Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: pbman1953 on September 29, 2017, 07:52:09 pm

Title: KT 120 in a Sunn / Fender 300T
Post by: pbman1953 on September 29, 2017, 07:52:09 pm

Has anyone tried the KT120 in the Sunn/ Fender 300 t?


I've tried them in a Traynor and a Sunn 2000, so far fine in the Sunn. I may have my reservations in the Traynor, still testing.




The voltage in the 300 with 6550's get up to 700 volts or so. 550ish with the Traynor and Sunn for the 120's.

Title: Re: KT 120 in a Sunn / Fender 300T
Post by: 92Volts on September 30, 2017, 10:56:30 am

The KT120s are better suited to handle that voltage than the 6550s. The biasing and other behavior should be very similar.

The KT120s draw 100ma to 350ma more heater current each though which can really add up over 6 tubes! But I don't know where their heater current falls in practice. That's a big range shown on the datasheet