Siemens - Klangfilm

Introduction / Overview

Klangfilm History

Moving Coil MC preamps

KLV Eurodyn Rack Amps

KLV Preamps

Output Transformers
Siemens 2000 Amps

6SELA Preamps

6SELA Power Amps

6SELA Tuners

Spare Parts

Typical Tubes




Eugen Bauer

Klangfilm KLV 204 amp

  This is (maybe) my favorite Klangfilm amp and I have a pair with almost consecutive serial numbers. The attached date labels show that they are from July and August 1952.

  Klangfilm Siemens KLV204 KL-V204 KL V204 V203 204a F2a11 Single Ended Amplifer tube amp Röhrenverstärker tube classics   Klangfilm Siemens KLV204 KL-V204 KL V204 V203 204a F2a11 Single Ended Amplifer tube amp Röhrenverstärker tube classics  

  The V204 is a single ended F2a11 amp and was used as reserve amp for Eurodyn systems with KL-V402 or KL-V502 power amps. Parts and building quality is on the same level as in those.

  The driver tubes are a pair of EF12k tubes in triode connection.

  This is the only single ended Eurodyn power amp and in later systems it was replaced by the KL-V410 EL84 push pull amp.


Model history:

Kl. V 203 (recommended !!!)

  Earliest version - introduced in 1952. 2 knobs + pilot light on front panel. On/Off switch labelled "AUS EIN"

Kl. V 204 (recommended !!!)

  Also introduced in 1952. Same as before, but on/off switch with signs.

Kl. V 204a (also great !!!)

  Later version. Only one knob + pilot light + switch on front panel. Now with dangerous input transformer: The input supplies the projector with DC power, so be careful with your sources here !!! FB correction needed!


  The tech part !!! Before connecting I recommend to ground the amp's chassis !!!



  The ground cable must be screwed to connector #12.

  Then you can connect the lines voltage to pin 14 and 15.

  The 15 Ohm power output is connected to pin 1 and 2.


  You can now run the amp using the original input (be careful with 204a models), but you may discover an unclean sound with a high hum level.


   Using the amp for HiFi purposes:

1 Add a filter cap

  This amp uses great MP (non-electrolytic) oil caps in the power supply. But 16uF is not very much and I propose to reduce hum by adding a cap of higher capacity. I hid this cap behind the resistors.

2 Install a (usual) high level input

  Solder a cable with RCA jack to point 8 and 7 (ground) of the upper connection panel counting from the right (as shown on the picture below).

  Now you only use the last EF12k tube.


  The frequency response is not absolutely linear (see picture below). The bass response is a little bit too loud, but this may be helpful with some horn speakers or open baffles.


  The V 204a uses a different (from V 203 or V 204) feedback design where it is necessary to make a slight correction to eliminate the high frequency decrease.


  I use my V 204s in my home cinema system driving my Altec 9844 speakers.