Universum System 7500 SL (V 2315)

This amplifier (V 2315) is part of the Universum System Hifi 7500 SL, it was first offered for sale in 1981. In addition, a tuner, a record player and tape decks in different versions were offered in a coordinated design.

The amplifier was produced in two different versions at that time. The first version had a surround sound facility, with the help of which a so-called "4D-Quadro surround sound" could be produced. In addition to the usual stereo speakers, two rear effect speakers were needed for this. A later version of this amplifier no longer had this surround sound function, instead a "mute function" was implemented in the device.

Special features of this device were its liquid-cooled power amplifier (heat pipe), a massive front made of aluminium, as well as a comparatively flat housing design. Presumably this is the reason for the name "SL", which was called "Slim-Line" in the advertising for this series at that time.

Technical data:

Rated power at 1 KHz: min. 2x60 Watt into 4 Ohm

Music power: min. 2x100 Watt

Distortion factor at nominal power: 0.5%

Intermodulation: 0.1 at full modulation according to DIN 45403 (250 HZ + 8 kHz, 4:1)

Loudspeaker damping factor: 20

Minimum speaker impedance (connected load): 4 Ohm

Frequency response: 20 Hz to 40 KHz

Power bandwidth: 30 Hz to 40 KHz

Crosstalk attenuation between the two channels: 45 dB at 1 KHz, 35 dB from 250 to 10 000 Hz

Crosstalk attenuation between the different inputs Crosstalk attenuation between the different inputs: 55 dB at 1000 Hz, 45 dB from 250 to 10 000 Hz Synchronisation of the AF section (left/right channel): less than 2 dB

External voltage spacing for nominal power: 74 dB

External voltage spacing for 50 mW: 60 dB

Control ranges:

Treble control: + 10, - 10 dB at 10 KHz

Bass control: + 10, - 10 dB at 100 Hz

Balance control: - 40 dB

Input sensitivity and impedance at 1 KHz for nominal power: TB/monitor: 350 mV/500 kOhm

Magnet TA: 3.5 mV/50 kOhm

Dynamic TA: 0.2 mV/0.1 kOhm

Tuner: 350 mV/500 kOhm

Max. Input voltage:

TB/monitor: 5 V

Magnet TA: 50 mV

Dynamic TA: 5 mV

Tuner: 5 V

Output voltages and impedance:

TB: 1 mV at 1 kOhm

Headphones: 400 mW into 220 ohms