Krell KSA-200S Class-A Amplifier Repair and Restoration

Krell KSA-200S Class-A Amplifier Repair and Restoration

I am about to embark on a Krell KSA-200S Class-A Amplifier Repair and Restoration, in this case for a very good friend of mine.   

As many of you will know, the Krell KSA-200S is a beast of an amplifier, up there with the very best products Krell ever made. It is almost unliftable by one person, being hewn from solid slabs of steel and aluminium. Consider for a moment that this nominally 200 watts per channel amplifier contains a 2,000VA mains transformer and weighs the best part of 50kg! You really get a sense of the term ‘overbuilt’ and the way that Krell approached the engineering of their amplifiers in the 80’s and 90’s, when you look at and try to move one of these monsters.

If you would like to read a little more, take a look at the excellent Stereophile article written on the beast, back in the day. A few specs might be helpful:

Description: solid-state stereo power amplifier with “Sustained Plateau” output-stage biasing. Power output: 200Wpc into 8 ohms, 400Wpc into 4 ohms, 800Wpc into 2 ohms, 1600Wpc into 1 ohm, one channel driven (all power outputs equivalent to 23dBW). Damping factor: 80. THD: 0.1% at 1kHz, 0.2–0.5% at 20kHz, at full power.
Dimensions: 19″ W by 8.5″ H by 21″ D.
Price: $7500 (1994); no longer available (2007). Approximate number of dealers: 55. Warranty: 5 years parts and labor, limited transferable.
Manufacturer: Krell Industries, 45 Connair Drive, Orange, CT 06477.

More on this KSA-200S project as it happens! For now though, some images to whet the appetite…

 

Krell KSA-200S
Krell KSA-200S  Krell KSA-200S

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 5 Comments

  1. Eugene

    Hi Mike,
    I’m also about to start the same exercise.. have you managed to find a service manual for this amp?

    1. Mike

      Hi Eugene, I do have it but am not permitted to release it. Try contacting Krell and see what they say about the availability of the SM. I think they may give you a copy. Cheers, Mike

  2. Tony

    Hello,

    Would you know how to adjust the DC Offset for the Krell Power Amps (MDA 300)?

    Thank you!
    Tony

    1. Mike

      Hi Tony, it’s usually straightforward on Krell amps, just a trimmer for servo adjustment of each channel. I would need a service manual or actual amp in front of me though to provide detail on MDA300. If unsure or you don’t have precision test gear, definitely do not adjust anything!

  3. Paul

    Could be time Fitz…Lets rebuild this beast!

Feel free to leave a comment, technical questions should be asked via our Contact page