ARP9600 IC - Playback Looper 60 second Record Length

[chromesphere]

Hey, just wondering if anyone has seen any diy guitar pedal projects using this chip before?  The '1.5 second delay' on the looper he mentions could be a problem, the sample rate at 60s record length could also be a problem.  Yeah just wondering mainly if there are any projects that use it? (or maybe not because of those issues).  60 seconds of record length would be pretty cool, good quality or not!
Cheers!
Paul

Video:
http://www.youtube.com/watch?v=vkgcwxK7nw8

Datasheet:
http://www.datasheetcatalog.org/datasheet/aplus/APR9600.pdf

[cloudscapes]

Reading the datasheet, I think the ISD chips are better speced, and there is already a DIY project based around them. Look for the payback looper on here!

[chromesphere]

Thanks cloudscapes, ill check it out!
Paul

[armdnrdy]

I've been immersed in one of The Tone God's projects, Payback ver.1.1

The Payback v1.1 uses the ISD series record/playback IC which depending on the model can deliver up to 40 seconds record/playback....but just like the ARP9600 IC...at a price. Quality!!!

The ARP9600 sample frequency at 60 sec. recording is a dismal 4.2kHz. Not very impressive! The ISD series is about the same.

With these ICs, longer duration equals lower sampling frequency equals low quality sound duplication.

Andrew (The Tone God) mentioned something that makes sense in one of the Payback threads.
He stated "for the style of playing that he does, he wouldn't have much need for more than 20 seconds"

I thought about that statement...and it makes sense! You can record a rhythm, play something else over it and then record another backing track and play something else. Over and over! This is a looper so it will loop the same thing until you bypass it. When in bypass you hit record and then bypass when you're finished. You just have to be quick on your feet with the buttons!

Although if you did have the full 60 seconds you could play 2/3 of "Let's Get Together" by Hayley Mills (1961) which clocked in at 1 minute 25 seconds. 

The ISD series ICs that I mentioned seem to only be available these days in the SOIC-16 format. I made a little adapter board to go from SOIC-16 to DIP-16.

I'm waiting on the IC and other components before I breadboard the circuit and work out any bugs. In the meantime I've routed a board with three separate ground planes, and three separate power paths. When I'm finished I'll post a project.

[chromesphere]

interesting info armdndry!  I agree, I have a 20 sec record length on my damage control timeline and it is really all I would need.  Nice to have to option to go longer though (at the cost of poor quality audio).  Ill check out the payback, cheers!
Paul

[armdnrdy]

The sample frequency in the Payback v1.1 (ISD1620) is controlled by a resistor from ROSC (pin 14) to ground. One could always switch two different resistors for a Lo-Fi and a Lower-Fi.

80K resistance for 20 seconds @ 8kHz
160K resistance for 40 seconds @ 4kHz

One could use a rotary switch or a pot to control the frequency and sample time.  

I just pulled this out of the data sheet:
This feature allows frequency shifting where a recorded audio can be played back faster or
slower than normal for special sound effects.

Can you say expression pedal? 

[frequencycentral]

The 1.5 sec delay makes the ARP9600 unusable in my experience.

[Lurco]

Does it really beep each time you start to record or play back?

[chromesphere]

The 1.5 sec delay makes the ARP9600 unusable in my experience.

Yeah that's what I thought.  The guy in the video said "im going to try to find a way around that" so not sure if anyone has yet or even if it could be. Anyway, sounds like the payback is the way to for this sort of thing anyway!
paul

[Jaicen_solo]

I have several 9600's. when I get around to it I will build something with them.
Not sure if it is possible to use them for loops, but a one shot sampler thing could work.