At your risk. A suitable fuse must be in series with any battery for safety. Protect your ears from high SPL. There is a broadband click sound when turning off the amplifier.
It sounds very nice. Drums sound like the real thing.
Singal path:
On the Border - Al Stewart (on origianl CD) - Sony CD Walkman line out - Marantz Imperial 5G (one speaker so far)
Power supply is just 12V from a 1.3AH lead acid battery.
Ic is 120mA. So power output should be less than 1W.
Output hand wound transformer is about 3 to 1. So from an 8 ohm speaker the amp sees about
8 ohms x 3 x 3= 72 ohms. Air gap is by gluing one layer of scitch invisible tape across the stacked Es.
The transformer used on this prototype is rather big.
Bias is by a resitor from collector to base.
There is a 50uF film wound input capacitor.
And a variable series resistor (rheostat) connected to base for volume control.
It should be nice making 2 such monoblocks inside a transparent plexiglass box powered by 8 AA batteries in series with a suitable fuse.
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