Sampler with analogue sequencer?

[Guest peshay]

hi there, i had this idea of building a gritty 12 bit drumsampler, like a emu sp1200 or a casio rz-1. It would use the MIDIbox64 SEQ as sequencer and trigger the samples. But how do u store samples? i know u need ad da converters, and memmory but is that really hard to do? i also found these speechrecorderchips,

http://www1.int.conrad.com/scripts/wgate/zcop_in53767f81/~flN0YXRlPTExMDMwOTg4Mzc=?~template=PCAT_AREA_S_BROWSE&shop=A_B2C_IN&p_init_ipc=X

wich can record play and erase at the push of a button, i think i can make a drum sampler with that, simply using 8 chips for 8 voices, but i dont think u can store the sounds somewhere else can u?

ps. here is a specsheet of such a chip only with more memory http://www.winbond.com/e-winbondhtm/partner/PDFresult.asp?Pname=99 they say u can control it using a  microchip and it even has a looping function as well as a addres assingment so u can use multiple samples per voice. i think u can use this with a chip per voice as a playbacksampler. But is it possible to get the samplse out of the chips into another memorychip for external storage and then load it back in again later? by storing an simple program message, like sample1 goes to voicechip1 etc.

[DrBunsen]

I also looked at some of those voice recorder chips for just the idea you are outlining above.  It should be possible to build a sampler out of them.  The ones I looked at could be configured for one long message or 8 short ones (or was it 16?).  You'll need to do some MIOS programming, although there might be others on the list who are interested too.  Try posting a message in the MIOS Programming forum.  And have a search for "sampler" to see other messages about this idea.

You'll just need to program a pulse to go to the right pins on the chip in response to the right MIDI messages (ie for note playback) or button presses (ie for recording).  The Midibox 128 project might be a good starting point, as it is a general-purpose MIDI to pulse converter.

Read the application notes for the chip very carefully.  The ones I looked at had a pause between playing one message and another, and between recording and playing, and obviously you won't want that.  There was a pin that you could pulse though which did some kind of reset on the whole chip, and I seem to recall thinking that that would work to bypass the pause.

As for the input and output stages, I suggest you have a look at one of the voice recorder kits which has been designed around these chips, and adapt one of those.  In Australia they are available from www.jaycar.com.au, www.oatleyelectronics.com, and www.dse.com.au.  Your local kit and hobbyist shop or website will probably have one too.

One other design function you might like to include is a variable playback rate, so you can pitch your samples up/fast and down/slow.  The playback rate is sometimes adjustable in circuit.

Your other alternative might be to build a MIDIBox SID and use the wavetable function built into it!  TK, please tell me if I am barking up the wrong tree here.

[stryd_one]

OK really, how do you guys find these chips ???

This is the 2nd time in about a week that someone has come in here, mentioned ideas that I've had in the past, and then linked to spec sheets for a chip that I couldn't find which made me give up...  LOL   ;D

Anyway the wavetable in the SID's won't do this, I'm told... Apparently it's not a wavetable as we usually call them, but a table for sequencing waveforms which are already on the chip, more like those old vector synths... Could be wrong here...

[timofonic]

Interesting idea...