Payback v2.0 Feature Requests

[Beo]

Hey TG... any updates on this project?

[The Tone God]

Yes they are updates on the work in progress.

I have moved from the breadboard to the test case I built awhile back with all the changes reflecting the newer audio circuit design. It looks like everything works on the audio side so I think everyone will like the smaller simpler design. Easier to build. Now I can test in a real usage environment to make sure everything works well.

I have another ISD1700 varient for testing so I can make sure the software works properly and not just on the current ISD.

I was going to add a level trigger function but then I realized that setting up the controller to accept external logic signals, by switching to external debouncing as with the TapTation, this can be done with other circuitry so the general user can stick with the simple design as is and those who want more can add the need functionality on their own.

There is still some little tweaking to be done and one more software bug I'm still chasing but I think I'm getting a handle on what is causing it. Right now I'm busy building but when I'm done its right back to it and to see if I'm right about that bug.

Andrew

[xman]

Hi TG,
thanks for sharing this fantastic project!

Any news ?

[El Heisenberg]

We all wait so excited

[The Tone God]

I have had to step away from this for a few. There is still one bug that is causing a seemingly random glitch in behaviour that I haven't quite nailed down yet. I know its one of those small stupid things but I have been looking at the code for so long that I started to go blurry eyed. I need to step away from it for a bit and come back with fresh eyes and nail that last problem.

I was also going to add a few things to help the user debug the design if there are problems. I think that would be appreciated with such a complex build for some.

Andrew

[jkokura]

Thanks for the update.

I'm looking forward to this. I was hoping for overdubbing - is that a possibility?

Jacob

[Taylor]

Overdubbing is not possible with a single recording chip, since it can't record and playback at the same time. 2 chips would be needed, and as I understand it from previous discussion, the time to go between record and playback is too long to make it usable except for soundscape stuff. This technology is not going to be the ideal medium for a looper with overdubbing - will be necessary to go digital.

[jkokura]

Thanks for that Taylor.

Jacob

[Taylor]

There was a guy here who posted some months ago about how he was designing a PIC-based looper, acted like it was the kind of thing he does in his sleep. I exchanged some mails with him encouraging him and trying to facilitate the development however I could. Then he disappeared. Might've been bluffing, or if he was telling the truth, maybe he got caught up in some better use of his superior mental skills; missile guidance or similar.

I've looked at this problem from a few angles... tricky in a variety of ways.

[Musikermomo]

There was a guy here who posted some months ago about how he was designing a PIC-based looper, acted like it was the kind of thing he does in his sleep. I exchanged some mails with him encouraging him and trying to facilitate the development however I could. Then he disappeared. Might've been bluffing, or if he was telling the truth, maybe he got caught up in some better use of his superior mental skills; missile guidance or similar.

I've looked at this problem from a few angles... tricky in a variety of ways.

Do you mean darwin_deathcat? I wrote him a message yesterday, let's see what he answeres. I'm very curious about that.
You can read the description of his isd1700 based looper here: (reply 23 & 26): http://www.diystompboxes.com/smfforum/index.php?topic=72482.20
He is using a looper that is capable of recording overdubs in one video in his youtube channel.

Moritz

[Taylor]

Nope, somebody else - this was supposed to use a PIC (maybe dsPIC) to do the looping, no ISD chips at all.

I tried to find darwin_deathcat's youtube channel, couldn't find it - any links?

I do think, though, that The Tone God's ISD designs are awesome. I have built a Payback 1.0 and use it all the time - lots of fun, even without overdubs.

[Musikermomo]

This is the video, but it's very "inexpressive"... I mean regarding the features of the looper
http://www.youtube.com/watch?v=oYB2rMZN7Ew

I'll definetly built the new Version 2.0, when it comes out. The new chip seems to be available more easy.

[Taylor]

Hmm, don't see any info about the looper in his videos. I'm guessing he's using a commercial unit or a computer, but I'd love to be wrong about that.

[joer0952]

I emailed him and he said in the video he is using the Digitech RP155

[Musikermomo]

He said he used the fully assembled ISD 1700 sample board that you can buy from digikey
http://parts.digikey.com/1/parts/406973-board-demo-isd17240-isd-cob17240.html
He combined that with the loop circuit snipet from Payback 1.0.

It seems that the chip is capable of recording multiple messages and looping them:

Also, one cool feature of the ISD1700's is the inclusion of a "reset" switch option that when pushed while the thing is looping causes it to go back to the begining of the loop. This not only will help you "sinc" up the loop to something else, but also lets you do a very cool "stutter" effect where you can make the first bit of the loop repeat, kind of like a DJ scratching a record! The ISD1700's also alow the recording of multiple tracks, so that if you do not erase the first track, whatever you record just gets tacked onto the end of the loop. Pressing an "erase" switch quickly ereases the last recorded track, or holding it down for about a second erases everything.

That would be perfekt! I am a bit confused about what the thing can do or cannot do. Please enlighten me!

[Hides-His-Eyes]

Cloudscapes (tape) built a looper using a PIC/RAM. It was not trivial by any means and is by its very nature pretty glitchy (as he intended)

[Taylor]

He said he used the fully assembled ISD 1700 sample board that you can buy from digikey
http://parts.digikey.com/1/parts/406973-board-demo-isd17240-isd-cob17240.html
He combined that with the loop circuit snipet from Payback 1.0.

It seems that the chip is capable of recording multiple messages and looping them:

Also, one cool feature of the ISD1700's is the inclusion of a "reset" switch option that when pushed while the thing is looping causes it to go back to the begining of the loop. This not only will help you "sinc" up the loop to something else, but also lets you do a very cool "stutter" effect where you can make the first bit of the loop repeat, kind of like a DJ scratching a record! The ISD1700's also alow the recording of multiple tracks, so that if you do not erase the first track, whatever you record just gets tacked onto the end of the loop. Pressing an "erase" switch quickly ereases the last recorded track, or holding it down for about a second erases everything.

That would be perfekt! I am a bit confused about what the thing can do or cannot do. Please enlighten me!

That's not overdubbing, it just records several loops in sequence. It's not possible to record and playback at the same time, unfortunately.

[El Heisenberg]

Unless you have two chips?? 

[Taylor]

Unless you have two chips?? 

Well, right, as I said above:

Overdubbing is not possible with a single recording chip, since it can't record and playback at the same time. 2 chips would be needed, and as I understand it from previous discussion, the time to go between record and playback is too long to make it usable except for soundscape stuff. This technology is not going to be the ideal medium for a looper with overdubbing - will be necessary to go digital.

So it's possible, but not very usable for people who play regular rhythmic type music. For soundscapes, it would be great, and I've actually fooled around with the idea a bit, but it's tricky.

[Musikermomo]

too bad, but thank you anyway.

Nonetheless several loops in sequence could be useful, too.