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.
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!

8 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.


    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?

  2. Sorry but anyone can do this voltage conversion in less than 5 minutes, it’s ridiculous you’re charging for this

    1. Hi Chad and thanks for your ‘contribution’..!

      Sadly, your comment illustrates why much great hi-fi gear is damaged or destroyed and why I run this successful, specialist business. I’m guessing you made it from a lack of understanding, rather than mal-intent, which is why I’ve chosen to publish and respond to it. Please be aware though that I run a positive, educational website and comments I deem to be disrespectful or potentially dangerous to other readers will be deleted. I think I’ve blocked one comment in 10 years, so let’s see how we go.

      So, this unit was imported from Japan and needed voltage conversion, a new mains plug, operational testing and an expert report, in case the buyer had any problems. All of this takes time, just removing the covers and carefully inspecting the unit took a lot longer than “5 minutes”! This is a complex, rare and very expensive amplifier, not a bluetooth speaker. My customer didn’t want to take the lid off, he definitely didn’t want to fiddle with transformer taps on his just purchased $5K amplifier. Do you think he has the 1kW variac, multimeters and other test gear needed verify this amp is working correctly or access to the service manual and the ability to interpret it..?

      Reality check needed here. If you want to fiddle with your amp or take 5 minutes to inspect, convert and test a $5k amplifier, go for it. But I see far too much low-quality work and beautiful equipment destroyed by people carelessly fiddling, rushing, thinking they know better. Worse still, there is the potential for death by messing with cheap tools and mains voltages.

      People bring equipment to me because they don’t have the knowledge, skills, tools etc to do the work themselves and they want the best care possible. They don’t want the work done by an armchair expert. Of course I must charge for my time to do a job properly (in this case well over an hour), expertise, parts and equipment. My customer now has piece of mind, a perfectly working unit and the knowledge that his amplifier has been professionally inspected and converted, and he is very happy!

  3. Although it’s fair to say that a real check-up for such an expensive amp will need some time and resources, but despite all the words you needed to make that clear to the contributing fellow Chad, you did not address his statement that a voltage conversion only takes five minutes with this amp especially when there’s a rather user friendly provision for it. My Rowland 7 amp can also easily be converted on the toroid by just relocating a wire from one terminal to another which will cost 10 minutes in total because there’s two of them.
    If you don’t want any criticism on your work Mike you should give your readers not any opportunity to fill in these entryfields. The amount of words you need to brush off this fellow Chad indicates to me that he’s right about the time for the conversion on this P600.

    Cheers mate

    1. Hi Robert, actually I did clearly address the ridiculous 5 minute comment, at length! You perhaps didn’t read or understand that response, however… I addressed the comment at length because it demonstrated such a profound misunderstanding of the nature of professional service work. As is common with such trolling though, he chose not to respond, likely because of my rational, reasoned response. Regarding people commenting, my comments are completely open. I receive virtually 100% polite, respectful comments and questions, from around the world! If you’re open to learning something, by all means ask questions, that’s a nice way to approach things I think. If you think you know better though, this probably isn’t the place for you 🙂

  4. Let it go Mike, there’s no pleasing these people mate. If they want to blow themselves up or risk munting their kit let them at it.


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