Author’s note – This is a historical article, originally written in the early days of my activity and recently revised and expanded. The photos date back to the time of the first intervention and may appear below today’s standards, but they faithfully document the work done and preserve the charm of the original “behind the scenes”.
In the mid-1970s, at the height of the tube hi-fi revival, the small British maison Michaelson & Austin launched the TVA-1: a stereo power amplifier in KT88 push-pull capable of about 70 W per channel, created by Tim de Paravicini. Its robust construction, generously sized output transformers and a sound that combined power with refinement quickly made it a cult component. Even today original units are sought after by collectors and enthusiasts of the classic “British sound”.
The 2MT: an Italian clone with personality
Around the same years, in Italy, a few artisan workshops decided to replicate the TVA-1, both for cost reasons and because importing British amplifiers was not easy. This is how the 2MT was born, a declared clone of the Michaelson & Austin that reproduced the original KT88 push-pull topology and twin-triode drivers but used locally sourced parts and a distinctly Italian chassis. It was not a servile copy: some units reveal typical local touches such as neater wiring, power transformers sized “Italian-style”, and small adaptations for our 230 V mains.
The restoration work
When this 2MT arrived on my bench its condition was surprisingly good. The issues were mostly fine-tuning:
- a few cold solder joints to reflow,
- driver tubes that had been swapped around, causing channel imbalance,
- routine bias and voltage checks.
After verifying and repositioning the tubes, I gave the contacts a thorough cleaning, replaced a couple of grid resistors that were drifting out of tolerance and refreshed the input-coupling capacitors, which showed the usual signs of ageing.
Bench tests
The 2MT confirmed its distinguished heritage once powered up:
- Maximum power: 60 W RMS
- Bandwidth at 1 W: 15 Hz – 55 kHz (-3 dB)
- Bandwidth at 25 W: 15 Hz – 50 kHz (-3 dB)
- Damping factor (DF): 11.5
- Output resistance (Rout): 0.69 ?
For a 1970s hi-fi power amp these are excellent figures. Spectrum analysis at 1 W, 25 W and just before clipping confirmed a clean, well-controlled behaviour.
A small caveat: the input sensitivity is quite high—full power is reached with only about 1 Vpp (?0.4 V RMS). This can slightly raise the noise floor and sometimes calls for a passive preamp or a source with adjustable output.
This restoration shows that the 2MT is not a mere copy but an Italian reinterpretation of a great British classic. With a few targeted interventions and careful bench testing, the amplifier is ready to sing again as it did forty years ago, for many more decades of music.
If you own a 2MT or an original Michaelson & Austin TVA-1 and need service or restoration, feel free to contact me—I can bring your amplifier back to its best performance.