New vero layout: The Tone God's Payback v1.0

[cathexis]

Hi,

There's a new veroboard layout in my gallery: The Tone God's Payback v1.0. One of my all time favourites, my sense of time passing disappears as I play with this pedal. I haven't found much use for it in a band situation but for woodshedding it's the bee's knees . You're going to have a real hard time finding the ISD25 chip, but if you do you really shouldn't miss this one. Andrew is another genius in my book - I've built his Vanishing Point once, and I'll soon be making another one. Check out his site at http://www.geocities.com/thetonegod/ , lot's of interesting stuff there, including the schematic for this one.
There's a sound clip in my gallery as well.

http://www.aronnelson.com/gallery/main.php/v/cathexis/

LARS

[kurtlives]

Nice!

Id build this in a second if I had a ISD25 and a gaint hunk of vero.

[sean k]

I built something like this a few years ago but used the regular switching that I got from the isd 2540 kit that the chip came with though I used the tone gods in and out opamps... but it never went so into the forget about it box it went. Lately I've brought it out and have been downloading data sheets for the isd25xx chips as well as datasheets for the APR9301-v2 which I happened to buy a bunch of as surplus... but they aren't anywhere near as interesting as the isd25xx chips. At this point I've got to go back into this stuff and your jump into this couldn't be more timely. First thing I'll do is build the Tone Gods version as specified using the 4093's.

I had used the original isd25xx configuration with the kit because I could use momentary switches but seeing that it didn't work I'll go back to basics and copy someone who knows whats actually happening in those chips. Thanks for the reminder Lars!, it's funny and reeks (in a nice way, of course) of synchronicity that all of the work you're doing right now is either stuff I've got to get back to or stuff I've thought about but haven't gotten round to or is similar to what I've already done. I appreciate that, it's a good thing!

What I find interesting about that is that you love the vero board and bringing schematics to it while I have the same passion for taking schematics to my own designed DCB's (drawn circuit boards)

Long live problem solving!

[sean k]

Hey Lars, I'm almost ready to etch my payback!
I've read and re-read Andrews stuff on the switching of the 2540 but it's really somewhat above me. Does it all become rather obvious once the thing is up and running?


This is the version I made years ago that didn't work. I've gotta soot out now but I've got a question or two for you about the payback.

[cathexis]

Sean,

I gotta ditto the guy that made the R. Crumb reference in the skyripper thread - there's a clear "comix" vibe to your penmanship. I like it! Your drawings on the skyripper thread are super cool!
Now I get what DCB means, as well.
Remember, Andrew's v 1.1 uses the ISD1600B chip, supposedly because that would be easier to find. You have a ISD25XX chip right?
I must admit to never really understanding what goes on with the switching in this design either - I just did like Andrew's schematic told me to, and it fired right up

LARS

[sean k]

            isd2540 is what I've got.
I was just wondering whether or not the record select switch could or should be momentary. As soon as I get it working I'll sub in the APR9301 chips and see if they work as they are supposed to be a copy and it really is a bit of a read isn't it? But thats how we learn eh.

As for the vanishing point sequencer setup with the random thing I've been looking for something like that to time up a bunch of kids toy sampler boards. I've got as far as 555 into 4017 then switching with 4066's but I still need something to control all that but with a randomness and it seems Andrews schematic might do the trick for me.

[The Tone God]

isd2540 is what I've got.
I was just wondering whether or not the record select switch could or should be momentary.

The 2540 should work as Payback v1.0 can work with any 25xx. The only thing that may change is the exact position of where the second loop will start if you are using the loop select feature. The loop select switch should be toggle. If you use a momentary switch when the loop finishes it will start at the other loop position. You may want that if you want to flip between loops on the fly otherwise you will have to put the switch back into the position before the end of the loop.

As for the 1600B in v1.1 I did that because the 25xx series is EOL'd. You can still find them if you look around but once they are gone thats it. I decided to update the design using the then newly released 1600B as it looked like one of the only production ICs that would fit the needs of Payback. I figured since it was new it would be around for awhile but some things have happened since.

Winbond spun off the portion of the company that made the recorder ICs. I'm sure this has caused issues. Also I don't think the DIP version of the 1600B sold well so most places that had initially stocked them have decided to not carry them as normal stock. This makes getting the 1600B difficult thus the v1.1 probably not see too many builds.

Andrew

[sean k]

Hey Andrew, Thanks for that.
I mentioned the APR9301 V2... I think, and from the looks of this they are still readily available. Supposedly they are equivalents to the isd chips, mentioned somewheres or other, but I could send you a few to play with if you like.
http://www.sunrom.com/index.php?main_page=index&cPath=56_18_97&sunid=f4tccnnca4c1lkbvj3m6lsngl6

[The Tone God]

Thanks but for what little free time availible I have Payback v2.0 to play with first.

Andrew

[Valoosj]

I am one of the lucky few that got hold of the ISD1616 ICs and I'll be building 5 paybacks v1.1 soon. Just need to finish the new pcb I just made.

[chilecocula]

Hi, the only chips i have found in my city are ISD25120 (120 seconds of maximum recording time ) and ISD1420 (which i think is the one in  zvex lo-fi junky,based on both products descriptions). Can i build the payback with any of those chips?

[The Tone God]

The 25120 is good but you may need to remap the address pins if you are using the loop selection feature. You will have lower quality audio but that may not matter as this is "Lo-Fi" to begin with and tastes vary.

The 1420 is out. Payback v1.0 only works with the 25xx series.

Andrew

[chilecocula]

The 25120 is good but you may need to remap the address pins if you are using the loop selection feature. You will have lower quality audio but that may not matter as this is "Lo-Fi" to begin with and tastes vary.

The 1420 is out. Payback v1.0 only works with the 25xx series.

Andrew

Thanks i'll give it a try.
edit: in order to get a higher sampling rate with a 25120, can i speed up the clock like with the 1600B?

Alfonso

[The Tone God]

edit: in order to get a higher sampling rate with a 25120, can i speed up the clock like with the 1600B?

No. The clock is set internally.

Andrew