LTC1799 Precision Oscillator

PolyPhuckin · January 15, 2009, 12:19:52 AM

Has anybody had a go at making the Precision Oscillator posted up on the GetLofi.com (http://www.getlofi.com/?page_id=1302) site?

Just wanted to know what peoples experiences with it were before i ordered the chip.

Cheers

Gordonjcp · January 22, 2009, 02:13:19 PM

It looks okay, but how accurate do you need your oscillator to be? If the chip is cheap enough then fair enough, but I'd just use a little single-tranny oscillator for a few MHz and up, or a couple of NAND gates for up to about 1MHz.

PolyPhuckin · January 23, 2009, 12:00:11 AM

To be honest its only so i can have an adjustable pitch on my SA-21.

I think they're £2 a pop and SMD.

Gordonjcp · January 23, 2009, 02:09:59 PM

What frequency is the crystal or ceramic resonator in the SA-21?

Bogus Noise · January 23, 2009, 02:37:32 PM

22Mhz I think. There's a good bit of info about changing the SAx crystals by Paul Oceanus on Casper Electronics, haven't tried it with a precision oscillator though, would be interesting to hear how you get on! I'd guess if it works it will probably crash if you change the pitch while it's switched on, but be ok to set the pitch before turning it on.

http://www.casperelectronics.com/finished-pieces/casio-sa-keyboards/

PolyPhuckin · January 25, 2009, 09:37:37 PM

i've actually just finished that mod on my SA-5 but i used a 3PDT instead of a DPDT. It works really well.

This is where i first saw the idea, so i thought i might give it a go http://www.getlofi.com/?p=1383#comments

the_zombiest · January 26, 2009, 11:16:36 AM

I think these are great. I've got one in my sk-1 and a couple of vtech toys. They do the trick and offer a really stable osc with a good range. The boards are already populated so you don't actually need to solder the chip onto the board, just the wires. You've gotta be careful how much power goes to the chip though cos anything over 5v is gonna burn it up.

PolyPhuckin · January 26, 2009, 09:23:29 PM

cool, i think i'll go ahead and have a go building my own.

i'll tell you how it works out.

Bogus Noise · January 28, 2009, 06:18:29 PM

Cheers for the link, I'll give it a try next time I open an SA! Good luck with yours

PolyPhuckin · January 29, 2009, 12:39:34 AM

Thanks man.

Well, the chips arrived today, so, time to break out the etching tank (i have to buy one first though

)

Bogus Noise · January 29, 2009, 01:07:07 AM

hahaha... I know *exactly* what you mean!

I will get one... one day...

strssmmnt · February 28, 2010, 01:59:15 AM

I really like the LTC1799... I've put one in an sk-1, and I will do another soon!