An interview with Gary Morrison of Plinius

Talking with the designer of Plinius

by Michael Jones

January 2004

You may be unfamiliar with the name Gary Morrison, but you will be familiar with the amplifiers he designs. Since joining forces with Peter Thomson in 1987, Gary has been the main force behind the design of Plinius amplifiers. Before that, Gary designed and built the well received Craft Audio range of amplifiers (see our 1987 review of the classic C3/C4 amplifiers).

Talking to Gary in his Wellington home, I began by asking him to describe his role in Plinius.

Gary Morrison: I'm the technical director, which means that I'm responsible for anything technical associated with Plinius Audio development. That doesn't mean to say that I do all of the technical work, but it's my responsibility to make sure that it happens.

I'll give you a breakdown of the process when we decide to produce a new product. The first thing is that we would decide that we needed a particular product for a particular market, which is usually something that comes back from our distributors. That's how the Odeon, for example, was conceived.

We'd talk about the product, how it would fit into the market, how we would make it, what functions and features it would have.

As the technical director I'm involved in making sure that the appropriate technical elements are completed, and for me that generally means I will do the electronic design of the power supply and analogue sections, amplification circuitry etc. Scott Hunter, who is our tech responsible primarily for production test engineering, has skills with microprocessors, so he does all the microprocessing software and remote controls.

In essence, my job is to make sure all of that comes together, so that the technical side of the product is complete and makes the original brief.

AudioEnz: How did you get started with amplifier design?

Gary Morrison: From when I was at primary school I listened to radio "pop music programs". (That was before we had TV even!) That was my motivation - I really liked music, particularly rock music. I wanted to make something through which I could listen to that music.

Before I left school I built an amplifier and I really didn't have the slightest idea of what I was doing. I bought a hobby magazine and made a "bird's nest" based on what the magazine article said. It sort of worked...

As I got a little older I built a few of Linsley Hood's 75 Watt amplifiers and began to figure things out.

I was working for AWA at Porirua on VHF communications and did an NZCE while I was working for them. I spent all of my lunch hours working on my own audio projects at my bench. I did quite a few projects there and after hours.

Gary Morrison's first amplifiers: the CA1 power amplifier (below) and the CA2 preamplifier

Eventually I realised that the only way I was going to be able to work in audio was to do it myself. So in 1980 I took the plunge, left AWA and started Craft Audio Limited.

At that stage I had designs in my head that I wanted to use. That became the first Craft product - the CA1 power amplifier.

There was subjective evaluation involved in the design - it had to satisfy my ear, but back then I was still pretty new to audio design and I think I was lucky that I managed to produce a design that people told me sounded okay. John Button, at Wellington Audio & Records, was probably the   person who confirmed the sonic qualities of the product I was producing.

AudioEnz: How did you and Peter Thomson join forces?

Peter Thomson and Gary Morrison of Plinius

Gary Morrison: At that time Plinius and Craft Audio were competitors in the amplifier market. We were coming up against each other in retail stores occasionally. It was probably the end of 1986 or early 1987 when Pete rang. He said that I had some skills in designing products and he had the manufacturing facility. What about putting our skills together?

It was a good idea. We took the strengths of both businesses and made them one.

AudioEnz: The SA250 power amp is now in a mark four version. What's your process in trying to improve an existing product.

Gary Morrison: Its an evolutionary process. Every product we are making now has some element of what we were making ten years ago   in it. The new era of Plinius designs started with the SA50, around 1993. You'll find a common thread through all of the power amplifiers developed since then.

We developed the SA50 and the SA100 along side that, which grew into the SA102. We have the SA250 which grew out of the SA100 - it's basically a big version of that product.

My understanding of an audio circuit evolves so that my   perspective on it gradually changes, and I realise that there are things that could be done differently.

To produce a new product we take what we know and look at how we could make it better. Are there ways that the output stage could perform a little better? Is the voltage amplifier stage optimal? It's a very organic process.

With the SA250, we had a series of incremental changes. Each change was small but we felt each had some sonic value. We realise though that it is possibly confusing in the market to have too many "mark" versions of a product and it may create dissatisfaction among customers.

On the other hand when you go from an SA100 to an SA102, or from the 8200 to the 9200, you're looking at a culmination of thought that has come together to be a more substantial change to the product. But it's still an organic process of change.

AudioEnz: What's behind the development of the Odeon power amp?

Outside and inside the Plinius Odeon

Gary Morrison: We had a market niche identified - we needed to produce a multi-channel power amplifier for the home theatre market. Fundamentally it was for the USA. We knew we had to put at least six channels into the box. The US market likes as much power as you can give them, but realistically we had to be sensible and do what was able to be done within the size constraints. The Odeon is large, but for each module we are constricted in space and heat dissipation. So it ended up being 200 watts per module into eight ohms.

In essence we took a single channel of an SA102 and put that into a module board. Then there were additional refinements to it, which could only be realised when you have a modular design. Each individual card has onboard regulation.

The power supply had to be designed differently because it had to serve the needs of six channels. For the Odeon, we developed a very big, very low impedance power supply shared across six channels. The Odeon has a more substantial, much lower impedance power supply than any other Plinius product has ever had.

We knew we had created an amplifier that sounded good, but we were surprised at the degree of enthusiasm with which it was greeted.

At the time we did the Odeon, we also decided that we needed to add to our product appeal by bringing in some professional product design. The Odeon was the first product to demonstrate that.

Our industrial designer Ross Stevens came through with the concept for the Odeon. In the initial presentation he gave to us he included a mock up of the Odeon and a variety of other cases, all in the same sort of look. We decided to do the Odeon in this style and follow up by releasing other products   as seemed fit.

With the recent M8 and P8 we were specifically looking to define those two products as entry level separates. The M8 preamplifier draws on some of the power supply understanding that we got from the Odeon and the P8 amplifier really embodies, in two channels, what we've done with the Odeon. The P8 draws on the Odeon development in that it has individual power supply regulation on each channel, and also includes some further development in the output stage. But built to its price point - you can't ever get away from that.

AudioEnz: What do you see in the future for both Plinius and the hi-fi market?

Gary Morrison: Obviously we have products in development and that we are considering developing, but I simply can't tell you about them.

In terms of the general audio market, there's absolutely no doubt that home theatre and multichannel are something that every manufacturer has to embrace. When I talk to retailers, it's obvious that this is an important part of the market that they are selling to. We want to be part of that market so we have to develop products that integrate with it or serve all of the needs of that market.

The Odeon is obviously aimed squarely at that market. Realistically, we need to be looking at the upper end of that market, because we're a specialist manufacturer and it costs money to do what we do. It's very hard to produce inexpensive value for money products without losing our edge. And then what happens with the various disc formats? When that settles down it will give us some further direction because there's pressure on us to produce a disc player - our retailers would love to have a Plinius CD player alongside the amplifiers.