Marantz 2270 Brochure 2

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36

PERCENT IM DISTORTION
o
m

RESPONSE IN DB

10 2a 100 1K

FREQUENCY IN HZ

ERCENT THD

p
.0
S

as
g

0.05

air
500 1K 2K
FREQUENCY IN HZ

100 200

2 345 10 20304050100
POWER OUTPUT IN WATIS

mal use. in addition to the inputs and outputs for two
tape decks, there are two input pairs for magnetic
phono cartridges and one for aux. In fact, everything
about this receiver (except its sometimes unclear in-
struction manual) is carefully planned and beautifully
executed.

Tuner performance is excellent. Quieting descends
steeply to -40 dB at only 2.5 microvolts and achieves
full effect (-48 dB) at 50 microvolts, making it possible to
receive clean sound from stations that would be borderv
line at best with many receivers. The S/N ratio is, at
more than 79 :13, one of the best that CBS Labs has
measured for us. And distortion is unusually low.

The amplifier section is a real powerhouse. Marantzs
rating of 70 watts per channel is very conservative;
many companies would rate such a design at 90 watts
or more per channel. To put it another way, at rated out-
put the distortion is exceptionally low-no more than
0.1% of eitherTHD or M in any.of the lab measurements
at 3 ohms. Note, however, that power output at 4 ohms

are;
500 1K
FREQUENCY m HZ

l
50 100 200 5K

Marantz 2270 Receiver Additional Data

Tuner Sectlon
Capture ratio 2.0 dB
Alternate-channel selectivity 62 dB
S/N ratio more than 79 dB
IM distortion 0.3%
THD Mono L ch Ft ch
80 Hz 0.34% 0.52% 0.33%
1 kHz 0.30% 0.30% 0.25%
10 kHz 0.25% 0.95% 0.30%
19-kHz pilot suppression 66 dB
38-kHz subcarrier suppression 64 dB
Amplliler Seotlon
Damping factor 35
Input characteristics (tor 70 watts output)

Sensitivity S/Nratio
phone 1 & 2 1_9 mV 65 dB
tape 1 & 2 179 mV 86.5 dB
aux 179 mV 86.5 dB

is relatively restricted if M distortion is to be kept low. if
all speaker taps are to be used, particularly if the listen-
ing rooms are large or the speakers unusually
inefficient, B-ohm speakers would appear to be in order.
The most distinctive feature of the control section is
the three-knob tone-control system. The maximum ef-
fect of the midrange control is not as extreme as that of
bass and treble-and indeed it need not be for most pur-
poses. It can be used to add a bit more presence to a
soloist, or to subdue an overly forward" soloist-typi-
cal of some older recordings. And we found a use that
may become increasingly important in the near future:
to balance dissimilar loudspeakers in four-channel lis-
tening (with the addition of an extra stereo amplifier).
Normal treble and bass controls had failed to match the
tone color of the front pair with those used for the back
channels; the three-way controls, with their added flexi-
bility, did a much more satisfactory job when we substi-
tuted the 2270 for the receiver that we had been using.
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