Jeff Rowland Research Model 7
We're glad to offer an undisputedly excellent monoblock amplifiers from Jeff Rowland.
They are in very good conditions considering their age, they had just a single owner that treated them very well.
The original packaging are on arrival, wooden crates, they were too big to fit in the car.
Herin below some features and specs to give you an idea of what we're talking about.
Model 7 Features
- Lack of overall or nested negative feedback eliminates time domain distortion.
- Proprietary distortion canceling techniques minimize amplitude related distortions.
- Each transistor individually tested and matched for optimum operating characteristics.
- Constant output impedance is maintained over the entire audio range, allowing for universal compatibility with associated equipment.
- The large number of high-speed bipolar output transistors provides uncompromising reliability and eliminates the need for electronic protection circuitry.
- A single voltage amplification stage utilizes field effect transistors (operating in transconductance mode), which increases low-level signal recognition.
- The absence of capacitors, inductors, fuses and protection circuitry throughout the signal path eliminates the adverse effects of these devices.
- A specially designed toroidal power transformer is supported by the substantial output stage capability.
- All critical circuitry is encapsulated in a thermally-conductive epoxy to ensure excellent thermal stability, mechanical integrity and to facilitate ease of service.
Model 7 Specifications
350 watts RMS continuous, 8 ohms
700 watts RMS continuous, 4 ohms
1100 watts RMS continuous, 2 ohms
0.15 Hz to 175 kHz, -3 dB
50 volts per microsecond
THD and Noise
Less than .015%, 1 kHz, 8 ohms, 20 watts
Less than .045%, 1 kHz, 8 ohms, 100 watts
Less than .06%, 1 kHz, 8 ohms, 200 watts
Greater than 300, 20 Hz to 20 kHz, 8 ohms
Greater than 90, 100 kHz, 8 ohms
50 amps peak, continuous
150 amps peak, 0.1 ohm, 20 msec, 1 kHz
136 mV, 1 watt, 8 ohms
Selectable: 100k, 20k, 600 ohms
19 in. W x 8.75 in. H x 24 in. D
48 cm W x 22 cm H x 61 cm D
Greater than 120, 20 Hz to 20 kHz, 8 ohms
Greater than 80, 100 kHz, 8 ohms