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Rare Plinius Model 10 Amplifiers Restored!

3 Comments / Amplifiers, Restoration & Overhaul / By / / amplifier repair perth, plinius, Plinius Model 10, power amplifier
Contents:

Join me as I discuss the restoration of this pair of beautiful Plinius Model 10 power amplifiers.

Welcome back, folks, and I hope you are doing well! I always planned on writing this article about this pair of absolutely stunning Plinius Model 10 power amplifiers, back in 2019 when I completed the work, but you know how it is: you’re busy, you keep working, and eventually you forget to do some of the things you wanted to do.

There are so many more like this, but trust me when I tell you that all of them take a ton of time to put together – the best part of a day in cases like this one. The older they get, the harder they are to put together too, and I have so many: Bryston, Krell, Simaudio, Kenwood, Pioneer, Accuphase, Stax…

Anyway, this article became topical for me this week because I have some exciting news. Plinius, a great manufacturer of serious hi-fi equipment like the lovely old Model 10 power amplifiers you will read about here, reached out and asked if I’d like to become their official repairer in Western Australia.

Now, I’ve worked with Plinius before, repaired various Plinius models, and always enjoyed the equipment and the relationship we’ve developed. Nothing has ever been too much trouble for the guys in Christchurch, NZ, and that’s exactly what you want when dealing with a manufacturer of complex hi-fi electronics.

Despite declining some other official partnership offers, I’ve worked closely with a select few manufacturers and importers, including Krell and Musical Fidelity. This relationship with Plinius is another excellent fit for Liquid Audio, and I hope for Plinius, so I gladly accepted.

Nothing will change here; that’s the beauty of working with a company like Plinius. I’m still completely independent, but I’ll hopefully be able to assist a few more Plinius customers. There’s more on my News page, but basically, this news prompted me to gather and edit the images and clips from June 2019 and create this article and accompanying video about the Plinius Model 10 power amplifiers for you. I hope you enjoy them!

Here is the video about this pair of monster power amplifiers:

Background

Plinius has been manufacturing serious high-end hi-fi equipment in New Zealand for a long time, since 1980 in fact. This is similar to Perreaux, another favourite NZ company of mine. Many Kiwis, Aussies and folks around the world will be familiar with newer Plinius products like the beautiful Plinius M-16 preamplifier I repaired in 2025. Not many will have seen these monster Plinius Model 10 power amplifiers from around 1985, though.

You can read more about the Plinius Model 10 power amplifier in this brochure:

Plinius_Model_10_monoblockDownload

Given that it was 7 years ago, I can’t recall many of the details, but the owner of this pair of Model 10s had seen plenty of my work, and I distinctly recall wanted me to overhaul and restore his power amplifiers. He reached out, and we had a chat about the work. I then spoke with Plinius in NZ, and things went from there.

I recall there might have been a matching Plinius preamplifier and a Sony CD player. I definitely do remember that this customer still has a test CD I left in the CD player by mistake, so Craig, if you are reading this and have that disc, I’d love to have it back!

Plinius Model 10 Specifications

Courtesy of Plinius, compiled by Liquid Mike

Power: 200 Watts minimum, into 8 Ohms, per unit

Distortion: 0.1% THD

Frequency response: 1Hz – 150kHz, -3dB

Signal-to-noise ratio: -90dB

Current capability: 80 Amps (no time frame specified, but I believe it)

Input impedance: 47kOhms (nice, easy load)

Size: 435mm (W) x 450mm (D) x 200mm (H)

Weight: Approx 30kg

Colour: 2001 black!

Issues

This pair of Plinius Model 10 power amplifiers needed recommissioning and some remedial/overhaul work involving both chassis and electronics. One of the pair had received a new transformer at some point, and that wiring needed attention. Both lids needed to be taken back to bare metal and re-powder coated; both units needed new rubber feet, some new capacitors, board rework, cleaning, adjustment, etc.

Plinius in NZ was very helpful and amazed that I had this pair here for overhaul, but unfortunately, they were unable to locate any service data for me. This was no problem, and the reality is that things get lost over time, 40 years in this case. Luxman famously lost just about everything from a certain very important period!

Let’s get into the nitty-gritty!

Plinius Model 10
As you can see, these Plinius Model 10 power amplifiers needed a little TLC, and I was still working inside at this point.

Restoration

Diving in, my first job was a thourough visual inspection and check of wiring, parts, connections, fasteners, etc.

Plinius Model 10
The fascias of these two are dirty, and that’s just the beginning…
Plinius Model 10
With the lid off unit #1, we see the large original transformer, heavy gold-plated bus bars, three pairs of output devices and robust rail filtering, with each rail sporting three 27,000uF filter capacitors, two premium quality bypass film capacitors and one bleeder resistor. That’s 162,000uF of energy-storing capacitors per amplifier, a scary amount. Those bleeders are critically important here.
Plinius Model 10
Here is unit #2, and you’ll note it looks slightly different. The main change is obviously the transformer, which has been replaced at some point. Because of that, some of the associated wiring and grounding need a little attention. I can’t recall, but I must have removed the transformer mount here for some reason.
Plinius Model 10
The casework is a little bit worse for wear, visible here in my images taken at the powder coater’s.
Plinius Model 10
Gnarly…
Plinius Model 10
This is bad, but it will look like new once re-powder-coated.
Plinius Model 10
Err brother, errrr….
Plinius Model 10
And so these lids sit at the power coaters awaiting their magic work. My time to deliver and collect these things is built into the invoicing, of course, as it has to be. While the powder coaters had these though, I got on with other things…
Plinius Model 10
Here is a little of that non-factory, hokey wiring that we can’t leave looking like this.
Plinius Model 10
So here, I’m getting stuck in resolving whatever I find that needs attention, including the soft-start board on the right and the driver board on the left.
Plinius Model 10
Not happy with this, let’s resolve it.
Plinius Model 10
Part of that requires us to expose bare chassis metal so that we can make a secure ground connection.
Plinius Model 10
With a shakeproof star washer, lugs and bolted connection, like this.
Plinius Model 10
I believe this is my grounding arrangement in the second amplifier, but I can’t recall; it could just be another shot of the work I did above. My apologies, it’s been too long!
Plinius Model 10
Here I’m tidying up the soft start board. This board is needed because of the ultra-low impedance and therefore massive inrush current spike of the power supply, and its 6 large filter capacitors per amplifier. The soft start board allows the amplifier to initially draw a lower amount of current over a longer time, making things much easier on capacitors, diodes and switches. That’s also why Perreaux introduced them later to the PMF-5150, for example. You can think of inrush current like acceleration – the gentler it is, the less wear and tear on the car, motorcycle, human, etc.
Plinius Model 10
Here, I’ve refurbed the all-important driver board. Only two electrolytic capacitors need to be replaced. I’ve used some premium axial and radial electrolytics, as per the original design, but of only better quality. Everything else measured well, and no need for silly multi-turn trimmers here for what is a low-precision, drifty bias trim potentiometer and circuit. DC symmetry is handled by accurately matched differential transistor pairs.
Plinius Model 10
It’s worth noting that when drive circuitry is connected via a multi-pin connector like this, connector integrity and cleanliness are of paramount importance. I carefully cleaned and treated these and the females they connect with.
Plinius Model 10
I also fitted these new heavy-duty rubber feet to the amplifiers.

A few of you will be wondering: Mike, Mike, how did the lids turn out..?! Let me show you.

Plinius Model 10
Wow, these looked absolutely fantastic.
Plinius Model 10
I could not have been happier with the way the lids came back from the powder coaters.
Plinius Model 10
They were literally flawless.
Plinius Model 10
Just a little bit more to do here on these Stax speaker terminal connectors. They need cleaning and lubrication. Mike, can you really lubricate plastic..? Yep, you can.
Plinius Model 10
Lovely, but filthy…
Plinius Model 10
And this is what they looked like after a little TLC. That toggle switch is a mute actuator.

And here is what the amplifiers looked like after a little TLC:

Plinius Model 10
That’s Plinius Model 10 number 1…
Plinius Model 10
And that’s Plinius Model 10 number 2. Note that I re-tightened and torqued every single fastener in each chassis, and many were loose at this age. That detail is important because many of those connections are conductive and must be tight. Naturally, everything else has been cleaned, checked, and I had also re-biased the amplifiers at this point, too. I don’t seem to have images of this, but I’ll add them if I find them.

Time to put their lids back on:

Plinius Model 10
Amplifier number 1
Plinius Model 10
And number 2.

Amplifier number 1 is prettier, so lets take a closer look at her:

Plinius Model 10
Here, the Plinius Model 10 is ready for final reassembly.
Plinius Model 10
A detail shot, because I know my readers love such things!
Plinius Model 10
Beautiful power supply rail details, including bypass caps and bleeder. Super-neat construction.
Plinius Model 10
After going to all this trouble, there was no way I was reusing the old fasteners, so I purchased a new set from my local fastener supplier.
Plinius Model 10
Not one of my greatest images, but you get the idea.
Plinius Model 10
And last, but not least, these cork dampening tiles had to be removed from the lids before powder coating, so here I’ve used a contact adhesive to bond them back together!
Plinius Model 10
Let’s go, baby!

Results

I think you’ll agree with the owner that this was quite a transformation for this lovely old pair of Plinius Model 10 power amplifiers. I recall that, like me, he was very pleased with the results and just thrilled to have them looking lovely and running nicely again, after somewhat of a troubled history.

Plinius Model 10
What an incredible improvement!

Trying to replace something like these two babies is not easy, both in terms of performance, and collectibility/vintage cool. I’d hate to think what a pair of really good 200 Watt NZ-made monoblocks like this would set you back now, but you know what – we’re going to find out, because I’m about to work on a pair of Plinius RA-150 power amplifiers, so stay tuned for that!

Plinius Model 10
I like this view, which shows how much the refinished covers improve these two.

The bottom line here is that equipment like this is almost always worth maintaining and repairing. All amplifiers need periodic care and maintenance, so try not to skip that stuff, as mundane as it might seem. Good, careful inspection and adjustment can often catch issues before they become serious. That’s basically what happened here.

Plinius Model 10
A few beauty shots are needed to convey the monolithic presence of these, at the time, flagship power amplifiers from Plinius.
Plinius Model 10
Rear shot showing the simple layout and heavy duty power cables.
Plinius Model 10
The front panels could be refinished, but that would mean messing with the lettering, and so I left that part alone. Other than a little scuffing, they are in remarkably good condition.
Plinius Model 10
All in all, an excellent result I reckon!

Thank You!

As always, thank you for visiting, thanks again to my customer Craig, and to Plinius for supporting my business and having trust in my work. I hope you enjoyed reading about another classic and very rare power amplifier. If you’d like me to look at your Plinius Model 10 or any other high-performance power amplifier, don’t hesitate to get in touch.

It’s hard to explain how much work goes into these articles, but if you can imagine writing a 2000 – 3000-word essay with 50 or so images that you took and edited, and then editing together a 20-minute video, all from scratch with no help, every week or two, you’ll get the idea!

You can support me and my efforts to spread the word about beautiful hi-fi equipment and keep it alive by engaging our services, commenting, liking, sharing, subscribing, spreading the word and donating, using the button in the footer. I sincerely thank you for it, and there is a list of recent donors in the sidebar/footer.

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3 thoughts on “Rare Plinius Model 10 Amplifiers Restored!”

  1. Tony O'Brien

    Your a genius Mike. And unique – not just in it for a dollar like most people. You really care – even sometimes a little too much! Don’t change.

    Reply

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