[Paul[_13_]]

Since the TR5, TR6, and TR8 are all pretty
similar, we can just look at the TR8 for this
discussion:


https://www.gearslutz.com/board/atta..._schematic.pdf

Ok first off, the TR5 is similar to the TR8 on the front end, with
the TL072 Opamp configured as an inverting, unity-gain buffer amp.

So it's normal to NOT see any signal on the input differential pins 2
and 3, right? I remember reading about the virtual ground on the input
pins of this topology.

Secondly, on all these models, the so-called "power" switch only
turns on the LED, and turns off the mute on the two power amps,
which means the rail voltages are ALWAYS ON the Opamp and the final
amp, no matter the state of the switch, as long as the 3 prong AC
cord is plugged into the unit. This means the leakage currents in
the ICs are always there, which would explain why the back plates
of these units stayed warm, even when I turned them "Off."

Is this what they typically do with these smaller reference speakers
to maybe save money for the bean counters? Why not put a switch
with more poles, so you can turn the rail voltages off too?