DIY sampler

[Mikko Helin]

Elliot wrote:
>Someone with a better knowledge of IC's probably has simple solutions all
>of these problems.  After all, 12-bit AD converters are apparently very
>cheap.  Hook up a 256K EPROM to a 12 bit AD/DA converter, trigger it with a
>555 Timer controlled by a single POT to control loop speed, add a mic in
>(through a 386 op-amp) and audio out (through another 386 op-amp), and you
>have the world's cheapest sampler.  (Possible??)  Now, that's
>entertainment!  I look forward hearing what others have to say.
> 
EPROM can be used to store samples, but you can directly store sampled
data on them. SRAM (static RAM) is what you want to use instead. Anyway,
this discrete approach will not solve the triggering delay problem,
as you don't have any means to edit samples. A 486 PC motherboard
with some RAM, a 1.4Mb floppy disk and a sound card with MIDI, all put in 
some nice rackmount case would be a cheap sampler. Without monitor and
keyboard your sample playback & editor software could communicate through 
the RS-232 interface, or you could build your custom LED display & keyboard 
to work on parallel port. If you take for an example the UI of EPS-16/ASR-10
samplers they are really simple to use to set the sample start, end and loop
points with just a few buttons and two lines of 16 characters. Every sound
card's got a joystick port or two, which could be used as well as an input
device, so only the LED display interface is what needs to be planned.

-Mikko