The instrument
The Klemt Echolette M40 Gold Cage Amplifier came onto the market in 1959 as one of the earliest echo devices. Almost identical versions with a slightly different design (buttons) have been produced since 1962. The amplifier was used by musicians such as the Beatles.
Details
Operating voltages: 110, 130, 150, 220. 240, 250 V at 50-60 Hz; power consumption: full load 150 VA, without signal 150 watts; tubes: 5 x ECC 83, 2 x EZ 81, 4 x EL 84; semiconductors: OA 150, SFD 108; 4 preamplifiers, tone control and driver stage, phase reversal stage, push-pull B-end loop; power: Sine 32 watts, music 40 watts; distortion factor less than 2% at 1000 Hz; frequency range 40 Hz - 15 kHz +- 1 dB; 4 inputs for treble - 8 dB at 6 kHz, bass - 8 dB at 100 Hz, treble +- 15 dB at 6 kHz, bass +- 15 dB at 100 Hz; input sensitivity for microphone approx. 1 mV at 150-500 Ohm, for guitar / bass approx. 15 mV, for echo / reverb recording 11 mV, playback 20 mV, for pickup playback 30 mV, recording 25 mV.
(Source: Hans Ohms, Hi-Fi Archive)