HT DUAL - channel 1 died last night

[paulphoenix]

Hi Guys,

A little help/advice/opinion sought from fellow Blackstar enthusiasts please.

So i'm at practise last night and channel 1 of my HT Dual dies - press the switch and there is no audible sound.

The LED works to show the is channel on/off, and the pedal works on channel 2 and in bypass.

So is my 12AX7/ECC83 busted? (I will be swapping it out tonight for a spare one that I have as a matter of course)

Or any other thoughts as to my potential problem?

Excuse my ignorance on all things tubey - the pedal has cascaded gain stages. Does this mean channel 1 gets it's gain from the first half (triode) of the 12AX7 and then channel 2 gets its gain from both triodes (cascaded)?

If this is the case - how can channel 2 work fine and channel 1 have nothing?

Would a 12AX7 still work if only one of the triodes is functioning? (or) Is it possible for just one half of a dual triode to go tits up?



thanks for any help.

[paulphoenix]

so I changed the 12AX7/ECC83 in my HT Dual last night (using the bottom entry method - ooo err missus!) for a rebranded ENGL ECC83s that I had kicking about at home (originally from V1 in my amp) and voila! back to full working order! hoorah!

I will order up and drop in, a decent 12AX7 valve (one which this awesome pedal deserves) ASAP - but at least this quick fix should get me through my up and coming gigs.

just thought i'd let you all know.


....ever get the feeling you're talking to yourself....they say its the first sign of madness...it echoes in here......mommy!!..........