The Karplus Strong eChucK DIY Project

Jaba · Joined: Feb 27, 2009 Posts: 45 Location: Genova, Italy

Hi Woody,
it would be great to have another run, thank you!

I would surely buy at least one PCB

Paolo

dnode · Joined: Aug 07, 2009 Posts: 11 Location: Nederland

At last found the time to read through the whole thread, great stuff! Thanks, Les et al!

I would be mucho interested in five boards ... and willing to help out anyway I can!

Idea is to built up two for a module in, well, my modular ... and use three for a separate box incl. sequencer (of any kind?! BS?)

Please, shout if help is needed!

Inventor · Posted: Sun Sep 25, 2011 12:21 pm Post subject:

dnode, i created "the brick"which was a bs into two ks boards, and it sounded awesome. into three would be something else. I strongly recommend your approach to use multiple ks together in each of the ways you choose to use the board as the sound so much better that way.

you might want different voices or you might chain them together for dronish weird sounds, lots of possibilities. I hope there is enough interest for another run.

Les

de_engineered · Joined: Jul 16, 2009 Posts: 18 Location: USA

de_engineered · Joined: Jul 16, 2009 Posts: 18 Location: USA

Is the stage count of the BBD essential btw? Sorry if this was answered somewhere in this thread - it is 22 pages long a this point Smile

!

Ie: is there a minimum for the effect to work, or might it be like reverb tanks with larger springs :: longer reverb times?

Inventor · Posted: Sun Sep 25, 2011 9:50 pm Post subject:

de_engineered · Joined: Jul 16, 2009 Posts: 18 Location: USA

Inventor · Posted: Thu Sep 29, 2011 3:19 am Post subject:

well, i would suggest prototyping any circuit geometry that you would like to create in software to see if it's what you think it is. Karplus Strong is powerful in it's simplicity, but physical modeling can be much more complex. Yes, you could parallel them for interesting effects. The KS board has a tap in it for inserting different filters and I'd suggest playing with that foremost.

Les

mosc · Posted: Thu Sep 29, 2011 7:43 am Post subject:

mono-poly · Posted: Wed Apr 18, 2012 9:44 am Post subject:

Totaly missed this one.
If anyone got a spare pcb, i'd be interested!

Inventor · Posted: Wed Apr 18, 2012 10:00 am Post subject:

Hi mono-poly, welcome to the KS thread, lol. I have recently learned that www.sparkfun.com has a circuit board service in which you can get just one board made or any number you want. They queue up people's boards onto a large panel, much like the MOSIS chip service that queues up people's chips to a wafer, then they have the panel cut up to individual boards for us. With this service there is no longer any need to get a large enough order together - we can just order the number of boards we want. Prices are always reasonable at Sparkfun too (If not darned low).

It's up to woody, but I would be in for four boards myself. Why don't we start a board run tally with this post. Please end your post something like this:

----------------------------------------------------------------------
Attention Woody Monk
Inventor: 4 boards requested
Running Total: 4 boards requested
----------------------------------------------------------------------

elmegil · Posted: Wed Apr 18, 2012 6:10 pm Post subject:

I assume the service you're talking about is this one? http://batchpcb.com/forums.html/Products

Inventor · Posted: Wed Apr 18, 2012 8:22 pm Post subject:

elmegil · Posted: Wed Apr 18, 2012 9:11 pm Post subject:

I'm far too new to this to have ordered custom PCBs already Smile

. But it took me a bit to find the SparkFun link so I figured I'd post the direct link.

I'm still playing with small circuits...although most of my parts are here at this point, life has prevented anything very ambitious. Just a variant on the MFOS calibrator and a ridiculous variant on Ian Fritz's transistor matching circuit...and those are both really still in planning because I need additional 1% resistors for the first and sockets for the second. I'm building both on protoboard (though the demands of the Ian Fritz ckt are so minor that I could practically wire it into the lid itself instead).

When I say ridiculous...I ordered a 4PDT on-off-on switch to switch between NPN and PNP variants with one circuit...without paying close attention to dimensions...and the switch I got was HUGE. It fits in the planned project box, but it's going to look very silly. Luckily the switch for transposing the emitters is from the same series/mfr, so they'll look silly together.

Inventor · Posted: Wed Apr 18, 2012 9:21 pm Post subject:

elmegil, nice to read your sharing of your project experiences. Those of us who have been around longer get a kick out of beginners' stories because they remind us of our own beginnings, both the success and the failures. The giant switch is a learning experience, and thanks for the link.

Les

elmegil · Posted: Thu Apr 19, 2012 10:04 pm Post subject:

I posted the unwired but mounted picture here: http://electro-music.com/forum/topic-51990.html Hopefully I'll get a chance to wire it up tomorrow, at which point I'll take some more pix and post to the build thread.

e-grad · Joined: Sep 12, 2008 Posts: 142 Location: Berlin

I’m stuck with my project. Could someone please tell me whether I got the following right:

Some panels for this project include a ‘resonance pot’ and a ‘trigger level’ pot:

R43 of the summing amp is „resonance pot“?

Trigger level = a pot not shown on the schematics which is wired in front of “X4/Stim”?

There are three pads right above U3. Does a 100nF (= 0.1µF) goes here leaving the middle pad unused?

I received in a trade two different Les Hall’s Karplus Strong boards. One is from 2010 which is discussed in this thread. The second one is from 2009. Is there any documentation for this board available?

Any hint is highly appreciated!