2017 fender 65 deluxe reissue

[Kt500]

Hi I am new to this forum.
I have a stock fender 65 deluxe reissue dated 2017. I didnt like the harsh sounds thru the fender del strat single coils.
I used fender deluxe reverb modifications posted by swinging.lil.guitarman at ted weber amp board dated 2001.
Did most of the mods less spkr. Also installed jjs tubes. The only thing I did not remove yet is the treble cap c7 . It sounds way better. I do have a question
I used a bias probe to see the ma and it was 45 on my fluke after amp was warmed up 5 to 10 mins. I have yet to find out true info on how to correctly bias this. I am trained , experienced in all safety . Please help
Thank you for your time

[The Dude]

This might help.

Weber Bias Calculator

[Kt500]

Thank you for this!
Btw I found an old marshallforum post that debunks the posts seen these days on biasing .

[g1]

Btw I found an old marshallforum post that debunks the posts seen these days on biasing .

How about a link so we can read it?

[pdf64]

Some bias probes require the meter setting to current mode, others use a current sensing resistor and so require the meter being set to voltage mode.
So best to check the probe's instructions and re-measure.

[Kt500]

Titled Biasing-70%vs90%vsPlate currentvsCathodecurrent by wilder amplification
Am using a mobile phone

[Audiotexan]

How about a link so we can read it?

For convenience:
http://www.marshallforum.com/threads...current.10890/

[g1]

For convenience:
http://www.marshallforum.com/threads...current.10890/

Funny you should bump this, I remember following up on it and finding that thread. Could not make heads or tails out of what on earth he was on about.
I think he tries to separate plate dissipation from screen dissipation and does some math tricks that end up to the users detriment.
(I have never heard of the 90% rule he talks about and I think it is a 'straw-man' that is creating more confusion rather than explaining anything)

[Audiotexan]

Funny you should bump this

Yeah, what can I say. Still catching up on what I've missed!

I have never heard of the 90% rule he talks about

I hadn't either until now.
Seems to be have been running rampant on their site at some point though (according to thread snippets contained therein).

Maybe I'm just ignorant of the issue since I haven't ever used one of these aftermarket bias probes. /shrugs

[g1]

Well, it seems some are trying to compensate for screen current when biasing via cathode current. Allowing for 90% because of it is crazy, but what Wilder suggests is no more correct. He says to add the screen max. diss. and bias for 70% of total screen + plate diss. when using cathode current to bias. Again, you end up WAY hot. His example for EL34 is to add 8W (screen max) to 25W (plate) and set cathode current to 70% of 33W. So you end up with what, somewhere around 30% high?
As far as I know, screen current is typically around 5% of plate current? If someone wants to argue to allow an extra 5% current when measuring at the cathode, I have no problem with that.
This other stuff is totally nuts.

[alexradium]

anytime you read about biasing hot is better,think this:"are these guys trying to sell more tubes?"

[DrGonz78]

Someone posted on that thread "This is why Randall Smith's amps are not adjustable." Which might be partly true in the respect that they wouldn't want noobs setting the idle current at 90% dissipation. But the real reason is Mesa wants to sell tubes and keep their customers at the mercy of their design. Never heard of this 70% vs 90% debate before either. That Marshall thread is confusing to read as per the examples G1 pointed out.

[Leo_Gnardo]

Someone posted on that thread "This is why Randall Smith's amps are not adjustable." Which might be partly true in the respect that they wouldn't want noobs setting the idle current at 90% dissipation. But the real reason is Mesa wants to sell tubes and keep their customers at the mercy of their design. Never heard of this 70% vs 90% debate before either. That Marshall thread is confusing to read as per the examples G1 pointed out.

Early on, Mesa/Boogie amps DID have bias adjust, surprise! Back in the mid 70's when they were just starting up. Sure, Randall got tired of having to respond to warranty repair demands when amp owners or their friends with screwdrivers whacked the bias up to red plate territory. "But that's the only way amps sound good!" In order to cover his, uh, posterior, Mr. Smith left out the bias adjust. And that was all before Mesa were selling tubes as a sideline. Once tube sales commenced in the 80's, then the advice was "try 'em all, find which color makes your happy, and stick with them." For those who haven't encountered Mesa output tubes, they sort by emission matching and assign colors to various levels. Of course there's never been a guide to which color means what in terms of emission, so customers have to blindly select among yellow, red, blue, green, grey etc. Also, what music store keeps a selection of all colors available? You guessed it: none. So Mesa tube buyers can purchase direct and keep UPS/Fedex rich while they endure the color selection process. Phooey!

[nevetslab]

Early on, Mesa/Boogie amps DID have bias adjust, surprise! Back in the mid 70's when they were just starting up. Sure, Randall got tired of having to respond to warranty repair demands when amp owners or their friends with screwdrivers whacked the bias up to red plate territory. "But that's the only way amps sound good!" In order to cover his, uh, posterior, Mr. Smith left out the bias adjust. And that was all before Mesa were selling tubes as a sideline. Once tube sales commenced in the 80's, then the advice was "try 'em all, find which color makes your happy, and stick with them." For those who haven't encountered Mesa output tubes, they sort by emission matching and assign colors to various levels. Of course there's never been a guide to which color means what in terms of emission, so customers have to blindly select among yellow, red, blue, green, grey etc. Also, what music store keeps a selection of all colors available? You guessed it: none. So Mesa tube buyers can purchase direct and keep UPS/Fedex rich while they endure the color selection process. Phooey!

I'm sure the question has been asked and answered long ago, but, is there a chart that shows the plate current/dissipation relative to their 'color-coded' matched tube sets? This would, of course, depend on what amp of theirs is used. Even with other brands of tubes that can be purchased in matched sets, one doesn't really know what the plate current/dissipation is until you install them and check the current, whether by current probe, measuring across a plate resistor or cathode resistor or IR drop across the Primary leads of the Output Xfmr and computing what that current is, noting if more than one tube is installed, do you know for sure what the current sharing is.

BTW, if you're really measuring 45mA thru the cathodes of your 6V6GC power tubes, you're WAY too hot.