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DIY Stompboxes => Building your own stompbox => Topic started by: bobbletrox on July 15, 2004, 11:02:48 PM

Title: Sequencer: only 2 steps working?
Post by: bobbletrox on July 15, 2004, 11:02:48 PM
(http://users.bigpond.net.au/styrowfoam/eightstep.gif)

I perfed the sequencer up and connected it to a PWM perf -but something's not quite right- I can only seem to only get 2 steps working so it just sounds like a weird tremolo effect.  It sounded like I managed to get all 8 steps working briefly by gently pressing the solder side, but after reheating all the joints and making sure they were good, it still only goes 2 steps!  I gave up in frustration when the +9v wire finally broke off from all my wire jiggling and sent a loud spike through my amp.

The crazy thing is that it does cycle back and forth between steps 1 and 3...which it shouldn't be able to do by my understanding.  I just...don't...get it.
Title: Sequencer: only 2 steps working?
Post by: Arno van der Heijden on July 16, 2004, 03:16:40 AM
Try installing the other two 100k resistors between the cd40193 and v+.
I don't know why, but it made a difference for me....
Title: Sequencer: only 2 steps working?
Post by: bobbletrox on July 16, 2004, 08:22:04 AM
http://www.geofex.com/FX_images/ud-rand.gif

Do you mean the 100k resistors on the CD and -Ld pins?  Which pin is -Ld on a CD40193 anyway?  The TI pinout is slightly different than the 74C193:
http://focus.ti.com/lit/ds/symlink/cd40193b.pdf
Title: Sequencer: only 2 steps working?
Post by: Arno van der Heijden on July 16, 2004, 08:35:15 AM
Yes, those are the ones. Mine did the same until I connected those resistors.

The -Ld pin is # 11. Look here:

http://www.musicfromouterspace.com/analogsynth/new32x1and16x2sequencer.html
Title: Sequencer: only 2 steps working?
Post by: bobbletrox on July 16, 2004, 10:29:32 PM
Thanks!  :o

I hooked 'em up and now 4 steps work lol.  Four out of Eight ain't bad I guess.  I'll keep at it and see if I can get the others to work...

Here's what 4 steps sound like controlling a PWM: sequenced-pwm.mp3 (http://users.bigpond.net.au/styrowfoam/sequenced-pwm.mp3)

I might post this sample on the Harmony Central effects page to see what pedals users think...because I was really just interested in the electronics side when choosing this project.
Title: Sequencer: only 2 steps working?
Post by: Jason Stout on July 16, 2004, 10:37:47 PM
:twisted:  I like the sample!
Title: Sequencer: only 2 steps working?
Post by: mikeb on July 17, 2004, 02:41:16 AM
Quote from: bobbletroxI might post this sample on the Harmony Central effects page to see what pedals users think...

"Cool - how much?"
"When can you make one for me?"

(then you tell them a reasonable price and ask if they are REALLY interested)...

...deathly silence...

:D

Mike
Title: Sequencer: only 2 steps working?
Post by: Arno van der Heijden on July 17, 2004, 03:34:21 AM
Quote from: bobbletroxThanks!  :o

I hooked 'em up and now 4 steps work lol.  Four out of Eight ain't bad I guess.  I'll keep at it and see if I can get the others to work...

Mine does all eight steps, so there's still something wrong I guess....
Title: Sequencer: only 2 steps working?
Post by: LinuxMan on August 24, 2004, 04:46:07 PM
Hi.

I was wondering if you still have the problem with the above layout?

The thing is your 40193 (IC2) is wired incorrectly. Move the pin #5 wire
(which is a count up timer) to pin #6 (O3). And you're there.

I did the sequencer with your layout and it works now (all 8 stages). I
changed the 47k resistor to 4.7k though. Gives me more speed...

I hope that helped... Nice redraw of a circuit btw. You could fill in the
corrections one day (100k to voltage + wrong pins) and repost the thing.

Cheers
LM