VAS transistors

[tlf9999]

I have used mosfet as both input and vas for quite sometime. I usually use small signal mosfets, like FQU1N or FQP1N / IRF510 from Fairfield. The FQU comes in dpak and is great for small signal applications; and FQP in TO220 and is great for hot VAS.

I have never had problems with either.

 

[powerbecker]

For ultimate Ft look for BFQ232A
And for PNP BFQ252A.
95v VCE rating and Ft=1.2GHZ
300mA 3watt
but beta sucs big time, around 20.

, they are since some years obsolet!

 

[jwb]

Not to jump in to a dead argument or anything, but Zetex ZVN3310A and ZVP3310A FETs are good for VAS as well.

 

[LineSource]

Anyone know of a 1.5 Watt equivalent to BC559C and BC549C in terms of hfe and low noise? My driver stages use +/- 15V, and the VAS needs 60ma of bias current. So, I need about 1.5 watt, low voltage complementary VAS bipolar transistors.

 

[tiefbassuebertr]

Option to High Voltage Medium (Video) and High Power Devices for Output and VAS Stage

in this case this thread could be of interest:
http://www.diyaudio.com/forums/soli...wer-devices-output-vas-stage.html#post2239333