When most individuals consider tube circuits, the very first thing that involves thoughts is usually using high-voltage energy provides. It wasn’t a given for tube circuits, although, as a spread of low-voltage gadgets have been developed for functions similar to automobile radios. It’s one in every of these, an ECH83 triode-heptode, which [mircemk] has taken as the premise of an audio preamplifier circuit.
The preamp circuit is fairly easy, being a two-stage single-ended design utilizing each halves of the tube. Between the 2 is a three-band tone management circuit as utilized in traditional guitar amplifiers, making for a serviceable and simply achievable method to chase that elusive “valve sound.”
There may be a lot dialogue amongst audio fanatics concerning the supposed advantages of vacuum expertise versus transistors in an amplifier. A lot of it centres round the concept tubes distort within the even harmonics whereas semiconductors are supposed to take action within the odd harmonics. Nonetheless, we’d be inclined to identify a little bit of snake oil as a substitute and level to early transistor amplifiers merely being not superb in comparison with the tube amps of the day. That mentioned, a well-made tube amplifier set-up will sound simply as superb because it at all times did, and since this one is paired with an identical energy amp we wouldn’t say no to it ourselves.
When you fancy messing about with tubes for not quite a bit, there’s an affordable module for that.
