ARP Odyssey Oscillators

numbertalk · Posted: Thu Oct 23, 2008 10:14 am Post subject:

Also saw your posting on the 4035. Any advice/resources for etching your own double-sided board? Always has seemed undoable to me.

blue hell · Posted: Thu Oct 23, 2008 10:16 am Post subject:

Broadwave · Posted: Thu Oct 23, 2008 12:06 pm Post subject:

numbertalk · Posted: Fri Oct 24, 2008 11:13 am Post subject:

LetterBeacon · Joined: Mar 18, 2008 Posts: 454 Location: London, UK

Peake · Posted: Thu Oct 30, 2008 12:54 pm Post subject:

Here's a cheap batch of some 2N5910 (caveat emptor, even though I know the seller and am a happy repeat customer with them. If they say it's good, it's in all likelihood, good.).

http://tinyurl.com/5osz3f

Don't forget to share with the rest of us.

Broadwave · Posted: Thu Oct 30, 2008 1:13 pm Post subject:

Broadwave · Posted: Thu Oct 30, 2008 1:15 pm Post subject:

Peake · Posted: Thu Oct 30, 2008 1:31 pm Post subject:

Ah, good to know- I like those folks a lot. Cheers!

Peake · Posted: Thu Oct 30, 2008 10:01 pm Post subject:

ericcoleridge · Joined: Jan 16, 2007 Posts: 889 Location: NYC

Someone bought these 5910s.

If it's someone here, I'd like to have some Smile

-- I just didn't really want 40.

I'd be happy to buy 4 though. Very Happy

LetterBeacon · Joined: Mar 18, 2008 Posts: 454 Location: London, UK

Heh, *raises hand*

PM me and I'll send some out to you (when they arrive, obviously).

LetterBeacon · Joined: Mar 18, 2008 Posts: 454 Location: London, UK

I've been through the pdf file and have made up the attached BOM. I've been through it twice and so I don't think I've missed anything.

Quick question: The 680pf timing cap should be polystyrene or silvered mica, but what are the rest of the caps made from?

Arp Odyssey BOM.txt

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Arp Odyssey BOM.txt

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Broadwave · Posted: Fri Oct 31, 2008 4:22 pm Post subject:

e-grad · Joined: Sep 12, 2008 Posts: 142 Location: Berlin

Now this VCO is on my mind. Some of the resistors are not very standard - at least not in my project box. However, if I take e.g. the 221K and calculate a 1% deviation I get: 218K79 and 223K21 thus I think any resistor within that range will do? Or do I miss something?

Even better for substitution: such old design as the ARP VCO based on older parts which are having usually a greater deviation than modern day 1% resistors. Or am I'm misguided here?

bubblechamber · Posted: Sun Nov 02, 2008 4:51 pm Post subject:

urbanscallywag · Joined: Nov 30, 2007 Posts: 317 Location: sometimes

There are 1% specified resistors on the ARP schematics...

Peake · Posted: Sun Nov 02, 2008 7:32 pm Post subject:

urbanscallywag · Joined: Nov 30, 2007 Posts: 317 Location: sometimes

Looks like there are some 1% resistors in the CV summing section which seems like a good idea. The actual VCO core doesn't look like it has anything specified.

etaoin · Joined: Jun 30, 2005 Posts: 761 Location: Utrecht, NL

Note though that even when 5% resistors were used, they could still have been matched to 1% before they went in. So it's perfectly possible to see a 5% where 1% is specified. It doesn't say "use a 1% resistor", it says "use a resistor with a value within 1% of the specified value".

Using 1% resistors is easier today, but it might have been cheaper to just hand-match a batch of 5% ones in the 70's.

LetterBeacon · Joined: Mar 18, 2008 Posts: 454 Location: London, UK

So what's everyone using for the temp. compensating resistor? Does anyone have a couple spare that I could swap for a few 5910s?

ericcoleridge · Joined: Jan 16, 2007 Posts: 889 Location: NYC

etaoin · Joined: Jun 30, 2005 Posts: 761 Location: Utrecht, NL

LetterBeacon · Joined: Mar 18, 2008 Posts: 454 Location: London, UK

That's a good idea - where can you buy 2k tempco resistors though!