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PAiA 9308 FatMan Rackmount Midi Analog Synth #3
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PAiA FatMan #3!!


PAiA FatMan #3 - 2u Rackmount
Yes, call me insane. This is my 3rd Fatman.
Well, I picked this one up i think around January 2005. It's built, quite new, fully working and around US$90.
Hey, I thought, I couldn't even order the kit for that price, and this one's fully working.

So it came to me like this...

This one (as opposed to the 2nd Fatman which I also bought built), came with newer v1.9 firmware, and the builder actually did quite a good job on it.

So it spent nearly 1/2 a year sitting on the shelf, and in July 2005 I finally decided to bring him to life.

(Actually, I couldn't stand it just sitting there, and starting to gather dust. Thought maybe I should quickly give it a proper rackcase, so at least it can start functioning, and not just sit there "being fat"!)



The FatMan #3 - 2u Rackmount

Well, there were a couple of things in mind... either make this a Stereo Fatman - but that requires either getting a 4th Fatman or dismantle Fatman #2. Or I could just rackmount it, in nearly its original form - since my other 2 Fatmans are both in custom 1u cases, I've not got an ''original'' Fatman! So say we all - let it be fat then.
I got a spare 2u 19'' case around, but, it's kinda not very standard - as the Front Panel is another one of those that has right angled sides on the top & bottom, with screw mount holes.
I thought maybe I can just find some right angled mounting L brackets, and so I did.
I'm not gonna go thru how to rackmount this, I also didn't take any pictures.
But basically, I moved the MIDI In / Thru, the CV Outs to the back, and then added the standard IEC Mains Inlet Socket, a transformer and also put a Rocker Power Switch on the front.



Well, I tried to keep it as original as possible, but there are a few tiny mods that have to be done.
The must-do Lee Diodes, 7555 and VCO Pitch were done. 
-> See the MODS page for details of these MODS.
Notes: Most of these mods are from Scott R. Gravenhorst's excellent Synthaholic's Fatman Site.
- Lee Diodes Replace R38/R39 with LEDs + add 100uF caps to C28 and C29
- 555 -> 7555 Replace 555 IC's with 7555's
- VCO Pitch Extend Change R35 (1k resistor) to a 680R
On FatMan Rack#1, I added a Switch to bypass R35, but this time I feel I don't wanna spend lots of time tuning this thing - so I just reduced the 1k resistor.
This is the same as my Fatman #2.

I didn't bother with the other mods, not even the VCOs Sync or Filter Extend.




The Front MIDI In/Thru and CV/Gate plus the Audio Out are now routed to the rear panel of the rack. So I just "Blank Out" these empty holes.
It's actually very low-tech DIY. I cut out some spare DVD blank cases, and tape it on the back of the front panel. With the MIDI/CV/GATE, this bit of DVD Box actually covers the 2 LEDs and the AR Switch. I just re-drilled thru the plastic to let the LEDs and switch pass thru.
(This also helps holding the plastic in place, cos taping it is kinda fragile - otherwise it could break if you "poke" the blanking black bits!)

To make the square-ish hole for these illuminating Power Switch, another one of these Hand Hole Cutter is needed. This one is the M10 rectangular hole cutter,22x19.6mm, RS Code: 600-161.
The Power Switch is one of those DPST green (or red) illuminated rocker switch, 10A/4A.
RS Codes are Green: 318-070, Red: 318-064




This case is actually quite nice, silver-ish, not black, so I used transparent stickers for labeling!
On the Left:

Just the mono Audio Out Jack Socket!

In the Middle:

The CV OUT (on mini-jack sockets)
and the MIDI In and Thru.

On the Right:

Well, there's the IEC Mains Inlet Socket and FUSE Holder. 

I also made an Earth Life switch, that life the Ground from the Mains input.

Also, since I have had under-powered Fatmans before, this time I used a big dual 6VA 12V AC transformer - I only used one side of it, which should be enuf for the Fatman's power requirement.
The other AC 12V 6VA, I routed to a stereo jack socket on the back, wired to the Tip & Ring, in case any equipment nearby needs AC12V - then it can be powered frm here instead of a wallwart!

To make the IEC Mains Inlet hole, I use a screwing hand tool, which is an M10 Radius Hand Hole Cutter, 28x21mm (
RS Cat.#543-614 or or 541-501), with matching 10A Snap In PCB Mount IEC 320 Plug Socket (311-8031 or 488-191).



As of 28th July 2005




Some Comments on 3rd FatMan...


bulletEven tho without the mods I did on Fatman1 or Fatman2, he still sounds roughly the same, I suppose the Fatman has that distingue sound!
bulletThe Midi Channel DIP Switch is a different one on this Fatman. It's a push one instead of a flick one.
somehow, it doesn't correspond to the Fatman Midi Channel table, so it's a little hard to set...
So I just keep it on Midi Channel 16 for the time being.
bulletWell, still, PAiA Fatman is a very powerful and useful synth. For US$90 (or £40), this particular Fatty is really cheap - the actual kit costs more, plus it needs to be built.
Recently (June/July 2005) I have seen 2nd hand Fatmans going at like £90 or EUR100 or even £110 ~ £200 (with rackcase)! So this one was cheap.
But as I've said b4, building a synth is a great achievement - and the PAiA Fatman is definitely one good one to start!!




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