Question about how I run my Amp?

Bellycaster

So my Bogner Goldfinger 45 has only ever(or 99.9% of the time) been run on Half Power Mode - 23 Watts("High Mode Position"), and probably will always be run like that.

The Amp runs 4 X 6V6's, so am I right in saying it has only ever been using 2 of those 4 Valves? All the Valves are lit up even in Half Power Mode, so I wondered if this was the case. It also can run at 30 Watts on Full Power("Low Mode Position") and 15 Watts on Half Power("Low Mode Position")

I want to see if it needs Biasing as I've had it 4 years, it's only been gigged 3 or 4 times, so it's been played at reasonable volume for the most part. So this leads me to think there will be a mismatch in "wear" or a mismatch in Biasing between the two pairs(if they run separately), maybe I'm miles out though.

Amp sounds fine, the Valves might have a load of life in them, but I wondered if two valves were..for want of a better word "fresher" than the other 2, or if they could be swapped over, a bit like putting the back tyres on the front when the front ones are worn

Or if you're not a tight git like me, would you just replace all 4 when the time came? Or if you did just replace 2 of them how would the new ones be "matched" to the remaining 2.

Yep, I'm not that clued up with this stuff, I could get to grips with the Maz and changing Valves in that as it's Cathode Biased and does not have any lower watt settings.

Thanks for any help.

ICBM

Swap valves 1 and 4 for 2 and 3, and think about it again in another 4 years .

Yes, the chances are that it turns off two of the valves - I'm not certain since I don't have a schematic for it but it's the usual way of doing half power. There are a couple of different ways of doing that, one of which is worse for the unused valves than the other, but I don't know which is used. Probably neither will cause any real harm.

I would expect that 'High Mode' and 'Low Mode' are either pentode and triode, or full voltage and reduced voltage, since those are the two usual ways of doing that as well.

ecc83

Just like to say. This does NOT work for the Artisan 30! The EL84s are cooking at max all the time.

Dave.

Bellycaster

Thanks @ICBM and @ecc83 ;

I'll keep all that in mind. I've sent of an email to Bogner anyway, might as well see what they say.

Bellycaster

Contacted Bogner and the guy said that 2 of the 6V6 are switched off when in half power, the other 2 are lit up because of the filament, shows you what I know.

@ICBM

If I play the guitar and look at the valves whilst playing should I see the two that are functioning from the "flicker", the guy couldn't say off the bat which 2 were on or off.

ICBM

If he's correct that the filaments are turned off, two shouldn't be glowing at all.

That's also the best possible way of turning off the two valves and doesn't wear the unused ones at all.