supply.

The 9720 

The 9720 is the Dual Voltage Control Oscillator and Modulator.  In effect it is the noise maker of the synthesis unit.  My build ran into a few road bumps.

First, while soldering in an Integrated Circuit (chip) a drizzle of solder ran out the top of the board and bridged to and adjacent resistor.  I applied heat while desoldering and was able to suck up most of the excess metal.  Using a razor blade I was able to scratch the remaining bridge free.  Testing with a multimeter indicated no bridge.

When I fired up the unit (connected to the 9700 for power) everything seemed ok.  The modulation test worked and Oscillator 1 was working fine.  Oscillator 2, however, made no sound.  I grabbed my multimeter, which I am very inexperienced with, and started doing some testing.  When I was done Oscillator 1 no longer made any sound.


Ok…Like the late Douglas Adams says… DON’T PANIC!

I contacted PAiA and, long story short, their support is OUTSTANDING and the VCO is going back on an RMA.  I’d like them to fix it and tell me what I broke so I can avoid something like that in the future.  I’m also wary of my desoldering skills at the moment.  If an IC needs replacing I’d rather the pros do it.

IMG_3140 IMG_3145

The 9730

I went on to build the 9730 Voltage Controlled Filter.  Once again the kit was excellent and the documentation easy to follow.

While building this kit I got careless on a transistor from a matched pair set and soldered it in backwards.  I got to practice my desoldering skills on it.  While the board was fine the middle connector of the transistor became detached from its body.  I’ve written to PAiA requesting replacements.

At this point the entire board and front panel are ready to connect but I have to wait on the transistors before I go on.  Stay tuned…

Holding Pattern While I Wait For Some Matched Transistors Lesson – Check Twice Before Soldering


The 9710

The last module in the build is the 9710 Voltage Controlled Amplifier / Mixer.  I will be starting its build later this week and will keep you posted.

Once all the modules are built and working I’ll cover connecting them up, interfacing them with the outside world and adding more modules to the mix.

So Far…

Working with these kits has been exceptionally easy.  They are well packaged, well designed and the documentation is laid out in a step by step build methodology.  Any problems I’ve had so far have been my own and the folks at PAiA (Scott in particular) have been great in resolving my problems.  As my build continues and when my 9720 returns I’ll write of the updates to my build.

Some Tips

  • I cannot state how important a good soldering station is to your project.  Forget soldering guns or even soldering irons.  A temperature controlled soldering station can be had for well under $100.  You want  35 watts max or at least adjustable around there.  I use a Weller WLC100 Station.  Don’t scrimp.  Make sure to get the correct soldering tip as well.  You’ll want a fine pin-head tip for precision soldering.
  • Remember The Green Mile?  If the sponge isn’t wet the job won’t get done.  Not dripping, soaking wet.  Just wet it.  If you don’t know what I’m talking about… read the first point.
  • Don’t let position position you – If your soldering target is in an awkward position… move it.  Don’t bend all bendy to get to it.  Take that extra time to make the target easy to hit.  Stop and move things around to suit you.  Not vice versa.
  • Ventilate your work area – Otherwise you’re breathing in lead.
  • Having said that – Breathe.  Don’t inhale while you’re soldering the part but time your breathing so you’re not holding your breath.
  • Go slow and relaxed.  Don’t work when agitated, rushed, pissed off, nagged at by your significant other, tired, drunk, or otherwise in a condition where you think you might do good work but will actually do a pile of damage.  This project will not happen in a few days so stretch it out and enjoy it.
  • Have your documentation handy and make sure you PRE-READ IT!  You will run into far less surprises if you just skim the documentation to see what’s in store.  Make sure to have all the tools and materials described so you don’t have to stop mid-way.
  • DO NOT second guess the documentation – Nuff said
  • Be organized.  There are hundreds of components in the 9700 rack project.  Isolate the projects from each other, especially if you’re working on multiple projects at once.  For me, one at a time is the way to go and while I have a couple of setbacks I can proceed forward with the last project while I wait for parts and my repaired VCO.
  • Watch the Collin’s Lab Soldering video (and others – his stuff is excellent)

Live and learn….

But I can’t wait to play with these toys once they’re working!!!

Stay tuned…..

PAiA - DIY Sound
PAiA – DIY Sound