Marantz Model 1122
¥ 79,800 (around 1977)
Commentary
Low TIM design DC configuration pre-main amplifier.
It is equipped with an MC head amplifier that realizes a high gain of 26 dB by adopting the newly developed super low noise high gain FET 2SK130A.
The audio FET 2SK130A has characteristics equivalent to about five FETs of the type used in the conventional MC amplifier, and various characteristics such as frequency characteristics, distortion factor, S/N have been greatly improved.
The power amplifier circuit uses a DC-configuration OCL-inverted Darlington circuit connected to all stages to produce an output of 65W per ch.
Moreover, a FET cascode bootstrap circuit is adopted in the first stage of the power section to solve the problem of drift. The phase characteristics from ultra-low band to ultra-high band and high transmission capability unique to DC amplifiers enable extremely transparent and flat playback.
If you use the Main In terminal on the rear panel and combine it with another preamp as a separate type. If there is a risk of DC leakage from the preamp to be combined, you can switch the DC/AC amplifier change-over switch to AC.
To prevent oxidation of each terminal and reduce contact resistance, all input terminals are gold-plated to prevent deterioration of sound quality.
In addition, the wiring inside the amplifier and the parts used are carefully selected, and special parts are added to the selection and stabilization measures are sufficiently taken.
Equipped with a PEP protection circuit that protects power transistors and speakers by instantaneously detecting excessive current / voltage or DC at the output terminal.
This circuit is designed to withstand a 10-minute short circuit.
The microphone terminal is mounted on the front panel.
Equipped with a tritone control that also allows mid-range control.
Uses a Bessel filter with excellent roll-off characteristics to ensure excellent phase characteristics.
Wooden cabinet is sold separately.
Model Rating
| Type | Stereo pre-main amplifier |
| Rated output (20 Hz to 20 kHz, both channel drive) |
65W + 65W (8 Ω) 80W + 80W (4 Ω) |
| Frequency Response (20 Hz to 20 kHz) | + 0, -0.2 dB |
| Total harmonic distortion factor | 0.03% |
| Cross modulation distortion factor | 0.03% |
| Damping factor | 60 |
| Input Sensitivity / Impedance | Main amplifier input : 1.5V/30k Ω Phono MM : 1.8mV/47k Ω Phono MC : 0.09mV/40 Ω High level : 180mV/25k Ω |
| Rated Output / Impedance | Pre Out : 1.5V/200 Ω |
| RIAA deviation (20 Hz to 20 kHz) | ± 0.3 dB |
| Input equivalent noise | 0.48 μ V (Phono / IFF-A) |
| Dynamic range (phono) | 112dB |
| Tone control characteristics | Bass (100 Hz) : + / - 10 dB Mid (700 Hz) : ± 6 dB Treble (10 kHz) : ± 10 dB |
| Filter | Low : 50 Hz, 6dB/oct. High : 5 kHz, 6dB/oct. |
| Power consumption | 180W (Electrical Appliance and Material Control Law) |
| Pwer | 100 V, 50Hz/60Hz |
| External dimensions | Width 416x Height 146x Depth 316 mm |
| Weight | 12.5kg |
| Sold Separately | Standard Walnut Cabinet WC-110 (¥ 7,000) Standard Mahogany Cabinet WC-110N (¥ 12,000) |