DC 762

[micro1_de]

Hello,

does anybody have any experiences with a DC 762 as valve for a microphone?

Greatings Reiner

 

[strangeandbouncy]

HI,


  i think you mean AC761(?)


    Kindest regards,


      ANdyP

 

[micro1_de]

Hi Andy,

thanks for your answer. No really I mean the DC 762. It should be the eastern sucessor of the Ac 761.


Kind regards

Reiner

 

[strangeandbouncy]

Hi,

  when you say "eastern successor", I am confused! The AC761 IS the "eastern" (ie DDR) successor(well, read pale imitator) of the AC701, made by Telefunken in West Germany . . .



            Please tel us more!



        ANdyP

 

[strangeandbouncy]

HI,


  http://www.radiomuseum.org/tubes/tube_dc762.html


  looks a bit like the successor to a Hiller MSC4(?) Directly heated 1.1V version of AC761. MSC4 has 4V heater though, I think.


 http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Hiller/Hiller.htm


  Why? have you got some?


    ANdyP

 

[mad.ax]

Datasheet says Ua max = 12V, Ia max = 600µA, S = 150µA/V, µ =0.9
Definitely not your average tube mic triode! It's an electrometer tube

Axel

 

[PRR]

http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Hiller/DC762.pdf

 

[PRR]

.

 

[micro1_de]

Have also read the PDF at Jogis Röhrenbude und thought it might be an usefull alternative for an tube amp.
PRR: Do you have calkulate the schamtaics or have you already tried it in reality?

Kind regards
Reiner

 

[Snoopy]

This is an inverted triode in which the grid and anode are swapped. However, it can be used as a triode (see picture). The system is identical to the DC960 = AC761 = AC701, but directly heated with 1.1 volts. So it is comparable to the Hiller MSC1.2 (1.2 volts directly heated).

Since the Hiller MSC1.2, MSC2 and RFT DC760 / DC762 are all directly heated, you need a very good power supply. You also have to pay attention to the positive and negative pole of the heater, otherwise you will have a louder noise.

The DC762 can be used in a triode circuit as a replacement for a Hiller MSC2 or Telefunken AC701 without any problems. Of course, you need an additional series resistor for the heater. And more space, because the tube is 2 cm longer. But this is no problem in the Neumann M49 and M50 as well as in the CMV3 and B-V30 bottle microphones. Unfortunately, this tube does not fit into a small-diaphragm condenser microphone like the KM54.


https://www.radiomuseum.org/tubes/tube_dc762.html