Home › Forums › Design and Building › 2 Stroke Amplifier Design and Building › Voltage readings too low (first build)
Just finished my two stroke build using a 125ESE and one 12ax7 (thanks to the revised TAN 1.13.2011 revised 1.0 schematic). I checked voltage readings against D.Hunters book and mine are low. Perhaps I should look into smaller PT dropping resistors?
Tube. Pin. Expected vdc. Measured vdc
6v6. 3. 340-360. 332
12ax7. 1. 140-160. 100
12ax7. 6. 140-160. 96
Figured it out. The original target values from Daves book expect a 325v power feed. The revised schematic and layout are using 275v, which I adopted. This is why its lower
Sorry this is so late! Glad you figured it out.
What Power Transformer are you using? For our kit, we are using the Hammond 290AX which is 325V.