Alternative to rebiasing...

[Pierre]

Re: Alternative to rebiasing...

Never done this (!!) but I think you want unload the filtercaps before you solder the 1Ohm resistor in?!?
Isn't it easier too build/buy a bias probe adaptater which you can use with a multimeter?
You can get a kit for 14€...

John: can you recommend a good book about working on tube amps etc?

FOURTEEN EUROS??? Where? I want! Ah that may just save my life haha...

[Marcel]

Re: Alternative to rebiasing...

http://www.tubetown.de/ttstore/product_info.php/language/en/info/p471_Bausatz-Bias-Messadapter.html

it's the 1ohm resistor method too
but better ask someone who has done this... I've just mailed with bob and he suggested me to get a simple bias probe. I can forward your the mail if you want.

[Chaos]

Re: Alternative to rebiasing...

After reading this thread, a couple of safety tips come to mind:

Electrical safety gloves are thick and very expensive. They are rated for voltages higher than you will find in a typical amplifier. They are awkward and unnecessary.

On the other hand, using cheap rubber ‘work’ gloves can be dangerous as they might contain materials other than rubber (i.e. vinyl, nylon, etc) which could melt onto your skin in the event of an arc flash. Cheap gloves might also be coated with dry lubricant (to keep the gloves from sticking together). Some coatings could be electrically conductive.

Better to use you clean dry bare hands. Make sure you are not wearing any jewelry (rings, watches, etc) Electrical contact with a gold ring will not only guarantee shock, but deep burns.

Use meter leads with clips so you can make the connections with power off. Connect the leads, power on and take your measurements.

When reaching into your amp, use only one hand (put the other in a pocket). If you should get shocked, it will be localized to your hand. If you’re holding on to the chassis with one hand and ‘probing’ with the other, there is a good possibility that your heart will become part of the circuit.

Don’t assume a capacitor is discharged, measure it with your meter. If the cap is still charged, jumper a 5w 10–20k resistor across the terminals and wait for a few minutes then measure again. Don’t use a screwdriver.

Working on amplifiers is not like disarming bombs. It isn’t all that dangerous if you use common sense and understand the risks.

[Pierre]

Re: Alternative to rebiasing...

Thanks for all these Chaos! Is it really needed to discharge the capacitors though?

[Pierre]

Re: Alternative to rebiasing...

WOaa Marcel thanks buddy! I'll get one of these. Do you guys think they work with 6V6s?

[Chaos]

Re: Alternative to rebiasing...

Thanks for all these Chaos! Is it really needed to discharge the capacitors though?

It isn't neccessary to discharge caps if all you are doing is measuring / adjusting bias voltage. However, if you need to any repair work, soldering, component replacement, etc then you should meter your caps (only takes a second) to be sure they aren't charged.

[Pierre]

Re: Alternative to rebiasing...

Alright that clears things up. Thanks dude

[Pierre]

Re: Alternative to rebiasing...

Bump... I have money now and I would be VERY grateful to know whether this item could work with 6V6s if some of you know... I emailed them but I won't be able to order it as easily tomorrow as I'll be away from my parents.

[STRATDELUXER97]

Re: Alternative to rebiasing...

Bump... I have money now and I would be VERY grateful to know whether this item could work with 6V6s if some of you know... I emailed them but I won't be able to order it as easily tomorrow as I'll be away from my parents.

The 6V6s have the same pin outs as a 6L6...

[Pierre]

Re: Alternative to rebiasing...

ok! I'll buy this then along with a pair of 6V6s from the site. Cheers dude!

[Pierre]

Re: Alternative to rebiasing...

Eh well I just bought it along with 2 JJ6V6s, and on another site I got the Madamp G2 amp kit. I'm happy. I wanted their rangemaster clone but I decided I'd better save up... Thanks for all the help dudes!

[STRATDELUXER97]

Re: Alternative to rebiasing...

Eh well I just bought it along with 2 JJ6V6s, and on another site I got the Madamp G2 amp kit. I'm happy. I wanted their rangemaster clone but I decided I'd better save up... Thanks for all the help dudes!

You're better off this way....Best of luck...