Using the newest technologies we succeeded in designing some low priced amplifiers for the serious audio amateur.
The most simple one is this D-122 module. That module is a prionted circuit board (PCB) where already a number of SMD parts are mounted. Some components have to be added in the classic way. This certainly is not a problem for a d-i-y audio lover.
The stereo module is an amplifier delivering 2 x 12 Watt into 8 Ohm and 2 x 20 Watt into 4 Ohm.
The picture shows that a pair of extra electrolytic capacitors are used. Those, together with the capacitors in the power supply, provide an extra filter. This supresses the feedback of the switching signal and forms an extra isolation for disturbances from the mains. The capacitors are long life types with low ESR and withstand temperantures of up to 105°C.
All you need apart from this pcb is a simple power supply with a transformer, giving a single 18 Volt supply, delivering 50 Watt. Thereafter a bridge rectifier, a capacitor and a fuse.
The price for the module is only 65 Euro. Components for a simple power supply are available for around 50 Euro. Apart from the electronic parts you will need a small cabinet which fits all parts.
This amplifier can also be delivered with a complete power supply (with PCB and an extra filter), a cabinet and all mechanical components.
Prices:
When ordered in combination with a set of FR-1 loudspeaker the total price is 510 Euro.
D-123 stereo amplifier with subwoofer
We offer an alternative being a set with the possibility to connect a passive subwoofer. The amplifying part then holds two D-122 modules, where one of them is functioning as a "bridge" amplifier. This is combined with a special control unit having an active filter for the bass amplification. This control unit is supplied with special (discrete!) shunt regulators.
The picture shows the control amp on the left with its separate bass preamp. The basslevel can be fixed with the blue preset potentiometer. The volume is controlled with a reliable Alps potentiometer.
Rear panel of the D-123 amplifier
