Rare ICs

Cardboard Tube Samurai · December 15, 2006, 07:26:56 PM

I am compiling parts to make a Small Stone Phaser (from the GG layout) and have struck a major hurdle! I can't seem to get the ICs anywhere in Australia, or at least I can't find where to get them. So I am in desperate need of 5 CA3094 ICs or a suitable substitute. Can anyone help?

darron · December 15, 2006, 07:55:02 PM

i couldn't find any with the large name suppliers, so you'd have to ring around. there are some on international ebay though.

Papa_lazerous · December 15, 2006, 08:08:38 PM

Ok I know its not in Australia but Small bear have them. Not particularly cheap though http://www.smallbearelec.com/Detail.bok?no=222 That shoul dfix you up. I havent searched ebay to get a price comparison I will leave that up to you. Small bear is good though I think. Got plenty of bits from them now I am in the UK and they are in the states. Shipping is pretty swift. Cant seeing it being any more of a problem getting bits to Oz

Cardboard Tube Samurai · December 15, 2006, 11:09:22 PM

Yeah thanks guys! I did some more looking around then just ordered some through Small Bear. While I was at it I ordered some reverse log pots because they seem to be as rare as rockinghorse sh!t in Australia too! I think I did find some on eBay AU once but it works out cheaper to get them from the States. If this works well, I might be doing it more regularly!

Papa_lazerous · December 16, 2006, 12:11:45 AM

Funny you should meniton the reverse log pots, I got some on order right now. I asked down at Maplins for a reverse log pot they guy brought me a standard log pot I told him that wasnt right he said cant you wire it backwards I had to draw him a simple chart with linear log and reverse log on it to show him what it actually means.

I remember when that place employed qualified people...

Seljer · December 16, 2006, 03:08:18 AM

Quote from: Papa_lazerous on December 16, 2006, 12:11:45 AM
Funny you should meniton the reverse log pots, I got some on order right now. I asked down at Maplins for a reverse log pot they guy brought me a standard log pot I told him that wasnt right he said cant you wire it backwards I had to draw him a simple chart with linear log and reverse log on it to show him what it actually means.

I remember when that place employed qualified people...

I'm pretty sure a standard log pot can be used as a reverse rog if you wire it backwards (and your not bothered by your controls going from 10 -> 0 instead of 0 -> 10)

Cardboard Tube Samurai · December 16, 2006, 03:50:24 AM

My understanding of 'reversing' a pot involves actually pulling the thing apart and flipping the wafer... I'm probably wrong... I guess that's why I haven't bothered doing it

RaceDriver205 · December 16, 2006, 04:46:33 AM

If you flip the wiring to a log pot, you get a pot which increases a setting when you turn it anticlockwise. A reverse log pot increases the setting when you turn it clockwise.

QuoteI remember when that place employed qualified people...

Well Dick Smith electronics has never employed people with IQs above their age. They generally employ young people as well.

Seljer · December 16, 2006, 05:18:06 AM

^^
but while you turn it anticlockwise, the resistance changes with the reverse log taper (first very quickly then slower)

RaceDriver205 · December 16, 2006, 08:03:19 AM

Im confused, I think I mean this:

Quote(and your not bothered by your controls going from 10 -> 0 instead of 0 -> 10)

Paul Perry (Frostwave) · December 16, 2006, 08:42:16 AM

Back in the day, Electronics Australia (before it turned to a consumer electronics trash rag & disappeared) had a frequency generator kit, that required an antilog pot... instead they made a GIANT knob, with the frequency marks on the knob around the edge, wiht a pointer fixed to the box! So it felt to the user that everything was going the 'right way'.
The strange thng about using the knob, was that it DIDN'T feel strange!

JimRayden · December 16, 2006, 09:17:29 AM

Quote from: Paul Perry (Frostwave) on December 16, 2006, 08:42:16 AM
Back in the day, Electronics Australia (before it turned to a consumer electronics trash rag & disappeared) had a frequency generator kit, that required an antilog pot... instead they made a GIANT knob, with the frequency marks on the knob around the edge, wiht a pointer fixed to the box! So it felt to the user that everything was going the 'right way'.
The strange thng about using the knob, was that it DIDN'T feel strange!

So you will either need a rev log pot or a backwards labeled strat knob.

---------
Jimbo

Ronsonic · December 16, 2006, 10:15:32 AM

For the reverse log pot, I'll often connect a Log pot backward and then give it a different name. That's how I have a couple with labels like "Caution," "Underdrive" and "Nice."

Ron

MartyMart · December 16, 2006, 10:27:12 AM

For the times when I wire a pot backwards, either for the taper or by mistake ! - I just label
it "CLEAN" --- turn it up and it gets cleaner

MM

Seljer · December 16, 2006, 12:33:49 PM

this reminds me of the dashboard in the Aston Marton Vantage AMV8 : http://www.dieselstation.com/wallpapers/Aston-Martin-Vantage-AMV8/Aston-Martin-Vantage-AMV8-006.jpg [copy and past the link]

that counterclockwise tachometer would bug the hell out of me if I owned the (otherwise absolutely amazing) car
**dreams**

wasn't it mentioned in some thread a while ago, that you can get away with the backwards wired pot strangeness by mounting it on the side of the enclosure? makes the numbers seem less weird

Cardboard Tube Samurai · December 16, 2006, 06:20:13 PM

But with the backwards wired pots, don't you get the same response/reaction from them, just in reverse?

Ronsonic · December 16, 2006, 07:10:10 PM

Quote from: Cardboard Tube Samurai on December 16, 2006, 06:20:13 PM
But with the backwards wired pots, don't you get the same response/reaction from them, just in reverse?

Only if it's a linear pot. Try it sometime, if you've got a control where all the action is bunched up at one end of the pot's rotation with a linear pot. The fuzz knob on a fuzz face is a common example. Use a log pot and wire it up backward and you'll find it a lot smoother to dial in.

The other answer is to stack a resistor under the pot and give up some range to get a better feel for the travel of the pot.

Ron

Cardboard Tube Samurai · December 16, 2006, 08:26:06 PM

Quote from: Ronsonic on December 16, 2006, 07:10:10 PM
Quote from: Cardboard Tube Samurai on December 16, 2006, 06:20:13 PM
But with the backwards wired pots, don't you get the same response/reaction from them, just in reverse?

Only if it's a linear pot. Try it sometime, if you've got a control where all the action is bunched up at one end of the pot's rotation with a linear pot. The fuzz knob on a fuzz face is a common example. Use a log pot and wire it up backward and you'll find it a lot smoother to dial in.

The other answer is to stack a resistor under the pot and give up some range to get a better feel for the travel of the pot.

Ron

Interesting! I might have to give it a crack. I made the MXR Dist+ and really only have the last 1/8 of a turn to actually tweak the distortion. This usually means that I just crank it to full which isn't always a bad thing, but I'd like to be able to control it more if the need ever arises. I had a similar problem with the DOD250 build

Ronsonic · December 17, 2006, 10:31:51 AM

It works extremely well for that sort of circuit. The Dist+ / DOD 250 are very, very similar circuits and I built one very much like them, not quite a clone, and the reversed Gain control work perfectly. Didn't take any time to get used to the reverse rotation, and was real easy to get used to the smoooove curve on the pot.

Ron

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