Marantz Model 5

 The Power Amplifier Model 5 it is  a revised and more attractive version of the Model 2

Marantz Power Amplifier have been designed and constructed to give a long, trouble-free life of fine listening quality. Here is the type of performance and workmanship that previously was found only in high quality broadcast or laboratory equipment. Built-in metered test instruments permit simple, accurate adjustments for optimum performance.

 The Model 5  is essentially a smaller version of the 40 Watt Model 2, with certain minor simplifications, never theless embodying fully the same quality.

Its exterior design adapts itself to instalation requirements for multiple amplifier systems such as in stereophonic applications and in those embodying the Marantz Electronic Crossover.

Specifications

Power Output:  30 Watts (60 Watts peak) "Ultra-Linear" operation.

18 Watts of excellent Triode operation can be had by altering two connections inside chassis.

Output Connections:  4, 8 and 16 ohms

Input Sensitivity (for 30 watts):  1,3 volts RMS into 250 kohm

Response:

At 30 Watts : Within 0,2 dB from 20 cps to 20 kc 9equivalent of ±0,1 dB from 15 cps to 40 kc into "Grid" (or test) input.

At ½ Watt : ±1 dB from 3 cps to 40 kc. Response has been deliberately rolled off approx. 7 dB at 100 kc to control transient response.

Subsonic Filter in standard "Input" slowly rolls response off below 20 cps (less than 1 dB at 20 cps, -10 dB at 3 cps, etc)

Distortion at 30 Watts

Total Harmonic Distortion :  less than 0,1% at mid-frequencies. Less than 0,5% from 20 cps to 10 kc. Less than 1,0% at 20 kc with resistive load (much less of equivalent voltages with inductive speaker loads).

Intermodulation Distortion :  less than 0,5% (60 cps/12 kc, 4:1)

IM measurement of typical amplifier: 35 W equivalent  0,5%;  30 W equiv.  0,28%;  20 W equiv.  0,17%; 10 W equiv.  0,11%

Distortion below 30 W is largely of 2nd order and reduces rapidly with signal level

Damping Factors:

Greater than 20 from 20 cps to 20 kc (instructions given for optional insertion by the customer of two additional resistors to provide damping factors of 2, 1, or ½)

Inverse Feedback and Stability:

20 dB of overall feedback. Great care has been taken to ensure stability and low distortion under widely varying loods, both resistive and reactive, such as are encountered in loudspeaker systems.  Power supply surges are balanced out of signal channels providing excellent recovery from strong transients. Will not oscillate under any condition of open circuit capocitive load.

Hum:

Beter than 90 dB below 30 Watts containing proportion ately little of high order components.

Metered test and Adjustments:

Built-in meter and test switch provide acurate adjustment of each output tube bias. This makes the use of matched tubes unnecessary. Adjustable A.C.  Balance (located subchassis) pre-set at factory

Power Supply:

The use of a transmitting type oil condenser, choke, telephone quality electrolytic, and GZ-34 heater-cathode rectifier provide protection from starting surge voltages, improved regulation, and thorough filtering, together with long life.

Power Requirements:

Design center 117 volts, 60 cycles. Range 105 -125 volts. 100 watts at zero signal; 130 Watts at maximum signal

Tube Complements:

1 x 6BH6;  1 X 6CG7;  2 X EL34/6CA7;  1 X GZ34

Dimensions (W x H x D):  6" x 7 ⅜" x 15 ¼"

Weight:  35 lbs (shipping with grille)