After uncle Doug retired i have been watching this channel often . Got to say , your definitely one of the best technicians out there . Thanks for the long video . 🎸
The long format videos are valuable. As an electrical engineer trained in the early days of solid state (old) I am continually surprised out how much I learn and how much I’ve forgotten. And how much practice is required. You are a worthy successor to Uncle Doug.
On the contrary, these long theme episodes are the definitive format. Not only as a teaching session, but more importantly, a safety guide for those novice techs who lack the formal experience to avoid possible electrocution. Not to mention it affirms your rhyme and reason for the hourly fee(s); which are mostly due to safe disassembly, and reassembly. If the choice were mine, I'd opt for this format always. Then again, I don't have to edit the video. I hope that these continue in the future. I too have the Hakko FX951. I optioned it for the auto shutoff, and locking key card features as well as the overall performance of the station. Well done as always, Mr. Lyle.
Thanks for turning your 'last' Blues JR into a comprehensive How To. And have a wonderful trip to London. I dare you not to sing 'These Are The People In Your Neighborhood" to yourself at least once a day...
Many thanks for this, Lyle. I know you say you have shown it a million times but for some of us, we need repetiton in case I ever get the confidence to try anything like this on my DRRI and make the mods you suggest. Appreciate how thorough you are with these and all the videos!
Long format videos like this are so educational, with the average age of a valve amp tech hovering around retirement age, it is literally a capsule to save a dying art.
33:41 concerning cleaning up the pin pads...No good deed goes unpunished. Nice of you to fix it though. We all agree I am sure, the $900 new (tax and shipping I assume) one pays to own these things should buy more. Glad I bought my Blues Junior used. I can use the $700 to effect repairs. It is a nice, small, relatively light tube amp so I still think it has its place in the guitar ecosystem, but I have seen more than one fail in performance. Once repaired, they have all been solid workhorses, so to all those Blues Junior owners, keep on keeping on.
Really enjoy these long form videos. Ever thought about doing something similar for a long single video going over adherence to electrical safety standards, the most recurring rules that amp builder fail to adhere to, and how to make amps safer (if they are worth being fixed)?
Awesome, as always, I learn something new with every one of your videos. I have repaired the same USA BJ many times and realized after the last repair that the solder joints of the male blades for the OT can easily be fractured on the back of the board. I surmise it was from removing and reconnecting the connectors so many times. It was an intermittent noise problem that I found using a chopstick.
"...FM, no static at all". Great song and this is another great video. My buddy has this amp and this video may come in handy for future reference. I already had to replace his reverb tank. Muchos gracias amigo!
Great to see you do another video on how to improve the Fender Blues Junior. Your previous videos on this amp were my inspiration 2 years ago to find one in order to make it as good as you can by doing all the work on it yourself. I've done all the basics on it, and then some including upgrading the rectifier diodes and an aftermarket tube board. The Celestion A type speaker was the last mod I have done on it and i am happy to say i might have one of the best sounding Blues Juniors out there. Thanks for the great teaching videos and I hope you do a few more Blues Junior videos in the near future.
im often critical of you, but i really appreciate you doing one of these amps that you openly don't like. It's great to see stuff like this for us poors.
The first few of his vids I watched I thought he was being a d-bag, but the more I watched I realized he's not wrong with what he says, they're not opinions but objective truth and the truth doesn't care about your feelings
After repairing many (I mean a lot) of Fender Blues and Reissue series amps, I ask my clients to subscribe or at least research, on this channel, any amp they are interested in owning. There are always compromises in a particular amp but knowing what inherent issues you have or will have is very valuable information.
@@altcountyemoyea, I'm not so sure I'd have bought a new Hot Rod Deluxe a few days ago if I had researched them on here beforehand lol. I'm actually glad I did, though, because it appears Fender has possibly attempted to rectify one of their biggest issues - the 5w resistors burning the pcb board. They actually seem to have lifted them off the board finally, and protected the legs with cloth covers. I have a nice warranty so I'll stick with it and see how things go. If it still burns, I'll deal with that IF it happens.
Hey Lyle, another rock solid long form on you man. If you’re out of resistors or desperado, you could actually ground a filter note through a tubes plate resistor. Hope all is well with you and yours. Stay safe and have fun.
I have a Hot Rod Deville and a Deville ML that I need to get all the preventative items you have documented previously done on...just got to find someone willing to do it BEFORE they fail! Thanks for the great video Lyle!
Just a related comment - I love that A Type speaker... have two of them as my main speakers. Sometimes they are a little cheaper than a Greenback and have some of the same scoopy quality. Just FYI. Love the vids PA! Also love that you are connected to five watt world. That is a good pairing!
Thank you for taking your time to do these, they are definitely very informative. I couldn't find the Hakko soldering station you mentioned as an alternative to the FX951.
I hear you about the cheapness and poor quality the one you upgraded has better quality than the Rev D I have; no bushings to protect the pot stems and cheaper on/off light, and push on chicken head knobs, no set screws! WTH. BTW, I got a Friedman R20. Man, you were right, what well-built amp! Kicks ass!! Woohoo!😊
I wasn't aware of all these issues with this amp before I bought mine a couple of years ago. Fortunately, I got a good deal on a gently used demo model, so I didn't pay a ton for it. If anything goes wrong I may try some of these repairs. I do have some electronics background, but not a lot. I built an All American 5 AM radio years ago from a kit, so I'm sure that I can do a bit of repair.
Hoffman Amps offers a Tube Board for the BJr which I used already a few times successfully. It is no PCB, more like a carrier PCB for the sockets and you need to wire directly to the sockets, but this also eliminates the chance of breaking one of the strands in those cheesy ribbon cables... Also Tube_Town has a replacement which is a mix of PtP and PCB.
I save my plastic leftover Asian carry-out containers for parts storage. ( I wash them!) The lids lock tightly and I'm assured I'm not all thumbs. But yeah, I also go looking for a part I dropped. And I drop many parts...I guess it comes with age. My shop floor is a vinyl composite (the cheap $hit)...so for some magic anomaly, the suspect part is never where I heard it hit the floor! Nice to know we are of similar mindset on these Blues Jrs.
It doesn't matter if the shop floor is laminate, concrete,, wood or industrial carpet squares: the part you dropped never winds up where you'd first think to look for It. Sometimes it appears to have migrated into another dimension, and there were occasions in my working career that I never did find whatever it was that I had dropped.
At 38:40, Lyle mentions the special pliers designed to put a nice rounded half-bend in component leads to form built-in standoffs; similar loop-forming pliers can be purchased for a pittance from companies marketing tools to jewelry makers, such as Beadsmith, Wubbers, Xuron and others, for typically about $15 to $25 at most. No need to spend over $100 on a specialty item like this that probably wouldn't get used that much unless you're doing electronics repair full-time.
I love this kind of video. Thx! Btw these amps were made to go broken. It's a company philosophy to have things break eventually so people buy new ones. Capitalism at it's finest. A flatscreen tv of 1800euros might last less long.
You should see what the e-waste dumpster (a walk-in shipping container) in my small town looks like after only 3 or 4 days of drop-off collection. I have a video of it on my channel ---- It continually gets filled up with dozens of flat screen TV's old vacuum cleaners, audio-video and stereo equipment, and so on.. And yes, the occasional guitar amp, although so far I've only found solid state guitar/bass amps; but I did find a nice pair of old Heathkit tube'type mono blocks there a while ago..
Another great video, thanks Lyle @PsionicAudio . How do you like the A type speaker in this amp? I just picked up a BJ loaded with a C-Rex, and it sounds like ass. No idea why people suggest them. Anyhow I need to replace the CRex with something. I have a Tone King Gremlin, it has a Celestion 870, the BJ sounds good with it, don't know what an 870 is since it's custom for Tone King. Maybe an A type is similar to an 870? I have a WGS ET-65, it sounds pretty good too, maybe a little too clean sounding for a BJ?
The bad EL84s and bad screen grids were what it came in for. Discovered the tube socket damage in the process. The bias resistors are to help keep that from happening again (and the amp sounds better biased sanely). The filter caps and input jack were preventative maintenance as they commonly fail on this model, even if these had not failed yet. Total billed time for the amp is two hours. If Fender built these right none of this would be necessary…
Great video Sir Lyle! I have a BJ III. I am sorry to ask, but can you please list all parts and brands for the upgrades needed so I can order them all at once? I would like to do this one day soon. Thank you and God bless .
Maybe it's a common sense thing (what's that?) but can you explain more about why you shouldn't have the chassis grounded through the ground wire as well as the input jack? Is it just a noise thing or can there be other negative effects. Thanks and love the videos!
FYI - I agree with cutting any lead to length before solder, but for a different reason. Probably too anal, but reducing any sharp ends, reduces the potential for RF generation. Yes at guitar amps the potential for interference is minimal, but I sleep better at night.
For those screws like that one that are more difficult to reach and control, I try to have my daughter come over and start them for me. I'm 70 with arthritic fingers and still coping with poor fine motor coordination from a stroke a few years ago. I find her 40 year old girlie fingers are much better suited for that, plus it gives us a chance to spend some time together. Fortunately she only lives a few blocks away.
I just ordered 10k 5w resistors. Going to hook up the multimeter and see how long one of these takes. You mention 10k 10w so hopefully this 5w is enough. 🤞
@@goodun2974 Steel mill....you drop a socket or something else there is only a river of water catching the hot scale, etc. You'll never see it again...
Hey Lyle, I see you left the heater wires on the PCB rather than moving to the sockets as you often do. Is that not needed on the BJ, or just not cost-effective? thanks
I repaired primarily solid state audio electronics for a living for 2 decades and it was not uncommon to find 1960's to 80's equipment where capacitors were installed backwards compared to the silkscreened polarity markings on the circuit board; and so you had to look at the schematic and trace it out on the board by eye and maybe take a volt meter to it to find out which polarity orientation would be correct. I've seen plenty of low value, low- voltage electrolytics installed backwards at the factory compared to the measured polarity of the circuit, which means that even if the reverse-installed caps don't let out the magic smoke, or explode, they usually go bad.
why does my blues deluxe usa from 94 pick up cell phone tower frequencies? Can this be prevented somehow? Love the amp but cannot record it anymore due to said problem. thank you
I'd guess that filling unused PCB through holes with solder at minimum guarantees that the hole plating won't oxidize, pit, etc. over time and become difficult to solder in the future.
@@chipsterb4946 In evaluating the overall design, it’s clear the choice became, implement an op-amp reverb drive + recovery circuit and have an unused triode on a tube they needed anyway, or go with a tube driven reverb circuit and at a minimum, have to add one more tube. When the imposed constraint is making this a budget amplifier, the choice isn’t really a choice at all, when you’re looking at a $12-15 tube, $2-3 socket ,$20-35 reverb driver transformer, not to mention higher wind on the power transformer to comfortably accommodate another 300mA in filament current - VERSUS - a 50 cent 4558 opamp chip and less than $2 in associated circuit components. Make sense?
A) The radial caps used in this amp are much higher quality than the axials B) The radial caps here are low voltage but rated for higher voltages than present, so they should last a long time. I rarely find bad radials in these amps.
Sometimes with traces on both sides(or multi layered boards) a trace needs to get from one layer to another. An eyelet is used to connect the two traces. It looks like a perforation, sort of. Maybe that's what you are seeing?
I recently had the same tube socket issue in a 2003 Pro Tube Reverb. Funny thing, it was on V6, not one of the power tubes. Also lots of bad solder joints throughout the amp….. This was an amp I didn’t even know existed, much less had my hands on. Definitely could not recommend this model!
I am very ignorant in this subject matter. However, I know what I am watching is artistry. Slowly, but surely, learning little things here and there. Does anybody know anything about the RANDALL BLUESMAN 4x10. I inherited it. I called Randall and they didn’t even know it existed! Any help is appreciated.
Luckily even quite high DC voltages are usually not life-threatening because ventricular fibrillation of heart is most likely caused by 50-60 Hz AC voltage causing AC current through body, not DC. I have tasted both quite high AC and DC voltages and I can assure that AC voltages are very unpleasant and dangerous. DC voltages often make you only change your underpants, as happened to me when I last time touched a electrolytic cap at 300VDC.
@@PsionicAudio 12VDC cannot kill you. Seriously. In army relay corps in the 80's, we got appr 30-60 VAC to between our both hands as a initiation rite, just to make things clear about voltages. It was quite unpleasant and even very painful but nobody died. Shaken, not stirred. 😁 You can connect 12VDC to your tongue and it just stings a bit.
High current low voltage DC can certainly kill you. Fortunately we’re not great conductors. But my point is I don’t want someone reading this and thinking the DC in the amp is safe. It’s just safer than AC.
@@PsionicAudio You cannot usually get high currents out of low voltages (ohm's law) because of quite high normal skin resistance, if skin is not sweatty or otherwise wet.
The circuit and its faults are the same for all versions, except the most recent cathode biased examples. The first ones had one extra cap the later ones omitted.
After uncle Doug retired i have been watching this channel often . Got to say , your definitely one of the best technicians out there . Thanks for the long video . 🎸
The long format videos are valuable. As an electrical engineer trained in the early days of solid state (old) I am continually surprised out how much I learn and how much I’ve forgotten. And how much practice is required. You are a worthy successor to Uncle Doug.
Much better camera than Uncle Doug, lol
On the contrary, these long theme episodes are the definitive format. Not only as a teaching session, but more importantly, a safety guide for those novice techs who lack the formal experience to avoid possible electrocution. Not to mention it affirms your rhyme and reason for the hourly fee(s); which are mostly due to safe disassembly, and reassembly. If the choice were mine, I'd opt for this format always. Then again, I don't have to edit the video. I hope that these continue in the future. I too have the Hakko FX951. I optioned it for the auto shutoff, and locking key card features as well as the overall performance of the station. Well done as always, Mr. Lyle.
Hi Lyle, I’m going to do about the same upgrades you did for my B Jr. Love your vids. You’re a great teacher with Great technique! ❤
Thanks for turning your 'last' Blues JR into a comprehensive How To. And have a wonderful trip to London. I dare you not to sing 'These Are The People In Your Neighborhood" to yourself at least once a day...
Many thanks for this, Lyle. I know you say you have shown it a million times but for some of us, we need repetiton in case I ever get the confidence to try anything like this on my DRRI and make the mods you suggest. Appreciate how thorough you are with these and all the videos!
Great video Lyle thank you so much. I am one of the ones that love this amp and this just helps.
Long format videos like this are so educational, with the average age of a valve amp tech hovering around retirement age, it is literally a capsule to save a dying art.
Thank you for these videos Lyle. You sir are a treasure to the amp community.
33:41 concerning cleaning up the pin pads...No good deed goes unpunished. Nice of you to fix it though. We all agree I am sure, the $900 new (tax and shipping I assume) one pays to own these things should buy more. Glad I bought my Blues Junior used. I can use the $700 to effect repairs. It is a nice, small, relatively light tube amp so I still think it has its place in the guitar ecosystem, but I have seen more than one fail in performance. Once repaired, they have all been solid workhorses, so to all those Blues Junior owners, keep on keeping on.
Really enjoy these long form videos. Ever thought about doing something similar for a long single video going over adherence to electrical safety standards, the most recurring rules that amp builder fail to adhere to, and how to make amps safer (if they are worth being fixed)?
I too would love to see that
The "Best Practices" to which Lyle refers, I personally use the word "Integrity".
As a '96 HRD owner ho's had my tech implement many of your Rx, I appreciate your soup to nuts approach here!
Awesome, as always, I learn something new with every one of your videos. I have repaired the same USA BJ many times and realized after the last repair that the solder joints of the male blades for the OT can easily be fractured on the back of the board. I surmise it was from removing and reconnecting the connectors so many times. It was an intermittent noise problem that I found using a chopstick.
"...FM, no static at all". Great song and this is another great video. My buddy has this amp and this video may come in handy for future reference. I already had to replace his reverb tank. Muchos gracias amigo!
Great to see you do another video on how to improve the Fender Blues Junior. Your previous videos on this amp were my inspiration 2 years ago to find one in order to make it as good as you can by doing all the work on it yourself. I've done all the basics on it, and then some including upgrading the rectifier diodes and an aftermarket tube board. The Celestion A type speaker was the last mod I have done on it and i am happy to say i might have one of the best sounding Blues Juniors out there.
Thanks for the great teaching videos and I hope you do a few more Blues Junior videos in the near future.
im often critical of you, but i really appreciate you doing one of these amps that you openly don't like. It's great to see stuff like this for us poors.
The first few of his vids I watched I thought he was being a d-bag, but the more I watched I realized he's not wrong with what he says, they're not opinions but objective truth and the truth doesn't care about your feelings
After repairing many (I mean a lot) of Fender Blues and Reissue series amps, I ask my clients to subscribe or at least research, on this channel, any amp they are interested in owning. There are always compromises in a particular amp but knowing what inherent issues you have or will have is very valuable information.
@@altcountyemoyea, I'm not so sure I'd have bought a new Hot Rod Deluxe a few days ago if I had researched them on here beforehand lol. I'm actually glad I did, though, because it appears Fender has possibly attempted to rectify one of their biggest issues - the 5w resistors burning the pcb board. They actually seem to have lifted them off the board finally, and protected the legs with cloth covers.
I have a nice warranty so I'll stick with it and see how things go. If it still burns, I'll deal with that IF it happens.
Hey Lyle, another rock solid long form on you man. If you’re out of resistors or desperado, you could actually ground a filter note through a tubes plate resistor. Hope all is well with you and yours. Stay safe and have fun.
Thanks. Yeah, I often ground through a plate. But that would have resulted in answering the same questions hundreds of times in the comments.
Always something to learn no matter a re hash blues Jr or not, another job well done. 😊
I have a Hot Rod Deville and a Deville ML that I need to get all the preventative items you have documented previously done on...just got to find someone willing to do it BEFORE they fail! Thanks for the great video Lyle!
An incredibly valuable resource. Thanks Lyle!
Just a related comment - I love that A Type speaker... have two of them as my main speakers. Sometimes they are a little cheaper than a Greenback and have some of the same scoopy quality. Just FYI. Love the vids PA! Also love that you are connected to five watt world. That is a good pairing!
Thank you for taking your time to do these, they are definitely very informative. I couldn't find the Hakko soldering station you mentioned as an alternative to the FX951.
I hear you about the cheapness and poor quality the one you upgraded has better quality than the Rev D I have; no bushings to protect the pot stems and cheaper on/off light, and push on chicken head knobs, no set screws! WTH. BTW, I got a Friedman R20. Man, you were right, what well-built amp! Kicks ass!! Woohoo!😊
Although I've seen you doing this before it was well worth watching. Thanks for posting.
I wasn't aware of all these issues with this amp before I bought mine a couple of years ago. Fortunately, I got a good deal on a gently used demo model, so I didn't pay a ton for it. If anything goes wrong I may try some of these repairs. I do have some electronics background, but not a lot. I built an All American 5 AM radio years ago from a kit, so I'm sure that I can do a bit of repair.
Hoffman Amps offers a Tube Board for the BJr which I used already a few times successfully. It is no PCB, more like a carrier PCB for the sockets and you need to wire directly to the sockets, but this also eliminates the chance of breaking one of the strands in those cheesy ribbon cables... Also Tube_Town has a replacement which is a mix of PtP and PCB.
Excellent, informative video! Thanks for sharing the knowledge. ❤
Thanks for this excellent video Lyle 👍👍
Great video. I hate Blues Juniors, but still love the videos.
The maestro at work
I save my plastic leftover Asian carry-out containers for parts storage. ( I wash them!) The lids lock tightly and I'm assured I'm not all thumbs. But yeah, I also go looking for a part I dropped. And I drop many parts...I guess it comes with age. My shop floor is a vinyl composite (the cheap $hit)...so for some magic anomaly, the suspect part is never where I heard it hit the floor! Nice to know we are of similar mindset on these Blues Jrs.
It doesn't matter if the shop floor is laminate, concrete,, wood or industrial carpet squares: the part you dropped never winds up where you'd first think to look for It. Sometimes it appears to have migrated into another dimension, and there were occasions in my working career that I never did find whatever it was that I had dropped.
Yes! Thank you!
At 38:40, Lyle mentions the special pliers designed to put a nice rounded half-bend in component leads to form built-in standoffs; similar loop-forming pliers can be purchased for a pittance from companies marketing tools to jewelry makers, such as Beadsmith, Wubbers, Xuron and others, for typically about $15 to $25 at most. No need to spend over $100 on a specialty item like this that probably wouldn't get used that much unless you're doing electronics repair full-time.
The input jack upgrade is something that should be done on all circuit board amps.
I love this kind of video. Thx!
Btw these amps were made to go broken. It's a company philosophy to have things break eventually so people buy new ones. Capitalism at it's finest. A flatscreen tv of 1800euros might last less long.
You should see what the e-waste dumpster (a walk-in shipping container) in my small town looks like after only 3 or 4 days of drop-off collection. I have a video of it on my channel ---- It continually gets filled up with dozens of flat screen TV's old vacuum cleaners, audio-video and stereo equipment, and so on.. And yes, the occasional guitar amp, although so far I've only found solid state guitar/bass amps; but I did find a nice pair of old Heathkit tube'type mono blocks there a while ago..
Very informative 👍
Thanks😎
Another great video, thanks Lyle @PsionicAudio . How do you like the A type speaker in this amp? I just picked up a BJ loaded with a C-Rex, and it sounds like ass. No idea why people suggest them. Anyhow I need to replace the CRex with something. I have a Tone King Gremlin, it has a Celestion 870, the BJ sounds good with it, don't know what an 870 is since it's custom for Tone King. Maybe an A type is similar to an 870? I have a WGS ET-65, it sounds pretty good too, maybe a little too clean sounding for a BJ?
I watched this video from beginning to end and enjoyed it immensely, but my main takeaway was don’t buy a Blues Junior.
Damn! That’s a lot of work for what should be a straight forward repair.
The bad EL84s and bad screen grids were what it came in for. Discovered the tube socket damage in the process. The bias resistors are to help keep that from happening again (and the amp sounds better biased sanely). The filter caps and input jack were preventative maintenance as they commonly fail on this model, even if these had not failed yet.
Total billed time for the amp is two hours.
If Fender built these right none of this would be necessary…
@@PsionicAudio are all of these mods ideally required on the Blues junior iv or have some of them been solved on that?
@7:17 I like using the special tone zip-ties myself. Tone-Ties or Zip-Tones are my favorite.
nice video lyle, thanks
Great video Sir Lyle! I have a BJ III. I am sorry to ask, but can you please list all parts and brands for the upgrades needed so I can order them all at once? I would like to do this one day soon. Thank you and God bless .
I found not buying a Fender Blues Jr in the first place sounds better! 🙂
Wouldn’t it be cool if amps had a built in cap drain switch? Dare I say make it a mandatory safety feature.
I hope you do the same for the Vox AC15C1!!!!!!
Maybe it's a common sense thing (what's that?) but can you explain more about why you shouldn't have the chassis grounded through the ground wire as well as the input jack? Is it just a noise thing or can there be other negative effects. Thanks and love the videos!
FYI - I agree with cutting any lead to length before solder, but for a different reason. Probably too anal, but reducing any sharp ends, reduces the potential for RF generation. Yes at guitar amps the potential for interference is minimal, but I sleep better at night.
Another great vid. Would you ever offer a psionic amp? Asking for a friend...
For those screws like that one that are more difficult to reach and control, I try to have my daughter come over and start them for me. I'm 70 with arthritic fingers and still coping with poor fine motor coordination from a stroke a few years ago. I find her 40 year old girlie fingers are much better suited for that, plus it gives us a chance to spend some time together. Fortunately she only lives a few blocks away.
Did you specify the components of interest? I didn't hear anything about the diodes. Why did they go south? Cool vid.
The diodes are fine. I mentioned all the components changed. Two 24k .5W resistors, two 1K 2W resistors, the filter caps, the input jack.
"I'll tell ya what I'm 'a gonna do..."
I just ordered 10k 5w resistors. Going to hook up the multimeter and see how long one of these takes. You mention 10k 10w so hopefully this 5w is enough. 🤞
When I drop things at work, there is no dang floor. Floors are so unappreciated. :)
You do your work in outer space? 🤔😉
It does, however, seem to be no floor, no bottom, to how low Fender and many other companies will go in order to make a buck....
@@goodun2974 Steel mill....you drop a socket or something else there is only a river of water catching the hot scale, etc. You'll never see it again...
what's is a good hand wired Deluxe Reverb style amp do you recommend me
Hey Lyle, I see you left the heater wires on the PCB rather than moving to the sockets as you often do. Is that not needed on the BJ, or just not cost-effective? thanks
It’s not as common a failure on these and there are no chassis mounted sockets so no great option for securely moving them.
Ah, putting the electrolytic caps in backwards. I think that's where the phrase "Letting the magic smoke out" comes from.
I repaired primarily solid state audio electronics for a living for 2 decades and it was not uncommon to find 1960's to 80's equipment where capacitors were installed backwards compared to the silkscreened polarity markings on the circuit board; and so you had to look at the schematic and trace it out on the board by eye and maybe take a volt meter to it to find out which polarity orientation would be correct. I've seen plenty of low value, low- voltage electrolytics installed backwards at the factory compared to the measured polarity of the circuit, which means that even if the reverse-installed caps don't let out the magic smoke, or explode, they usually go bad.
Can you please share your thoughts on the Pro Junior IV?
Complete garbage that shows a complete lack of respect for their customers.
I would take a hard look at the coupling caps in the Blues Jr amps. So many I found with high bias because of it.
I’ve never encountered leaking coupling caps in any of these. But I’ll keep an eye out.
why does my blues deluxe usa from 94 pick up cell phone tower frequencies? Can this be prevented somehow?
Love the amp but cannot record it anymore due to said problem. thank you
I'd guess that filling unused PCB through holes with solder at minimum guarantees that the hole plating won't oxidize, pit, etc. over time and become difficult to solder in the future.
I get a sense that this amplifier was designed by engineers who cared about the end product only to be thwarted by bean counters.
Eh … if they really cared about the circuit, would they have an unused triode on a preamp tube?
@@chipsterb4946 In evaluating the overall design, it’s clear the choice became, implement an op-amp reverb drive + recovery circuit and have an unused triode on a tube they needed anyway, or go with a tube driven reverb circuit and at a minimum, have to add one more tube. When the imposed constraint is making this a budget amplifier, the choice isn’t really a choice at all, when you’re looking at a $12-15 tube, $2-3 socket ,$20-35 reverb driver transformer, not to mention higher wind on the power transformer to comfortably accommodate another 300mA in filament current - VERSUS - a 50 cent 4558 opamp chip and less than $2 in associated circuit components. Make sense?
Is there enough room between the board and the chassis to install thru-hoie pots instead of the PCB mounted ones?
Nope
@@PsionicAudio Thank you, and I have a Sold-A-Pult and yes they do clog all the time.
Honest question... Why not change all the little electrolytic caps?
A) The radial caps used in this amp are much higher quality than the axials
B) The radial caps here are low voltage but rated for higher voltages than present, so they should last a long time. I rarely find bad radials in these amps.
Wow I love as unsubscribed I subscribe just a month ago..
I was wondering about that.
The best mod for the BJr is to convert it to 6V6. I did mine but once I got my Deluxe Reverb and Princeton Reverb I never looked back.
Lyle, why are some of the traces on the board perforated?
I don’t know what you mean.
Sometimes with traces on both sides(or multi layered boards) a trace needs to get from one layer to another. An eyelet is used to connect the two traces. It looks like a perforation, sort of. Maybe that's what you are seeing?
@@PsionicAudio I think he's talking about the ground planes.
Use a magnetic tip screwdriver so it holds onto the screw.
Great unless the screws are stainless steel. Which they are. ;)
1:24 10k or 22k / 10 watt?? Woa! Why so high value? I use 100 Ohm 10 Watt. Not saying that my way is better, I'm legitimately asking. Safety reasons?
I wanted to give newbies less chance of sparks.
@@PsionicAudio Good call. Sparks = flinching. Flinching = much bigger sparks.
I recently had the same tube socket issue in a 2003 Pro Tube Reverb. Funny thing, it was on V6, not one of the power tubes. Also lots of bad solder joints throughout the amp….. This was an amp I didn’t even know existed, much less had my hands on. Definitely could not recommend this model!
I am very ignorant in this subject matter. However, I know what I am watching is artistry. Slowly, but surely, learning little things here and there. Does anybody know anything about the RANDALL BLUESMAN 4x10. I inherited it. I called Randall and they didn’t even know it existed! Any help is appreciated.
Luckily even quite high DC voltages are usually not life-threatening because ventricular fibrillation of heart is most likely caused by 50-60 Hz AC voltage causing AC current through body, not DC. I have tasted both quite high AC and DC voltages and I can assure that AC voltages are very unpleasant and dangerous. DC voltages often make you only change your underpants, as happened to me when I last time touched a electrolytic cap at 300VDC.
Some distinctions aren’t good in this format - I don’t want anyone thinking high DC voltage is safe.
A car battery is “only” 12VDC and can kill you.
@PsionicAudio It's the volts that jolts, the mills that kills.
@@PsionicAudio 12VDC cannot kill you. Seriously. In army relay corps in the 80's, we got appr 30-60 VAC to between our both hands as a initiation rite, just to make things clear about voltages. It was quite unpleasant and even very painful but nobody died. Shaken, not stirred. 😁
You can connect 12VDC to your tongue and it just stings a bit.
High current low voltage DC can certainly kill you. Fortunately we’re not great conductors.
But my point is I don’t want someone reading this and thinking the DC in the amp is safe.
It’s just safer than AC.
@@PsionicAudio You cannot usually get high currents out of low voltages (ohm's law) because of quite high normal skin resistance, if skin is not sweatty or otherwise wet.
Is it a blues jr III ??
The circuit and its faults are the same for all versions, except the most recent cathode biased examples. The first ones had one extra cap the later ones omitted.
Some non polar capacitors should also be installed in a particular direction - ruclips.net/video/BnR_DLd1PDI/видео.htmlsi=NSh1ewRwmiZ-R8tG
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