CIRCUIT DESIGN
It has been our experience that simple designs with few active stages
when executed with care and great attention to detail will be both more
musical and more reliable than overcomplicated alternatives. Accord-
ingly, the audio circuit of the MV125 is remarkably straightforward. A
triode input amplifier comprised of paralleled sections of a 5751 is direct
coupled to a cathode coupled differential phase inverter using high
current triodes to provide balanced, low impedance drive to the push-
pull output stage. The output stage features ultralinear operation of two
pairs of 6550s for high power levels with reduced source impedance. As
a result, the amplifier is capable of supplying the large current demands
of high amplitude musical transients driven into reactive speaker loads.
A substantial main power supply of massive polypropylene capacitors
enables the MV125 to easily meet these extraordinary current de-
mands. Voltage regulators for the voltage amplifiers and phase inverters
provide nearly absolute isolation of these sensitive stages from the
output stages.
MV125 Owner’s Manual
4
