Potato Cakes

Re: Studer 169 EQ in API 500 format
« Reply #460 on: March 13, 2018, 05:08:20 PM »
Order the correct pots from AML. Seriously. Whatever you are trying to save as far as money will be overshadowed by the time needed to invest in research, math, and trial and error. And you'll have pair of great sounding EQ's.

Thanks!

Paul


Re: Studer 169 EQ in API 500 format
« Reply #461 on: March 13, 2018, 05:16:07 PM »
You might be right, Paul. On the other hand, I like to learn more about electronics, and DIYing my own rev log pot could as well be part of it. :)

Re: Studer 169 EQ in API 500 format
« Reply #462 on: April 20, 2018, 04:19:50 AM »
Hello everyone,

I’m sure this has been covered before, but I couldn’t find a quick answer: Why does the BOM for the Studer 169 EQ list dual-gang potentiometers for all controls, when the only pot that actually makes use of the dual-gang is P4? As for P2 and P3, pin row 1 and row 2 are directly connected on the PCB. The low shelf pot (P1) even uses the front row of pins only, i.e. there’s no path going from the second row. See attachment. So why use dual-gang pots?

If I’m right and we can replace them by simple 1-gang pots, do P2 and P3 have to be the same value as the dual-gang variants (i.e. 10k)? Or do the dual-gangs work like (variable) resistors in parallel here? Then the value for a 1-gang pot would have to be 5k instead of 10k, I guess [ Rtotal = R1 * R2 / (R1 + R2) ]. Or am I completely confused now?

On another note, how can I make use of the empty space on the PCB? This is all connected to ground, isn’t it? So if I want to install additional caps, for example, how do I prevent them from being connected to ground, when I drill some holes in there?

Sorry for the newbie questions, I’m only asking because I want to learn more about this. :)

Thanks,
Claudio
« Last Edit: April 20, 2018, 10:10:44 AM by Claudio »

Vac11

Re: Studer 169 EQ in API 500 format
« Reply #463 on: April 20, 2018, 04:42:08 AM »
So why use dual-gang pots?

Mechanical reasons? Dual gang pot keep the pcb better...

Re: Studer 169 EQ in API 500 format
« Reply #464 on: April 20, 2018, 04:45:56 AM »
Mechanical reasons? Dual gang pot hold the pcb better...
Is this really the only reason? Then you could add some cheaper mechanical support instead...

Vac11

Re: Studer 169 EQ in API 500 format
« Reply #465 on: April 20, 2018, 04:57:23 AM »
Not only, there are some pots traces on the pcb that are in parallel configuration... Pleas check original schematic pots values against audiox schematic.

tmuikku

Re: Studer 169 EQ in API 500 format
« Reply #466 on: April 20, 2018, 07:50:52 AM »
factor in quantity discount and limited component storage compartment count, audiox is a pro   ;)
« Last Edit: April 20, 2018, 07:56:28 AM by tmuikku »

Re: Studer 169 EQ in API 500 format
« Reply #467 on: April 20, 2018, 10:08:23 AM »
Seems like I found my answer in this old post. Thanks, Mike!

Claudio

Re: Studer 169 EQ in API 500 format
« Reply #468 on: September 15, 2018, 06:30:53 PM »
I finally built mine up after ordering the board and faceplate a long time ago. I got my DOA’s in the mail before the rest of the components, and wired them in with no pins.
When the rest of the components came in, I rushed them onto the board and never looked at the jumpers that reside under the DOA’s but are integral to the signal path.
Double check all jumper connections, its a single sided PCB!
I thought I read through the build posts but i never saw that detail listed, so Im passing it on. Hope this helps. Great sounding eq, especially with the stock frequency on the bottom

Fujirume

Re: Studer 169 EQ in API 500 format
« Reply #469 on: January 20, 2019, 10:45:45 AM »
Hi, can I use non centered type potentiometer? or only centered type? thanks!!


Potato Cakes

Re: Studer 169 EQ in API 500 format
« Reply #470 on: January 20, 2019, 04:41:22 PM »
Hi, can I use non centered type potentiometer? or only centered type? thanks!!

You don't need center detent. They're just helpful for keeping unused frequency bands flat (within the potentiometer's tolerance) when the EQ is engaged.

Thanks!

Paul

Fujirume

Re: Studer 169 EQ in API 500 format
« Reply #471 on: January 22, 2019, 05:11:03 AM »
thanks a lot!!

You don't need center detent. They're just helpful for keeping unused frequency bands flat (within the potentiometer's tolerance) when the EQ is engaged.

Thanks!

Paul


 

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