Studer 169 EQ in API 500 format

[kustohm]

Hello everyboDIYers!

Maybe somebody asked this but what size for the AML pots?
-16mm?
-20mm?

I don't want to use brackets and so I need to solder the good stuff to the PCB to insure faceplate solidity!

About AML, others ideas for differents pots with the same values?

THANX

 

[kustohm]

OK, I just read the introduction...and sorry...I know now...is 16mm pots!

 

[ctujoao]

Hello,

This is the kind of desperate post none wants to make, but if there's any surviving soul on this topic, help is more than welcome.
I've build 2 of these that worked immediately. Then the 3rd one...
Hi and Low shelf are working, but the mid is just insane: I get very loud feedback as soon as past 12:00 (the signal is still in the background, buried deeply). It's kind of a resonance since no input signal is required to trigger the feedback.

So I poked, and I poked until my fingers were numb.
I suppose the trick is to have C11 to vary between something like 7 to 15nF when turning the MID potentiometer.This is not the case.
I've reflowed every joints twice, cleaned them.
I've checked all values of component and the pots.
I've tried 3 different NE5534, all new.
I can't find a shortcut, everything look clean.

I just can't see it..

Many thanks for reading and any potential help.

PS: forgot to mention, it's NE 5534 all the way  and no transfo.

 

[Potato Cakes]

Here's a fun one...

So I got 2 of these boards from another member here and I finally got it assembled to the point where I could do some testing. At first no audio. Then some sort of pulsing audio. I checked my voltages on my op amps and I was getting  +16 on the V- connection and +1.5V on the V+. After lots of poking around and staring at it, I find that gold fingers 8-15 all had continuity with each other. And after some more time cutting traces and pulling components in vain, I finally just removed some PCB material between the fingers and that seemed to fix everything. The funny thing is that I could not see any sort of copper connecting the fingers, so I have no idea how they were all being connected. It just looked like every other 500 series card that I've seen. Unfortunately in the process, I fried something on the output of my SPL Madison that I was using to send out tone. The LED display says it's sending audio, but it is not actually producing output. The upside is that I got to watch one of the 10 ohm resistors catch on fire, and that's always kind of cool.

Has anyone else seen something like this with any of the 500 series PCBs? This was the only time I've had an issue where the problem wasn't some silly mistake I made.

Thanks!

Paul

 

[kante1603]

Read the thread?
http://groupdiy.com/index.php?topic=36522.msg697139#msg697139
Udo.

 

[Potato Cakes]

Thanks, Udo!

I had glanced through the thread and usually when there been an error with the boards it's a simple jumper that needs to be made. I had never figured that this would be a possibility. I should have read more carefully!


Thanks!

Paul

 

[kante1603]

 

[mhbunch]

Finally finished my pair. Sound great!

 

[maniman]

Hi friends , I'm doing this project these days and trying to do the lo and hi freq selectable mod http://goetzmd.de/tontechnik/studer-169-eq-teil-5-finale-und-front-panel I'm seeing one thing ,

- the C6 is the cap that low frequency depends on
- on the layout C6 is 220 nF

20 Hz is the Low freq default frecuency and this is not true , or the C6 layout value is wrong , 22 nF maybe are 2X Hz but if you see the graph can see 220 nF is more something near 2X0 Hz .

Not ?

 

[joshuabiehler]

First time poster/long time lurker.

I finally got this bad boy together and it sounds AWESOME.

I have a couple of comments/build notes:

- I'd definitely put in a trimmer at R4 - I set it to 10K prior to soldering it in and was 6DB+ from the level when bypassed.
- I received my boards this month, and they still have the "all pins connected" issue. I wouldn't have thought to check that were it not for this thread!
- I didn't build it with an input trafo, but have tried out the lone DOA I have (GAR1731). It sounds great with just the NE5534s but there's a lot more "bark" with the DOA. I have it in the the DOA2 spot for now.

Obligatory gutshot, waiting for the faceplate to arrive.

Thanks, AudioX!

 

[skeeler87]

Has anyone been able to source out knobs for the omeg pots? I'm having a hell of a time finding them.

 

[wadesey]

Curious if anyone has tried successfully to graft the 169 high pass filter circuit into this? Between C1 and C3 seems like where it would go? I see there's a lot of blank space on the PCB to possibly connect a little perfboard of it. Presuming there's no additional modifications needed... Worth the effort? Or better idea to just HPF some other way before the EQ?

 

[iprovlek]

Ok Guys!

I have this killer EQ for while now!!! This Eq is the bomb I like it a lot (right know Im planning to use DOA for input and output balancing) Forthmonkey gave me etch files for IC to DOA converter!!!

I try it with 5534, OA10, gar1731,gar2520, for me gar2520 is the best for this EQ!!! I use him a lot great for anything even mastering!!!

In beginning I have A BIG PROBLEM TO FIND POTS, so this the reason why Im writing this reply!!!!

There is no need for double POTS for this EQ ,only double POT you need it is to be 100K REV LOG for MID freq!!!

So I wanna share when can you buy POTS for this EQ....It is a little BIG but with little effort can be set very well!!!

http://www.musikding.de/Omeg-Pot-20mm-22k-lin_1

http://www.musikding.de/Alpha-Potentiometer-16mm-Stereo-100k-rev-log_1


This 16mm it is little smaller so I cut circle leg of it and solder on wires from resistors or anything that left from passive components!!!

You solder it on PCB by setting with other pots on frontpanel!!!

This Musikding is mostly for European countries, but if someone need from other countries this POTS I can send them ,cause they exist in my electronic shop in my neighbourhood!!!

Cheers

 

[Greg S.]

hi, built this unit and got offset at the outs! 12mV at the pos and -12mV at the neg. Checked the circuit and bridged c13(100uF E-Cap), worked fine after that mod!

 

[Potato Cakes]

Has anyone been able to source out knobs for the omeg pots? I'm having a hell of a time finding them.

OKW Enlclosures sells 4mm shaft collet style. Minimum order is 10. Only place I can find them easily. I have them on mine.

Thanks!

Paul

 

[eriksunding]

Hello! First time poster here, but I hope to get some help.

I'm building two of these and I just can't seem to get them to work. One is completely silent when eq is engaged and one just doesn't sound right. The frequencies are just wrong.

Something I did and later corrected was that I installed two LEDs, one for on and one for off, and I accidentally hooked the ground from those to the middle hole of the five holes connected to DOA 1 which lead to pin 4 of the bottom two 5534.
Could that possibly have destroyed some component and in that case, which?

I'd highly appreciate any help to get these things up and running.

 

[Gustav]

Hello! First time poster here, but I hope to get some help.

I'm building two of these and I just can't seem to get them to work. One is completely silent when eq is engaged and one just doesn't sound right. The frequencies are just wrong.

Something I did and later corrected was that I installed two LEDs, one for on and one for off, and I accidentally hooked the ground from those to the middle hole of the five holes connected to DOA 1 which lead to pin 4 of the bottom two 5534.
Could that possibly have destroyed some component and in that case, which?

I'd highly appreciate any help to get these things up and running.

First thing to check on these - A PBC batch had a problems with "hairs" between the connector fingers (pre 2017)

Gustav

 

[eriksunding]

First thing to check on these - A PBC batch had a problems with "hairs" between the connector fingers (pre 2017)

Gustav

I just ordered these a month ago and tested for that as well, so I don't believe that's the case.

 

[Gustav]

I just ordered these a month ago and tested for that as well, so I don't believe that's the case.

Just making sure its not an issue

You can test the voltages on the circuit without the DOAs inserted to start with.

DOAs bought pre-assembled and tested, or possible trouble there too?

Gustav

 

[eriksunding]

Just making sure its not an issue

You can test the voltages on the circuit without the DOAs inserted to start with.

DOAs bought pre-assembled and tested, or possible trouble there too?

Gustav

No DOAs. Just the four 5534s. But I accidentally hooked 16v to the DOA hole in the middle.