arr!fx - Two Step - Octave arpeggiator

[Ben N]

TOOBZ?

You have no idea how hard that is to do at 50  

A squarewave sounds like a squarewave no matter what technology you use  

I know. Just funnin'.

[~arph]

As you're using a 4024, and there are two unused gates of the 4066..........well it would seem like a wasted opportunity not to use those extra 4024 outputs with those extra 4066 gates........Four Step 

I have an even better idea...

Going to need a comparator and a 40106 instead of the 4093 (need extra inverters) also a 4015.
The two spare gates of the 4066 will be PWM'ed resistors for the filter (one for each octave)
The 4015 will be a walking ring counter putting out a stepped sine/triangle. The value will determine the PWM duty cycle for one filter, invert the PWM for the other filter.
Clock the 4015 with the same clock as the other two 4066 gates so the filter will step in time.

Now who's with me? 

[frequencycentral]

Moi!

[~arph]

Now if I didn't just get that baby..

I have arranged DIY time coming sunday 

[~arph]

Here's a little sketch for that...



Currently only working in my head.  
This thing is evolving in at least as interesting as the four step arcade pedal.

[~arph]

Schematic on page one works fine. 

The mod above works like  charm too. I will refine it this weekend and hope to post a sample.

[~arph]

Ok,

Here's the schematic for the deluxe version..
Now anyone wants do to a PCB?

https://picasaweb.google.com/lh/photo/MZqE3-aNC7jbO-Mf-MDE4tMTjNZETYmyPJy0liipFm0?feat=directlink

I've added the option to switch in the second octave down too.. sounds rad!
(BTW, On the breadboard I have that SUB diode connected to the 100k series at the output, this should work too.. I just noticed this)

My apologies for the worst guitar playing in the world, but the sound is what matters here.

http://soundcloud.com/arrfx/arr-fx-two-step-with-sweep

[mwynwood]

This thing sounds amazing!

[~arph]

Thanks, I tried my hand at a single layer layout, but it's madness..

[~arph]

(BTW, On the breadboard I have that SUB diode connected to the 100k series at the output, this should work too.. I just noticed this)

Connect it to the 100k, as drawn in the schematic it doesn't work properly.

[Valoosj]

I'd be willing to do a pcb layout for this one. Could you tell me which schematic you are referring to in your last post, so I can avoid any mistakes?
Maybe I'm crosseyed, but I don't see the steps switch from your finished pedal in the schematic.

[~arph]

Two differrent pedals    The arcade is a four step version, but without the stepped filter. I never made a pedal out of the one in this thread, the two step. Basically the two step is the same as the arcade but only toggles between one octaves. The arcade has a 4017 to toggle between three octaves (one octave is in two of the four steps)

[Valoosj]

I thought the arkanoid/two step was the basic form from which you created the Arcade.
The one I really like is this one: http://soundcloud.com/arrfx/arkanoid

Is this then the one from the first schematic in this topic? And which one do you want a pcb layout of?

[~arph]

Yes you are correct. That soundsample is done with the first breadboard experiment. Which is the two step minus the autofilter.  From here it split two ways, one version with two extra steps became the Arcade. The other version is what is in this thread, but as a result either the arcade or the version in this thread is capable of making the sound in that clip. (which has a lot of reverb on it). What I'd like to see a single sided (for home etching diy'ers) PCB of is the one in this thread.
You have to pay attention to two parts:

1. the sub octave is wired wrong. (as explained here)
2. The two resistor values along the manual filter setting pot must be calculated experimentally determined. I did not try this when it was on the BB.

The rest is good to go.

Thanks

[tyronethebig]

I'd like to try and make an etch-able 1 layer pcb for this, would you mind checking my values? C1 is hard to read but its in as 47n


https://dl.dropbox.com/u/105724178/Arrf%20two%20Step.pdf

[artifus]

chapter 24, page 94, sort of: http://www.nicolascollins.com/texts/originalhackingmanual.pdf

[~arph]

Yeah the fuzzy dicer. That is a gated oscillator nice little circuit.

[~arph]

I'd like to try and make an etch-able 1 layer pcb for this, would you mind checking my values? C1 is hard to read but its in as 47n


https://dl.dropbox.com/u/105724178/Arrf%20two%20Step.pdf

I think your values look good. I have a 27k as a fixed resistor in the oscillator section. Also, that R2 1meg to GND can be lowered to a 470k. Or increase the resistor above it to 1meg. One thing to try is to use a lower value pot say 25k for the volume control as this thing is VERY loud.

[tyronethebig]

Thanks for the replies and resources guys! Arph, I sent you a message about that 27k resistor. I'm confused about where to put that but the other changes have been made.

[~arph]

I've sent you a reply. You are sure btw that you want to Make the simple version? Not the deluxe version with the stepped filter?