Schematics for DR pre amp "MIKROFON FORST TYPE 3-1947"

[enur]

HI

I am looking for schematics for this old DR pre amp, all help will be appreciated

Thanks

 

[Conviction]

HI

I am looking for schematics for this old DR pre amp, all help will be appreciated

Thanks

Can't help you with the schematic, but that's a really nice pre I have two in the rack.

Do you need pinout or is that sorted out?

Is it faulty?

 

[mjrippe]

Jørgen Schou transformers and RCA transistors?  It must be nice!

 

[enur]

I do have some units, and some work better than others,

I actually got the prototype I will post a picture.







 

 

[Conviction]

I do have some units, and some work better than others,

I actually got the prototype I will post a picture.

Impressive I believe Disa made these for DR?

I had some issues with mine too. Both needed a thorough cleaning of the gain switch. Get some isoprop and a tooth brush + q-tips.

Have you recapped yours?

What do you mean by "some work better than others"? Am I right assuming it's related to the gain switch?

 

[enur]

Yes its tru, its mostly the gain switch that is causing the problems in my units to,

but I did have som problem with motor booting, pumping, and I think that was related to a capacitor problem, but I can't remember.

I did not recapped, I did test som of capacitors and there seems to be fine. 

I don't know if Disa made this units, on the side of the prototype there was a stikker, I will attache a photo. But it could be interesting to find out.

 

[Conviction]

This might get you/us somewhere. I haven't had time to analyze it, but I can confirm that the gain control circuit (feedback?) is not the same.