3
About the design
When you pick up the 1500.2 / 1500.4, you might realize
this amplifier is a bit different than most. The A series
amplifiers were originally developed from a Class A
home audio amplifier that our founders built for their own
personal use. They decieded to connect it to the front
stage of a car one day for fun back in 2012. The sound
of that system blew them away and drove them to
develop a mobile amplifier of the same exact circuitry.
They replaced the 120V AC power supply with a 12V DC
version and repackaged the amplifer into a mobile audio
amplifier chassis. The A series was born. High end
home audio for the car.
The A series amplifiers are based on a 3 stage Lin
design. This amplifier topology is the foundation for
some of the world’s best home audio hifi amplifiers.
They took the design, improved on it and made it
suitable for car audio by physically seperating the 3
stages for reduced noise; Input section, voltage
amplifier, current amplifier. They also made the voltage
amplification stage have two identical circuits, mirror
images of one another and run them in pure Class A for
the sonic characteristics generated by this topology.
Then added high current capability (1 ohm drive for
1500.2 and 2 ohm drive for 1500.4) and a high efficiency
DC/DC converter switching power supply.
The power supply uses MOSFETs, 12 of them rated for
75 Amps each. The output section uses high power bi-
polar junction transistors, 32 of them rated for 15 Amps
each in an emitter-follower design connected directly to
your speakers (direct coupled). This direct coupling is
partially responsible for the hard hitting dynamics and
lifelike realism these amplifiers deliver.
