You could use the 4222, and as for heat, you can always decrease the bias a little... I'm going to build a BA-3 Complimentary in a 4U, (with 24V transformer) and that's the exact same output stage as the F4.
However, the big (5U) case is awfully nice to have when swapping between different amps. The extra room makes a PCB change into a 1/2 job.
I would be very interested in a slightly higher voltage F4.
However, the big (5U) case is awfully nice to have when swapping between different amps. The extra room makes a PCB change into a 1/2 job.
I would be very interested in a slightly higher voltage F4.
I'm going to begin assembling my F4 today. Not certain at this point about one thing though - whether or not I should do the crippled version. Planning on building a BA-3FE preamp, but have to get a few more things here before work can start on it. In the meanwhile, it's really cold outside ( for Texas ) and all the parts for the F4 are here. The only preamp I have in the house is a GFP-555 which the manual says will do 10V out max, but I'm unsure how much gain it has, or how to figure that out ( no luck googling so far ). The F4 will, without question, be paired with the BA-3FE after that ( maybe a Luminaria pre in the future...who knows ).
So should I drop the input jfets as directed in the big F4 thread?
So should I drop the input jfets as directed in the big F4 thread?
I also have quite a few nice 5814's, 12AU7's, and a couple E80CC's - so theres a slight chance ( albeit remote ) that the F4 may get hitched to a MiniMax preamplifier one day as I could keep one of those in nice tubes for decades.
About to begin.....
Learned several important lessons in the course of assembling a DCB1. Don't get the iron too hot, dont touch said iron to ones skin, and start drinking beer at the beginning of the build ( not before ) so as to avoid excessively dulled cognitive function or reflexes ( for when the iron inevitably contacts the skin ). 🙂
Learned several important lessons in the course of assembling a DCB1. Don't get the iron too hot, dont touch said iron to ones skin, and start drinking beer at the beginning of the build ( not before ) so as to avoid excessively dulled cognitive function or reflexes ( for when the iron inevitably contacts the skin ). 🙂
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Power supply stuff
For a dual mono power supply ( other than the transformer ) would I need two or four bridge rectifiers? Have 8 50V capacitors @ 33k uF each.
For a dual mono power supply ( other than the transformer ) would I need two or four bridge rectifiers? Have 8 50V capacitors @ 33k uF each.
It's an Antek AS-4218, so dual secondaries. Which, interestingly enough, are scheduled to be available again tomorrow ( after a loooooong time ) according to their website.
Hello again, friends.
I am working on ordering parts for the v3 universal power supply. I was hoping someone could recommend parts or at least values for the two snubber resistors and the capacitors. The note on the BOM says "See forums for more information" which leaves a lot of ground to be covered, so I thought I'd start here.
I am working on ordering parts for the v3 universal power supply. I was hoping someone could recommend parts or at least values for the two snubber resistors and the capacitors. The note on the BOM says "See forums for more information" which leaves a lot of ground to be covered, so I thought I'd start here.
Snubbers are made to damp the ringing of a PSU when the load varies. Especially large power-on, power-off spikes.
A Class-A amp should have a constant draw. No snubber necessary.
A Class-A amp should have a constant draw. No snubber necessary.
