Marantz PM-8 Integrated Amplifier Repair & Restoration

I’ve been very busy repairing and restoring this stunning Marantz PM-8 integrated amplifier.

The Marantz PM-8 integrated amplifier is one of very the amplifiers from the golden era of serious hi-fi equipment. These amplifiers are monsters, massively powerful and massively heavy. They are also massively complex to work on and this one had a massive fault!

Specifications

Power output: 150 watts per channel into 8Ω (stereo)
Frequency response: 5Hz to 100kHz
Total harmonic distortion: 0.01%
Damping factor: 100
Input sensitivity: 0.2mV (MC), 2mV (MM), 150mV (line)
Output: 150mV (line)
Speaker load impedance: 4Ω (minimum)
Dimensions: 416 x 146 x 437mm

More photos and details of the Marantz PM-8 restoration soon. You can find my article about the exploded filter capacitors, here! In the meantime, here’s a video summary of the testing and setup of bias, DC offset and power supply voltage.

Liquid Mike

At 10 I was pulling apart electronics and by 13 I'd have Dad's hi-fi in pieces when my parents went out! Later, I started Liquid Audio, a specialist electronics repairer known for detail-focused service, repair and restoration of hi-fi electronics & turntables. Keeping classic hi-fi gear alive and well is what we do. Our mission: to deliver TLC for classic Japanese, American and European hi-fi stereo equipment. In my spare time, I ride motorcycles, travel, listen to music and research interesting topics.

This Post Has 4 Comments

  1. Quadklipsh

    Thanks for the response.
    Since process of restoration is quite laborious and then sometimes we are NOT truly satisfied with the performance, it would be nice to know a few superior models ….can you numerate some other amps that can be had for near a 1000 dollars (used) that would easily out perform a pm8.

    Also How please guide about the following ?

    Accuphase E 205
    Soulnote 710
    Adcom 555 mkII
    Luxman L550x.
    Sansui AUX 111 mos vintage .
    Quad 303
    Kenwood Supreme 600

    Thanks.

    1. Liquid Mike

      No problem, unfortunately I don’t have the time to provide a guide of the type you are looking for here and prices vary according to region. My whole site is devoted to this sort of thing though so have a good look around and try to have a listen to these units where possible. They all sound different and have various strengths and weaknesses. Every amplifier of this age will need overhaul, so this should be factored in to any purchase decision. I’m sure you’ll enjoy the PM-8 anyway!

  2. Quadklipsh

    Im going to be the next proud owner of a pm8 mkII. I would like to know how you rate its sound quality next to some of the best in the market.

    1. Liquid Mike

      Hi and well done on acquiring a PM-8. These are excellent integrated amplifiers and potentially sound very nice. How good they sound depends largely on state of service and whether they have been properly overhauled at this age. There are better sounding integrated amps out there but you’d have to go to something like an Accuphase to take that next step. Enjoy!

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