Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: mresistor on December 10, 2021, 04:26:58 pm

Title: Question for Sluckey re: British Dual Lite amp
Post by: mresistor on December 10, 2021, 04:26:58 pm

First let me thank Sluckey for the excellent documentation of his amp creations and sharing them with the world.


I am building the Dual Lite and arriving at the board assembly I came across some deviations from the schematic that are apparent in the photographs.


My question is why does your PI have components that are different from the schematic?   The schematic shows values for a typical 18 Watt amplifier.
Your photograph reveals that these values are different in your completed amp. 


I cannot determine exactly what value the tail resistor is
the grid resistors appear to he 560K
and the cathode resistor appears to be 1.2K


I'm trying to confirm these values and if they are correct before I proceed with populating the board. 

Title: Re: Question for Sluckey re: British Dual Lite amp
Post by: sluckey on December 10, 2021, 05:14:29 pm

It's hard to see the colors on those blue metal film resistors. But the resistors are two 470K for grids, 820Ω cathode, and 47K tail resistor. Schematic, pics, and my actual amp are all in agreement.

Title: Re: Question for Sluckey re: British Dual Lite amp
Post by: mresistor on December 10, 2021, 05:36:31 pm

Thank you ..  I'll press on.