MATRIXSYNTH: Fender Chroma Polaris Synthesizer

Tuesday, October 10, 2017

Fender Chroma Polaris Synthesizer

via this auction

Some details from the listing following. Interesting bit regarding the DC shift kill circuit. Maybe this will help some experiencing the same problem.

"This is a Chroma Polaris, a highly underrated analog monster. When I got it, it was missing all the slider knobs and a few sliders were broken off. The previous owner thought it looked better without end caps and lost them. The membrane was in bad shape.

Now, it's much better. I replaced all of the slider potentiometers with new ones. They have a shorter shaft to accommodate the plastic slider knobs I got for it. I replaced the membrane with a brand new one. I recapped the power supply with high quality capacitors. I put some batteries in, loaded factory patches and it sounds amazing. All the keys work perfectly, the MIDI works, sequencer and all the functions are 100% working. It's a punchy full sounding monster synthesizer.

The bad part, aside from the missing end caps, is that when it's stored on it's side, sometimes when you go to power up, it doesn't work. It happens because of a built in DC shift kill circuit. If the DC shifts a tiny bit, it won't power up. The field work around is to turn the potentiometer inside counter clockwise then clockwise till the LED inside lights. That puts DC back where it should be, then it works again. I've considered having it looked at because it's got to be something small that adjusts when it's on it's side. When I leave it on my keyboard stand, it's fine and turns on every time. It seems to only happen sometimes when it's stored on it's side for any length of time. It's something that could be looked into, though, it didn't bug me so I didn't bother with it. Also, the metal screws that line the back were removed for ease of opening, I will see if I can find them. The top latches down securely with two giant screws on the bottom so they aren't absolutely necessary.

I took a picture of the power supply board inside to show the potentiometers and LED. I will need to check but I think it's either R17, maybe R5 that you adjust. Before I ship, I will confirm this and adjust it fresh for the journey."

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