The HERs were originally advertised as having a lower Vf compared to competing ultrafast rectifiers. Tenth of a volt (or two) means nothing on a tube amp supply. If that’s the only difference no one would ever notice. Where Vf matters in DC-DC converters, nowadays they tend to use mosfets as synchronous rectifiers.
OP, are you sure it is a 1N4007, as the VTA kit schematic shows a UF4007 ?
The application has a load current of 3mA on a 100uF cap - that is a periodic voltage drop of less than 1V being topped up - the diode will hardly conduct at all, let alone have any turn-off dI/dt that could initiate reverse recovery. Anyone who is thinking of reverse recovery should brush up on what dI/dt levels initiate reverse recovery in a diode.
The VTA schematic shows quirky values for bias voltage levels - something is wrong.
The first response sentence in post #2 says it all imho.
The application has a load current of 3mA on a 100uF cap - that is a periodic voltage drop of less than 1V being topped up - the diode will hardly conduct at all, let alone have any turn-off dI/dt that could initiate reverse recovery. Anyone who is thinking of reverse recovery should brush up on what dI/dt levels initiate reverse recovery in a diode.
The VTA schematic shows quirky values for bias voltage levels - something is wrong.
The first response sentence in post #2 says it all imho.