Novice amp enthusiast here In planning my first amp build, I've come across an issue with parts I need. The reverb tank I need for the schematic I've put together requires a tank with high input impedance, in the K-ohm range to be close to the output impedance of a 12AU7 at 4k. These high impedance tanks are hard to come by, and I don't want to have to order from America (especially since no shipments can take place right now) If I had a tank with input impedance of 600ohm, would it still function ok? is there any way to improve the efficiency with that set up? Here's the general schematic I'm following (based off of a swart reverb, taken from https://guitar.com/guides/diy-workshop/build-tube-spring-reverb-unit-amplifier/ ) Thanks in advance!