Audio Research SD135 solid state Amplifier. one of the best sounding solid state amps ARC ever made! This amplifier has had an important reliability modification done to it that keeps the sonic character but improves stability and long term reliability. for you tech types, PM me and I will be happy to discuss at length the mod. In Short, Onsemi the manufacturer of the output transistors came out for a short time with a version of a transistor that had an internal temperature sensing device that controls the amps Bias. that temperature sensing device fails and when it does the amp looses control of the bias and the amp fails. I have designed and installed a circuit modification based on what most class A/AB amplifiers use that adds an external temp sensing/bias circuit, but keeps the functional part of the output transistors working, but adds a new temp sensor for bias control. this keeps the sonic character of the amp as it is literally the same parts just with a more conventional bias control method. makes the amplifier far more reliable over the stock design. Power output130 watts per channel into 8 ohms from 20Hz to 20kHz. 230 watts per channel into 4 ohms.Power bandwidth(-3dB points) 2Hz to 200 kHzFrequency response(-3dB points at 1 watt) 0.4Hz to 300 kHzInput sensitivity3.2V RMS BAL for rated output. (20 dB Bal gain into 8 ohms)Input impedance300K ohms Balanced, 150k ohms SEOutput taps-Output regulationApproximately 0.05dB 8 ohm load to open circuitOverall negative feedback7dBDamping factorApproximately 170 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 channels 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.

This AR SDP1 is in fantastic working and cosmetic condition. There are no known issues with this piece. Ships fast and well packed via FedEx.

Original Audio Research D-100 Gehäuse, Netzteil und Elkos mit neuer Endstufe ClassD Audio CDA-250 aus USA. Guter Zustand, 220/240Volt Gerät. Klanglich sehr gut: Offen, basskompetent und schnell. Feine Auflösung. Technik: 2x125W an 4 Ohm (RMS) 2x250W an 8 Ohm (RMS) Eingangsempfindlichkeit: 2V Eingangsimpedanz: 10kOhm THD: 0,003% 10Hz-35kHz User Bewertungen des Moduls: 7x 5stars***** Audio Nirvana sounds very very good...outstanding With Dynaudio speakers this amp bettered in dynamic, transparency and slam even heavy expensive ClassA poweramps. It is a true bargain in high-end amps

Unit only

No shipping. Local pickup only in San Diego, California. Amp in excellent working condition. Light cosmetic wear. Note: pickup must be within ten days of payment. Details: Power output: 200 watts per channel into 8? (stereo) Frequency response: 5Hz to 55kHz Total harmonic distortion: 1% Damping factor: 167 Input sensitivity: 930mV (line) Signal to noise ratio: 94dB (line) *************Thanks for looking!

Follow us| Sign up for our newsletter Synergistic Research HFT - 6 Gray 4 Black - Audiophile High Frequency Transducer For over 22 years HEAA has been selling the finest HiFi online, but did you know that we BUY your HiFi equipment as well? Contact our sister company STEREOBUYERS for a fair quote today!FREE SHIPPING in USA! Local Pickup in NYC Available All of the pre-owned items that we sell are thoroughly inspected and tested both on our test bench and in our listening room. Your satisfaction is guaranteed. Synergistic Research High Frequency Transducers Cosmetic Condition:9/10: Excellent - light use, no visible imperfections Cosmetic Notes:Like new condition. Please see all high resolution photographs below. Functional Notes:Functions as intended - 6 Gray - 4 BlackOriginal Box:NoManual:NoShipping Method:FedEx Ground (Domestic) / FedEx Economy, Ebay Standard Delivery (International)Shipping Weight (lbs):1 (8x6x2) High-End Audio Auctions has been THE trusted source for high-end, classic and vintage audio components on eBay since 2000! Our unique products, unparalleled service and bombproof packaging keeps our customers coming back again and again. We are experts at selling and shipping worldwide, with items ranging from $5 to $50,000. We look forward to earning your repeat business! By placing a bid on any of our listings, you agree to our terms & conditions Click here to learn more Home| About Us| Store Policies| FAQs| Feedback| Contact Us| Custom Tuned Cables _gsrx_vers_1436 (GS 9.0.5 (1436))