Tapco cp 500 brochure

Page 1

Modern Recording first publishcd the following LAB REPORT

in their June 78 issue. Since then. both ih: C9500 and CPSOOM /
have undergone significant electrical and mechanical changes

which have furlhcr improved their performance.

NORMAN EISENBERG AND LEN FELDMAN

TAPCO CP5OOM Power Amplifier with PowerLock TM puma.

"'l|AI""I-l"".ltl. IIIItI . I

General Description: The 'fapco CPSOOM is a two» put or singlechannel (mono) output. The cooling fan 15
channel power amplifier rated for up to 250 watts per centered on the rear panel. Completing the picture here
channel into 4 ohms or l50 watts pct channel into 8 are a fuse~holder with a 15~amp rating and the unit's
ohms. It is of rackvmount dimensionc and is fitted with AC power cord which is fitted With a three-prong
handles and a builtin cooling fan at the rcar. The front (grounding) plug,

panel sports a pair of output meters calibrated in The PowerLock circuit, which may be used to limit
power ratings and in decibels. plus a "PowerLock" fea» output power. uses output-voltage sensing which is
ture by means of which the operator can set the upper referred to a fixed reference voltage which in turn is a
power limit furnished by the amplifier: separately on function of the supply voltage itself. so that regardless
each channel. mo

__|~ID

The power off'on switch is a separate control at tho
left. Next to it is a power-on indicator. The two
PowerLock controls have four positions: out: 250
watts 1*0 dBl1125 watts (-3 dB): 62.5 watts (-6 dB).
Next to each of these controls is an indicator that
comes on when the upper limit selected is reached in
user Below each PowerLock control is a gain control.
Two additional indicators show conditions of a blown
fuse and of thermal protection.

Input connectors at the rear are standard lwinch
phone jacks. Each channel has two bridged inputs. 20
K unbalanced. Below these jacks is a recessed slide

DISTOnTION x

switch for converting the amplifier to singlechannel mERoUT/cfl ,wnrs
operation if desired Speaker output terminals are
standard binding posts, color-coded for polarity and Tapco CPSOOM: Distortion vs. power output, into

arranged so as to provide for two~channel (stereo) out~ 8-ohm loads. both channels driven.

Page 2

of voltage fluctuations caused by external sources. tlie"

mummhmnm this meals:

The basic amplifier circuitry itself is fairly conven-
tional in that full complementary outputs are used.
The output stages do provide gain. however. unlike
many other complementary designs. An input differen-
tial pair feeds signals to an emitter follower and then
to a class A stage which drives the bias string. Bias
sensing is accomplished at the drivers and predrivers.
and it also is based on ambient temperatures sensed at
the output stages. Driver and output stages constitute
a Darlington configuration which has a collector~
loaded output, The input stages are powered from a
zener-regulated :18 volt supply. while the output
stages operate at :62 volts filtered by a pair of 18.000
mFd capacitors.

Test Results

precondition their amplifiers (as per FTC require~
mental with 4-ohm loads. often even using a high-
frequency test signal at onethird rated power (in this
case. around 85 watts) for the test. They invited us to
do the same. and the results of our static measure-
ments represent readings taken after one full hour of
such preconditioning. Note that the amp just missed
making its 0.05 percent rated distortion at the 20-Hz
extreme for 4-ohm loads. but we would hardly fault the
unit for that since the difference between 0.05 percent
and 0.1 percent is rather academic from an nudibility
standpoint.

YHn
_.-_..IM

9.0
:8

DIST 03110 $
3

l o In a 100.9
DOVER OUTICK. WAT?!

Tapco CPSOOM: Distortion vs. power output. Into
wohm loads. both channels driven.

._- MLDDSJSUIGN
.. . . .. mammal/cu

mnormou « 'fi

"£006ch - NZ

Tapco CPSOOM: Distortion vs. lrequency at rated
output,

General Info: Dimensions: 19 by SV- by 17 inches.
Weight: 35 pounds. Also. as model CPSOO, less meter, fuse.
and theme] indicators.

Individual Comment by L F '

0 audio purist would ever tolerate the cooling fan
noise generated by the CP500M in a home listening en-
vironment. but mounted in a rack and subjected to the
kinds of environments that high power amps of this
type encounter in performance" and in sound rein-
forcement applications. the presence of the constantly
running fan just adds that much more to the safety
and long life of this ruggedly built powerhouse.

Since the amp is a wide-range unit that may find use
with almost any speaker arra

, Aside from the fan noise (which I didn't

L