Electro Harmonix - Instant Replay

[alteredsounds]

Anyone wanna have a go at this if I can get some pics and layouts etc done?

(Had loads request for pedal pics etc, sorry for not getting back, i will get round to them as I can, really really busy with work and band and websites and tryna learn this building thing!)

Cheers,

Nick,

Pedals! www.alteredsounds.com

[puretube]

someone could mail E-H,
and request a re-issue...

[Mark Hammer]

First some low-tech (text) info about the higher-tech aspects.

The Instant Replay is a simple stored sample device that was intended to be either externally triggered by a suitable trigger pulse, or via a thwack to the cork pad on the top (where I assume there was the requisite piezo element).  Inside, there will be some digital chips to store the sample and to convert it from A/D and back again.  I have little doubt that we're looking at 8-bit sampling, given the age of the device, but any idea what kind of memory capacity we're looking at?  I.E., what sort of RAM chip/s are in there?  My guess is some sort of modest static RAM chip like a pair of 6116 CMOS Static RAMs for 4k storage, but I say that sight unseen.

I posted a scanned POLYPHONY article detailing construction of a DIY sampled percussive voice at my site a ways back.  There is a PCB layout with the article ( http://ampage.org/hammer/files/Alphadrum.PDF ).  Pretty much all the components should still be available 18 years later, although you may have to peek a little harder for the 2732 EPROM and CA3080 OTA.

Note that you will likely have to retouch the PCB layout, not to mention flipping and rescaling it for use with PnP.

[puretube]

ISD1416 & derivates could do it,,,

[alteredsounds]

If anyones interested in trying this, I'll pull mine apart and grab some details.  Luckily I got the EH Trigger for it, funny sounding lo-fi pedal.

[Mark Hammer]

Probably easier too, and able to work from a battery.

I'm not familiar with the specs of the original Instant Replay.  The phone-message chips like the ISD1416 tend not to have anything more than 3khz bandwidth, if that.  What did the IR have?  And if one is interested in using it as a percussive voice generator, could either be made to have enough bandwidth to represent things like snares and cymbals with any degree of aunthenticity?  I'm not challenging, just completely in the dark.