Casio SK PHAT PHILTER BANK pics!!

gmeredith · November 22, 2007, 11:32:41 PM

Now that I've finally finished my PHAT PHILTER BANK mod, here's how my SK8 looks with it installed, plus all my other mods!

The PHAT PHILTER BANK, for anyone who has been living under a rock the last month or so, is a true polyphonic VCF unit with CV input, cutoff and resonance, with envelope, LFO, external CV or manual control!

External CV inputs from a MIDI-CV box such as a Kenton box, to control the filter via MIDI, can be used to sequence the filter control remotely!

The SK8 also has an adjustable attack/decay on all presets/samples, as well as a whole stack of other mods like sample memory expansion, pitch bend wheel, LFO, MIDI input and multitimbral MIDI mode. There is also a separate drums VCF module.

The Phat Hilter Bank and also the single VCF drums module guides can be found at the Yahoo Casio SK group, in the FILES section of that site:

http://launch.groups.yahoo.com/group/CasioSK/

Cheers, graham

gmeredith · November 22, 2007, 11:33:41 PM

And more

gmeredith · November 22, 2007, 11:34:22 PM

And the PHAT PHILTER BANK close up!

gmeredith · November 23, 2007, 12:22:29 AM

Front view labeled

Circuitbenders · November 26, 2007, 08:29:48 PM

Thats some fantastic work there, you should get a medal for that one!

gmeredith · November 26, 2007, 10:40:37 PM

Thanks! It took nearly a year of my spare time to get it to this, though. The Phat Philter Bank took about 3 months of that time!

I've attached below the original PCB layout of the single VCF filter by Tom. You can simply change the input and output resistors to suit whatever you're putting it in. It's really easy to make, too - you can just print this PCB out on cardboard at actual component size, then just poke the components through the cardboard and solder their legs together on the other side. Really quick and easy!

Cheers, Graham

mq4 · January 05, 2008, 01:24:45 AM

Wonderful work! I wish I was this good... $:-\$

gmeredith · January 18, 2008, 03:16:19 AM

Thanks, mq!

Be encouraged to know that I barely knew any of this stuff before I began it; help from kind people on forums such as this one and others steered me in the right direction on circuits and info, so that I eventually knew what to do before I even picked up a soldering iron to start on it. You might say I'm pretty chuffed with the people on this forum

Cheers, Graham

Signal:Noise · January 18, 2008, 01:00:37 PM

would this filter work at a lower voltage?

gmeredith · January 18, 2008, 09:56:59 PM

Yes, it will work down to about 3V DC, although it might not have much output at that voltage.

Cheers, Graham

Signal:Noise · January 20, 2008, 07:55:19 PM

Would be about 6v dc off four AA batteries. I want to add some filter action to my vetech laptop.

gmeredith · January 20, 2008, 11:20:40 PM

6V will run it fine.

Show us how you adaped it to the vtech when you're done he he!

You might need to add a separate on/off power switch for the filter - the vtech may not actually "switch off" completely when you hit the power off button, but just be in hibernation - like the Casio SK's. I flattened a few batteries with the filter still running after powering down because the part of the circuit I tapped into for the filter power still stayed on when you power the SK down, for memory retention etc.

Cheers

Graham

kick52 · January 21, 2008, 07:08:20 AM

Quote from: Signal:Noise on January 20, 2008, 07:55:19 PM
Would be about 6v dc off four AA batteries. I want to add some filter action to my vetech laptop.

When you're done, post some pics/videos. What VTech laptop have you got?

Signal:Noise · January 21, 2008, 01:04:25 PM

Sweet, I get paid this week so can buy all the nice components.

catweazle · January 21, 2008, 09:37:59 PM

hi,
you made me wet

is there a possiblilty to get the schematic?
Or ist it this one .... from "Circuit Snippets"
http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

Casio SK PHAT PHILTER BANK pics!!

mq4