Plinius SA-Reference Stereo Amplifier

by Keijo Tanskanen


A very trusted look!


Peter Thomson is a Plinius visionary who, out of his love of music and his interest in the design and engineering of audiophile amplifiers, began working on his own products in 1979. Finally Plinius Audio Systems Limited was formed in 1980. Through the years Peter’s audiophile enthusiasm is at the very heart of the Plinius development story, but passion needs technology as well. That's where Gary Morrison comes in as a Technical Director. He joined Peter Thomson in 1987 with the formation of Audible Technologies Limited. This merger allowed Gary Morrison to fully immerse himself in the design process. The development of the Plinius amplifier range has produced a close working relationship between the two and increasing critical acclaim and acceptance of the results of their business collaboration. Design Director Ross Stevens was then added to the mix and the Plinius specialties was ready to go.
In Finland Plinius is a new audio brand. Soundworks began to import Plinius products lately and noticed that there is surprisingly lot of interested enthusiasts, especially for the Plinius SA-Reference stereo and mono amps. Soon they sold couple of amps which was very honorable even world widely. After having my own experiences of the SA-Reference I don’t wonder the success at all!


The SA-Reference amp is a reference product for Plinius and it is based on champion asymmetric technology. By the help of the redesigned output stage construction a high frequency performance is said to be improved remarkably. Along with a premium component selection and other refinements the new Plinius reference for audio technology had been created.

The Plinius SA-Reference has been designed specifically to work as a balanced monoblock or as a stereo amp. It has a possibility to choose Class A or Class A/B operation mode. The Class A operation delivers 100 W per channel instead of A/B’s 300 W per channel.

All Plinius SA-Reference amplifiers are hand made and each has an individual built number engraved into the front panel. The overall look is quite stunning and willing at the same time!

For more information:

Test setups

I tested the Plinius SA-Reference amp in two different systems and rooms. I think this diminished the system dependency of the evaluation greatly. By the help of this I believe the nature of the amp had been clearly found during the test.

My listening room is approximately 25 square meters and has plenty of acoustic treatment. My friend’s listening room is over 50 square meters including acoustic treatment as well.

My reference system:

• CD player: Audio Aero Capitole Mk II SE on the Acapella Fondato Silenzio. Shakti stones were used as well.
• Amplifier: Audionet AMP II Max monoblocks
• Speakers: Wilson Watt/Puppy 7
• Interconnects: Transparent Reference MM (MM tech) unbalanced cables
• Speaker cables: Transparent Reference XL (MM tech)
• Power Filter: 3 x Transparent Reference XL (one outlet in each filter)
• Power cords: Shunyata Copperhead for the CD player and Shunyata Taipan Alpha (2005 model) for the monoblocks

My friend’s reference system:

• CD player: Audio Aero Prestige CD player on the Acapella Fondato Silenzio. Shakti stones were used as well.
• Amplifier: Audionet AMP II Max monoblocks
• Speakers: Burmester B-100
• Interconnects: Transparent Reference MM (MM tech) unbalanced cables
• Speaker cables: Transparent Reference XL (MM tech)
• Power Filter: Burmester 948
• Power cords: Transparent Power Link Reference XL15 for the CD player, Transparent Power Link Reference for the amps

I’ve always adjusted the volume as near the previous level as possible when an amp exchange has been done. That protocol was used this time as well. In the end of the sessions I listened louder to be sure that the amp can give enough power for all kind of listening situations. Naturally I listened to the SA-Reference also in both, Class A and Class A/B, mode. The amp for the test was already quite well in-burned by Soundworks.

Listening sessions

Used Music:
I used my standard test CDs for the evaluation: George Duke’s After Hours, Frank Marino’s Live, Pink Floyd’s The Wall Live, Diana Krall’s Love Scenes and Reference Records Respighi. Especially George Duke’s After Hours is very good for testing because of its wide dynamics, wide frequency scale and spacious sound.

Session one:

When I sat down for a serious listening session in my friend’s listening room, I was immediately impressed of the SA’s clarity and the apparent lack of distortion. At once the sound was very transparent and clear, although a bit rough. The cymbals and bells had natural tones only being a bit more forward than I’ve used to hear. The SA-Reference seemed to have easy listening highs revealing huge amount of low level details! The bass was dry, dynamic and accurate, missing only a bit weight and tonality, especially when the most demanding music samples were used. The vocals were very transparent and the overall midrange cleanness was obvious, which was verified by piano music as well. Also the spatial distinctions and the other soundstaging features seemed to be in good hands – no lacks on the sonic picture dimensionality. The previously mentioned sonical features did not change during a long term listening either. So, the results were excellent almost in every area. Only slight roughness, bass weight and tonality left something to wish for, very much like the second best (for me) digital monoblocks, Bel Canto 1000s (almost bargains!), did some time ago.

It was time to switch the amp to Class A mode. After the warm-up, when eggs could have been fried on the amp, I listened to the same music samples again. The nature of the change was clear. This time the roughness was decreased remarkably and the listening results approached very much what the Audionet Amp II maxes delivered. In the Class A mode the sound was even cleaner and more natural than in the A/B mode, especially in midrange and treble. Still the punch of the bass was slightly lacked when compared to the best amps, especially monoblocks, I’ve heard. When I listened to live rock music I was surprised that I missed a bit the roughness what the Class A/B mode produced. I think the SA-Reference used its clarity, cleanness and even slight roughness successfully for the natural-like live rock performances, especially in the A/B mode! Anyway the Class A mode was surely a bit more neutral and even cleaner mode.

Session two:

Then the Plinius SA-Reference was taken into my listening room. It was quite a job because the weight of the amp is 56 kg, but I did it by the help of my friend. After the installation I listened to the same music samples as before, once more! My reference system is one of those which can resolve and reveal very easily all kind of lacks in the audio components or recordings. Also the Wilson Watt/Puppy 7 is a speaker which may produce a bit “over-sharp” sound especially when a recording feeds that. So, I could expect what was coming up.

The listening results were very much like what I experienced in the first session, they became only more aggravated. The very slight neutrality and coherency problems what I noticed especially in the Class A/B mode were now even more obvious. Some music samples caused casually even slight listening tiredness – here the system and listening room dependency seemed to rise on the spot. I think at least this time a different kind of system balance, a bit faster response speakers and more monitor-like listening affected remarkably to the listening results.

After switching the amp to the Class A mode the sound was slightly improved and naturalized, but not quite to the level achieved during the first session. Tonal richness was good, but if we look at the full harmonic complexity and the weight of the bass, there still were slight lacks. Otherwise the sound was marvellously transparent and it had highest class resolution, speed and control.


Balance: Quite neutral. The tonality of the bass had slight lacks which caused some suspects for absolute neutrality as well. Neutrality is better in the Class A mode than in the Class A/B mode.

Resolution: Marvellous resolution! I’ve heard very slightly better presentation only with the best digital amps. Here even Audionet Amp II maxes are in slight difficulties when compared to the SA-Reference stereo amp.

Transparency: Excellent transparency! No mistiness, no greyness. You are just there or they are just here!

Treble: The treble was generally excellently clean, but sometimes, especially in the A/B mode, very slightly rough and overdosed.

Midrange: Clean and natural but slightly crisp and rough in the A/B mode. That may be at least partially due to the treble nature.

Bass: Very dry, fast and very well controlled bass. Only the slight lacks of punch and tonality, which are clearly more or less system and recording dependent issues, disturbed frequently the listening results.

Dynamics: Excellent overall dynamics. Slight lacks were noticed in the low register especially when very demanding music was listened to.

Spatial information: Excellent! All dimensions of the sonical picture were beautifully produced. The sonic picture features were very good as well but left some thoughts that focussing and imaging could have been even a bit better produced.


My two sessions surely verified the nature of the Plinius SA-Reference stereo amp. Most of the listening experiences were absolutely positive. Although the envelope of the sound did not quite reach a richly textured finish in every pace and the weight of the bass did not quite achieve the best results, the overall result is still quite stunning. I can only imagine how good the SA-Reference monoblocks are! Supposedly at least the weight of the bass, dynamics and overall clarity will be still improved, as in monoblock cases are used to happen.

Plinius SA-Reference is an extraordinarily good amplifier even when taking account its high price. It has very few and very low level lacks, and numerous excellent or overwhelming features. If I searched a stereo amp, the SA-Reference would be so far among the best ones on my list. It’s a powerful amp that boosts very purely the signal it has given. Listen to it! If you can afford monoblocks, try them.

Technical Details

• Power: 300 W continuous per channel into 8 Ohms in two channel stereo mode. 1000 W continuous into 8 Ohms in balanced mono mode.
• Frequency Response: 20 Hz - 20 kHz ± 0.2 dB, 0 db at 1 kHz, -3 dB at 70 kHz.
• Distortion: Typically < 0,05% THD at rated power. 0.1% THD and IM worst case prior to clipping.
• Current Output: 100 A short duration peak current per channel. Fuse protection.
• Rise Time: Typically 5 µs
• Hum and Noise: 100 dB below rated output 20 Hz – 20 kHz, A-weighted.
• Input Impedance: 47 000 ohms.
• Gain: 32 dB RCA inputs, 38 dB Balanced inputs.
• Height: 275 mm; Width: 510 mm; Depth: 532 mm;
• Weight: 57 kg
• Colour: Silver or Black
• Price: 11 990 € in Finland