Even with the oldest good state audio circuitry now qualifying for a pension and a bus pass wherever this is remaining prepared, the thermionic tube retains a foothold in the globe of audio — cherished by lovers for the warm audio it is claimed to impart. For the electronics enthusiast a tube audio amplifier would make for an exciting and uncommon undertaking, and for that rationale it’s a single tackled by lots of. [Keri Szafir] is no exception, and she’s made a stereo tube amp with a couple of contemporary features.
Electrically it’s a relatively regular single-ended layout making use of a double triode and a ability pentode for every channel. It follows a so-named extremely-linear circuit, with a faucet on the output transformer feeding just one of the pentode’s grids. The modern capabilities appear by way of a switched Bluetooth input and a motorized volume regulate, one thing that would have by no means been located on these an amp when they have been the slicing edge.
We have to confess a tender spot for this style of amp, and we significantly like this one particular for its quite period construction design and style applying cable lacing to keep the wiring less than control. We extra normally see these amps utilizing the much less expensive integrated triode-pentode tubes which makes them especially quick to create, so the separate preamp is a very little diverse. We’re not guaranteed we’d have put in further on the extravagant E88cc tubes though.