The Casio SK sampler PHAT PHILTER BANK mod has arrived!!!!

[gmeredith]

Hi Everybody!!

Well, here it is - the magnificent PHAT PHILTER BANK mod!

This mod truly turns the humble SK5/8 into an analog monster machine!

It is also suitable for other SK keyboards, such as the SK1, SK10/100/200 etc, though the hooking up connections may be slightly different for them.

This true polyphonic 4-voice VCF filter has frequency and resonance controls, and CV input.

You can choose manual control cutoff frequency, or select "envelope" control, where the filter follows the attack/decay envelope of the sound selected. You can also select LFO control of the filter if you have the LFO mod installed.

For example, selecting a preset sound like the violin preset will give a "wwhhaahwww" type filter sound, if set to “Envelope” mode. Choose a fast attack/slow delay sound like piano or guitar will give an "aaaoowww" type sound!! Using the sample envelopes will give even more variety.

The fully illustrated, step-by step guide is in the FILES section onthe Yahoo groups Casio SK site:

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

It's in the FILES section on the site (you will need to join the group to access the file, though)

I will put some mp3's up there shortly, to give examples of the amazing sounds this thing produces.

Cheers, Graham

[gmeredith]

Hi all!

I've just uploaded an mp3 example into the FILES section on the Yahoo forum,
in the PHAT PHILTER folder, for you to all have a listen. When I get
time, I'll upload many more examples of different settings of the Phat
Philter Bank mod.

The one I just put up is the SK-8 trumpet preset
sound, with the Phat Philter Bank set at medium cutoff and fairly high
resonance. The sound also has my Slo-A/D Mod applied to it, giving a
nice slow attack to the notes!

Cheers, Graham

[Oceanus - XD515]

Hi Graham,

Do you have a schematic available, as I would like to lay out a PCB for this excellent piece of work.. I would also plan to use Xicor digital pots  for the Freq / Res controls to get the 4-gang effect.. If you don't mind I would like to have a crack at it :-)

Cheers

Paul

[gmeredith]

HI Paul, Sorry I didn't see your post in here first, I answered you via email and then realised you posted here. For those reading this and wanting to know the same question, the circuit is basically Tom Escobedo's Q&D VCF. I simply multiplied the circuit x4, and added some input and output resistors and capacitors to match the SK's circuit level gain. The Q&D VCF schematic is below.

Cheers,  Graham