Thanks for the great info in this video...I just picked up a used blues junior II (2003 cream board) and the power tubes were being cooked after a few minutes of turning the amp on. The 82k piggy back resistor cooled everything down with no loss of the sweet Fender tone...I also removed the bright cap as well and it tamed the harsh highs. Much much much appreciated!
Just when you thimk you've refined your "touch" to where it's decent... (?) Tis truly a never ending battle betwixt you and "your own worst critic" IMHO you've a great touch and you're obviously a great player. Thanx Lyle, I always enjoy all your videos and cheers
I have a first generation green board Blues Jr. that the late Bill Machrone modded doing pretty much the same things you've done. Only other tweak that I like is he changed the tone stack caps to match the values of a Princeton. I had to double check and he used 270pF on the treble and 0.1uF on the bass. Mid he left at 0.022uF. Really gets rid of the boxy sound.
I bought a new gen2 Tweed LTD BJr in 2006 that came stock with a Jensen P12N AlNiCo speaker. Made the typical changes to the bias resistors, filter caps, and power supply caps. A couple years later I put the unused half of the V2 preamp tube to work as part of an oscillator to add a tremolo effect to the bias voltage of the EL84 output tubes. A daughter card was put in for the circuit components, and a small box added to the rear to house the pots for speed and intensity. A Fender Rev/Vib footswitch was also added for those two effects while the FAT feature retained the original single footswitch. It is a versatile amp.
Thanks. That was informative and fun. I'd say as long as your right hand knows what your left hand is doing, you're doing all right. By the way, the equivalent resistance for two parallel resistors (product over sum) yields 23.5 ohms, Homes.
Like the guy that brought me his amp, "It's buzzing" I play it for hours. I go to see him at a gig, and notice his cell phone laying on the amp above the input...Oh I always put it there. I picked up the phone, "Hey the buzz is gone"...But, I like this far better than the BillM trim pot for bias. Next time I go into the amp, it's coming out, as are the cheap diodes and a few other bits. Thanks.
Bought 2 of theses amps in 2002. 20 years, 50 states half dozen overseas flights and too many long nights leaving it on and forgetting about it for days at a time, still on original power tubes on one. The input jack and reverb tanks I have had to replace over and again though. But they have taken more of a beating than I can describe.
My experience inside a Blues Jr. lead to “don’t move anything you don’t have to.” I added a trim pot for adjustable bias, but that meant lifting the board… which caused other problems with the ribbon cables.
I have a blues junior 3 that has the lightning in a bottle issue (from another one of your videos). I'm looking to fix that and do the bias fix in this video. Let me preface this question by saying: i am not an electronics engineer or technician, but I can solder, I can read a diagram and a multi meter, and I can replace parts. Also this amp has been down for about three years, so I'll still check to make sure its not hot before I get into it, but I don't expect it to be hot after so long. Looking at the diagram that fender put out for the blues junior, the resistor in r51 doesnt list a wattage rating (maybe I don't know how to read the diagram 🤷♂️). How do I determine the wattage rating for the resistor in r51 aside from assuming that its the same rating as the resistor on r53 (1w) thats next to it in the diagram?
I've been doing this for a while now but my procedure is a little different. I clip a couple test leads and use a 50k pot in parallel to get exactly what I want as measured with a couple bias probes then I get as close as I can value wise considering the particular pair of tubes which can vary quite a bit in current draw.
HI. Love your channel! I have a 2023 Blues Jr. LTD with a black board. R51 is in a different place. Should I still piggyback a 82k resistor off r51? or has Fender corrected the hot bias problem with this black boarded model?
I believe the black board has converted the bias from fixed to cathode bias so that specific resistor change isn't necessary. However, it seems the cathode bias is still a little hot. I'm trying to determine the correct cathode resistor value to cool the EL84s back to say 80% or so idle dissipation. Any thoughts, Lyle?
Unless I missed it you didn't mention it, but I noticed (during the soundcheck at the end) that you seem to have the master volume fully cranked and use the "normal" volume/gain to set the actual volume. Is this your default way with this amp? I actually found - more or less by accident - that my BJ tends to sound best when I do it the very same way: the sound is fuller, somewhat less ”boxy“ and the dynamics seem to be more sensitive to how softly or strongly I dig in with the pick... Would you generally subscribe to this impression I'm getting?
Hello again, I did a Fromel Complete made in Mexico Mod Kit back in 2009 on my blues junior 1. With that, the bias cooling mod was as follows "At R52 install the 33K bias resistor". Have I achieved the same bias cooling as you have here in this video. I noticed you installed the resistor at R51 not R52. Cheers mate Ollie
Speaking of eating '84s... A while back I replaced the stock 100R screen stops in a Carvin Nomad 50 (fixed bias like BluesJr) with 2k 2W wire wounds. Protects the tubes and changes the character of the amp: slightly softer and improved touch sensitivity. Not everyone will like it -- but I sure do!
Great videos on moding and troubleshooting the Blues Junior. I did this mod and I am measuring about 1.9 volts measured across Red (P2) to Brown (P3). Does this sound about right? I played it for about an hour and it sounds fine. No issues with tubes or other components. Others are saying that you should be in the 2.3-2.5 volt range for idle voltage. I did play with other resistor values and here is what I found for voltages, and here is what i found for results: Stock, 33k Resistor @ 3.5 volts 82K Resistor @ 1.9 volts 120K resistor @ 2.2 volts 150K Resistor @ 2.5 volts I went with the 82K mod per the video, and have a matched set f the EH EL84 tubes on the way to try. Thanks again for the great Videos and information!
Rather than rely on internet rules of thumb. Everyone should model their amplifier’s load line on the Vtiady website using the load line calculator to see where idle should be set. I have fooled around with the calculator and have noticed that sometimes on some configurations, your amplifier will generate more heat and lose audio power by increasing the idle current.
Remember folks, the 70% max idle dissipation rule was always supposed to be a maximum guide value. You can happily drop way below that. In my experience, most people will notice no change in tone or output until you drop below 50%.
Fender does appear to be exceeding the maximum 6BQ5 power dissipation. The RCA receiving tube manual lists the maximum plate dissipation as 12W. My SPICE simulation of the Blues Jr output section lists the 6BQ5 idling current power at 14.3W. The Blues Jr schematic lists the B+ voltage at 329V, with the grid biased at -10.6V. It makes me wonder if Fender is using a power transformer from an existing application that is actually a higher output voltage than the specified or deliberately driving the 6BQ5 above recommended specifications. The grid bias can be further decreased (more negative) to reduce power dissipation, but moving the 6BQ5 idling point may introduce more distortion. This all hinges upon what the actual B+ (plate) voltage from the power transformer.
5:38 can I ask how you solve for the new resistor amount? In parallel it would be 33x?/33+? = 24k Correct? I’m not much of a math guy but needing to learn. How is the unknown solved for? Thanks!
@@PsionicAudio thanks! Didn’t even think about that. I understand how the 33k and 82k make 24k (23.5 ish) but the calculator is asking for the resistor values and giving me the total. I can’t imagine that it would be trial and error until I came up with the second value needed would it? In other words, you have 33k and want 24k so resistor 2 is unknown. Seems like the calculators all want you to enter r1 and r2.
I'm trying to do this mod on an early green board US made Blues Jr. but the resistors aren't laid out the same. It seems like on the green board version I'd be piggybacking the new resistor across R31. Correct?
I don’t have that schematic handy but it’s the top resistor in the voltage divider that provides the bias voltage. I think the divider was 33K/24K on those, though it’s hard to measure the lower value because of the cap across it.
Man I wish I’d have seen this before I bought the Blues JR, I’d have just got the Vox AC15 instead. Now to decide, do the upgrades, or sell and get the Vox???
@@stormyweather2837i have a blues jr and want a vox ac15 so bad. Right now before I make another big purchase I’m deciding between a 100 dollar squire tele I’ll upgrade or a vox ac4tv
I did this mod early last year and my el84's have lasted over a year so far ,and i play this amp everyday so thanks lyle.pretty sure you said to put 67k resistor last time tho?
My BJ is so trebly I set the treble pot to off ! I've clipped out the bright cap on the volume as well but it's not made any difference. Tried with Les Paul, Strat,Tele etc, but can't get it to a place where you can't hear your hand touching the strings . Though about changing the 250pF cap on the treble part of the tone stack. Any recommendations ?
On right hand technique: there are days when my wife would prefer a "palm mute" ---- clamped down tightly over my mouth 😁! Oh, you meant guitar playing.... in my own case, the heavier the palm muting, the better! (Actually, when it comes to fingerstyle electric guitar, Sonny Landreth's right hand picking, muting and harmonic-chime technique just slays me).
@@mamulcahy, Vince Gill described Sonny's technique as "like an Algebra lesson ---- in a million years I could never learn to do what he does". I have also felt similarly watching Steve Morse, and Richard Thompson.
You mention that the bias is too hot in the first three iterations of the amp. I have a Blues Jr. IV so is there a bias problem with that one too or did Fender ever get their act together and fix this problem?
@@PsionicAudio ok thanks. I saw a video of a guy who did the same mod that you did on a IV But I had heard the same thing so I guess the true test is to measure where the bias is at before proceeding.
thanks...things can be so easy....I should have known this 2 weeks ago...now I have probably a dead power supply after an EL84 said goodbye with a blaze of beautiful purple lightshow glory...since then the amp is dead (fuses,screen grid resistors are ok though)...
Every junior I get in is biased way to hot. And I can place a bet that the pcb supporting the tube sockets is starting to fail. The only and best repair is to point to point to new tubes sockets. Dam I’ve done a lot of these!
Good point about these amps eating tubes. I used one at Lion King in NY for years. (With 2 as backups - any issue and the sound crew rushes in and switches it out - yes, like a “pit” crew). We changed those tubes 2 or 3x’s a year - except I changed them all because I could. Now I have quite a stash! (We lately changed the amps) Anyway, I love your channel! I was searching Gemini 1 (excellent info) but I have a 1st gen tan BJ that I haven’t touched for years. Input jack. Now I’ll do the other suggested mods as well. Btw, are you near NYC, since you know Fuchs?
hello, good video am french am not sure to understand everything i have one little question. i have blues junior III this mod whit the resistor 82k it is for this model also ? bye
@@retread1083 , "When the lights are out, I've got to hand it to me/ guess it's just you and me again tonight, Rosie.....". Jackson's song "Redneck Friend" is another one that isn't what it might seem at first listen.
No, the secondaries will behave the same even with different primaries used. The issue that would affect bias is primary voltage fluctuation. As the primary changes, all the secondaries change in proportion. So 240 isn’t harder on bias than 120. But if your “240” ranges from 220-250 then you may have concerns about the bias changing too.
Fender bought Groove tubes from Aspen Pittman, so why not make amps that eat up tubes quickly? Aspen was mostly just the main marketer for Groove Tubes. Hunter Dabney did all the really hard & heavy lifting by designing all of the equipment for GT. Hunt left GT around 1981-82, went out and got some other audio patents filed & approved. Then he went into a consulting business to sustain his patents. Hunt and my second cousin H.W. (Barney) Barnes Jr. were good friends who worked together on patents for a very wide range of purposes. FMIC knows less than NOTHING about tubes. They know how to print the name Fender & Groove Tubes on JJs or New Sensor tubes and that's it.
Go to wal mart and get you some Clarinex, u have to ask for it. 1 a day n u should be ok. I'm in the same weather as you....also not trying to tell you what to do...didn't wanna come off as well u know.
Bias is stated easily to think of it like it temp starting at zero . More bias more negative thus cooler . Less negative warmer . By calling it negative bias the effect is clearer . Well that the method I use to remember the effect. The real way to run 70% on the output is with a fully regulated high voltage and screen grid voltages that not happening with a fender at all.
10:47...well, "ya can't have EVERYTHING!!!" And I'm pretty sure that Alan Hines wouldn't be worth a DAM when it comes to fixing guitar amplifiers-(?) We're ALL a little different- that's why we are called "INDIVIDUALS"-(!)
Dude after THREE VISITS n NON fixes with NOTHING wrong ( was a working Working tech at Action Music Clt NC) The guy FINALLY brings in a TS-9 n the amp goes BESERK< YET i was the A-hole on the deal, go figure............
Glad I found this Brad acts like a jerk. I would like to clone a 1950 silvertone hifi medalist or medallion? Into a guitar head. I made one from a scrapyard find and it was stolen.
![BLACK BAG - Official Trailer [HD] - Only in Theaters March 14](http://i.ytimg.com/vi/Du0Xp8WX_7I/mqdefault.jpg)
...in high school. awesome.
Thanks for the great info in this video...I just picked up a used blues junior II (2003 cream board) and the power tubes were being cooked after a few minutes of turning the amp on. The 82k piggy back resistor cooled everything down with no loss of the sweet Fender tone...I also removed the bright cap as well and it tamed the harsh highs. Much much much appreciated!
Just when you thimk you've refined your "touch" to where it's decent... (?)
Tis truly a never ending battle betwixt you and "your own worst critic"
IMHO you've a great touch and you're obviously a great player.
Thanx Lyle, I always enjoy all your videos and cheers
I have a first generation green board Blues Jr. that the late Bill Machrone modded doing pretty much the same things you've done. Only other tweak that I like is he changed the tone stack caps to match the values of a Princeton. I had to double check and he used 270pF on the treble and 0.1uF on the bass. Mid he left at 0.022uF. Really gets rid of the boxy sound.
I bought a new gen2 Tweed LTD BJr in 2006 that came stock with a Jensen P12N AlNiCo speaker. Made the typical changes to the
bias resistors, filter caps, and power supply caps. A couple years later I put the unused half of the V2 preamp tube to work as
part of an oscillator to add a tremolo effect to the bias voltage of the EL84 output tubes. A daughter card was put in for the
circuit components, and a small box added to the rear to house the pots for speed and intensity. A Fender Rev/Vib footswitch was
also added for those two effects while the FAT feature retained the original single footswitch. It is a versatile amp.
I started guitar by playing country music in the 90's.
Consequently, I got to know my right hand very well.
😂 join the club.
Oh my...that last line😄 Keep up the good work, great channel.
Thanks. That was informative and fun. I'd say as long as your right hand knows what your left hand is doing, you're doing all right. By the way, the equivalent resistance for two parallel resistors (product over sum) yields 23.5 ohms, Homes.
Like the guy that brought me his amp, "It's buzzing" I play it for hours. I go to see him at a gig, and notice his cell phone laying on the amp above the input...Oh I always put it there. I picked up the phone, "Hey the buzz is gone"...But, I like this far better than the BillM trim pot for bias. Next time I go into the amp, it's coming out, as are the cheap diodes and a few other bits. Thanks.
Bought 2 of theses amps in 2002. 20 years, 50 states half dozen overseas flights and too many long nights leaving it on and forgetting about it for days at a time, still on original power tubes on one. The input jack and reverb tanks I have had to replace over and again though. But they have taken more of a beating than I can describe.
Thankyou for the tips and repair help fender blues jr
Back to the top. Still relevant.
My experience inside a Blues Jr. lead to “don’t move anything you don’t have to.” I added a trim pot for adjustable bias, but that meant lifting the board… which caused other problems with the ribbon cables.
I have a blues junior 3 that has the lightning in a bottle issue (from another one of your videos). I'm looking to fix that and do the bias fix in this video. Let me preface this question by saying: i am not an electronics engineer or technician, but I can solder, I can read a diagram and a multi meter, and I can replace parts. Also this amp has been down for about three years, so I'll still check to make sure its not hot before I get into it, but I don't expect it to be hot after so long. Looking at the diagram that fender put out for the blues junior, the resistor in r51 doesnt list a wattage rating (maybe I don't know how to read the diagram 🤷♂️). How do I determine the wattage rating for the resistor in r51 aside from assuming that its the same rating as the resistor on r53 (1w) thats next to it in the diagram?
I've been doing this for a while now but my procedure is a little different. I clip a couple test leads and use a 50k pot in parallel to get exactly what I want as measured with a couple bias probes then I get as close as I can value wise considering the particular pair of tubes which can vary quite a bit in current draw.
HI. Love your channel! I have a 2023 Blues Jr. LTD with a black board. R51 is in a different place. Should I still piggyback a 82k resistor off r51? or has Fender corrected the hot bias problem with this black boarded model?
I believe the black board has converted the bias from fixed to cathode bias so that specific resistor change isn't necessary. However, it seems the cathode bias is still a little hot. I'm trying to determine the correct cathode resistor value to cool the EL84s back to say 80% or so idle dissipation. Any thoughts, Lyle?
I was wondering if putting in a adjustable bias pot is recommended by you ?
Unless I missed it you didn't mention it, but I noticed (during the soundcheck at the end) that you seem to have the master volume fully cranked and use the "normal" volume/gain to set the actual volume. Is this your default way with this amp? I actually found - more or less by accident - that my BJ tends to sound best when I do it the very same way: the sound is fuller, somewhat less ”boxy“ and the dynamics seem to be more sensitive to how softly or strongly I dig in with the pick... Would you generally subscribe to this impression I'm getting?
I prefer to use MVs as little as possible.
With the 24k ohm cooled bias can you put in mullard el84's no problem without having to bias for those specific tubes?
What temperature are you using for the solder iron?
Hello again, I did a Fromel Complete made in Mexico Mod Kit back in 2009 on my blues junior 1. With that, the bias cooling mod was as follows "At R52 install the 33K bias resistor". Have I achieved the same bias cooling as you have here in this video. I noticed you installed the resistor at R51 not R52. Cheers mate Ollie
Cool video !! so are all the blues jr 3s biased hot ? And do you think these are better then a marshall origin?
Speaking of eating '84s... A while back I replaced the stock 100R screen stops in a Carvin Nomad 50 (fixed bias like BluesJr) with 2k 2W wire wounds. Protects the tubes and changes the character of the amp: slightly softer and improved touch sensitivity. Not everyone will like it -- but I sure do!
Does cooling the bias effect the tone? Like is 50 to cool?
Great videos on moding and troubleshooting the Blues Junior.
I did this mod and I am measuring about 1.9 volts measured across Red (P2) to Brown (P3). Does this sound about right?
I played it for about an hour and it sounds fine. No issues with tubes or other components.
Others are saying that you should be in the 2.3-2.5 volt range for idle voltage. I did play with other resistor values and here is what I found for voltages, and here is what i found for results:
Stock, 33k Resistor @ 3.5 volts
82K Resistor @ 1.9 volts
120K resistor @ 2.2 volts
150K Resistor @ 2.5 volts
I went with the 82K mod per the video, and have a matched set f the EH EL84 tubes on the way to try.
Thanks again for the great Videos and information!
Nice Monster cable in there, I’ve used the same one almost everyday for 17 years. Incredible
Rather than rely on internet rules of thumb. Everyone should model their amplifier’s load line on the Vtiady website using the load line calculator to see where idle should be set. I have fooled around with the calculator and have noticed that sometimes on some configurations, your amplifier will generate more heat and lose audio power by increasing the idle current.
Thanks for the video, but, 68k resistor or 82k resistor?
Remember folks, the 70% max idle dissipation rule was always supposed to be a maximum guide value. You can happily drop way below that. In my experience, most people will notice no change in tone or output until you drop below 50%.
split the difference and make it %60 I say.
@@jasoneugenides5770 Nothing wrong with that.
Funky Wahwahs...my next bands name!
I have a TSL60 and long story short i got the bias wrong and had it half of what it should be 35mv but it still sounded good why is that?
Fender does appear to be exceeding the maximum 6BQ5 power dissipation. The RCA receiving tube manual lists the maximum plate dissipation as 12W. My SPICE simulation of the Blues Jr output section lists the 6BQ5 idling current power at 14.3W. The Blues Jr schematic lists the B+ voltage at 329V, with the grid biased at -10.6V. It makes me wonder if Fender is using a power transformer from an existing application that is actually a higher output voltage than the specified or deliberately driving the 6BQ5 above recommended specifications. The grid bias can be further decreased (more negative) to reduce power dissipation, but moving the 6BQ5 idling point may introduce more distortion. This all hinges upon what the actual B+ (plate) voltage from the power transformer.
Can you recommend a small, very low mass, surface mount VR that is a high quality component and will last. Once again great work and info.
Did you say if the Blues Jr IV has the bias issue too?
Do these resistor values work for every revision of the blues junior?
The BJ 4 is suppose to have the bias corrected from what I've read.
5:38 can I ask how you solve for the new resistor amount? In parallel it would be 33x?/33+? = 24k Correct? I’m not much of a math guy but needing to learn. How is the unknown solved for? Thanks!
Google parallel resistor calculator.
@@PsionicAudio thanks! Didn’t even think about that. I understand how the 33k and 82k make 24k (23.5 ish) but the calculator is asking for the resistor values and giving me the total. I can’t imagine that it would be trial and error until I came up with the second value needed would it? In other words, you have 33k and want 24k so resistor 2 is unknown. Seems like the calculators all want you to enter r1 and r2.
Thanks
I'm trying to do this mod on an early green board US made Blues Jr. but the resistors aren't laid out the same. It seems like on the green board version I'd be piggybacking the new resistor across R31. Correct?
I don’t have that schematic handy but it’s the top resistor in the voltage divider that provides the bias voltage. I think the divider was 33K/24K on those, though it’s hard to measure the lower value because of the cap across it.
Man I wish I’d have seen this before I bought the Blues JR, I’d have just got the Vox AC15 instead. Now to decide, do the upgrades, or sell and get the Vox???
Why is the vox way better of an amp ?
@@stormyweather2837i have a blues jr and want a vox ac15 so bad. Right now before I make another big purchase I’m deciding between a 100 dollar squire tele I’ll upgrade or a vox ac4tv
I did this mod early last year and my el84's have lasted over a year so far ,and i play this amp everyday so thanks lyle.pretty sure you said to put 67k resistor last time tho?
He mentioned a 68K resistor last time. Just rewatched it...
@@whapaso must have bn what i used then,defo worked great mod
It seems like after doing this mod the amp no longer breaks up. Can you still get gain out of your amp?
I think the Billm mod varies both r51&r52. Raises one, lowers the other. Keeps the ground potential the same.
My BJ is so trebly I set the treble pot to off ! I've clipped out the bright cap on the volume as well but it's not made any difference. Tried with Les Paul, Strat,Tele etc, but can't get it to a place where you can't hear your hand touching the strings . Though about changing the 250pF cap on the treble part of the tone stack. Any recommendations ?
@@Vintage_375 .. I'm on the third speaker change and none have made a difference to the treble. Back to the Celestion now. Thank for the suggestion.
On right hand technique: there are days when my wife would prefer a "palm mute" ---- clamped down tightly over my mouth 😁! Oh, you meant guitar playing.... in my own case, the heavier the palm muting, the better! (Actually, when it comes to fingerstyle electric guitar, Sonny Landreth's right hand picking, muting and harmonic-chime technique just slays me).
After I watched Sonny play from the front row, I wanted to put my guitar thru a table saw. Why bother playing if I can’t be that good!
@@mamulcahy, Vince Gill described Sonny's technique as "like an Algebra lesson ---- in a million years I could never learn to do what he does". I have also felt similarly watching Steve Morse, and Richard Thompson.
You mention that the bias is too hot in the first three iterations of the amp. I have a Blues Jr. IV so is there a bias problem with that one too or did Fender ever get their act together and fix this problem?
I don't know. I was told they changed that on the IV but haven't had one in.
@@PsionicAudio ok thanks. I saw a video of a guy who did the same mod that you did on a IV But I had heard the same thing so I guess the true test is to measure where the bias is at before proceeding.
thanks...things can be so easy....I should have known this 2 weeks ago...now I have probably a dead power supply after an EL84 said goodbye with a blaze of beautiful purple lightshow glory...since then the amp is dead (fuses,screen grid resistors are ok though)...
Every junior I get in is biased way to hot. And I can place a bet that the pcb supporting the tube sockets is starting to fail. The only and best repair is to point to point to new tubes sockets. Dam I’ve done a lot of these!
Good point about these amps eating tubes. I used one at Lion King in NY for years. (With 2 as backups - any issue and the sound crew rushes in and switches it out - yes, like a “pit” crew). We changed those tubes 2 or 3x’s a year - except I changed them all because I could. Now I have quite a stash! (We lately changed the amps)
Anyway, I love your channel! I was searching Gemini 1 (excellent info) but I have a 1st gen tan BJ that I haven’t touched for years. Input jack. Now I’ll do the other suggested mods as well.
Btw, are you near NYC, since you know Fuchs?
And btw, I watched your vids while playing the show, but with sound off/ captions on/ 50%speed! Lol. … yes, I pause it at times. ;)
Thanks! No, I’m in Memphis. Andy and I are in tech forums together. You get to know a lot of other techs all around the world.
Ah ok, cool. Yeah the forums can be a great community, especially once you find the handful of experts. ;)
hello, good video am french am not sure to understand everything i have one little question. i have blues junior III this mod whit the resistor 82k it is for this model also ? bye
yes. he was working on a BJiii because the control panel was black - it’s silver on the older BJ.
Does any of this apply to the Hot Rod Deluxe series?
No, they have a bias trim pot and the factory suggested 60mA (30mA each) is quite sane.
They have other issues but the bias is ok.
Lyle, didn’t Jackson Brown write a song about the expertise of his right hand technique….
I heard that song three or four times before I paid attention to the words. Then I couldn't stop laughing!
@@retread1083 , "When the lights are out, I've got to hand it to me/ guess it's just you and me again tonight, Rosie.....". Jackson's song "Redneck Friend" is another one that isn't what it might seem at first listen.
Dumb question - in Europe we use 230 V instead of 120 V....Is this Biasing issue more pronounced here?
No, the secondaries will behave the same even with different primaries used. The issue that would affect bias is primary voltage fluctuation. As the primary changes, all the secondaries change in proportion.
So 240 isn’t harder on bias than 120.
But if your “240” ranges from 220-250 then you may have concerns about the bias changing too.
Tone that works ensemble is very different than what sounds good playing solo. It did not take me many disappointing gigs to learn that one...
Preach it!
Everyone knows EL84’s sound best at 69.420% idle dissipation. Duh!
Yes, it’s a joke.
Use wooden chopsticks from a local Asian restaurant. They’re solid and no conductor.
Are you saying 8.2k or 82k?
82k
D’oh!!!
comedy gold! #especiallycloseinhighschool
Fender bought Groove tubes from Aspen Pittman, so why not make amps that eat up tubes quickly? Aspen was mostly just the main marketer for Groove Tubes. Hunter Dabney did all the really hard & heavy lifting by designing all of the equipment for GT. Hunt left GT around 1981-82, went out and got some other audio patents filed & approved. Then he went into a consulting business to sustain his patents. Hunt and my second cousin H.W. (Barney) Barnes Jr. were good friends who worked together on patents for a very wide range of purposes. FMIC knows less than NOTHING about tubes. They know how to print the name Fender & Groove Tubes on JJs or New Sensor tubes and that's it.
Go to wal mart and get you some Clarinex, u have to ask for it. 1 a day n u should be ok. I'm in the same weather as you....also not trying to tell you what to do...didn't wanna come off as well u know.
Bias is stated easily to think of it like it temp starting at zero . More bias more negative thus cooler . Less negative warmer . By calling it negative bias the effect is clearer . Well that the method I use to remember the effect. The real way to run 70% on the output is with a fully regulated high voltage and screen grid voltages that not happening with a fender at all.
10:47...well, "ya can't have EVERYTHING!!!"
And I'm pretty sure that Alan Hines wouldn't be worth a DAM when it comes to fixing guitar amplifiers-(?)
We're ALL a little different- that's why we are called "INDIVIDUALS"-(!)
"never mind"... ha ha
Dude after THREE VISITS n NON fixes with NOTHING wrong ( was a working Working tech at Action Music Clt NC) The guy FINALLY brings in a TS-9 n the amp goes BESERK< YET i was the A-hole on the deal, go figure............
I use someone else’s finger to move the ribbon cables on these.
🤣🤣🤣
Glad I found this Brad acts like a jerk. I would like to clone a 1950 silvertone hifi medalist or medallion? Into a guitar head. I made one from a scrapyard find and it was stolen.