Accuphase P-600 Monster Stereo Power Amplifier Voltage Conversion

Holy balls, the Accuphase P-600 Stereo Power Amplifier is one B-I-G mother of an amplifier. It actually gets physically tiring moving these beasts around the workshop!

Anyway, I’m not complaining, I LOVE working on equipment like this, even if it is bloody heavy. The Accuphase P-600 was, as far as I recall, Accuphase’s best class A/B stereo power amplifier back around the early 80’s. There were class A amps which were probably more expensive, and the ridiculous M-100 monophonic power amps, but as far as stereo amps go, this was king of the hill.

The P-600 produces 300 watts per channel into 8 ohms, much more into lower impedances. It weighs 38.5kg and this one even has the optional persimmon wood side panels. It’s superbly well-built, impeccable, typical of Accuphase. The P-600 also has some useful features like cool digital power output meters, stepped attenuators and lots of protection.

This one came in for a voltage conversion. Her owner purchased her from Japan, a location where 100V mains is the norm. Naturally, he wanted her converted to 240V operation. He also wanted an Aussie mains plug added. I was happy to assist.

More details and specs on this monster can be found at the audio-database page for the P-600. I’ve also made a short video looking more closely at the P-600. View it and others, on my YouTube channel.

A look inside the Beast!

Let’s face it, you don’t want to hear me rabbiting on, this is what you’re really here for…

Pretty from the front. People generally either love or hate the Accuphase champagne finish. I’m not a huge fan, but yes, I own some Accuphase. You just deal with it when something performs this well.
With the bottom panel off, you’ll see there’s lots going on. Top right, we have voltage stuff. Middle, we have rectification and filtration. Note the polypropylene film caps snubbing the rectifier diodes, and the big fasteners and buss bars on the filter caps. Below that, there’s a protection relay.
Close-up of the crazy buss bars, high-current fasteners and rectification. Again, note the snubbers, these are a nice touch and undoubtedly add to sound quality of this great amp. It’s the little things that really make a difference, all added together.
Here’s a view from the top. Note the superb layout, lack of wiring, Sanken output devices and large toroidal transformer.
Output
Nice, very nice. MOSFET drivers, high current devices and lots of them, paralleled, but interestingly, I notice a kludge – can anyone see it? The black finned heatsinks in the middle of the board are designed for TO-3 devices, but I can see a couple of pissy TO-220 devices in their place, bolted to what are definitely TO-3 heatsinks! Did they run out the higher powered TO-3 devices? Did they become obsolete mid-production run..? I’m curious.
And yes, it really needs the handles. I had to lug this thing around the Liquid Audio facility, and it was h-e-a-v-y. But look at those stunning persimmon wood side panels – they were 16,000 Yen on their own at the time!
Oh, so pretty, and now able to run on 240V! Let me know if you’d like your unit converted!

2 thoughts on “Accuphase P-600 Monster Stereo Power Amplifier Voltage Conversion”

  1. Hey Mike, yes these were absolutely wonderful machines. On the M100’s…I had the privilege of listening to a pair of M100’s driving Gale GS401’s with a LP12, FR12 tonearm and a FR7 cartridge many years ago in a hifi shop in Freo. Geez the hair on my arms stayed up for a week ….I couldnt afford the amps or the gales, but i still have that same LP12 and tonearm to this day…just couldnt leave the store emptied handed after that experience.

    Cheers
    Mal

    1. Hi Mal, agreed, I also had a pair of M-100’s at my place a few years ago on audition. I was comparing them to my Krell KSA-150, they were beautiful, airy sounding amps. The Krell had a little more oomph though. Glad to hear the LP12 is still going strong! Have you made any progress on the phono pre front?

Thanks for reading, leave a comment and let me know what you think!