The No.1 Website for Pro Audio
 Search This Thread  Search This Forum  Search Reviews  Search Gear Database  Search Gear for sale  Search Gearslutz Go Advanced
Old 3rd September 2007
Here for the gear


I found an old STUDER 69 mixer build in 1958. The problem is that there is no power supply.

The mixer has 3 mic input module model 57
2 line input module model 70
1 eq module model 83
2 suming amps model 56
and 1 module ??? model 82
and all module have transformers on input and output (beyer, malotki and home made studer transformers).
All inputs and outputs are balanced.

Does someone know something about this unit ? Voltage needed ?
I have contacted STUDER switzerland but they dont have nothing anymore.
Old 2nd February 2016
Lives for gear

Heaters run at 12.6 Volts DC and HT is around 250 Volts DC.
I too am looking for the EQ schematic as well as the schematics for the supply.
The supply is interesting as it has the supply for the mixer, a 10 Watt power amplifier and loudspeaker and the 'drive' electronics for the modulometer.
If anyone has any other info it would be appreciated. Having just got the power amp working properly, and most of the channels it is great just to listen to although a separate 'Hi Fi' speaker sounds better but quieter.
Matt S
Old 3rd February 2016
Lives for gear
gyraf's Avatar

The Studer S69 could apparently be wired for either 6.3V OR 12.6V FF (heater voltage).

attached what I have on the subject - studer-s69-pages.pdf

Jakob E.
Attached Files
File Type: pdf studer-s69-pages.pdf (4.85 MB, 130 views)
Old 3rd February 2016
Lives for gear

Granted the channel modules have the 'option' of either 6.3 or 12.5 but the power amp which uses a pair of EL34 has them wired in series with no extra wire available for 'choice'.
As the heaters are run with DC it would be a massive current to supply at 6.3 Volts.
If any information is available for the power amp (actually pretty simple but has a good response to over 30KHz) 10 Watts output level.
Calibration details for the modulometer (and schematic) would be much appreciated.
I will be taking lots of pictures but 'reverse engineering' it all could take some time!
The design of the faders is a masterpiece but 'outrageous' in detail!
Matt S
Old 26th February 2016
Here for the gear

I have one of these Studers it came from Decca Studios in Vienna. Its just about finished being repaired by my local tech here in Los Angeles. He too was having trouble with the EQ module but I think it will be sorted out by the weekend. If anybody needs information on these modules I will be glad to tell you what I know or put you in contact with my man thats been working on it. Really an interesting piece of gear. Peace to all!
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.

Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Similar Threads
Thread Starter / Forum
runek / High end
johnnyjellybean / Gearslutz Secondhand Gear Classifieds
m.faust / Gearslutz Secondhand Gear Classifieds
Stefbossa / High end
echorec / Gearslutz Secondhand Gear Classifieds

Forum Jump
Forum Jump