Need suggestions for a "pedal organ" project

[methodofcontrol]

i think moog made something like what i'm looking for. basically...what i want
is the foot pedals off of an organ. nothing crazy. an octave or two would be fine. and i want a low cello/organ-ish sound not unlike a synth. ideally this would be the size of a small suitcase (2ft wide by 1ft deep max.) and would be plugged into an amp or P.A.
i'd like to be able to use it with guitar/bass gear (pedals, 1/4" cables, amps and cabs).
i'm not afraid to build one myself...but i don't know where to start. i was thinking perhaps i can find a thrift store organ and hack the foot pedals off as a unit. but then i might be stuck trying to figure out what parts of the circuitry need to stay from the rest of the organ.
bottom line is that i want to play this thing with my feet while playing guitar with my hands.

[Enzo]

Moog Taurus maybe?

http://www.retrosound.de/jenpedalbass.htm


Here is a whole lineup about them.
http://jpsongs.com/troubadortech/pkbd.htm

Check out the XPK-100 and XPK-200 here
http://www.hammondsuzuki.com/default.htm

From Musician's Friend:

Roland PK-5A


Studiologic MP-113


Look on ebay for used ones, and ther are older brands like Crumar and Univox that used to make them.

Look for pedal bass, pedal keyboard, pedal MIDI controller.

[methodofcontrol]

thanks for the links enzo! that's great help!
i just heard about the PK-5 on another forum, if that can just plug into an amp i think it will be my most cost-effective bet barring i don't find a deal on a vintage unit sooner. thanks again!

[R.G.]

I recently built one of these for myself. I got the pedal section from an old electronic organ for free. As an aside, electronic organs are often free. People buy them and then find out that they have to actually develop skill to play, so the organs sit in living rooms for 20 years then get junked.

I used a PIC microcontroller for the tone generators. I generated notes three octaves up from the real bass frequencies, then used CMOS dividers and resistors to add the resulting several notes into a triangle wave. Worked fine.

[Enzo]

Yeah, and they also find out what it costs to get an organ repairman out to their home - if they can find one locally.

[methodofcontrol]

hey RG,
sounds like you found a way to do what i need for so cheap i'd be stupid not to try it before shelling out money for anything else.
mind if i pick your brain?

i'd like pics, sound clips, schematics....whatever you got! i'd love some more info
on the unit you built!

[Enzo]

I forgot about throw-away home organs. A lot of those little organs had a single octave or octave and a half pedal assemblies on them. The pedal unit unbolts, and you can wire whatever you want to the switches. Yuo see them in the local want ads in the paper for little or nothing, and even on the streetside waiting to be hauled away.

[Paul P]

It's too bad, and sort of sad, how useless organs have become. I see
ads regularly for big, full feature organs with two and three manuals in
perfect shape that the sellers can't get rid of for 100$. If I had the
space I'd buy one just for the hell of it.

I couldn't bring myself to carve one up but they're probably being
thrown in the trash.

Paul P

[methodofcontrol]

my original plan involved canibalizing a thrift ship organ for parts. the problem is i don't know how to build the circuit i need.
i can follow a schematic and i am very handy with a soldering iron, but i don't know what to keep and what to throw away as far as an existing organ circuit.
i am also unsure of how to make the instrument put out the appropriate levels for plugging into the front end of a guitar amp.

[IronmanMC]

I play bass pedals with guitar and harmonica. I play jazz, blues, and the kitchen sink. Yeah, I know, Bob Dylan/Neil Young, right? Can Bob and Neil (hmmmm..... sounds like an Andrew Dice Clay bit) play Take 5 on guitar and harp?

http://www.mp3.com.au/images/buttons/track/play2.png

Bass makes - or breaks - the band. I'm very fussy about my bass sound. Originally, I thought that any bassy sound would be OK. After years of experience, I find myself extremely fussy and demanding about my bass sound. I like to rattle glasses off the bar when I hit my lowest notes. And I like it to sound like a double bass or good electric bass.

I've tried most of 'em. I currently own Creager, a pair of Elka's (1 octave fixed velocity, 1-1/2 octave velocity sensitive), a pair of Roland PK5's, and a PK7 1-1/2 octave non-ve3locity set.

I don't know how set you are on building, but there are features available in MIDI pedals that would be very difficult to duplicate in a homebrew project. One that is IMHO crucial is velocity sensitivity. You play hard to play loud, and softly for lower volume, like a piano. A lot of bass patches respond with different sounds, attacks, etc., as MIDI volume varies.

My favorite bass pedal unit, hands down, is the Roland PK-5. They're one octave, built like a tank, have a number of different function buttons that I find helpful, and are reasonably compact. If you want 2 octaves, plug a second PK5 into the first and set it for an octave higher. I have two, but they cover an enormous amount of stage real estate. Roland's support and parts availability is nothing short of incredible. (Elka's out of business - try finding oddball parts anywhere.)

You'll also need a sound module. You can cheap one out, but your bass will probably sound like it. I use a Korg X5DR. The existing patches are good, and editable. I edited several for monophonic (one note at a time - so your mistakes aren't so readily apparent) with an extended release time so it doesn't "chop" between notes. This makes it sound a lot more like "real" bass.

A great bass amp is more important for bass pedals than it is for a real bass (and I'm a bass player). Mine go down to C 31 Hz, almost as low as a 5 string bass's B. Don't try to save money here. I have a Hartke Kickback 15, Peavey MK-III 300 watt head and 115BX 4 ohm cab, a large 15" Carlson enclosure ( http://home.planet.nl/~ulfman/images/krlsnkts.jpg ), a 2x15" bass reflex cab, and more. For small low volume gigs, the Kickback 15 is usually OK, and fits in my Toyota Matrix with all my other stuff.

[methodofcontrol]

well...i'm not SET on building my own. i just figured that a few hours tinkering on a free set of organ pedals is worth checking out before i sink $400+ into anything else.
as for amps, i plan to use my ampeg V4 through an ampeg V2 4x12. (really big bass 4x12 from the 70's)
the PK-5's seem nice, i'm just not that interested in MIDI. could be fear of the unknown, but i feel like i'd have to sink a lot of money into some rack gear just to check it out in the first place. i'd rather buy or build a relatively simple unit and run it through effects pedals for character. some of the 70's units seem like that have everything i need. velocity sensitivity is probably going to be important, and i'm not sure how to build that into a home-brew deal. (unless the organ i canibalize already has that feature.)
i'm keeping an eye out on ebay for a vintage unit in my price range, but no luck so far. once i get more info on how to go about home-brewing one i'll be sure to start up that project ASAP! (RG.-still waiting for that info if you can help)

[IronmanMC]

I am a fellow cheapskate. I'm also an electrical engineer and build a lot of gear. A non-velocity pedal will work. It's just that velocity adds so much.

Velocity is detected by special switches. They have double contacts (likea double throw switch). When you press the key, the armature liftsfrom the first contact, then contacts the second. The velocity circuit detects the time between these and sets velocity for that one event accordingly.

The PK5 has other useful functions such as retrigger (allows you to hold one note and tap the other and alternate the notes), double (adds an octave), and hold (sustains notes after you release).

If your existing pedals have velocity switches, and they have compatible params for your sound generator, it shouldn't be too hard to get it working. If you have a scope, you can measure the time between the 2 contacts on both keyboard and pedal board.

If you go non-velocity, things are simpler.

I hope I've been able to provide you some useful information.

-Mike

[methodofcontrol]

thanks for the pointers mike.
i'll check out my local thrift shops for velocity sensitive pedals.
i think i'd prefer that option if i can find it.
i don't own a scope, but i build effects pedals for a living. so my soldering
and electrical understanding are competent. hopefully someone is willing to guide me through this a bit when i score the parts.

[IronmanMC]

You probably can get by without the scope. It's a time saver. It won't damage anything if the switch velocity is off. It just won't have the proper velocity. Your keyboard may or may not have a velocity adjustment.

[methodofcontrol]

right!
i'll be trolling for used/vintage cheap/free organs this weekend. hopefully i'll find something good and will be able to get this project underway!
i'll keep you guys posted! thanks for the help.