19 February 2008

PAIA 9700S (Part 2)

The next module I started on after the MIDI2CV8 module was the 9720 Dual VCO module. This module actually has two separate VCO's (Voltage Controlled Oscillators). Oscillator A has Ramp, Pulse, Triangle and Sine waveforms and Oscillator B only has Ramp, Pulse and Triangle waveforms. There is also a modulator on the module that actually is an Envelope Generator.

During soldering the PCB again found out that I missed a part. There should be two 10K trim potmeters in the bags, but I found only one and three of another value where two where supposed to be. Again I e-mailed PAIA about this and again I got a prompt reply with apologies and that the part was send off immediately. I really must complement PAIA on this. Off course this didn't hold me back from starting with finishing the PCB. I had not problems whatsoever with the PCB. The manual is very clear and if you just follow instructions you are done. A clever thing in the manual is that is acts as a checklist for parts. When you install a part you just mark it on the checklist and you know in the end for sure that you didn't miss anything.

After finishing soldering the PCB I mounted the front panel components and then I attached the front panel to the PCB. Then I started the wiring from the PCB to the front panel components. This is a bit more difficult. The first thing I found though is that the wire that is supplied in the kit is not very easy to strip. It is doable, but a lot of force in needed when you use a cutting tool for it like I usually do. The second thing I noticed is that the quality of the mini jacks is not so good. The soldering points are very thin and you need to bend some to get the wire through. And it didn't take much force to break two of them. I managed to fix this, but I think PAIA should look into this. But the manual again is very clear on which wire if going where. There is again a nice checklist for this and even the length you need to cut the wires to is supplied. Divided over three very clear drawings you can double check that you connected the right wire to the right component. Again compliments here for PAIA. I couldn't test the module yet, because I didn't connect the power yet and I didn't have another Midi to CV module to test.

Talking of Midi 2 CV. I also connected the front panel to the MIDI2CV8 module. Here on the left you see a picture of the PCB with(out) the missing parts. And coincidentally today I received an envelope with all the missing IC's in it! And also a separate envelope with the missing trim potmeter. All in all much quicker than I expected actually. On the bottom right you see a picture of the IC's. The big one on the top right is the microprocessor and left of it you see the Eprom with the software code in it. All nicely put in anti static foam to protect them from electro static discharges.

So I should be able to finish this module very soon and test it. I only need to get an external power adapter from my local electronics shop, because the one supplied is 110 Volts and I need a 230 Volts one. But I guess that won't be much of a challenge. It is a simple 12 Volt AC adapter with just 1 Amp. I just don't understand that PAIA send a 110 Volts adapter to Europe. They should know it will end up in the garbage :) OK enough for today. Another post soon in Part 3.

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