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DEWD
Member
Do you set it to el34 or 6l6?
I have a 4 adapter bias rite so do I set each tube to be around 45 to 50?
Thanks!
I have a 4 adapter bias rite so do I set each tube to be around 45 to 50?
Thanks!
Ailean
New member
Diezel website":3j8qlqwl said:
A little hotter by the looks of it.
http://diezel.typo3.inpublica.de/tech-corner.3.0.html
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DEWD
Member
Hmm....so I set it to 6l6 and biased the 6550's to 45 on my 4 adapter bias rite and it sounded okay but the eq was very unresponsive and the cleans weren't very loud. So I did it again using a DMM and biased the amp the 90-92 per side like the instructions on the Diezel site say. When I did this my bias rite was reading 62-63 per tube. Any ideas why it's different? Shouldn't the bias rite be saying 45-46 per tube and 90-92 per side with a DMM? I've left it set at the bias rite 62-63 per tube and 90-92 with the DMM and it sounds better but I can't really turn it up that much until later today.
Should I have the amp set to el34?
Any help would be appreciated.
Should I have the amp set to el34?
Any help would be appreciated.
MARK2C
Active member
Bias in the 6L6 position. The bias adapter is also picking up the screens so the reading will be different than the shunt method.
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DEWD
Member
okay now I'm really confused. someone in the regular rig talk forum said to use the el34 position. which one is it?
is the shunt method better/more accurate than the bias rite? which one should I use?
thanks!
is the shunt method better/more accurate than the bias rite? which one should I use?
thanks!
duesentrieb
Well-known member
I'd use the 6L6 position (either one that works is good, you know - it depends if your range fits, not how it is labelled. So first try with the 6L6 setting and bias with the bias rite. If you get into a good range you're done, if not: use the EL34 setting).
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DEWD
Member
Thanks! Both get me in the range just fine so I guess it doesn't matter.
Since I have a 4 adapter bias rite each one should read about 45-50, correct? Is there any reason to pull the fuses on any of the tubes?
Since I have a 4 adapter bias rite each one should read about 45-50, correct? Is there any reason to pull the fuses on any of the tubes?
duesentrieb
Well-known member
The bias rite measures each tube !
The bias range: 80mA (per pair) or 40mA per tube is on the colder (and safer) side - in the end your ears decide. You can bias each tube up to 40-50mA (so 80-100mA per Pair).
45mA might be a good start (per tube), should be healthy enough for your tubes and sound good.
Additionally your bias rite reads the cathode currents, which include the screen current, while shunting only results the plate currents.
The bias range: 80mA (per pair) or 40mA per tube is on the colder (and safer) side - in the end your ears decide. You can bias each tube up to 40-50mA (so 80-100mA per Pair).
45mA might be a good start (per tube), should be healthy enough for your tubes and sound good.
Additionally your bias rite reads the cathode currents, which include the screen current, while shunting only results the plate currents.
duesentrieb
Well-known member
When using the bias rite don't pull fuses !!!
flownomis
New member
wtf is the el34 position?
i always thought i just pull out my old tube (e.g. el 34) , put in the 6550 and bias it new to 80mA.!?!?!?!
please explain!
i always thought i just pull out my old tube (e.g. el 34) , put in the 6550 and bias it new to 80mA.!?!?!?!
please explain!
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DEWD
Member
Thanks bro, that's what I needed. 
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DEWD
Member
flownomis":cd0q7zqu said:wtf is the el34 position?
i always thought i just pull out my old tube (e.g. el 34) , put in the 6550 and bias it new to 80mA.!?!?!?!
please explain!
There's a 6l6/el34 flip switch behind the power tubes (just in the VH4). Both positions got me in the right range for 6550's.
edited by Olaf
