I am I first time tube amp builder and I would like to use a Hammond PT to build the 2nd revision of the Two-Stroke Amp from Dave Hunter’s book I want to use Hammond PT because I live in Canada, have a local supplier (Next-Gen), and Hammond have a good reputation. I am undecided which transformer to pick and I am looking for help from experienced builder especially ones that have built this amp. The Tube Amp Network hosts a copy of the layout and the schematic The book suggests one of: Mojo760 Secondary: 330-0-330 VDC @ 75mA Filament: 6.3V @ 4A Rectifier: 5V @ 4A P-TF22772 Secondary: 325-0-325 @70mA Filament: 6.3V @ 2A Rectifier: 5V @ 3A Weber 125P1B Secondary: 330-0-330 100mA Filament: 6.3 V @ 4A Rectifier: 5.0 V @ 3A Or any transformer for a tube amp with: Secondary: 310-0-310 to 330-0-330 VDC at least 70 - 80mA Filament: 6.3 V @ 4A (note: the schematic from the Tube Amp Network says 2.7A) Rectifier: 5.0 V @ 3A Hammond Transformers Starting with the Fender replacements at the Hammond classic 290 series I see : Hammond 290 AX Secondary: 325-0-325 VDC @100 mA Filament: 6.3V @ 2.25 A Rectifier: 5 V @ 3A The filament voltage is low but according to the Hammond site this is the replacement for for Fender parts 125P1B and 022772. Would 2.25A be too low for this amp (this would be powering the lamp + 12ax7 heater + heater for one of 6V6/6L6/EL34). I wonder if the higher filament amperage is a left-over spec from the first revision of the amp which could have two power tubes ... Hammond 290 CX Secondary: 325-0-325 VDC @207 mA Filament: 6.3V @ 4A Rectifier: 5 V @ 3A The filament amperage is correct but the secondary is amperage is high - 207ma vs the 100ma or less for the other PT Hammond 290 CBZ Secondary: 325-0-325 VDC @120 mA Filament: 6.3V @ 4A Rectifier: 5 V @ 3A This seems to be closer to what I need according to the original spec. Looking at the Hammond classic 200 series Hammond 272 DX Secondary: 300-0-300 @144 mA Filament: 6.3V @ 4A Rectifier: 5 V @ 3A The 300-0-300 is lower than the spec’d 310-0-310 minimum Looking at the Hammond classic 300 series I didn’t see anything closer … Thanks for reading this far!