self osc is a feature in my book. if a filter doesn’t hit self osc its boring as shit 


if you want to tame the self osc for this just increase the 91k

i don't generally design for guitar, this is for line level with my usual focus on low end

if you want to increase the cutoff range use a larger value dual pot

if you want to alter the focus of the filter range then change the 100n cap values

if you remove any filter cap from an active feedback loop guess what will happen.....



this is just a toy

it does, "ground" or vref is 4.5v

a charge pump could be used to double the voltage to 18v total from a 9v source if you want but component values may be off. better? s/n would be and it could process larger sources without clipping, etc... better is relative. this design was made to be as simple as possible using common values that anyone should have or be able to scavenge, nothing more


if you want to run it from a +/-9v setup ignore my power section and use yours. again, some values may be off, the 91k for example is there to determine the max self osc, using the chips input clipping as a limiter instead of the common diode setup which is rather boring

breadboard it, play around, have fun

 9v ?

http://members.chello.nl/~m.heijligers/DAChtml/PLL/PLL1-8.gif



interesting idea, perhaps a simple crude way to add voltage control to an existing crystal setup depending on the way its used. i doubt the range would be that great but it should be usable. similar to some older paia ideas

an updated drench using easy to find component values, no real samples sorry

s

they are just some links i had sitting around

http://thesquarewaveparade.com/images/srlpfb.jpg

http://www.advancedcircuits.com/
http://www.aapcb.com/
http://custompcb.com/
http://www.expresspcb.com/index.htm
http://www.olimex.com/pcb/index.html
http://www.beldynsys.com/kits.htm  maybe useful to someone


http://www.pcbcart.com
used these guys last time around and i will be returning, the easiest and most considerate i've worked with


if anyone finds themselves in need of good DRC soft i'd recommend this. one man op i believe, great fast communication as well, for $50 you can NOT do better!!! http://www.pentalogix.com/Products/ViewMasterEZ/viewmasterez.html

welcome back, looks great colin!

doubt the pickups will take 10 watts and not break down. sorry i just skimmed, didn't realize you need to drive them that hard to get piano strings moving, but at that price they are worth a shot

s

thats not what i meant but who cares.

from what i understand of the diy ebow's you can use those cheap suction cup telephone pickup mic’s as a transducer. like these

http://shop.ebay.com/items/__telephone- ... uscZpickup



s

well you and the computer complete the feedback loop right?

:)

never messed with this design so this is all off the top of my head.

first the LM3900 is NOT the same thing as the TL072 so i'd guess that you will have to use the 3900 or you will have to redesign this around the TL072 which shouldn't be too hard, its simple shit but the biasing will be different. i have not spent too much time with the 3900 so you'll need to pull out the datasheet for it if you want any answers as to why, sorry

use these and just type in " lm3900 "

http://www.findchips.com/
http://burnit.co.uk/sdiy/part_search.ph ... &go=Search
and let this guy know how cool his search page is so it doesn't go away!!

the decay setup is the D2, R37 and C16 so make sure those stated values and parts are all correct, in the correct direction and that none of the chips were damaged by trading them for known good ones, etc...


s

cool, a computer controlled e-bow for piano, should be easy enough to get running in some capacity, making it pretty might be a chore :)

do you have a piano colin?


how's it aen, hope you're well sir

s

give it time.....