New Effect: Payback

[Valoosj]

I have six for sale. They come with three CD4093 for free. But it's quite an expensive IC.

[The Tone God]

Really alot of making Payback v1.1 work is tweaking the control logic but it is a collection of various hacks to make a limited IC do our bidding. I have a SOIC version I was going to test with to make sure the values I choose were wide enough to work with most ICs.

Payback v2.0 is coming out pretty good now. I am becoming quite pleased with it. It should make everyone's life much easier when it comes to building a Payback.

Andrew

[chilecocula]

what  isd chip will payback 2.0 use?

[The Tone God]

what  isd chip will payback 2.0 use?

17xx series. It will work with any length version.

Andrew

[Ben N]

Hey Andrew, would working a compander in this thing make sense? (Optimize input level, minimize noise, y'know...)

[The Tone God]

Hey Andrew, would working a compander in this thing make sense? (Optimize input level, minimize noise, y'know...)

I actually was thinking about that awhile back. Most of these ICs have 3-5v range so when driving them hard you get distortion. Granted you can bring down the input level but then you have to boost the output which also means boosting the output hiss which there is still a fair amount of at the high resolution settings. I thought a compander would be an interesting approach to attempt to solve this. Basically treating the recorder like a delay.

I will give it a try later. I don't have any compander ICs handy and I'm busy chasing down a couple of minor bugs with the current design.

Andrew

[cloudscapes]

many chips are still available at digikey, but they're the surfacemount kind. you can find adapters on ebay for pretty cheap, or if you're masochistic like me you can make your own

[Radamus]

what  isd chip will payback 2.0 use?

17xx series. It will work with any length version.

Andrew

If you don't mind me asking, how far off is that? Both of these projects sound really amazing. I had no idea that looping was something you could even do DIY. I'm getting ready to order some parts soon, so just let me know if I should plan to put that in the next order or hold off for a little while on this order. Also, futurlec still claims to have the 25xx series, which you said was going to be obsolete. I know from experience that they don't let you know when something's out of stock. Can anyone verify that? What are the limitations of the 17xx series? futurlec carries them, but the stat sheet is MIA.

Thanks for this awesome project. Combine this with an echobase, and no one needs those high end pedals.

[MarcoMike]

with 480 seconds of playback I don't even need an mp3 player anymore... 

[The Tone God]

If you don't mind me asking, how far off is that? Both of these projects sound really amazing. I had no idea that looping was something you could even do DIY. I'm getting ready to order some parts soon, so just let me know if I should plan to put that in the next order or hold off for a little while on this order. Also, futurlec still claims to have the 25xx series, which you said was going to be obsolete. I know from experience that they don't let you know when something's out of stock. Can anyone verify that? What are the limitations of the 17xx series? futurlec carries them, but the stat sheet is MIA.

Thanks for the comments!

I have couple of minor bugs that I am chasing right now. I am hoping to have everything done for FX-X entry at the end of the month. I will then write an article for it. I would guess a month and half maybe. Maybe alittle more. I can't be more specific as I am pretty busy at this point. If you want a Payback now and you can get them grab the 25xxs. If they have them they are old stock and are hard to find. There have been many reports of people being happy with v1.0.

As for limitations of the 17xx I really don't see any atleast with the IC itself compared to the 25xx and 16xx. It will be better in just about every respect to previous versions. The only real trick with v2.0 is that it will have one specialized part but I am working on that too.

with 480 seconds of playback I don't even need an mp3 player anymore... 

480 at 4Khz sampling which is fairly low. 240 at a better level or around 200 at the best level. Right now for testing I am using the 60 second versions at the highest level which gives 40 seconds and I have yest to run out of time.

Andrew

[Radamus]

I have couple of minor bugs that I am chasing right now. I am hoping to have everything done for FX-X entry at the end of the month. I will then write an article for it. I would guess a month and half maybe. Maybe alittle more. I can't be more specific as I am pretty busy at this point. If you want a Payback now and you can get them grab the 25xxs. If they have them they are old stock and are hard to find. There have been many reports of people being happy with v1.0.

As for limitations of the 17xx I really don't see any atleast with the IC itself compared to the 25xx and 16xx. It will be better in just about every respect to previous versions. The only real trick with v2.0 is that it will have one specialized part but I am working on that too.

What is the sampling rate like on these chips?

Thanks for the quick response. I guess the answer, then, is that I'll put this in the next order. I'm sure I'll have another five or six effects I want to build by then anyway, the 17xx chips are a little cheaper and available from futurlec, which is good for me (and probably a couple other people). Do they have the ability to record multiple tracks like the original design? And what's the deal with the ISD40xx? The data sheet says something about limited analog storage, which has me pretty confused.

Again, very excited to build one of these, very disappointed that I'll have to wait. Thanks for the great project, though.

[The Tone God]

What is the sampling rate like on these chips?

Thanks for the quick response. I guess the answer, then, is that I'll put this in the next order. I'm sure I'll have another five or six effects I want to build by then anyway, the 17xx chips are a little cheaper and available from futurlec, which is good for me (and probably a couple other people). Do they have the ability to record multiple tracks like the original design? And what's the deal with the ISD40xx? The data sheet says something about limited analog storage, which has me pretty confused.

Sampling on rate on the 25xx change based on the length of the storage time. I think I mention that in the article. Winbond back then used the same memory structure in the series and just changed the internal clocks to get more time but at the loss of sampling rate and cutoff frequency. Now with the 16xxB and 17xx they set the clock through an external resistor allowing control of the sampling rate and cutoff and offer different memory amounts. Much better IMHO.

v2.0 will not have multiple loops this time. Just one big loop. Most people seem to do that anyways.

I used the 400x series in another Payback called Double Payback. They suffer from a number of problems I found. They have the same memory/clock/sampling rate structure like the 25xx series. The cost as much or alittle more then the 17xx series. They lack a few features which are handy with the 17xx. My ICs for some reason started developing an annoying tick that I could not get rid off. I decided to stop using them. As I had a 17xx around I started using it and I have been alittle happier. Not completely but alittle.

Andrew

[aziltz]

Hello everyone,

I posted a new effect called Payback at the site. It is a looping sampler with a host of features. There is article explaining it's operation and several modification suggestions.

Enjoy.

The Tone God's Domain

Oh and about that little challenge:







Happy Canada Day to all my fellow Canadians. Happy 4th of July to all my brothers and sisters to the south as well.

Your Tone God,

Andrew

is that an ISD digital recorder?  i have the same chip from an electronics class project.  I've been meaning to make a pedal out of it...

[The Tone God]

is that an ISD digital recorder?  i have the same chip from an electronics class project.  I've been meaning to make a pedal out of it...

It is an ISD25xx IC although it is not digital in a pure sense. The audio storage is analog. Nuvoton (the spin off from Winbond that now handles the ISD series) will be offer a new series that is digital. 15100 I think.

If you do have a 25xx IC you can use v1.0 and make a pedal out of it. Its alot of fun.

Andrew

[aziltz]

is that an ISD digital recorder?  i have the same chip from an electronics class project.  I've been meaning to make a pedal out of it...

It is an ISD25xx IC although it is not digital in a pure sense. The audio storage is analog. Nuvoton (the spin off from Winbond that now handles the ISD series) will be offer a new series that is digital. 15100 I think.

If you do have a 25xx IC you can use v1.0 and make a pedal out of it. Its alot of fun.

Andrew

yeah, i have a 25xx.  i basically built a breadboarded pedal as my project, only with trem on the output.  vibrato was a bit daunting.  i'm guess from the length of this thread and all that your design is quite stable?

your design, at least as far as functionality, reminds me of the lofi loop junky.  Do you know if these ISD chips are similar to what that uses?

[cloudscapes]

I didn't work on it at all this evening! still on the breadboard.
I'm trying to accomplish something a little odd. I have a simple oscillator wired into the ISD's input with a volume pot. the idea is to then modulate an input signal (guitar or whatever) with the loop for a crazy wave-shaped trem I think
it does loop the oscillator (with a loud pop every loop, but whatever I'll figure that out some other time) but the output isn't drivign the vactrol led as it should. according to the voltage I'm getting out of the chip, the noisy quiet parts are "as loud" as the looped oscillator. I'll mess around with the AGC to see if that helps.

your design, at least as far as functionality, reminds me of the lofi loop junky.  Do you know if these ISD chips are similar to what that uses?

yeah, vex confirmed in one of the payback threads that the loop junky uses one of the ISD chips

[The Tone God]

yeah, i have a 25xx.  i basically built a breadboarded pedal as my project, only with trem on the output.  vibrato was a bit daunting.  i'm guess from the length of this thread and all that your design is quite stable?

your design, at least as far as functionality, reminds me of the lofi loop junky.  Do you know if these ISD chips are similar to what that uses?

For the number of positive reports I have received I would call v1.0 stable.

I was shooting for something in the same realm. I do believe that the ISD ICs are used in the junky, ISD1420 I believe.

I'm trying to accomplish something a little odd.

Awhile back I made a looper that after recording a loop you would have the controller lock onto a note on your guitar then when you played another note the speed of the playback would be shifted to match the note difference. Kinda funky.

Andrew

[kierc]

Is the ISD1790PY that Futurlec sells the right one for v2?  It says "SPI Interface" - is this still DIP?

I'd like to order one while I have the chance so I can actually build it when it's ready 

[cloudscapes]

Awhile back I made a looper that after recording a loop you would have the controller lock onto a note on your guitar then when you played another note the speed of the playback would be shifted to match the note difference. Kinda funky.

Andrew

that actually sounds like it could pretty great, even if glitchy! sort of like a guitar-controlled mellotron.

[cloudscapes]

the diode is really sensitive 
sometimes it loops, sometimes it doesn't. sometimes it loops half a dozen times then stops, untill I wave my hand over the breadboard or something.