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Posted: Wed Sep 08, 2010 2:47 pm
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canucklehead wrote:
Thanx for the advice, markara. What would you suggest as a quality "contact cleaner" - rubbing alcohol?

My new GT tubes (white labels) are only about 4-6 weeks old, so i doubt there would be much dirt/residue left in the sockets when installing the new JJ El84s (pair of #38s) and EH 12AX7s. My understanding is that the new JJs and the white labelled GT tubes are fairly close in bias rating. Consensus is just "plug and go"!.


I guess everyone else has answered this for you. Contact cleaner is actually a product that you can buy at places like Radio Shack.

On the bias adjustment, or lack thereof on the BJ. I have read and read and read about this and cannot come to a personal opinion. Most notably Billm highly recommends modifying the BJ to allow for adjustment, Eurotubes says no need to.

I have come to the conclusion that since I can't find a true consensus, I will just not mod my amp. I bought it because I like the tone as is.

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Posted: Wed Sep 08, 2010 3:34 pm
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As an electronic technician myself and guitar player, I fix many amps and I can't understand people saying that no bias is required with new tubes.
I'm able to mesure and "see" the need of bias, and ear to.
This is a proof to me that on the web many thing are false.

In the case of what markara said about eurotube what I can say is :
1- markara do a" mistake" when he read what Eurotube write.
or
2- The guy at Eurotube don't know what is bias


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Post subject: BJr bias
Posted: Wed Sep 08, 2010 4:35 pm
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I agree with you stratele52, and I agree with Billm; tubes should be properly biased. As hard as it is to believe, Bob at Eurotubes says the following.

"I get almost daily inquiries about the VERY popular Bill M. mods for these amps so please note, the following is simply my opinion and will not be shared by everyone!!!! (Sorry Bill)

While some of the Bill M. tone mods are nice I completely disagree with his theory on correct bias for these amps. The BM bias mod will suck the life and tone right out of the amp. I can't tell you how many players have called me wanting tubes that will breath life back into their Junior's and Pro's and during the conversation they will fess up to the BM bias mod. This mod will get the bias way too low. Players like these amps because they sound good right out of the box and they are biased hot which gives them a great juicy tone with a very good dynamic response so my recommendation is to leave the bias as is and make sure that who ever you buy your tubes from knows what the tubes are for and grades their tubes. Hopefully they will also know something about these amps too.
"

Imagine that, two experts that disagree.... :lol: Bob is completely wrong about: "This mod will get the bias way too low", as the mod is an ADJUSTABLE pot and can be set hot or cold or roasting, wherever you want. From my own personal experience with tube biasing and the BJr, my tubes were idling at well over 100 percent dissipation, and I've read the same on forums. I can't see where Bob is getting 85-95 percent idle (which is better than most I've heard of) on the BJrs he has checked. If it were only 85 percent idle, then it wouldn't be as important to change the bias, as it would be if the idle was higher. And I completely disagree with Bob about "juicy tone" from tubes that are melting from being too hot. General rule of thumb, cooler operation of tubes = longer life. <-- Who can argue with that?

It seems that nearly all of the amp manufactures are keen on proper bias. I read in an Egnator manual about the bias being set too high that "Warning: DO NOT be tempted to run your tubes hotter than the maximum values in the chart. You may find the sound really cool as you destroy your expensive tubes..." So, I guess that Bruce Egnator also recommends proper bias. I believe that some Egnator amps even have a bias adjustment on the outside so that you won't have to open up the amp. Eurotubes seem to be the only ones that recommend torturing your tubes and sending them to an early grave. :)

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Posted: Thu Sep 09, 2010 2:15 am
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You are right shimmilou.

And what I can say :
The bussiness at Eurotube is....to sell tubes.
Wrong bias (too hot) will sell tubes........


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Posted: Thu Sep 09, 2010 10:44 am
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stratele52 wrote:
You are right shimmilou.

And what I can say :
The bussiness at Eurotube is....to sell tubes.
Wrong bias (too hot) will sell tubes........


And Billm sells mods! Saying the bias is too hot and cooking tubes will sell his mods.
I think if every musician who uses these amp fried tubes every week, Fender would have possibly done something about it. Well.... Maybe not, but biasing tubes hot will shorten their lifespan. It's a trade-off that most professional musicians including myself live with. Bob also only sells one brand of tubes.... JJ's. I find them to be one of the most robust current production tubes on the market. Bob also knows his stuff. Bill likes to tell folks their amps tone is seriously lacking and needs his mods. Total BS in my book.

Tone is a subjective and personal matter. I've heard some of the Billm mods in person and the stock Jr side by side. Was it a huge improvement? Not to me, and not worth the hassle, expense, or voiding a warranty over. It is different, but not a huge improvement to my ears. There is a difference between a difference and an improvement. Tons of folks love the amp stock. I know dozens that do. There is a 5 year warranty on these things too. I won't buy any amp that I need to mod in the quest for tone.

I don't have any agenda on this topic, I'm just amused that everyone thinks the sky is falling because the tubes are biased hot. Neither Bob nor Bill are wrong on this subject. I did find a huge improvement when I had my HRDlx using JJ's ans Bob's biasing advise not by voiding the warranty and modding the amp.

If you want to mod the Blues Jr, do it. The way I modded my HRDlx was to sell it and get an amp I really love instead of settling for something that's just okay. The era of Fender making hand-wired masterpieces is long over. That's why I won't buy a current production Fender amp. Sorry... Flame suit on.
:shock:
This is only my opinion and not intended as a personal attack on anyone. If I offended anyone, I apologize in advance.

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Post subject:
Posted: Thu Sep 09, 2010 11:49 am
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I don't know about Billm mods, but a proper bias give the best tone and tubes have long life.


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Posted: Thu Sep 09, 2010 12:28 pm
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Like I said, tone is a personal preference. What's good for you and the style you play might not be right for me. Your ears will be the final judge. If your tubes are red plating, you obviously have a problem. Just because the tubes are biased within "spec" doesn't mean it will automatically sound better to someone's ears either. Some tubes will take the abuse better than others. Is "proper bias" better for tube life, sure. Does it mean it will sound great to you? Possibly. It usually never really works that way for me. I bring a spare set of tubes and multimeter to every gig as well as another amp. Even "properly biased" tubes can fail at any time without warning so the long life statement is a moot point.

This should not really be an issue for the bedroom player or weekend jammer.

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Posted: Thu Sep 09, 2010 1:01 pm
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I agree with you 63supro, you seem to have khowledge to work with your tube and bias and make tests. If you don't like, you change bias.

But I just try to answer to canuklehead about swaping tubes. He can't take chance without knowing how is the bias with is new tubes.


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Posted: Fri Sep 10, 2010 2:23 pm
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Fender's motivation -- like all for-profit endeavors in the age of the "me generation" -- is the bottom line.

And marketing is job one.

Period, end of story, nothinig follows.

You forget that to your own detriment.

Arjay

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Posted: Fri Sep 10, 2010 4:06 pm
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Even if you like running your tubes hotter than the design spec for an EL84 (12watts max dissipation), if you have adjustable bias you have the abiltiy to get the new tubes back into the range where you like it.

Without checking the bias your new tubes may run a lot cooler than the old ones and you just lost that "hot running" tone you so like. By adjusting the bias you can get the new tubes back up to where you like it.

63supro wrote:
Quote:
And Billm sells mods! Saying the bias is too hot and cooking tubes will sell his mods.


As far as Billm telling people their tubes are cooking so as to sell mods, I think that's a bit of an off-base comment considering he shares how to do the bias mod for anyone to follow for free on his website at the cost of a readily available $0.25 resistor or a similar 25 turn adjustable, he even has a link on where you can get the parts.

http://home.comcast.net/~machrone/bjr/bjbias.htm


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Posted: Sat Sep 11, 2010 1:38 pm
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No457 Snowy wrote:
Even if you like running your tubes hotter than the design spec for an EL84 (12watts max dissipation), if you have adjustable bias you have the abiltiy to get the new tubes back into the range where you like it.

Without checking the bias your new tubes may run a lot cooler than the old ones and you just lost that "hot running" tone you so like. By adjusting the bias you can get the new tubes back up to where you like it.

63supro wrote:
Quote:
And Billm sells mods! Saying the bias is too hot and cooking tubes will sell his mods.


As far as Billm telling people their tubes are cooking so as to sell mods, I think that's a bit of an off-base comment considering he shares how to do the bias mod for anyone to follow for free on his website at the cost of a readily available $0.25 resistor or a similar 25 turn adjustable, he even has a link on where you can get the parts.

http://home.comcast.net/~machrone/bjr/bjbias.htm


Nah, I don't find it off base at all. Most people that buy an amp buy it because they think it sounds good or even great to them. Then some guy comes along and because he doesn't like the way the amp sounds gets all the people who were happy in the first place thinking, hey, my amp must sound bad because this amp guy says so. I better mod it. It's just silly. With all my rants about the HRDlx, 99% were about build quality, not tone. I tweaked my tone to my liking with just a simple tube change and bias, but adjustment. I never felt it needed a ton of mods. The funniest thing I see is people doing $300 Fargen mods to a Champion 600 which you can buy the amp for $150 or less.

I would build a Tweed Champ before sinking all that coin into a cheaply made cabinet like that. That's just me. Some people like my comments, some don't. It doesn't bother me because I think we're all entitled to our opinions. Lets face it, most people who buy these amps usually just use them for practice amps and rarely play professionally. I wouldn't lose any sleep at all over an amp that biased hot unless I was having problems with red plating or other heat related issues.

The sky is not falling.

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Post subject:
Posted: Sat Sep 11, 2010 4:02 pm
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Your comment that Billm is telling people their bias is running too hot so as to sell mods, is inaccurate.

The method to install an adjustable bias is freely shared on Billm's website, he's not asking anyone to pay for that. He even provides a link to Mouser where you can purchase the $3.00 worth of parts.

As for anything else people do to their amps, that's their business really and not for any of us to judge.


Last edited by No457 Snowy on Sat Sep 11, 2010 4:06 pm, edited 1 time in total.

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Post subject:
Posted: Sat Sep 11, 2010 4:02 pm
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63supro wrote:
....Most people that buy an amp buy it because they think it sounds good or even great to them. Then some guy comes along and because he doesn't like the way the amp sounds gets all the people who were happy in the first place thinking, hey, my amp must sound bad because this amp guy says so.....


Man, that sounds just like a guy on this forum who tries to convince people that they aren't happy with their Hot Rod Deluxe. :wink: The fact is, as the poster above said, Bill shares his knowledge for free, he makes no money by sharing the info. 8)

But, I agree that accusing comments about Bob and Bill are uncalled for. I think that they are both honest business men. Do you really believe that either one of those gentlemen are dishonest? I don't. And, quite frankly, if a person is happy with the sound of the BJr, then they find out that the tubes won't last long being abused as they are, they would be silly not to want to correct that problem. I don't agree with Bob about the bias on the BJr, and I think that it is best to leave it at that. :)

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Posted: Sat Sep 11, 2010 5:48 pm
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Bill does offer the mods as a paid service too as well as giving the info freely correct? I would venture to guess more people would rather have it done than do it yourself. I'm not picking on Bill or Bob, but the whole hot bias cooking tubes thing on the Blues Jr. is blown completely out of proportion, but again, that's just my opinion.

And shimmilou, I never tried to convince anyone of trying not to like their HRDlx. The HRDlx does that without my help. I warned people of potential reliability problems with the amp, not how it sounded BEFORE they even bought the amp. Tube changes help the tone without modding the amp and voiding the warranty. But if all my complaining and eye opening information as well as alternative amp choices has even a minute percentage of Fender coming out with the new and improved HRDlx III I'm happy.

I have helped many forum members privately through my personal email with their HRDlx problems, also for free even though I have charged some folks for some simple repairs on their amps.

And yes, they were pretty cheap shots at Bob from Eurotubes. Bob is the one who told me not to mod the HRDlx and he was correct. I was ready to mod the snot out of it. He also told me the amp had some design flaws but sounded great with a proper bias and tube change.

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Post subject: Bob, Bill
Posted: Sat Sep 11, 2010 6:05 pm
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63supro, you are cool in my book, just pokin' ya a little. :P 8) Bob has also been fantastic, lightning fast helpful email responses. And guess what? I was having some farty/weird sounds from my HRDlx at higher volumes lately and when I checked it out, two of my DC supply caps are leaking. But, partly due your advice I already had some spares on hand. Got some work to do! :)

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