LVA/B 30 with RV12P2000
In 1940 Lorenz acquires the
Schaub Apparatebau. In 1944 about 24.000 people working for Lorenz
only build equipment for military purposes. In the same year Telefunken introduces the LG12 rectifier tube
for the German Wehrmacht.
In 1946 Lorenz returns to
the production of consumer electronics. The LVA/B 30 is introduced
with a set of "Wehrmacht tubes": RL12P35 output, RV12P2000 drivers
and LG12 rectifier tube.
Design and circuit of this amp:
Input: 200 ohms unbalanced (no input
transformer, input applied across
200 ohm potentiometer)
Output: 200 ohms or 100V line
First Gain Stage: RV12P2000 wired in
Second Gain stage: RV12P2000 wired in
Phase inversion: interstage transformer
to two grids
of RL12P35 tubes
Output stage: Push Pull RV12P35 pentodes
Bias: Adjustable cathode resistors with bias
Mains Voltage: 110V, 125V, 220V, 240V
A new feature are the individual meters for the bias control of the
The choke is now mounted on the top of the output transformer.
Though electrolytic caps became more and more popular the amp still
uses the better paper in oil capacitors in the power supply.