368
Item nr.
Micro stereo amplifier
| Production | The Netherlands, 2013. |
|---|---|
| Semi- conductors | 4 diodes (rect), BA4560 (preamp), A2007A (output). |
| Cabinet | Plastic. |
| Power | AC adapter 15V. |
At some time I wanted a small amplifier to drive my speakers from a PC in my office. The PC speakers by Harman Kardon are quite good and consist of two plastic speaker cabinets, one with a small stereo amplifier that delivers 2x4W to the speakers. I decided to use the amplifier of an old HK195 set. 
The speaker in this set is just 3 inch. I opened the cabinet and found the amplifier, 
to my surprise without any transistor on the circuit board. There are four rectifier diodes (indeed, the power supply gives 15V AC so rectification and smoothing is on board) and two ICs, one mounted on a large cooling plate. The preamp is an BA4560 IC, a double opamp. The output is an A2007A power amp IC. This IC must dissipate something like 4 to 8W when the amp is used at full power, so it is connected to a large aluminium heat sink.
| Obtained | 11/2013 from Gerard. |
|---|---|
| Condition | 8. |
| Disposed | Storage (inquire if interested to buy). |
I sawed the upper half from the speaker case and glued a transparant top over it, so you can see the inside while using the amp. Some DIN loudspeaker connectors completed the job. A small 4W speaker plus scalp of a cabinet remained as left overs.