Circuitbenders Forum
Circuitbenders Forum => Show off your kit. => Topic started by: Pancra85 on July 16, 2018, 10:41:09 PM
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I recently made an AVE5 circuit bend and considering it took me a while to research and understand how it's done, I thought it needed better documentation, so I made a schematic for it, and added a few things of my own.
Demo video: https://youtu.be/hqFQAG0jxSA (https://youtu.be/hqFQAG0jxSA)
Schematic (better resolution): https://drive.google.com/file/d/1vDx4AuZEVaFkfUzHu8jLSfVzHwPk0VK8/view?usp=sharing
My version is based of karlkomp's (http://karlklomp.nl/pro/vbend.html#av52 (http://karlklomp.nl/pro/vbend.html#av52)) and Lushprojects' (http://lushprojects.com/videobend/) version.
It works basically the same way, RAM pins go to either GND or to audio in, and there is a 500ohm potentiometer to attenuate the effect, also they can go straight to other RAM pins.
If you activate more than one FX switch on the same bus, it will make a drastic effect as the two RAM pins are connected directly in between without any attenuation.
It's impossible to fit everything inside the original case, so I made an external box to control everything from there.
There is a switch that makes audio go to pin 14 of IC224 that makes an audio reactive wipe effect.
By activating the "interconnect A&B/mono" switch, you can mix RAM pins between both buses, also it makes it possible to send left audio input to the Channel B FXs.
There are some "Patch jacks" that by connecting cables on it you can patch RAM pins, also you can just touch two connectors together with your finger to make it react more organically.
Finally the left and right jacks are taken directly from the AVE5 audio connectors, as seen on the left bottom part of the schematics, in order to integrate everything and take advantage of the existing feature.
There are two 28 pin RAM chips on each bus, so you have 56 pins to bend, but most of them make the same effect. I decided to go with the ones on the schematic, and thought of which ones where best to put on a switch and which ones to put on a patch jack, but you can experiment of your own.
Notes and some things I discovered along the way:
At first I planed to make everything go to a DB25 connector that could be connected to the external box to make it transportable, but there was a lot of interference between the cables and even if every FX switch was off, I got a noise image. I couldn't figure out how to reduce the noise and ultimately decided to just send the cables I already soldered to the external box.
I discovered that pin 17 of the lower RAM chip was very noise prone, and at first I wanted it to be sent to a patch jack, because it made cool glitches by interconnecting it with other RAM pins, but it made a noisy image even with nothing connected, so I droped that idea. It's very sensible apparently.
I suspect that a 40 pin IDE cable could lead to less interference as it's flat cable, my cables were twisted and that was a very bad idea.
It's worthy to comment that accidently, while experimenting bend points, I connected 5v to GND and got a big scare because the AVE5 stoped responding, it only turned the power led but didn't respond. Finally I got it fixed by replacing a fuse (I think FS2) on the power board, it was easy to find and replace
EDIT 08/08/2020: Corrected schematic