We're supposed to "Experiment" with this amp, right?
I have Grado headphones which benefit tremendously from an L-pad attenuator, as PB suggested in
https://forum.bottlehead.com/index.php?topic=13832.0. It works great.
My conundrum is that I want to also drive my low sensitivity Spendor speakers without placing the 10 ohms resistance in parallel with the speakers as PB's design does. The resulting reduced total load impedance isn't that big a deal, but I wanted to try to design something that would remove those 10 ohms for speaker use.
So I added a DPDT switch after the OT. It was easy to drill out a 1/4 inch hole in the top plate beside the phone jack. Switched right it connects the OT directly to the speaker binding posts. Switched left it sends the OT signal through the 8ohm/2ohm L-Pad then on to the headphones.
(Another bonus, this setup removes the possibility of burning up the 2 ohm resistors under weird settings. See the earlier thread for more details on that.)
Thought this idea might be of use to others with similar setups as mine.
