Quencho092
New member
I was just curious about the average bias settings for each respective power tube "species". Anyone here plays 6l6's, KT66's, EL34's, and bias their own amps? If so at what values.
What value do you bias your amp at?
- Thread starter Quencho092
- Start date
TwilightOdyssey
Darkness on the edge of Tone
Re: What value do you bias your amp at?
I let my tech do all that stuff!
I let my tech do all that stuff!
Quencho092
New member
Re: What value do you bias your amp at?
hmmm....plate voltage, don't know?
hmmm....plate voltage, don't know?
Quencho092
New member
Re: What value do you bias your amp at?
how do i check the ...plate voltage
how do i check the ...plate voltage
Quencho092
New member
Re: What value do you bias your amp at?
so what's your bias/plate voltage
so what's your bias/plate voltage
Re: What value do you bias your amp at?
In my Bogner it's ~460VDC and in my friends JCM 800 it's ~480VDC. When you plug that info into this form (http://www.ionpool.net/arcade/tech/Weber_Bias_Calculator.html), you'll get the correct bias.
Quencho092 said:
In my Bogner it's ~460VDC and in my friends JCM 800 it's ~480VDC. When you plug that info into this form (http://www.ionpool.net/arcade/tech/Weber_Bias_Calculator.html), you'll get the correct bias.
STRATDELUXER97
Stratoblaster Tone Meister
Re: What value do you bias your amp at?
Pin 8 is the cathode....You want pin 3...Be very careful or you will never forget the shocking experience! :yell:
The safeset way to bias your amp is to put a 1% 2 watt or better resistor across pin 8(The cathode to ground)...The resistor is placed in series between pin 8 and ground..You then measure your current in millivolts...The resistor converts milliamps to millivolts...That's how I bias all of my amps..
Plate voltage is found at pin 3
Pin 5..Gives you your - bias voltage
Pin 8 is your cathode...This is for the EL34,6L6,6550,5881 tubes...
John
mrid said:
Pin 8 is the cathode....You want pin 3...Be very careful or you will never forget the shocking experience! :yell:
The safeset way to bias your amp is to put a 1% 2 watt or better resistor across pin 8(The cathode to ground)...The resistor is placed in series between pin 8 and ground..You then measure your current in millivolts...The resistor converts milliamps to millivolts...That's how I bias all of my amps..
Plate voltage is found at pin 3
Pin 5..Gives you your - bias voltage
Pin 8 is your cathode...This is for the EL34,6L6,6550,5881 tubes...
John
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STRATDELUXER97
Stratoblaster Tone Meister
Re: What value do you bias your amp at?
I got your back buddy.... :dance:
mrid said:
I got your back buddy.... :dance:
Gearjoneser
Gear Ho
Re: What value do you bias your amp at?
Thanks for that bias calculator link MRID. I use a mA bias tool I got off Ebay for $15.
I strum the guitar while turning the minipot, also watching the number on my amp meter. That way, I know when my amp sounds the best, and I also see that the mA value is close to what it usually is....36-38mA for EL-34's and 31-34mA for 6L6's, depending on the amp and tubes.
Thanks for that bias calculator link MRID. I use a mA bias tool I got off Ebay for $15.
I strum the guitar while turning the minipot, also watching the number on my amp meter. That way, I know when my amp sounds the best, and I also see that the mA value is close to what it usually is....36-38mA for EL-34's and 31-34mA for 6L6's, depending on the amp and tubes.
Quencho092
New member
Re: What value do you bias your amp at?
what about the groove tubes bias thing, looks cool...does it work. I think you just probe the pins, plug in the tube and watch the meters, but yet again, theres gotta be a catch
what about the groove tubes bias thing, looks cool...does it work. I think you just probe the pins, plug in the tube and watch the meters, but yet again, theres gotta be a catch
aleclee
Major General GAS
Re: What value do you bias your amp at?
I use the Weber Bias Rite. Plug it into the tube socket(s) and check current. Mine has the V/I option so I can also check the plate voltage. The hardest part of biasing my amps is pulling the chassis to get access to the trimmer pots.
I use the Weber Bias Rite. Plug it into the tube socket(s) and check current. Mine has the V/I option so I can also check the plate voltage. The hardest part of biasing my amps is pulling the chassis to get access to the trimmer pots.
D
DeadSkinSlayer3
Guest
Re: What value do you bias your amp at?
Sorry to hijack...
My XXX has a multimeter test point on the back, and a bias knob, like an actual knob next to the tubes. Do I use this to set the bias, or would I need to get something like the weber?
*EDIT* Ok I checked some Peavey forums, and those test points test the voltage, and apparently the factory setting is -55v. WTF Does that mean?
Sorry to hijack...
My XXX has a multimeter test point on the back, and a bias knob, like an actual knob next to the tubes. Do I use this to set the bias, or would I need to get something like the weber?
*EDIT* Ok I checked some Peavey forums, and those test points test the voltage, and apparently the factory setting is -55v. WTF Does that mean?
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L
Lewguitar
Guest
Re: What value do you bias your amp at?
Good call John...that's exactly how I do it too. Buy a bunch of 2 watt resistors (1 ohm...right? :smack: ) and then measure them and make sure the one you solder in measures exactly 1 ohm. If it's off, you're reading will be off too. Boy I hope I remembered that right!
STRATDELUXER97 said:
Good call John...that's exactly how I do it too. Buy a bunch of 2 watt resistors (1 ohm...right? :smack: ) and then measure them and make sure the one you solder in measures exactly 1 ohm. If it's off, you're reading will be off too. Boy I hope I remembered that right!
STRATDELUXER97
Stratoblaster Tone Meister
Re: What value do you bias your amp at?
Yep...That's the reason for the 1% resistors,so the value is pretty much 1 ohm...Tube amps are very forgiving and the ever changing wall voltages coming into our amps makes alot of difference to the readings than that small difference in resistor values..The difference in our readings between 120 volts and say 122 volts really changes things on us.. :smack: I usually stay within a range on my BF Fender amps with 6L6s between say 30 to 34 millivolts and I'm good to go as a rule..My Marshalls with EL34s I set higher..More like 35 to 36 but my readings are based on plate voltages..
John
Lewguitar said:
Yep...That's the reason for the 1% resistors,so the value is pretty much 1 ohm...Tube amps are very forgiving and the ever changing wall voltages coming into our amps makes alot of difference to the readings than that small difference in resistor values..The difference in our readings between 120 volts and say 122 volts really changes things on us.. :smack: I usually stay within a range on my BF Fender amps with 6L6s between say 30 to 34 millivolts and I'm good to go as a rule..My Marshalls with EL34s I set higher..More like 35 to 36 but my readings are based on plate voltages..
John
L
Lewguitar
Guest
Re: What value do you bias your amp at?
Yep...that's pretty much the range I use too. Actually, I set the bias by ear, but I always go back and measure to just to make sure I'm within that range. Lew
STRATDELUXER97 said:
Yep...that's pretty much the range I use too. Actually, I set the bias by ear, but I always go back and measure to just to make sure I'm within that range. Lew
STRATDELUXER97
Stratoblaster Tone Meister
Re: What value do you bias your amp at?
I Like to keep my readings on the low side if possible..It gives the tubes a bit more life...Lower settings also gives you more headroom...Depends on what you need though,headroom or quicker breakup? I keep Blackplate RCAs in my BF amps also..They can take anything you throw at them..
John
Lewguitar said:
I Like to keep my readings on the low side if possible..It gives the tubes a bit more life...Lower settings also gives you more headroom...Depends on what you need though,headroom or quicker breakup? I keep Blackplate RCAs in my BF amps also..They can take anything you throw at them..
John
