Hi guys I was able to power up my first channel of the Poseidon, initial power up I got -50vdc from Gnd to H, all ok.
Shut down and added the 5AR4 and powered up again (from start I had a 8 Ohm speaker connected) as the tubes warmed up the cone started to vibrate, by the time it took me to start taking measurements the cone went silent. The speaker was dead, I found that the cause was coming from the 5AR4 at first.
Once I disconnected between pin 8 of the 5AR4 and #1 of the cap and also the choke from #1 I ran another test I connected pin 8 back to #1 and all seemed ok but once the choke was reconnected, there it was again.
What have I done wrong? I’m getting 420VDC between pin 8 and ground.
Can anyone help?
Greg