Audio Research SD 135 High Definition / überholt & Service f. 500€

Audiophile Transistor Endstufe mit Kontrolle und leicht "röhrigem" Klangbild. 2x130/240W an 8/4 Ohm. Cinch/RCA & XLR Eingang. Wurde in 2022 vom Vorbesitzer für 500€ überholen lassen. 6 Monate Garantie. Inklusive Manual & Schaltplan/Scematic als Kopie. Europäisches 220/240Volt Gerät. NP ca. 5.000€.

Das sagt Audio Research:

""" The SD135 is an entirely new amplifier for Audio Research involving a new mix of discrete devices within the framework of a pure analog, solid-state design.

Like the larger HD220, the new SD135 ("SD" for "Silicon Drive") uses Thermal Trak® self-biasing output devices in a Class A-B design. And like the HD220, it accommodates either single-ended or balanced inputs. But unlike the larger hybrid, the SD135 features an all-solid-state input stage using multiple JFET devices in each channel, directly driving the output stage – no interstage coupling capacitors needed. Because expensive coupling capacitors and high voltage regulated supplies required in tube circuits can be omitted, the SD135 is within reach of many more music-lovers.

The SD135 is an amplifier with amazingly fast response time, explosive dynamics and plenty of current delivery for a wide range of speaker types including difficult, low impedance models. Frequency response is an amazing 0.4Hz to 300kHz! Bass is deep, controlled and quick to the punch. The noise floor of the SD135 is extremely low, rendering micro-dynamics and subtle sonic nuances with vivid clarity against a black background. Its presentation is transparent, detailed, and grainless – no listener fatigue here. Pair it with an Audio Research preamp and you will hear an immense soundstage in a highly refined and purely musical presentation.

Reassuringly, the SD135 features protection circuitry that is sonically invisible. If there is DC at its inputs, or if its outputs are shorted, the SD135 will go into protect mode, muting the output and protecting your valuable loudspeakers.

A low-speed (and quiet) 12V D.C. fan cools each channel's internal heat sinks, helping to insure long, trouble-free life. The detachable power cord is a high quality IEC-type rated for 20 amps. The anodized front-panel is available with a natural or a black finish. Front panel handles are included but may be easily removed if the installation demands it.

The SD135 provides the Audio Research hallmarks of high definition® and musicality in a compact, affordable package that will simply eclipse the competition. You must audition the SD135 for yourself to hear the latest evolutionary step in solid-state technology."""

Technik:

Specifications
POWER OUTPUT: 130 watts per channel into 8 ohms from
20Hz to 20kHz. 230 watts per channel into 4 ohms.
POWER BANDWIDTH: (-3dB points) 2Hz to 200kHz.
FREQUENCY RESPONSE: (-3dB points at 1 watt)
0.4Hz to 300kHz.
INPUT SENSITIVITY: 3.2V RMS BAL for
rated output. (20 dB Bal gain into 8 ohms.)
INPUT IMPEDANCE: 300K ohms Balanced, 150k ohms SE.
OUTPUT POLARITY: Non-inverting. Balanced input pin 2+
(IEC-268).
OUTPUT REGULATION: Approximately 0.05dB 8 ohm load
to open circuit (Damping factor approximately170).
OUTPUT CURRENT: 60 Amps peak (1 millisecond)
OVERALL NEGATIVE FEEDBACK: 7dB.
SLEW RATE: 50 volts/microsecond.
RISE TIME: 1.0 microseconds.
HUM & NOISE: Less than 0.05.1mV RMS – 116dB below
rated output (IHF weighted, input shorted).
POWER SUPPLY CAPACITANCE: 96,000 uF.
POWER REQUIREMENTS: 210-250VAC
50Hz) 500 watts at rated output (130 WPC 8 ohms) 600 watts
max, 150 watts idle.
DIMENSIONS : 19" (48.3 cm) W x 6.25" (15.9 cm) H x 15"
(38.1 cm) D. Handles extend 1.5" (3.8 cm) forward.
WEIGHT: 42.8 lbs. (19.5 kg) Net; 55.3 lbs. ( 25.2 kg ) Shipping.