Ice Amplifiers

6021 - SQ Tube

The 6021 is of interest due to its ruggedness, small size, and generally being a fantastic example of a tube designed and manufactured towards the end of the 'golden age' of tubes.

I developed the model for use in the design of a low power guitar amplifier. The datasheet for the 6021 is available from

When the following circuit is simulated in LTSpice, it produces the graph below.

Simulated Circuit in LTSPICE

Anode Charecteristics of 6021 SQ tube