Siemens U273

[chriss]

Hi there,

I have a few questions regarding the U273-compressor:

- For the gain-reduction-Meter-option: This is specified as 150kOhms, 1,5V. Now I wonder if I can simply connect the standard LM3914-configuration like the one 0-5V in the datasheet and trim it a bit. Would that do the job?

- For the two-knob version: This on has a Comp/Bypass/Lim-switch: I guess this is the multi-stage-switch S1 - S7 (seven-stage-switch? :shock: ) And it has an relese-pot, is this R3/R4?

- I'd like to add some more control to it, so could I take some of the inside trimmers and lead them to a front-panel? I think of R7, wich I think is the threshold-level? I think the compression-rate like in the U273a is too complicated to upgrade?!...

- Is there any circuit-description around the web? Only found it for the U273b-Version.

Any experience here with my ideas?

best

Chris

 

[clintrubber]

[quote author="chriss"]
- Is there any circuit-description around the web? Only found it for the U273b-Version.[/quote]

Hi Chris,

You've seen the file at Jakobs site ? I guess is not the one you already have.

http://www.gyraf.dk/schematics/Siemens_U273_Limiter.pdf

Cheers,

Peter

 

[chriss]

Thanks Peter,

I already have this file (from Kubi's site), but I think the text is very general. Honestly I didn't go too much in it because it's bit complicated. I will give it a second try. But I'd love to have a circuit-description like in the good old Braun-Buch.

regards

Chris

 

[opacheco]

Hi there,

I have a few questions regarding the U273-compressor:

- For the gain-reduction-Meter-option: This is specified as 150kOhms, 1,5V. Now I wonder if I can simply connect the standard LM3914-configuration like the one 0-5V in the datasheet and trim it a bit. Would that do the job?

-  For the two-knob version: This on has a Comp/Bypass/Lim-switch: I guess this is the multi-stage-switch S1 - S7 (seven-stage-switch? :shock: ) And it has an relese-pot, is this R3/R4?

- I'd like to add some more control to it, so could I take some of the inside trimmers and lead them to a front-panel? I think of R7, wich I think is the threshold-level? I think the compression-rate like in the U273a is too complicated to upgrade?!...

- Is there any circuit-description around the web? Only found it for the U273b-Version.

Any experience here with my ideas?

best

Chris

Chris,

Did you finaly find any info about this??, I have a pair of them too and I would like to get the any "circuit-description" and mods for threshold, release, attack and make up gain too in order to get more control of!!

 

[opacheco]

To everyone interested in that Compressor Machine!!

Well after of hard work I made a CLEAR German to English Translate(I think!!) of this manual .....but I would like someone to review it because there are some German words I cannot untangle its meaning.

If Someone wants to help me, please send me your e-mail address for send the PDF file.

Thanks a lot anticipated!
Opacheco.

 

[synthiaks]

Hi,

The U273a has exactly the same basic scematics as the u273 except the extra controls. If you compare the two schematics its easy to see how to Mod the u273 to a u273a. Attack mod might be a bit more tricky you would have to switch between caps of different value (i think, i havent come that far with mu experiments yet)

Sebastian

 

[opacheco]

Hi,

The U273a has exactly the same basic scematics as the u273 except the extra controls. If you compare the two schematics its easy to see how to Mod the u273 to a u273a. Attack mod might be a bit more tricky you would have to switch between caps of different value (i think, i havent come that far with mu experiments yet)

Sebastian

Sebastian, Thanks for your notes!

Let me to check that.
Opacheco

 

[synthiaks]

No problem, i have the A version Schematics somewhere if you can't find it online but i know i found them through a popular search engine... Its the u273 schematics with Threshold  and an Input step resistor switch added to it nothing else is different. If you find out how to fix a attack mod, before i do, PM so i know if i'm wrong with the Capacitor theory

Seb

 

[clorax hurd]

Hello,
please, could someone share the translated version of service manual?
I tried to message opacheco, but his inbox seems to be full :/
Send me a PM if you have it. Thanks!

 

[opacheco]

Hello,
please, could someone share the translated version of service manual?
I tried to message opacheco, but his inbox seems to be full :/
Send me a PM if you have it. Thanks!

Dear Clorax,
I so sorry for my full inbox!, I will take care of it.

The document isn't a service manual are general  functionality notes only with some  diode variable resistor principle ......I will send a PM tonight when I come to home again ........tell us what have had your experience with these units or if you had tried to mod??.....My translate have some German to English problems too and maybe yup or someone else o can help us to be a better translate of it.
Thanks
Opacheco

 

[L´Andratté]

Hey Opacheco, pm me the file plus the problems and I will check against the original (german native)!

 

[opacheco]

Hey Opacheco, pm me the file plus the problems and I will check against the original (german native)!

L´Andratté Excellent!!....I will send it right now, but please be sure to upload here when you have corrected it.

Thanks for your disposition to help in this community!
Opacheco.