I have three Futterman OTL's. Two mono's and a stereo chassis version that Julius made and sold as the Harvard Music H3 in the mid-Sixties. That one got a review in the old High Fidelity mag! The H3 I bought has an added pair of Altec autoformers because the first owner used it to drive a large custom-made pair of panel speakers that had ten oval cone drivers per side! Consequently these presented a low impedance that the stock H3 couldn't drive - hence the Altec autoformers!
Are all amps being built wrong?
The power amplifiers that drive our loudspeakers are mostly built as a low impedance voltage source. They have always been ... but why?
Loudspeakers have a (greatly) varying impedance over the frequency range. A current drive amplifier would eliminate the issues that stem from this varying impedance, and at the same time make discussions about esoteric speaker cables that strive for optimal R, C, L superfluous. Although there still would be these un-measurable ’this (very expensive) cable sounds better’ debates and opinions ... and that’s OK, that’s part of the fun. :)
So ... why are amplifiers not built as a high impedance current source?
This is an interesting read: https://www.current-drive.info/
Loudspeakers have a (greatly) varying impedance over the frequency range. A current drive amplifier would eliminate the issues that stem from this varying impedance, and at the same time make discussions about esoteric speaker cables that strive for optimal R, C, L superfluous. Although there still would be these un-measurable ’this (very expensive) cable sounds better’ debates and opinions ... and that’s OK, that’s part of the fun. :)
So ... why are amplifiers not built as a high impedance current source?
This is an interesting read: https://www.current-drive.info/
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- 81 posts total
- 81 posts total