Studer 169 EQ in API 500 format

Yes, you can get center detents from Omeg, but you're better off getting all the pots from Audio Maintenance, as they will be (believe it or not) cheaper.  I was quoted 4.86 pounds each for a minimum of 10 from Omeg for the same pot.  Colin from Audio Maintenance advised me that the 16mm dual rev 100k will be back in stock in a week or two.  I've done some serious hunting for these pots, and always come back to Audio Maintenance.  With center detents on 2 and a rev log on the other, they're all very hard to source. 

Without center detents, I can get all the pots here in the US for cheaper than audio maintenance, and with 1/4" potshafts.  The center detents are just a cool feature, IMO.  But I hate those tiny potshafts.  Guess I'll go without detents...

Can anyone recommend a switch cap that will fit the 10mm hole on the front panel?  I've ordered some switches from classicapi but I'm assuming their switch caps have a much smaller diameter of 10mm.  Also, anyone have another front panel layout they'd like to share? 

Can someone please post some audio samples of this? just 1 sample and dialing all knobs...
i dont know seems very interesting eq...
Thanks...

dbeeson said:

Can anyone recommend a switch cap that will fit the 10mm hole on the front panel?  I've ordered some switches from classicapi but I'm assuming their switch caps have a much smaller diameter of 10mm.

Click to expand...

I had front panels made (from the drawings on page 1) and ordered switch caps from ClassicAPI and can tell you they're way too small.  I should have paid a little attention to that.
I know those larger caps are out there - my Demeter reverb uses both red and chrome caps.
Any ideas?

this one's 8.8mm diameter.  i think those ones from classic api are 7mm or thereabouts.
not sure if your switches are C&K.  If not you might need to look for the ones for your brand of switch.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1115298&k=f0201

Hey guys,

Yes mine are the bullet caps and they are about 7mm at the bottom and taper to 5mm at the top.

Try searching Digi for the following.

F11010102 (white)
F11010106 (yellow)
F11010107 (blue)
F11010108 (green)
F11010112 (orange)

You will need to check out the F-series data sheet to see them as no one seems to have a product pic. They are 9.94mm in diameter.

I have never used these myself but they are very similar to the old Schadow "fish-eye" caps. Out position color is black and depressed color is what I have shown. Digi does not have them all but they have 3 or 4 colors. They are not cheap either.  ???

Cheers, Jeff

Cool. Thanks for the info Jeff.
It looks like they have the green, orange and white caps.  Are you saying that these particular caps are "fish eye" style?  I have an old MCI tape machine that has those.  They're really cool.  They are a little expensive though, almost twice the price of the switch! But since I'm only building a pair, it's no biggie. 

Keep in mind that those fish eye caps need some sort of "catch" installed behind the panel in order for the eye to open and close, which is triggered by a small hook that protrudes from the switch cap.

If you don't have something in place to catch the hook (too many fishing puns here!) that eye will not open and close when you press the switch.

An 1/8" or 3mm hole, properly placed in the PCB is enough to catch the hook on the fish-eye style. If that is possible. I am not super familiar with the switch location and what tracks may be under the switch for this particular PCB.

It appears like the F11 style don't need a catch? Anybody ever used these before?

The F11's need a catch as well.  The "hook" on these comes out from underneath the switch cap and sheaths over the end of the switch like a plastic square condom, so the "catch" would need to stick up from the pcb and hug the end of the switch under the switchcap.  If you look at the datasheet, the left diagram of the F11 has the "hook" up inside the cap, and the right diagram has the "hook" slid out.  It kinda looks like two little legs in the drawing.

I went through almost every option with these switch caps with a custom build I did recently that used the C&K 6pdt pushbutton switch.
I had ordered most of them and played around to see which one I liked best.

Jeff, would this style of cap be the cap with the "hook" you're talking about?  http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=CKN10020-ND  It's the F08 style, with a 9.94mm diameter. The spec sheet has pics. Looks almost the same with a top and bottom notch on the color insert.  Would this work better? I like the idea of strategically drilling a hole in the pcb for the hook to catch.  These also come in 3 colors from Digi. 
John, did you find it finicky with the square condom style on the f11 buttons? 

Yes, F08 is the winky with the hook that needs a hole.

Jeff you dirty dog,  Thanks man.  ;D

Guys, is there a simple way to link 2 modules (dials from one unit controlling both units) so they could be used in a mix/mastering situation? 

I thought I'd share this link with you guys looking for the 100k 16mm rev log pots in North America: http://www.newoldsounds.com/index.php?main_page=product_info&products_id=1137

Audiox,
How would I go about installing switches for the 3 selectable frequencies?  I'd like to do this, but don't really know how.  Excellent build btw, got them up and running last night and they sound excellent.  Need to mess with the resistance for unity gain, but it's not far off.  Thanks again, to you and Gustav.

dbeeson said:

How would I go about installing switches for the 3 selectable frequencies?  I'd like to do this, but don't really know how.

Click to expand...

Low filter: Use a single pole on-off-on toggle switch. The first "on" position connects a capacitor in parallel with C6 and the other "on" position connects another value capacitor in parallel with C6. In the middle "off" position there is C6 alone. Now you have 3 selectable frequencies.

High filter: Same idea but you need a two pole on-off-on switch since there are two capacitors which determine the frequency (C4 and C5).

Note that I have included some extra pads on the PCB to make wiring easier.

if using the input transformer, is U1 needed?

Thanks Audiox! What values would I use for the frequencies you put on the front panel?

Does anyone have a front panel express file for the 169 layout? I'm looking forward to these builds!