A crystal instead of oscillator module

[Davo]

I'm seeing if I can come up with an all-in-one board for implementing a quad midibox SID.  My design software (geda) is throwing fits over oscillator module footprints, so I thought I'd try implementing a 1MHz oscillator using just a crystal and support parts.  I remember seeing somewhere a schematic that uses a crystal, a couple resistors, a couple capacitors, and a transistor to get a 1:1 pulse train.  Can someone show me something like this?

[TK.]

Hi Davo,

I made some experiemts with a self-built oscillator some time ago (based on three inverters), but the results where not so good - sometimes the oscillator didn't start after power-on. If you are still interested, I can search for the schematic (I guess that I found it on a german website)

However, for the MBSID the oscillator is not required, you can also clock the SIDs with the PWM output of the PIC - more infos can be found here: http://www.ucapps.de/mbhp_sid.html

Best Regards, Thorsten.

[Davo]

From the referenced page:

I'm unsure if I ever require the PWM output for a future extension, that's the reason why the oscillator option is provided.

I read this as you saying that the 1MHz output is there because you had room for it in the core MIOS code and that it might be removed in the future to make room for something else.

[DragonMaster]

Actually, you can use any clocks like kwak clock or XO clock normally used to get less jitter on CD players(The kind of upgrades audiophiles do). In the ones I named, only kwak clock is DIY. You build it using a small crystal instead of an oscillator, you give it it's own PSU, and you connect the output pin to the xtal input of the chip (available between one of the osc. pins.). After having built that, you only need one of the 4 pins used by the oscillator. Scheme is available @DIYaudio.

Also, if you want just a crystal, don't use the power supply pins of the oscillator, use Xtal IN and Xtal Out pins instead. Add a small ceramic cap on each side and you get the standard clock scheme.

You want to feed multiple sid modules? Just install an oscillator on 1 SID module and wire Xtal Output to the other PCB.