Marantz Model 3250

Commentary

As a control console, it is a control amplifier that pursues rich functions.

The equalizer amplifier uses a specially designed low-noise differential input amplifier, buffer amplifier and A-class amplifier with constant current load. It uses a 5-transistor first stage differential and 3-stage direct-coupled differential circuit, resulting in a 300 mV follower load, 40 dB closed-loop gain, and minimal RIAA deviation.

Built-in MC head amplifier with low distortion design.
This circuit is not a conventional multi-use FET, but a new super low-noise high-gain type FET developed for audio applications. It realizes excellent S/N and low distortion factor. This FET has approximately five times the capacity of the conventional FET. Various characteristics such as distortion factor, S/N and frequency characteristics are greatly improved at the element stage. In addition, it realizes a high gain of 26 dB and sufficient sensitivity of 90 μ V. It can be used for MC cartridges by simply switching the selector.

In addition to the conventional Bass and Treble, a Mid-position tritone control is used for the tone control section.
The tone amplifier consists of a differential amplifier and is a low-distortion NF type. In addition, it is a linear slide type similar to a graphic equalizer for easy fine adjustment.
This circuit also has a turn-over frequency switching function and a tone defeat function that enables one touch jump in the circuit.

It is equipped with a loudness contour.
The loudness contour adopted in the Model3250 has a structure in which the optimum Fletcher Munson curve is set continuously variable at each stage of low volume, and it is independent of the master volume.
When this circuit is OFF, flat frequency characteristics can be obtained.

The high filter uses a Bessel type filter with excellent roll-off characteristics, and achieves a steep roll-off curve of 18 dB per octave at 9 kHz, thereby successfully reducing phase distortion.

It is equipped with an independent tape copy circuit capable of mutual dubbing and monitoring.

Equipped with a tape selector that can switch between up to 2 pairs.

Gold-plated terminals are used for input / output terminals.

The wood case was sold separately as an option.
You can choose the finish of the exterior of this wood case, and there are 2 kinds of variations, walnut and mahogany.

Model Rating

Type	Control amplifier
Rated Output / Impedance	Pre out : 1.5V/220 Ω Tape out : 180mV/330 Ω
Input Sensitivity / Impedance	Phono1 : 1.8mV/47k Ω Phono2 MC : 90 μ V/40 Ω Aux, Tape : 180 mv
Total harmonic distortion factor	0.01%
Cross modulation distortion factor	0.01%
Frequency characteristic	20 Hz ~ 20 kHz + 0 -0.1 dB
RIAA deviation	20 Hz to 20 kHz ± 0.2 dB
Input equivalent noise	0.24 μ V (Phono1, IFF-A)
Tone control	Bass : + / - 10 dB Treble : + / - 10 dB Mid : ± 6 dB
High filter	9 kHz, 18dB/oct.
Low filter	15 Hz, 18dB/oct.
Power consumption	11W
External dimensions	Width 416x Height 146x Depth 243 mm
Weight	6.5kg
Sold Separately	Wood Case WC-121 (Walnut Finish, ¥ 6,000) Wood Case WC-121N (Mahogany Finish, ¥ 11,000)