DIY sampler

Pehr · Posted: Mon Mar 27, 2006 5:24 am Post subject: DIY sampler

There are a lot of things I want to build and one of them is a DIY sampler. 0k, 0k actually it is a message recorder kit, based on a ISD25XX chip.

Maybe it doesn't sound like the best sampler, with sampling frequency up to 8 kHz (dunno the bits Confused

), but I think that with the "loop"-option it could sound really cool! Cool

Has anyone tested the ISD25XX? Any tips? Ideas how to modify circuit?

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bugbrand · Posted: Mon Mar 27, 2006 7:41 am Post subject:

I've had ongoing fights with the older ISD1416 - pretty similar chip but less recording time.

Buffer signal straight into the AnaIn (miss out the mic pre) for general audio work.

Can this chip not be clocked externally? Get the full datasheet from Winbond (they make the ISD chips) - that allows repitching

This chip has slightly different control than on the 1416 - you can randomise a sample with the 1416.

I had loads of problems with the output 'cos its meant to be hooked up direct to a speaker -- the analogue circuit from the Mobius Trip works well around the circuit ('cos you probably don't want it to be a box with mic-in, speaker-out -> would be better line in/out).. I've got links and some circuit details on my electronics page

Pehr · Posted: Mon Mar 27, 2006 11:34 am Post subject:

dnny · Posted: Thu Mar 30, 2006 8:01 am Post subject:

i have couple of those ISD chips waiting ... for me to do something whit them .. but as we know i'm not the fastest guy in here .. but anyway
" We have a member here, nescivi, that might know something about this device. send him a PM. Maybe he'll chime in."

nescivi´s page

mi_dach · Joined: Dec 17, 2005 Posts: 133 Location: Sweden

bugbrand · Posted: Sat Apr 01, 2006 11:32 am Post subject:

I started off using hispeed CMOS 555s - seemed to have problems (maybe because of my poor electronics....) - wanted to use the CV inputs.

Ended up using a 40106 supersimple RC osc circuit.

One difficult thing is that you often seem to get a capacitive problem - kind of like a theremin, the osc changes speed when you get nearby - thinking 'cos its running at such hispeed and probably isn't meant to??

Bascially - what'd be ideal is a clock up to 2Mhz - but there's nothing all that apparent - higher speed clocks are available but they seem too high.

Also - you get a wierd glitch at the looppoint when you sample at speeds other than the internal clock speed (about 1Mhz)

Argh, it all drove me nutty.

mi_dach · Joined: Dec 17, 2005 Posts: 133 Location: Sweden

bugbrand · Posted: Sun Apr 02, 2006 3:05 am Post subject:

That's probably the smartest way to do it actually! Yeah, micro-control - you could make power for the control as well - -> auto looping once you've recorded, improved randomisation. ...gotta learn more about PICs...