Re: Re: Following 2 Power Tube Amp Design

[Robin]

Andy’s post has it covered (again). The input jack wiring is the single biggest area of confusion in the 2Stroke layout. Many people have struggled with it. The revised (single power tube) version of the layout is clearer. Check out any Fender Tweed-era chassis layout or schematic for an example of how it’s supposed to be wired up.It sound like you have the input jack tip lug wired to ground so no signal can pass through to pin 2 of V-1. I posted a photo in my 2Stroke photo album of the input jack wiring. Thanks to the creator of this photo, I found it on the web.

Regarding lead length, it’s true that shorter is better, not allowing the signal path to cross back over itself, isolating the heater circuit, etc are all good basic rules. Poor lead dress can lead to hum, hiss, parasitic oscillation and so forth. The 2Stroke can be built to be very quiet (no noise or hum) so if you end up with a noise problem, use the “chop stick” method to push some leads around and see if you can find and resolve the issue. Resolving things like that input jack wiring can result in little ah-ha moments that I think has encouraged a lot of us to continue on with amp building. Good luck with the 2Stroke.