current driver tube amplifier

[loderunner]

Ultrasound Otello this Italian amp, ten PL519 tubes per channel, not a wattage amplifier but a current/amperage amplifier.

The revolutionary Ultrasound amplifiers

Does anyone know how it works or circuit architecture?

thank you!!!

[SY]

"practically everything has been built ad hoc by three engineers"

Unintentionally funny.

In any case, one can make an educated guess- they're running the tubes in pentode mode and attaching the speaker at the plates.

[Loren42]

"Three engineers who have worked for almost 5 years on it:"

I hope that was not full-time or 15 man-years! They will never recoup their investment.

[godfrey]

Don't know what their circuits looks like but...

Current drive does give lower distortion and less power compression.
Frequency response tends to be a problem though.

Here's a paper Mills and Hawksford wrote about it 20 years ago:
http://www.essex.ac.uk/csee/research...nt%20drive.pdf

and here's their ideas for circuit architecture:
http://www.essex.ac.uk/csee/research...0amplifier.pdf

More Hawksford papers on various subjects here:
Malcolm Hawksford - Publications



p.s. Here's a book: The Secret of Tube Amplifiers Revealed - and much more!

[loderunner]

thank you! godfrey

[loderunner]

thank you ! godfrey