Scratch patcher

Oct 7, 2009 at 9:10pm

Scratch patcher

Hey, i’m interested in understand how to make a scratch patcher.
This guy has uploaded a video that shows very nearly what i want to do. At the begining of the video he shows some of the code, but not enought for me to understand how it works.

the video:

so any ideas?

Oct 7, 2009 at 11:23pm

dj kru represent

i went down the index~ route, probably better off with groove~ but this came quicker

will probably die with anything but jongly

but it should give you an idea

– Pasted Max Patch, click to expand. –
Oct 8, 2009 at 12:25am

I wrote a simple “scratching” application a while ago
that allows the “record” to play while you scratch-
you can download it here:


Oct 8, 2009 at 3:33am

First of all, thank you both for answering. I’m starting to get it.

But i’m on windows XP, so i couldnt make eli’s patch work. Can you upload a text version? or post it here? or could someone on mac download it and upload it as a text?

Oct 8, 2009 at 3:16pm

Another thing:
Mike S, does your patcher sounds crappy when not clicking on the scratch?
It generates a noise, on my computer at least.

Oct 8, 2009 at 3:56pm

obv my way is probably not the best! you want really small signal vector sizes (1,2,maybe 4) because it depends on the values coming out of the dial

Oct 8, 2009 at 9:57pm

so, i´ve been checking the video again and started to screenshot it to make the puzzle image of the patch.

here is the image:

And after that i tryied to recreate that in a new patcher, just to see if i can make it work just as the video. Unfortunately i couldn´t. I have not that wheel object, wich is different to the radial object.

I did my best, if someone can make it work, please talk to me!

Here is what i came in:

– Pasted Max Patch, click to expand. –
Oct 8, 2009 at 10:28pm

It appears to be a customised version of a [jsui], obviously I can’t see the new code inside but you could try patching something together.


Oct 9, 2009 at 1:56am

Ehm… i´m really new at Max programming. So, could you be more specific?
Anyway, if you can open the stine eli´s patcher and upload it as a text, i´d thank you a lot.

Oct 9, 2009 at 9:08pm

I have attached the patch I made, and also basic directions for getting it up and running. Enjoy!


May 2, 2011 at 8:01pm

I have been playing with the patch that Mike S posted, which is a great start for something I’m trying to work out.

My problem is I’m having a hard time getting my head round how to bolt my hardware interface onto this.

The interface in essence returns a series of deltas as it is turned, +/- 1 repeatedly fires (up to +/- 30 if you spin it fast).

Trying to find a way that I can feed these changes in but have it so when it stops moving the play head carries on playing.

May 2, 2011 at 8:30pm

play~ – with index~, or without.

May 2, 2011 at 8:39pm

I’ll try and strip down what I have so far and post it up later today, maybe someone can see where I’m going wrong easier with the code. I’ll take a look at index and play first though.


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