DIY Audio Home  A Power Opamp Driver and Bias Supply PCB, and
class-A2 experiments   I've wanted to try using a high-voltage
power opamp (like the TI OPA452) to drive the grid of a tube for
some time.  Though the voltage swing is a bit limited (about
+/-36V for the OPA452), it can source some current, so it seems
like an interesting driver for class-A2.  To facilitate this, I
built a small PCB with a power opamp, as well as a small PCB to
power it.  Details on the boards are below.  My thought was that
I should be able to use this driver and a cheap transmitting
tube driven in class A2 to make a cheap, simple amp.  I have
tried a number of tubes, but have more work to so.  So far I've
only tried single-ended designs.  I will eventually try some
push-pull designs - you can set up one power opamp as inverting,
and the other as non-inverting, and feed them the same input to
make a push-pull amp.  But I have not tried it yet...  I tried
the 2E26 and 1626 tubes in single-ended.  The 2E26 worked fine,
but really I