What is the highest ohm speaker?


2009-12-12 9:07 pm
I've been building several tube amplifiers lately and had the idea to eliminate the output transformer (or at least make it's values smaller). It seem like there is a lot of energy and expense that is lost in this last step...

Anyways, I'm curious if anybody's head of a speaker that is higher than 16ohm? Anybody have any information on a output transformer-less tube POWER amplifier? Seems like it would be entirely possible to make a speaker that's REALLY high ohm, just doesn't seem like it's being produced...

Thanks for the replies (if any),
Well, the obvious solution is to run a multi-driver setup with the drivers wired in series.

But there are reasons why speakers tend to be low-impedance. Beyond 16 ohms, it's hard to get enough power consumption as current is limited. To get equivalent power dissipation, output voltage has to rise to satisfy Ohm's law (P=I^2 * R).

There are tube power amps without output transformers. They typically run lots of output tubes in parallel to get the required current. Do a google search for OTL.
the output voltage was comparatively high (danger!) and the speaker difficult to build (very thin coil windings). There are also very good reasons to build any electromagnetic winding that has to respond to very fast changes in applied voltage at as low a resistance (fewer turns of windings) as possible. More windings = more self inductive effects that slow the response of the speaker in this case