Standard SR157SW amplifier

 

General:

Around 1965 issued amplifier for European markets made by 'Standard Electric' company Japan.

front ^

 

Owners manual:

not yet available

interior ^
 

special futures:

There are models of this kind amplifier with RCA input/output sockets.
Light and small footprint amp. Wood case. Well build and good parts used.
This amp employs a mix of germanium and silicon transistors.
 

Specifications:

Distortion (THD 20Hz - 20kHz) < 0.1% at continuous output per channel: 7 Watts RMS per channel.
Speaker impedance: 8~16ohms
Signal/noise ratio: 85dB power amp. section
4 x DIN input.

Germanium Power transistors ^

 

Schematic:

click here to download the schematic diagram of the Standard SR157SW (redrawn by Limhes.net)

PCB with silicon transistors and germanium drivers ^
 

Modifications:

You may replace some diodes, capacitors and resistors in the power supply and power rail.
After modification this amp is capable of producing 2x 10 Watts RMS.

interior after update ^

 

Back Panel with new speaker connectors ^

 

Sound:

The sound is very good for such a small amplifier.

 

© Hans Hilberink - PE1MMK ® 2003 - Last update: 10-09-2016.