Hitachi SR-904 Dynaharmony Stereo Receiver - Serviced/Works. 75 WPC Class G Amp

Description: This listing is for a Hitachi SR-904 Dynaharmony (Class G) AM/FM Stereo Receiver in very good cosmetic and functional condition. It is rated at 75 WPC @ 8 Ω with ≤0.09% THD. A more detailed list of specs is included at the bottom of this listing. Hitachi was one of the largest manufacturers and suppliers of Japanese made stereo components to many of the most respected brands in the 1960s-70s. In the late ‘70s the stereo wars caused manufactures to push the watts per channel to ever higher power levels. The SR-904 offered here is rated an “old school” 75 WPC at 8 ohms and was a newly developed Class G amplifier that instantly doubles its rated power to 150 WPC to avoid clipping distortion during demanding musical peaks. The SR-904’s big brother (Hitachi SR-2004) is still rated as one of the top 10 most powerful receivers of the era at 200 watts/channel (just below the Sansui G-22000 but one notch above the Marantz 2385). This unit was built in 1978 in Japan, and is of comparable build quality to other Japan built units of that era (Pioneer, Marantz, Sansui etc.) It offers a Phono input, AUX input and 2 Tape IN/OUT jacks as well as “adaptor” in/out rear panel jacks that provide an easy way to add an EQ or other sound processor with a front panel on/off switch. The unit also has twin VU meters showing output level provided to the R & L channels. The Tuner has both Signal Strength and FM Centering meters and an Auto Lock feature. A copy of a Product Intro piece for the smaller SR-804 details the Class G function as well as a copy of the SR-904 Service Manual will be included. The following outline covers the testing/service work done: · All speaker connections have been tested and are working, both right and left channels. · Headphone jack was tested and is working. · AM/FM radio stations were received as expected across the radio dial using only a basic wire antenna. Reception and meter function is greatly enhanced with an antenna attached. · Tape 1/Tape 2 inputs and outputs were tested and function as expected. · Both Aux and Phono inputs were tested and are working. · All Switches and Potentiometers were flushed with contact cleaner, followed by treatment with the appropriate Deox-It formula. · All Source function lamps (AM/FM/Phono/Aux) were working at time of testing – see pictures. · The Protection/Stereo/Auto Lock lamps were working at time of testing – see pictures · The faceplate, dial scale and all knobs were removed, cleaned and hand polished. · VU Meter and Radio Tuning lamps were replaced with Emerald Green LED lamps. · Cleaning on all exterior surfaces was done to improve appearance. · The power cord was inspected and cleaned. · Any missing top cabinet or bottom plate screws were replaced. · All feet were inspected and replaced as needed. · DC Offset and Idle Current adjustments were set to factory specification. · Watts/channel was checked using a Peak and RMS Output Meter to meet/exceed model specs. · A final extended use test was performed to ensure functionality. This listing describes the item to the best of our ability. Like all units of this era, they have some marks and other signs of wear. The most notable are highlighted in the last three pictures. Many high-resolution pictures are included, and should be considered part of the description to help you decide if the unit meets your requirements. All items are sold with the assurance that they will arrive and power on - we do not warrant them beyond that. Feel free to ask questions – we will do our best to answer them promptly. We have bought and sold many vintage stereo items and understand what it takes to package them for safe transit. Even with the most careful packaging, damage is still possible. All items are listed for Free Local Pick-up in Omaha, NE. Whenever possible, we encourage you to do so, as even the most carefully packaged items can still be damaged in shipping. Once the item leaves our possession, we have no control over how it is handled. The unit will be shipped fully insured with signature required on delivery. This listing is for shipment to the Continental USA only. Hitachi SR-904 – Specifications From HI-FI Engine: Tuning range: FM, MW Power output: 75 watts per channel into 8Ω (stereo) Frequency response: 8Hz to 40kHz Total harmonic distortion: 0.09% Damping factor: 45 Input sensitivity: 2.5mV (MM), 500mV (DIN), 200mV (line) Signal to noise ratio: 75dB (MM), 87dB (DIN), 87dB (line) Output: 200mV (line), 50mV (DIN) Semiconductors: 4 x IC, 1 x FET, 69 x transistors, 90 x diodes, 1 x thyristor Dimensions: 490 x 144 x 400mm Weight: 13.5kg Year: 1978

Price: 729 USD

Location: Omaha, Nebraska

End Time: 2025-01-16T17:07:51.000Z

Shipping Cost: 75 USD