Audio Database


Marantz SM-7 220,000yen

Power amplifier developed aiming at Low-TIM-izing.

A main-amplifier part is adopting the source follower amplifier by Dual-FET which had the perfect DC amplifier stream composition, and also arranged the pair property with the first rank, and has prevented the property failure by the impedance variation of an input stage. Moreover, it constitutes with the differential-amplifier -> emitter-follower buffer amplifier by Dual-Tr, and three-step darlington circuits which carried out parallel push pull adoption of newly developed super high fT-Tr are consisted of by the power amplification stage.
This super high fT transistor is an emitter ballast type power transistor of that time newest which was produced based on Low-TIM thought and which should also be called crystal of an LSI process technology and a RF Tr technology.
fT is a thing of the Marantz requests for price quotations which shows 60MHz, is excellent in a RF property and a switching characteristic, and has a stable amplification performance of a margin to a super-high region in spite of big Pc called 200W. Thereby, SM-7 is crossed to a super-low-pass wide band from a super-high region, and the high-speed responsibility is improving to particularly.

The large-sized power transformer which remains unmoved also at the time of the maximum continuous output in a rated load is carried in a power transformer. The secondary side has a separate volume structure into which the right-and-left channel was made to divide completely.
Furthermore, the mass type of 15000 micro Fx4 is used for a capacitor. The high power of 150W+150W is supplied calmly.

High precision meter loading which can carry out the Direct reading of the peek of an Output voltage in the wattage at the time of decibel and an 8-ohm load intensity.
The Koide power time to the time of the Oide power can monitor a tick mark without the change of a range for logarithmic compression mold.

An ASO detection type protection network is carried. If the output current and a voltage exceed an area of safe operation, a signal will be restricted to a safe value in an instant. An output transistor is protected without spoiling faithful reappearance of a music signal.


Rating of a mode
Form Stereo power amplifier
Output power 150W+150W (8ohm)
190W+190W (4ohm)
Output bandwidth 5Hz - 100,000Hz
THD 0.01% or less (20Hz - 20kHz, 8-ohm load intensity)
Cross modulation distortion 0.01% or less
Frequency characteristic : (+0, -0.2dB) 20Hz - 20kHz
(+0, -1dB) :DC-100kHz
Input sensitivity/impedance 1.5V/30kohm
Dumping factor 100 (8-ohm load intensity) or more
Remains noise 0.034mV (IHF-A curve)
Power consumption At the time of the maximum output: 850W
Electrical Appliance and Material Control Law: 400W
Power source 100V, 50/60Hz
Dimensions Width 416x height 146x depth of 332mm
Weight 22kg
Option Cabinet WC-77(walnut finish):8,000yen
WC-77N(mahogany finish):12,500yen
Exclusive rack handle RHA-7:4,000yen(1 set)