Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: jeff on January 28, 2011, 01:05:35 am

Title: 18 Watt PI
Post by: jeff on January 28, 2011, 01:05:35 am

The phase inverter is fed from one side with the normal channel and the trem channel feeds the other. What's going on with the phase inverter if you're only playing through the normal channel and the trem channel is down, cap to ground, or up, cap to 500k to ground? If you were to build one with only the normal channel would you just ground that cap(C18)?

Title: Re: 18 Watt PI
Post by: sluckey on January 28, 2011, 06:09:07 am

The LTP PI is a differential amplifier. It amplifies the difference between the two grid inputs. If you build one with only the normal channel you would just ground that cap(C18).