Studer 169 EQ in API 500 format

[Potato Cakes]

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

 

[Claudio]

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.

 

[Claudio]

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

 

[Vac11]

So why use dual-gang pots?

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

 

[Claudio]

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]

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]

factor in quantity discount and limited component storage compartment count, audiox is a pro 

 

[Claudio]

Seems like I found my answer in this old post. Thanks, Mike!

Claudio

 

[Chrisfromthepast]

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 soldered them directly to the pcb.
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]

Hi, can I use non centered type potentiometer? or only centered type? thanks!!

 

[Potato Cakes]

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]

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

 

[Tiwaan]

Hello everyone,

I would like to build mine, but i'm not sure about the ref of DPDT . Where can I buy the same reference than used audiox  scheantic ? (or ref that can be used..)

thank you !

 

[STOERSENDER]

Hi Everybody,
I'm new here and I hope my question isn't too crazy if I ask whether one has a BOM on this EQ from Mouser or so?

Kind regards,
Boris

 

[Ricardus]

I love it when someone refreshes an old thread with a project I'd like to build. I see Gustav has these boards. Would love to build a pair of these.

 

[fazeka]

Hi,

There is no official BOM, per se. Just refer to the link of the schematic in the first post here to ascertain the components required.

I haven't read this thread in a while, but maybe there is a BOM someone created? If so, please use the search feature to find it within this thread.

Cheers,
Chris

I'm new here and I hope my question isn't too crazy if I ask whether one has a BOM on this EQ from Mouser or so?

 

[STOERSENDER]

Hi,

There is no official BOM, per se. Just refer to the link of the schematic in the first post here to ascertain the components required.

I haven't read this thread in a while, but maybe there is a BOM someone created? If so, please use the search feature to find it within this thread.

Cheers,
Chris

Thanks Chris

 

[STOERSENDER]

Hi,
I'm wondering whether PIN10 in schematic is PIN6 at the Neutrik Transformer as NTL1 has no PIN10. See attached:

Update: 11.10.

I'm wondering whether I've found the correct connection for balanced in, balanced out

 

[Claudio]

I'm new here and I hope my question isn't too crazy if I ask whether one has a BOM on this EQ from Mouser or so?

Hi Boris,

Perhaps my old Mouser cart will help you. It’s been a while since I built the Studer 169, so I don’t remember correctly if the cart is complete. Please doublecheck it with your documents and use at your own risk! I do remember though that I ordered some potentiometers from elsewhere. My 100k rev log is from Musikding: https://www.musikding.de/Alpha-Potentiometer-16mm-Stereo-100k-rev-log_1

Hope this helps anyway,
Claudio

 

[STOERSENDER]

Hi Claudio, thanks for sharing this. It is very much appreciated!