Loud crackling noises and sparks in the 6080! (Third post)

[Strikkflypilot]

Hi again.
I have just rebuilt the Crack in pre-Speedball form, (with film output caps, new pot, jack, RCAs, teflon sockets).
Voltages good and sound like it should.
I then proceeded with making the E80CC mod as illustrated.
Soldered in the speedball PCBs and tested in the "on" position with two 470ohms resistors in parallell yielding 235 Ohms for 12AU7.
All voltages good and proceeded installing a Siemens E80CC and flipping the switches to run 470 Ohms in both R1 positions.
That gave around 105-107 on both terminals 1 and 5, so disappointed, I switched back to 235 ohms to test the amp in 12AU7 mode.

I now only get sound in right phone and slight hum in the left.

A3 Led is out. All other LEDs light up. Both channels on both tubes light up. Voltages as follows:

1:74v
2:166v
3:0
4:164v
5:160v
6:0v
7:101v
9:160v
10:0v
11:0v
12:0v
13:165v
14:0v
15:182v
20:0v
21:201v

Oh, and I have tested the A3 LED with my DMM and it pulls 1,5v from solder point to solder point, so it isnt blown.
Can anyone help me out?

[Strikkflypilot]

So I really couldn't understand this. Everything looked very good, all soldering joints solid, tested for conduction, all good.
Turns out it helped to pull the 12AU7 out, and reinsert. Now all voltages (terminals 1-7 + 8 +9) are within specs. Maybe resolder the joints on the socket PCB just in case?

On another point, I was adviced that 470ohms was good for Siemens E80CC, but that gave me 105v on terminal 1 and 107v on terminal 5.
Could anyone suggest a particular input tube that would work with this resistance? (Want to keep my switches if possible)

[Strikkflypilot]

Referring to previous post. I tested the amp a bit and noticed crackling from the left channel that changed when the braid moved.
I resoldered the RCAs, the terminals 9, 10, and A1-A3. Reckoning nothing had changed, I plugged my headphones straight back in and switched the amp on.
I heard loud cracking noises from my right phone and the 6080 threw sparks inside the glass!.
I pulled the switch, and waited a bit.
Not leaving well enough, I did a new voltage test and everything tested out good. No more sparks. Needless so say I switched on power without headphones now.
All this resoldering did nothing for the left channel which stays silent.

My DMM tells me the white/left channel does not conduct anymore at all. I resoldered the left output on the pot and all good.
But what could have caused the sparks in the 6080 and the loud noises on the right channel?