Harrison 32c Eq Re-design (Some questions)

I need 3 gang concentric potentiometer.Dual 50K + Single 10K.Where can i find it?

Thanks.

It's my design.Really compact.Used 9mm pots.I will add more info.

But there is lots of via to connect layers.Is it problem? I'll double check.Then order...

And 3D view.

I had to change design cause it's really hard to find dual gang 9mm rev.log. pot.

It's final form.

Top view



Bottom view

http://www.omeg.co.uk

[silent:arts] said:

http://www.omeg.co.uk

Click to expand...

Thanks.

I looked at their web site but i didn't find any info about what i wamt.Should i contact?Or any other ideas?

Contact them. They do custom potentiometers in small quantities.

[silent:arts] said:

Contact them. They do custom potentiometers in small quantities.

Click to expand...

Thanks.I find what i look for but it's 20mm.I need 16mm.I'll contact.Thanks again.

Can you tell me which one controls which one?(Etc. 1 controls A & B / 2 controls C)

On 2-gang: the inner shaft controls the back pot.

It has to be that way. Any other order would require the inner shaft to pass "through" the wall of the outer shaft, which is not possible in this universe (or would demand a really tricky mechanism).

On 2-knob 3-gang- it could be either way.

Why are you asking here? Omeg can build it several ways. They can probably tell you which ways they want to do it. But in any case, I believe you should NOT be drilling hard metal or even laying-out PCB for a funny-part until you have the final part IN-HAND.

PRR said:

On 2-gang: the inner shaft controls the back pot.

It has to be that way. Any other order would require the inner shaft to pass "through" the wall of the outer shaft, which is not possible in this universe (or would demand a really tricky mechanism).

On 2-knob 3-gang- it could be either way.

Why are you asking here? Omeg can build it several ways. They can probably tell you which ways they want to do it. But in any case, I believe you should NOT be drilling hard metal or even laying-out PCB for a funny-part until you have the final part IN-HAND.

Click to expand...

Thanks for reply.

I'm asking hear because i have to know which shaft controls to which gang before asking them.

By the way i need this pots for my Harrison 32c Eq design.I will order from Omeg.But i have to know pot laws.What are laws of freq and gain?You have any idea?

They send me datasheet.Now i know how can i order.But i need to laws.

See if Colin has the set up you need!!

http://www.audiomaintenance.com/acatalog/potentiometers_carbon_16mm_diameter_concentic_shaft.html

GARY

You really have no luck.  If you would have asked earlier you could have bought 48 of the poteniometers you want (including knobs) for $ 80,--:
http://www.ebay.com/itm/A-H-B-ALLEN-AND-HEATH-BRENNELL-CMC24-VINTAGE-40-INPUT-MIXER-DESK-/191656552511?nma=true&si=ELNR2t7uTdPR0fik5QHwo1ABl4c%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

This desk has exactly the potentiometers you want inside..... 2 per channel.
http://www.allen-heath.com/ahproducts/cmc/

Service manual:
http://www.allen-heath.com/ahproducts/cmc/#tab4

Now you have to look for another AHB CMC24 or CMC32....
 

Thanks for your helps.

Now i have to find Omeg 16mm 3 and 4 gang pot libraries for Eagle...Anyone?

ForthMonkey said:

Thanks for your helps.

Now i have to find Omeg 16mm 3 and 4 gang pot libraries for Eagle...Anyone?

Click to expand...

The beauty of rolling your own board is that you can design with parts that are a lot easier and cheaper to source than a four-gang pot!

-a

Andy Peters said:

ForthMonkey said:

Thanks for your helps.

Now i have to find Omeg 16mm 3 and 4 gang pot libraries for Eagle...Anyone?

Click to expand...

The beauty of rolling your own board is that you can design with parts that are a lot easier and cheaper to source than a four-gang pot!

-a

Click to expand...

Actually yes,you're right.But pots are not too expensive.About €7 one piece.And Harrison 32c with concentric pots is really good to me.Small and compact.If ordering from Omeg is expensive,i will build with 9mm pots.Not concentric.My design is ready.Just i working on board design right now.

And it's my B plan.

Switches : http://www.classicapi.com/catalog/images/gallery/switches/PBN-datasheet.pdf

Pots : http://www.alphapotentiometers.net/html/9mm_pot_16.html

For now i only designed board and front panel placement for pots and switches.And i added "LP" labels to see it's okay.Front panel should be minimum 110mmx40mm.So you can convert it with adapter to 500 series or you can use it with 1U for 4 units.

Everything in "mm" and real size.

Updated first post.

Really hard to find 9mm reverse log pots,i guess.Maybe i can change 16mm.There is room for this.

Where can i find dual reverse log pots?(No Mouser or Farnell)

I had the same problem with some esoteric ssl potentiometer values, what i did was:

I bought mono anti logs and some stereo pots and just took the stereo back, added it to one of the anti logs. Filed the second mono antilog open and added the taper to the modified mono  (now stereo) pot. Omeg is even better as you don't have to file the tapers out, I think.

Is it even called taper? Well the thing with the resistive path on it is what I refer to as "taper"

I hope I make sense

Updated first post.

ForthMonkey said:

.....
I had to change design cause it's really hard to find dual gang 9mm rev.log. pot.
.....

Click to expand...

True, because dual pots are 11mm.