Re: Re: 2 Stroke kit build.

[Robin]

The 6.3v twisted pair heater circuit sounds likes you have it wired correctly if the tube filiments are heating up. There may be an issue with noise (hum) but you can address that when the amp is working.

The layout illustration in the book and on the revised layout is confusing about the wiring for the input jack. See the schematic in the wiki section for a clearer view of how the input jack is wired. You can confirm it’s wired correctly with a multimeter or by simply pluging a guitar cord into the input jack (do not connect the other end of the cord to anything), there should be a 60hz hum when you touch the cord. If you try this test and the amp remains silent, chances are that the tip of input jack is wired to ground. To be clear, the center wire from the shielded cable should go from the tip lug of the input jack to pin 2 of V1 (the 12ax7 tube). You may have the 68k resistor in between the input jack and pin 2 (but if you leave it out, nothing bad will happen). Remember that the input jack is a “shorting jack” and intended to keep the amp silent when nothing is plugged in, the tip lug should test to ground when nothing is plugged in, but test open (not grounded) when a cord is plugged in.