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Topic: Amp biasing meter and settings for Twin or amp w/6L6 tubes |
Len Amaral
From:
Rehoboth,MA 02769
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Posted 20 Feb 2016 2:37 pm |
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Thinking of biasing my own amps. Any info regarding meter/tools and setting are appreciated. Some of my amps are too heavy to take to a tech but I can get a hand to help pull a chassis and bias the amp myself.
Last edited by Len Amaral on 21 Feb 2016 5:59 am; edited 2 times in total |
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Don Mogle
From:
Round Rock, TX, USA
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Posted 20 Feb 2016 4:43 pm Biasing Amps
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Hey Lenny,
Look at the thread I posted on Jean-Sebastion's post regarding a problem he was having with his Fender TR. There is a post oh this thread that deals with this subject. Check it out!
Don |
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Tony Prior
From:
Charlotte NC
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Posted 21 Feb 2016 2:48 am
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regarding BIAS, the older Twins had a balance pot, not a BIAS pot for the outputs. Then they added a HUM balance which was an add-on to the balance circuit. I am not certain about the TR-RI, I have never had one apart.
This is called FIXED BIAS.
On the old NONE RI amps, the HUM pot was accessible from the tube side of the chassis, the balance pot on the circuit side. Place a meter on pin 5 of the output tubes ( screen resistor 1.5K) turn the pot and get them as close as you could. Its MV not volts...The so called purpose of the HUM pot was to reduce the overall HUM ( listen) when the tubes got older and getting farther away from each other in efficiency. If the pot was all the way to one end that was supposed to mean your tubes are done .
_________________
Emmons L-II , Fender Telecasters, B-Benders , Eastman Mandolin ,
Pro Tools 12 on WIN 7 !
jobless- but not homeless- now retired 9 years
CURRENT MUSIC TRACKS AT > https://tprior2241.wixsite.com/website |
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Len Amaral
From:
Rehoboth,MA 02769
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Posted 21 Feb 2016 6:32 am
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There is a meter called a "Bias Master" that looks easy to operate. A bit pricy at $249.00
There are other meters available at a user friendly cost since I will only use it on occasion? |
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Jon Light
From:
Saugerties, NY
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Posted 21 Feb 2016 6:37 am
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| Weber has the Bias Rite. I haven't done amp work in years but it was a good tool when I was doing a bunch of retubing. They have stuff ranging from whole packages to (I think) options for using your own meter with their sockets. |
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John Limbach
From:
Billings, Montana, USA
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Posted 21 Feb 2016 7:08 am
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Compu-Bias is worth the price if you do biasing with any frequency. Could not be easier to use, tells you everything you want to know, and keeps your hands out of the HV when it's late and you're tired.
http://www.compu-bias.com/ |
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Jeff Porter
From:
Stumptown, OR, USA
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Posted 21 Feb 2016 7:51 am
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I use the Weber bias probe and my own multi-meter.
http://www.tedweber.com/br-ah-vi-9
_________________
"I make dozens of dollars a year playing music." |
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Michael Butler
From:
California, USA
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Posted 21 Feb 2016 12:16 pm
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i got the amp head dual bias as most of my amps have two or more output tubes. i use my multimeter with it.
as someone else mentioned, you may need to verify whether you have a bias pot or hum balance. the hum balance would be tweaked for less hum.
here is the link to the amp head site.
http://www.amp-head.com/index.php?cPath=21
play music!
_________________
please see my Snakeskin's Virtual Music Museum below.
http://muscmp.wordpress.com/ |
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Eric Philippsen
From:
Central Florida USA
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Posted 22 Feb 2016 6:56 am
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| I got an Allessandro bias meter many years ago. It's worked well for me on every older Fender that crossed my bench. They all operate on pretty much the same principal but on some amps it's better to just adjust bias by ear. |
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