Changing tubes for an ENGL SCREAMER COMBO

[noodleplugerine]

What about turning it on, getting a reading, turning it off, making adjustments?

Or does the charge stick around after you turn it off?

[Ratrod]

Yeah, electricity stays in the amp. I think it's the caps that actually hold it.

You can't be too carefull. My advice: Take it to a tech.

[MDV]

What about turning it on, getting a reading, turning it off, making adjustments?

Or does the charge stick around after you turn it off?

Good theory, but thats a non-starter:  you need to know what effect your adjustments have made, and theres no way to read that with the amp off. Plus as ratrod says, there are caps in there that hold enough charge to kill you (whatever that is!!) as well. I dont know how long that takes to dissipate - it could be minutes, it could be days.

[noodleplugerine]

What about turning it on, getting a reading, turning it off, making adjustments?

Or does the charge stick around after you turn it off?

Good theory, but thats a non-starter:  you need to know what effect your adjustments have made, and theres no way to read that with the amp off. Plus as ratrod says, there are caps in there that hold enough charge to kill you (whatever that is!!) as well. I dont know how long that takes to dissipate - it could be minutes, it could be days.

You could easily calculte the discharge of the capacitors, but then you might aswell be a tech haha.

[_tom_]

The capacitors still hold charge even when the amps off as well I think..

[gingataff]

Indeed they do. I count myself lucky that I survived a shock from my 30w Laney when I accidentally put my finger across the on/off switch connections some years back. I feel sick just thinking about it.

Maybe some of the amp techs/builders/tinkerers here can tell us the best way to discharge the caps before working on them?

[Johnny Mac]

Take it to a tech and then maybe you could try out different valves as they have their own sound.

[dave_mc]

^ so, johnny, if your koch is acting up and you aren't sure what's wrong, you should take it to a professional? :lol:

also, what's a koch tube? o_O

Does 50mA stand for 50 mini amps? Micro amps?

milli (a thousandth) :)

Good theory, but thats a non-starter:  you need to know what effect your adjustments have made, and theres no way to read that with the amp off. Plus as ratrod says, there are caps in there that hold enough charge to kill you (whatever that is!!) as well. I dont know how long that takes to dissipate - it could be minutes, it could be days.

yeah, the caps will hold charge, that's what they're for (to smooth ac ripple etc. among other things). depends on the amp, the cap, chance too i guess... i think some amps may have a resistor somewhere around the caps which will self-drain the caps, but it's certainly not every amp, and it'd be safer to manually drain the caps anyway just as good practice.

[Johnny Mac]

^ so, johnny, if your koch is acting up and you aren't sure what's wrong, you should take it to a professional? :lol:

also, what's a koch tube? o_O

Does 50mA stand for 50 mini amps? Micro amps?

milli (a thousandth) :)

Nah my Kochs fine Dave just fine. I was thinking that by taking it to a pro' I may be putting it at more risk....hmm, we should leave that one as it may contain extracts of the lyrical content of a carcass song..

Ah a milli amp. Thanks for that  :D

Koch valves are just the usual rebranding of other valve manufacturers products. I can't remember who makes them now.

Anyway here's my naked Koch!!  :lol:

[dave_mc]

^ i meant that koch tube sounded like something which should be x-rated... :lol:

i guess it depends on what you mean by a professional... i meant a doc, but maybe you meant something else... :lol:

getting back to the serious stuff, that's pretty cool that you can mix and match power tubes in the powertone. that's one of the few things about my engl that i wish were different- it seems to take 6L6s/5881s, and that's your lot... :)

[Johnny Mac]

^ i meant that koch tube sounded like something which should be x-rated... :lol:

 :lol: :lol:

Ahh, Koch jokes are as old as this forum but that was a great new take on one!!

[dave_mc]

:D :drink: