Crown ma-24x6 Guía Del Usuario

All Macro-Tech amplifiers have transformer 
thermal protection. It protects the power sup-
plies from damage under the rare conditions of 
transformer temperatures rising too high. A 
thermal switch embedded in each transformer 
removes power to the channel if there is exces-
sive heat. The switch automatically resets when 
the transformer cools to a safe temperature.

It is very unlikely that you will ever see a 
Macro-Tech amplifier activate transformer ther-
mal protection as long as it is operated within 
rated conditions (see Section 7, Specifica-
tions). One reason is that ODEP keeps the 
amplifier working under very severe conditions. 
Even so, higher than rated output levels, exces-
sively low impedance loads and unreasonably 
high input signals can generate more heat in 
the transformer than in the output devices. 
These conditions can overheat the transformer 
and activate its protection system.

Macro-Tech amplifiers are designed to keep 
working under conditions where other amplifi-
ers would fail. But even when its limits are 
exceeded, it will still protect itself—and your 
investment—from damage.

The power supplies are protected by circuit 
breakers. With rated loads and output levels, 
the circuit breakers should only shut down the 
amplifier in the rare instance of a catastrophic 
failure. Other protection systems like ODEP 
keep the amplifier operational under most other 
severe conditions. The circuit breakers can also 
shut down the amplifier in cases where 
extremely low-impedance loads and high out-
put levels result in current draw that exceeds 
their rating. Again, this should only be possible 
when operating outside rated conditions, like 

when the amplifier is used to drive a 1-ohm 
load in Stereo mode, or when a signal over-
loads the input and is clipped severely.

Macro-Tech amplifiers do not trip their break-
ers unless something is wrong. If a breaker 
trips, try to identify and correct the problem 
before resetting the breakers with the back 
panel Reset switches. If the problem persists, 
refer the unit to a qualified technician.

Grounded Bridge is the name of Crown's 
unique four-quadrant amplifier topology. The 
Grounded Bridge topology takes full advantage 
of the power supplies delivering peak-to-peak 
voltages to the load that are twice the voltage 
seen by the output devices and twice the volt-
age generated by the power supplies.

The power supply bridge rectifier is not ground 
referenced, and the transformer secondary is 
not center-tapped. This allows the power sup-
ply to deliver +VCC and -VCC from the same 
bridge rectifier and filter as a total difference in 
potential regardless of their voltages with 
respect to ground.

Composite output devices are arranged to func-
tion as gigantic NPN and PNP devices. Each 
output stage has two composite NPN and two 
composite PNP devices. The devices con-
nected to the load are referred to as “high-side 
NPN and PNP” and the devices connected to 
ground are referred to as “low-side NPN and 
PNP.” Positive current is delivered to the load 
by increasing conductance simultaneously in 
the high-side NPN and low-side PNP stage, 
while decreasing conductance of the high-side 
PNP and low-side NPN in synchrony.

Crown's Grounded Bridge design delivers large 
voltage swings without stressing output tran-
sistors. The results are higher efficiency, lower 
distortion and superior reliablility.

VZ is the name of Crown's patented articulated 
power supply technology. This innovative tech-
nology permits us to pack large amounts of 
power into a compact package while achieving 
ultra-low distortion and without generating 
excessive heat.

An amplifier power supply must be large 
enough to handle both the maximum voltage 
and maximum current necesary for the ampli-
fier to drive its rated power into a specified 
load. In order to meet this requirement, most 
conventional supplies are heavy, large, and 
produce lots of heat. In contrast, the VZ supply 
gets more current AND voltage out of a smaller, 
lighter, and more efficient package by dynami-
cally adapting to both signal and load require-
ments in real-time. This provides the best 
power match to the widest range of loads. 

The VZ supply is divided into two segments. 
When the output stage requires high-voltage, 
the segments are arranged in series to deliver 
twice the voltage of a single segment. When the 
output stage requires high-current, the seg-
ments are arranged in parallel to deliver twice 
the current of a single segment. Sensing cir-
cuitry "watches" the voltage of the signal to 
determine when to switch VZ modes. The 
switching circuitry is designed to prevent audi-
ble switching distortion to yield the highest 
possible dynamic transfer function—you hear 
only the music and not the amplifier. 

With VZ, you get not only maximum power and 
safety, but you also get the best power match-
ing to your load.