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Re: Do you re-bias your amp after changing your power tubes?
Posted: Sat May 14, 2022 1:52 pm
by zhivago
johnnysomersett wrote: ↑Sat May 14, 2022 7:16 am
Whoop! Congrats!... A good hurdle overcome and a skill that'll be with you forever now - the best kind of learning experience.
I've found this useful ability to be quite handy in the help-friends-out-in-exchange-for-beers department...which is one of my preferred departments
Rock n roll.
Re: Do you re-bias your amp after changing your power tubes?
Posted: Mon May 16, 2022 11:40 am
by hexes
high five on your bias success! it’s nerve wracking the first time, and honestly, when firing up the first amp you’ve built with one.
also, double warning on not working on amps too late (and never on substances). I hyper focus and go for hours, not noticing I’m tired. that’s how I got zapped with 600v DC off a PT rectifier winding, and I certainly knew better.
Re: Do you re-bias your amp after changing your power tubes?
Posted: Mon May 16, 2022 12:34 pm
by zhivago
Many thanks!
Yes, I can see how working on amps while sober and/or well-rested is a definite plus!!
Re: Do you re-bias your amp after changing your power tubes?
Posted: Mon May 16, 2022 4:59 pm
by øøøøøøø
hexes wrote: ↑Mon May 16, 2022 11:40 am
also, double warning on not working on amps too late (and never on substances). I hyper focus and go for hours, not noticing I’m tired. that’s how I got zapped with 600v DC off a PT rectifier winding, and I certainly knew better.
Exact same
Re: Do you re-bias your amp after changing your power tubes?
Posted: Mon May 16, 2022 10:41 pm
by JSett
øøøøøøø wrote: ↑Mon May 16, 2022 4:59 pm
hexes wrote: ↑Mon May 16, 2022 11:40 am
also, double warning on not working on amps too late (and never on substances). I hyper focus and go for hours, not noticing I’m tired. that’s how I got zapped with 600v DC off a PT rectifier winding, and I certainly knew better.
Exact same
Ditto, also. 500v from an OR120 straight into the wrist woke me up pretty sharpish. Fortunately for me I was taking a drag off a cigarette at the same time so my left hand was well out the way of the chassis
Even though I know how to drain an amp down now, that very first *touch* inside, always gives my nerves a little flutter hahaha
Re: Do you re-bias your amp after changing your power tubes?
Posted: Tue May 17, 2022 3:10 am
by sessylU
That's one of the general "being quite handy at things" lessons that you learn doing a lot of airfix kits as a kid.
Re: Do you re-bias your amp after changing your power tubes?
Posted: Tue May 17, 2022 5:11 am
by luau
johnnysomersett wrote: ↑Mon May 16, 2022 10:41 pm
øøøøøøø wrote: ↑Mon May 16, 2022 4:59 pm
hexes wrote: ↑Mon May 16, 2022 11:40 am
also, double warning on not working on amps too late (and never on substances). I hyper focus and go for hours, not noticing I’m tired. that’s how I got zapped with 600v DC off a PT rectifier winding, and I certainly knew better.
Exact same
Ditto, also. 500v from an OR120 straight into the wrist woke me up pretty sharpish. Fortunately for me I was taking a drag off a cigarette at the same time so my left hand was well out the way of the chassis
Even though I know how to drain an amp down now, that very first *touch* inside, always gives my nerves a little flutter hahaha
When I first started tinkering I had my wife attach my left hand to my belt loop with a velcro strap.