• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Need help evaluating 2A3 transformer coupled designs

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thanks. Unfortunately I have quite a bit more and am now needing to sell some of it to make space. it is a learning experience though.

My problem is i spend more time making stuff than listening to it. I dont drink, smoke or carouse so this is my vice.
I have all my toys at home so I don't need to go anywhere to have fun.

Andrew
 
Ex-Moderator
Joined 2003
That cathode bypass capacitor...

You do need 1000uF rather than 100uF, otherwise the anode resistance of the 417A will rise at low frequencies, and cause bass loss due to the finite primary inductance of the inter-stage transformer. The high transconductance oif the 417A coupled to that low value cathode bias resistor means that you need a large capacitor.
 
Hi Bas!
I thought I was busy but I think you have been busier;)

EC8010. Yup. I used Nichicon Muse's, 1000uF on the 5842 and 100uF on the 2A3.

It is time to rebuild it but I have two projects inline, D-57 cabinets
for my 208 Sigma's and a 12B4 preamp as well.
I start expanding my house next week so will have more space to keep my ever expanding mound of diy stuff

:)

Andrew
 
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