There is tone out there

Live sound reinforcement, running PA's and general amplifier/amplification questions and discussion.
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rparker
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Re: There is tone out there

Post by rparker » April 7th, 2010, 7:16 am

Good luck with the tubes thing. I'm really hoping I never have to do them. Not sure why. I think I read somewhere that they had to be "biased" (?), and have no idea what or how to do that. I'm sure I'd do the research and find out, but still....
Roy

"I wonder if a composer ever intentionally composed a piece that was physically impossible to play and stuck it away to be found years later after his death, knowing it would forever drive perfectionist musicians crazy." - George Carlin

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cnev
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Re: There is tone out there

Post by cnev » April 7th, 2010, 10:07 am

Actually Roy you may or may not need to bias the tubes. I think you could do it fairly easily but when I was checking the tubestore website they have a set of replacement tubes that can be put in without biasing. I guess there is a bit of a safety issue since you'll be poking around capacitors and things that could shock you.

Biasing has to do with the current getting to each tube (OK I'm sure it's much more than that but that's about all I know) and you have to tweak the bias to the tubes otherwise the tube will run hot and burn out faster or run cold and I would guess give you less than stellar performance.
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TRGuitar
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Re: There is tone out there

Post by TRGuitar » April 7th, 2010, 10:21 pm

Alot of the smaller and newer tube amps (from what I have read anyhow) don't even have a bias adjustment. I know my Peavey Classic 30 doesn't. I believe I have read about class A amps like my Epi VJ being self biasing. I think it may be Fender and may the the Hot Rod series that I read have a color code on their tubes. Red, blue and white. The tubes are tested and color coded according to their bias so you replace your tubes with the same color. I could see where this would lock you into buying your tubes from Fender though. :lol: Do a search to see if your amp has a bias adjustment. Might not be an issue.
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cnev
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Re: There is tone out there

Post by cnev » April 8th, 2010, 4:24 am

Tr the Hot Rod Deluxe has a bias adjustment on it so it can be done. I hadn't seen anything about color coding of Fender tubes but doing some research on the Groove tubes that Fender puts in them there was a pretty fair consensus that those tubes should be replaced anyway since not many people had very good reviews of them.

I could in theory replace them with original Fender Groove tubes but I'm interested in something a bit different.

If I really wanted to have the amp biased I have a guy I know that's a sound engineer and has worked on anything related to musical electronics for years and I'm sure he'd do it for free for me.
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TRGuitar
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Re: There is tone out there

Post by TRGuitar » April 8th, 2010, 6:01 am

Image

Here is a pic of one ... and a link

http://accessories.musiciansfriend.com/ ... sku=211210

Interesting concept. Maybe it was the Blues Junior that is fixed bias? Oh .. I looked it up, here is the reason for my confusion.
The power section uses a "fixed bias" biasing scheme with an adjustable bias potentiometer installed from the factory. The factory bias is 60 mA total for both 6L6s.
It comes from the factory with a trim pot. That is a mod that can be done to my Peavey Classic 30. Turns out fixed bias is actually the adjustable one and cathode biasing is the non adjustable .... but you do need the trim pot to do the adjustment. Here is a neat article I found that explained it without exploding my brain.
http://www.theguitarfiles.com/guitarfile-print-183.html
"Work hard, rock hard, eat hard, sleep hard,
grow big, wear glasses if you need 'em."
-- The Webb Wilder Credo --

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cnev
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Re: There is tone out there

Post by cnev » April 12th, 2010, 4:05 am

FWIW I used my buddy's Jekyl and Hyde pedal Friday for practice and my Hot Rod Deluxe and I have to say the tone was 100% better. I still think my tubes might be on the way out but I does sound like they still have some life in them.

The one thing I noticed was that the pedal really boosts the output of the guitar, I was extra loud Friday. Also it seemed the distortion side cut the volume and the OD side increased it.

I didn't really liek the distortion by itself but it was OK with the OD, the OD sounded good on it's own.
"It's all about stickin it to the man!"
It's a long way to the top if you want to rock n roll!

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