The Pioneer SPEC lineup was almost like a victory lap in '76. In the war over wattage, few could touch Pioneer at this time, but none could hold on. This amp is an absolute unit. Massive, clean power, with physically separated signal paths for each channel. Like having two monoblocks in the same chassis. Fully rebuilt, over $1500 worth of parts and labor went into the restoration of this piece, using nothing but the highest quality parts. We don't believe there is a finer example today.
- Production
- 1977-81
- Condition
- 8/10
- Serial No.
- AG2602165M
- Orig. MSRP
- $795
- Restoration
- Over 30 new capacitors
- All electrolytic caps in the signal path replaced with Wima Film caps (ultra audiophile quality)
- Four New 22,000uf 100v Nippon Chemicon computer grade filter caps
- All other electrolytics are Nichicon UPW and UKL series Long life 105°C rated
- DC offset and bias current adjusted and meters adjusted
- RCA jacks cleaned
- All controls cleaned with Deoxit D5 and F5
- Complete clean and detail of faceplate and all knobs
- Each and every screw hand cleaned and painted with gloss black epoxy enamel
- Amplifier chassis polished
- All outer panels professionally stripped and painted with textured paint
- Factory Specs
Type Solid-state amplifier
Power output150 watts per channel into 8Ω (stereo)
Frequency response5Hz to 100kHz
Total harmonic distortion0.01%
Damping factor100
Input sensitivity1V
Signal to noise ratio115dB
Speaker load impedance4Ω to 16Ω
Semiconductors2 x IC, 61 x transistors, 62 x diodes
Dimensions19"W x 7.5"H x 17.5"D
Weight54 lbs.
- Documentation
Pioneer Spec-4 Service Manual
Pioneer SPEC-4 Brochure
- The History of Pioneer
- Pioneer was founded by Nozomu Matsumoto in 1938 in Tokyo as a radio and speaker repair shop. In December 1953 Mr. Nozomu Matsumoto succeeded in developing the first domestic dynamic speaker made of original parts. It was named A-8 and marketed in Japan under the Pioneer brand. It later became the origin of the HiFi ...
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- Liner Notes
The SPEC-4 employs DC construction which excludes capacitors from the NFB circuits and uses a dual transistor differential amplifier with a current mirror circuit in the 1st stage. This provides a stable operation and also high gain over a wide frequency range. The pre-driver stage is a class A circuit with a regulated current circuit for the load. This makes for high gain amplification with superior linearity. Furthermore, there is an overdrive limiter and power limiter circuit which is designed to protect the power transistors and make for added reliability.
- Stock No.
- 7601885610205
The Pioneer SPEC lineup was almost like a victory lap in '76. In the war over wattage, few could touch Pioneer at this time, but none could hold on. This amp is an absolute unit. Massive, clean power, with physically separated signal paths for each channel. Like having two monoblocks in the same chassis. Fully rebuilt, over $1500 worth of parts and labor went into the restoration of this piece, using nothing but the highest quality parts. We don't believe there is a finer example today.
