whell this small beast have great sound... and since i keeped one of few I had.... i spend some time using it in studio.

I notice that channels are actually very different in color and volume also noise level was different on each channel..
in studio I use it as preamps, expander for more channels to my MCI 500 and FX returns since my MCI have only 4 //

Studer is in use as 12 ch desk!!!

after some time I decided to do complete restauration of console

- For all channels recaping of electrolytic caps and tantalums is MUST!!!
after I open console and notice that 80% of FRAKO caps are lets almost dead i ordered panasonic and elna caps

almost all frako caps looked like this!!!


SCARY!!!!!


I/o Module Caps list is:

100uf/25v x8
220uf/25v x5
47uf/16v Tantalum x1
10uf/25v Tantalum x3
100uf/3v Tantalum x1

Cleaning faders is MUST !!! top end is in 90% dirty and make crackle while useing it ..so I cleaned that too

also I notice that poor made trim pot is used in I/O module for Fader Buffer calibration RUWIDO 4k7 ... I relpaced it with multiturn Bourns one!!!



still have to demagnetize transformers on modules and mod it for direct output!!!!!

STUDER 169 i/o module after restauration!!!!


169 MASTER MODULES!!!

List of recaping of each summing module !

100uf/25v x5
220uf/25v x3
1000uf/6,3v x1
1000uf/16v axial x2
0,47uf/35v Tantalum x1
3,3uf/25v Tantalum x2
6,8uf/25v Tantalum x1
10uf/25v Tantalum x3

also cleaned faders and thinking of replacing trim pots and recalibrating modules!!!!

on i/o modules REPLACE R47 trim !!!!!!!!!!!!
it make big difference on REV SEND, and output of each module in db!!!!!!!!!!!

that RUWIDO are BAD!!!!!!



This is bit crazy...

I have few modules from different revisions of 169 in my console... on 2 modules I dont have that BUFFER FADER TRIM.. and output on modules are different..removed factory trim and recalibrated all modules!!!!!

BINGO!!! INPUT MODULES ARE PERFECT!!! still to demagnetize tomorrow!!!!!! and route direct outputs from preamps!!!!!

bunch of I/o Modules ... you can see different revisions by different XLR colors on back of modules

ok here are Talkback module and Control room module



Recaping list for talkback module:

100uf/25v x4
220uf/25v x2
1000uf/6,3v x2
1000uf/16v axial x4
47uf/16v Tantalum x3
1uf/25v Tantalum x2
3,3uf/25v Tantalum x2
10uf/25v Tantalum x5

Recaping list for CTRL room module:

100uf/25v x2
220uf/25v x5
100uf/16v Tantalum x6

on CTRL room module remove RC 4136N from IC socket and clean pins ..they are heavy oxidated.

Recaping list for bridge meter:

220uf/25v axial x8

Modification for direct out :

I used idea that Dualflip explained in his racking design
....

Remove pins from patch bay that is on back of modules from connection points 95, 96, 97 on PCB .... and keep 98 yellow wire (on my modules) in place
that way you free patch points for use as unbalanced out!!!!

PBC is top mid connection point of patch bay on back of module (red wire)... extend wire and connect to connection point 14 or 15 on PCB under fader. (SIGNAL OUT)
PCM is lower left patchbay point (if looking from back) (blue wire) ... extend it and connect it to ground point anywhere on module where you like it...my module have ground point above connection point 98.. so i used that one!!!

leave PBL white wire patch point free...(maybe for future use)

thats it you have unbalanced exit from each i/o module !!!! thanx Dualflip!!!!


Before modification:


After modification...follow red extended wire:

recaping of DC/DC converter in front of frame

how it looks original


Recaped



Recaping list of DC/DC converter:

47uf/50v x1
220uf/25v x1
220uf/63v x2
1000uf/25v x6
2200uf/40v axial x2

OK now de-magnetizing!!!!!!!!

some time ago I found on DIY forum THANK you 1954U1

-------------------------------------------------------------------------------------------------------------------
quickly done the de-magnetizing procedure suggested:
sine wave at 30 Hz, 30 secs sweep 0V-3V [point of saturation], 30 secs sweep 3V-0V.
-------------------------------------------------------------------------------------------------------------------
so now 28 input transformers to de-magnetize :o

This is great!

I'm planning on doing some work on my 14 channel Studer 269 as well.
Some good tips here.

About the direct out mod, this would
give me an extra unbalanced ouput post fader, right?
That's exactly what I've been looking for. Up until now I've been using the insert as an direct out but I really want to be able to use the insert for comps and also the EQ while tracking. - 10dBu unbalanced is no problem for me.
Did you use one of the "signal" output jacks for the direct out?

Thanks for sharing.
Jonsson

I had a same experience working on a pair of racked 169 channels for a fellow engineer. Those trimpots are awful, and were the cause of uneven audio level between the two channels.

btw, I LOVE this eq!!!

Yes..and its simple to do it
its explained in my previous posts....

one with picture FOLLOW RED WIRE

Hi,

great thread! Sorry if this is asking for something obvious, but how exactly do you clean the faders in this desk?

Dirk

when you open module .. there are 2 screws holding fader to front panel... unscrew em

also remove 4 wire connected right under fader .. it will be easier to remove fader from module

..I use destilated warm water and maybe in it 3-4% of alcohol... just a few drops ....

and something that my wife call magic cleaner ... kinda of textil... and with wet magic cleaner i clean fader resistor slale and after that I clean all with just destilated warm water .... THATs it..IT works perfect!!!!
just put fader back in place after that!!! and have fun next cca 25 years till next cleaning!!!!

I've had good results replacing the noisy, spitty BC transistors with Toshiba 2SA1316 PNP and 2SC3329 NPN. Those are very quiet and smooth. Those LM301 opamps have to go too, I replace them With National LME49710NA.

Goodbye noise, hello fidelity.

Jim Williams
Audio Upgrades

Are those opamps directly compatible?
Pull out the old ones, put the new one in?

Thanks
Jonsson

You need to remove the 30 pf compensation cap used for the 301's. I added a 22 pf feedback cap in the fader circuit and added a pair of .1 uf mono ceramic psu bypass caps from pin's 4 and 7 to ground. I also removed/replaced those ****ty sockets with Millimax machine sockets.

Jim Williams
Audio Upgrades

ftp://ftp.studer.ch/Public/Products/...9-269/Manuals/

Thanks for posting this with pictures! Great thread, I have a 169 console with some spare modules. Will check them now.

im making Extender for 169 modules at the moment! after that .... I will put studer in 1 piece till end of next week! with more pictures!!!

OK .....

cleaned frame.... looks like new.... ready to be loaded!!!!



whell ... after that tried to recalibrate all trims on master modules and realized that allmost all are scratchy and no good to be used....

whell more work replacing trim post!!!!!! not just RUWIDO on i/o channels ... I replaced em all on console!!!!

1 hour of work and another 20 euro in parts.. well ok I want studer in perfect shape!!!!

example BEFORE change of trim potentiometers ... BAD, DIRTY, OLD....


and after .... NEW, FRESH.....


weekend is finish!! ..I will recalibrate and test console

GOOD

hahahhahaa I just realized I forgot to replace 1 ..... 22k .... hehe thanx to camera!!! .... I go fix that too..

Roginator:

Great thread. I am embarking on the restoration of a few 169 and 269 consoles. I am curious as to which series of Panasonic and Elna caps you used.

Scott D. Smith
Chicago Audio Works, Inc.

Jim:
I'm curious about the use of LME49710 as a replacement for the 301 in the Studer. Some sections of the console (such as IC1 and IC2 on the master module) use pin 5 (balance) on the 301, which according to the 49710 datasheet is not connected. How are you dealing with these circuit sections?

Also, I'm not exactly clear on where in the circuit you are referring to regarding 22pf feedback cap. When you say around the fader, are you referring to the input modules or the master module?

Also, how would I deal with replacing the 301 in the case of the EQ circuits on the input modules, which have feedback compensation to both pins 1 and 2?

I assume the .1 uf psu bypass caps to prevent the amplifier from becoming unstable at HF?

Scott Smith
Chicago Audio Works, Inc.

Jim:

Did you have to change any of the compensation in the circuits where the BC309B and BC239C were replaced?

Are you also using 2SA1316 to replace the 1st stage mic preamp on the input module (which is a selected BC560B)?

--Scott Smith

hi Audioguy
for capacitors I used FC and FM serie PANASONIC!
on mic pre part only 5% tantal is 47uf

and elna in PSU is any 105degree ..will work fine ..they are not in audio flow!!!


about changing ICS, transistors.....

I will keep as is .. I love sound of that console and i dont wanna mess with its great character that studer ppl put in that box!!!

all my lm 301 in console are old signetics and console sound awesome...
!!why to kill a good sound!!... just becouse somebody made modern replacmenet for tht IC! .... for 30 years sruder 169 sounded awesome..... whyto change that.. If i want modern preamp Ill buy one!! ( had a lot ..sold em allmost all)

have fun

Roginator:

Thanks for the comments. Always helpful.

--Scott

hi Rognator

you finally find a new DC/DC converter ?
i'm actulay doing the same thing ... full restoring a 289
https://www.gearslutz.com/board/geeks...der-289-a.html

i just have a question about the recaping ?
why changing the tantal caps too ?

time ago i do an excel tab for 169 electrolytic recaping
when i find it i will post it here

I changed tantals couse they die faster than electrolits and i had few dead in console..so all was replaced with new ones!!!!

OK UPDATE .. some new pictures..EXTENDER are FINALLY in function!!!

make a pdf with recaping list for 169

i do it for mine so it is a 8x4 desk with 2 input spare modues
and i don't have the same DC/DC converter

but all are detailed in the tab so it's easy tu have the total for other configuration

thanx for sharing that info with us!!
well I know 2 models of DC/DC

drop a picture of your DC/DC converter

yop !

i have the first version, 1.169.109.00
the schematic are not available in the 169/269 manual (studer ftp version)
but you can find it in the "TI 61-80 D-E" (technical instruction for 12v phantom mod) page 14

ftp://ftp.studer.ch/Public/Products/...echnical_Info/

by any chance have you an extender set (4pces) for sale ?!?