Thanks for continuing to support the channel, everyone. I couldn't do it without you. Here's the schematic on this one, if you want to follow along: images.gibson.com/Lifestyle/Support/Files/Schematics/EPIPHONE_BLUES_CUSTOM_30_SCHEMATIC_VER01-DPPT.PDF
Yikes, 22,000uf filter capacitor at the 11.5V winding? Not saying that it's a direct cause of the transformer failure, but that is a bit excessive capacitance for just filtering DC. There's a point of diminishing returns for filtering DC, and it probably only needs about a 6800uf capacitor at that spot. Much beyond that, and that winding will start seeing a "dead short" briefly at power up, as the cap charges up. Had an issue similar to this on a Marshall JCM600 combo, and I had to reduce the capacitance from 20,000uf to 6800uf to resolve the issue. No longer blew fuses, and had no noise increase in the preamp stages. Luckily, the power transformer did NOT short, and the amp will live on. I got lucky. GREAT video once again! Love your work!!
You worked your butt off on that amp,I liked the way you changed out the volume pot. I hate pots hooked directly to board, they seem to always give trouble. Hats off to you Brad you most definitely earned your pay.
Also board mounted tube sockets and jacks. Pcb construction doesn't have to suck but board mounted parts are one way to make it will have problems at some point.
Brad, I am amazed at your abilities. Truly. You can repair amps through understanding how they work (not just a replacement guy. There is a huge difference), you can repair guitars (frets, boards, acoustic tops, etc) and you can actually play a guitar, drums and sing! Watching you go through a amp repair has a calming effect on me. I love to watch yuo walk through the process. Thanks for your channel. I appreciate you. You are the kind of guy I would enjoy living next door to. lol Thanks, dude!
Thanks for letting us watch you troubleshoot the amp. Seeing how a good tech goes about finding the issues is the most valuable part for me. So many guys just post videos of them changing the bad parts, but don't clue us in to how they go about the sometimes long and frustrating process of finding the fault(s) to begin with!
You put a lot of work into this Brad and it shows, I don't just mean on the amp itself but the whole format and edits in the video. Really well executed, really interesting and informative. Thanx
Very illuminating Brad, the one thing I’ve always regretted not doing was taking up and learning to play a classical musical instrument, now after a couple of years watching this stuff & not understanding 90% of it, I also deeply regret not getting schooled in basic electrical engineering.
I can't wait to watch the entire video. It takes me several days when they are longer like this one, but I enjoy them. Thanks for all the work you put into your vids.
I've got one of these amps, absolutely love it. One of the best things you can do to it is add a master volume because they are crazy loud, even on the '15w' setting. Also moving the fan supply to the point by the 4 diodes and getting rid of standby switch
Glad to see you back at working on amps. I have been watching you for years and learned a lot. Not enough though. Colourblind + high voltage equaled a trip to the ER. Back to watching it is.
Hey mate I had one of these, that switch can short inside between poles when turned off and the only fuse behind it goes. They fixed it in the next revisions but best to just take the standby switch out of the circuit on these, as it can happen again.
When you pulled that lead - yeah, I was cussing with you. I modified my '68 Custom Reverb Deluxe this week. New board with circus boards just aren't built to be worked on. I exhausted my entire collection of choice words this week.
Finally got a chance to watch a new Guitologist video :) I tell ya every single section being fused is a troubleshooter/repair man's real dream I would think. Of course the one time you come across something like this it ends up being the transformer before all the fuses. And yes it is a nice design built by the lowest bidder.
Quick "Behind the scenes" question: Are all of the amps you feature on the channel these days from viewers? Or, do you find amps to work on through other avenues other than RUclips? Also, you must get a lot of requests to fix viewers' items. How do you make your selections? Thanks for the great video today. -Steve
Lately I'm fixing viewer amps. I have a ton of amps and guitars of my own I need to repair as well. I need to start peppering in some of my own stuff here and there too.
Looks like this repair will go sky high , he should have told you , take everything out and built me a real amp . I bet the cost would have been even at this point, super scary layout on this , love your videos , just keeps me updated on what NOT to buy , I can't believe the patience you have hats off to you. Alfred NYC/PR.
Loved it!!!! Every second, I paused to pee and get fresh beer and resumed. I liked all the fuses it helped you trouble shoot. When the pot issue came up my first thought was clip it out and wire to board! Great minds think alike! lol. Oh!, great playing. Thanks from a seventy three year old who lives to fix things. Z.K.
Could those slide-on 1/4" female terminals be the locking type? They look like it. Require releasing a small tab on the terminal, will pull the guts out of a device if not released.
@@richpayton7162 Hi mate! I'm pretty sure they're just your bog standard female quick connect terminals (q.c.), or sometimes called spade terminals. I've never actually seen them 'lock' onto the male terminals that strongly before. I've seen them sort of lock onto a hard plastic insulator though. I'm pretty sure the problem is that it's just a crappy chinese switch.
Dude, this was like watching a horror movie. Armchairing this, I thought for sure there was going to be a short in the switch or flyback voltage from a relay had blasted through a diode and that Mercury was gonna be toast! Well done! The tone on that amp shows why the owner packed it like the crown jewels! One of your best demos. Both of those guitars are special. I couldn't live without the digital multimeter on my Variac - thank you for that. FWIW, I have a 300 watt GE bulb on my C/L and it starts to light at almost exactly 500mA draw. Pretty handy when dialing up an amp and you're trying to watch four things at once. Seems to only suck 5-10% of the juice out of an average system. JCM2000? More profanity incoming...
I have that 65W flood light and that bigger bulb is I think 150W, IIRC. Those two do ok, but they light up bright pretty early on in the process. Thanks for watching. Glad you dug the video, Timothy. You're one of my OG channel supporters! I appreciate that.
@@TheGuitologist only thing i wondered was if you tested the transformer to see if that was indeed the issue, i mean it obviously was, but was just a wild chase you were on . good video my dude. pretty nice demo at the end too.
Keep up the good work, Brad! Thanks for the warning, and thanks for the French. I'd like to extend another warning on the Buggera v5. It sounds great, but the tubes are permanently installed (12AX7 and EL84). Cheers!
Oh cool Brad! I've set the notification. I wanna see this one mate! I've got a 'Legacy Valve Edition 15' combo amp, which is identical, & made in the same factory as the 'epiphone valve standard' amp. I bought this new & had overheating pt, melted pt fuseholder, clicks, pops & noises! I've added a separate 3.5A 6.3vdc regulated power supply, extra node caps, & shielded signal cables so far. The chassis you've got there looks similar, but not too different I'm sure. I'm excited!
Hopefully this helps you with your issue. It's no secret these transformers are not good. I can recommend the Mercury so far, if you have the money to spend on it to make it really right.
I knew a guy here in South Carolina that worked on amps years ago,and in this situation,I shit you not, He would cut a piece of 3/16 copper tubing and put it in the fuse holder and replace whatever the smoke came out of. Lol. I quickly learned how to work on my own stuff.
I love how he talks about the caps and that fact the amps 17yrs old I have a peavey deuce from 83 with the original tubes I plan to have it gone over because I have never cracked it open
Mr. Belov made amps for many folks.... you are correct. I own one of these amps. That FAMILY of Epiphone amps were a good value. I found the Blues Custom to be the least lively sounding of the batch though....... not that it's bad.
Brad, you had me screaming at the screen.. lol.. after one look at the schematic verifying the the only thing the fuse protects was the primary on the PT, the Diags should have been over... in like 45 seconds.. lol.. then again, the goose chase could be the plan all along.. wink.. I use Merc trannnys too.. when the build or repair can justify them.. you can buy the whole amp used for 300 bucks.. putting a $300 tranny in, the pot, bench time, crating, shipping, etc.. he's dangerously close to spending enough to get a decent amp.. for instance, i bought a good condition Silverface Pro reverb the other day for $600.. scratchy pots and a worn handle.. but fully functioning.. already capped and re-tubed then it sat a while.. it probably cost me less than this repair cost with shipping.. and this amp wont be sought after by collectors any time soon.. i'll never lose a dime on the silver pro.. but to each their own.. i've never played one of those.. personally, i didn't think it sounded good at all.. (your playing is always good.. and i sure dig that new fiddle) might be that Fender M series cab sounding like crap too.. then again, dont know what you have loaded in it. anyway.. thx for the content..
jeeeeze that is so frustrating! perhaps it's clever editing, but you seem to have more patience than I would dealing with this crap, especially that damn switch! glad you were able to get it working again for the customer, but just another example of the negatives and extra price we pay for cheaper mass manufacturing overseas. seems like quality control today is more about checking things aren't obviously messed up and no one is bothering to go through things from a true perspective of quality when it comes to maintenance, longevity, and reparability. seems everything electronic has gone this way these days, not just guitar amps. great video as always, Brad!
Not only will our kids have no future because of our selfish need for cheep stuff but they'll also inheret a bunch of broken down electronics they will have to pay to discard. Most Americans seem to really only care about themselves. Not the viewers of this channel though. That's why I'm here still. Many from the seventies and up inherited 60's strats and acres of land while their children get the junk that their selfish parents never got around to fixing. (The land was obviously sold so selfish Daddy can make pretend he's Jimi Hendrix and build a studio eventhough he can't really play). It's really a messed up thing we're doing to our kids. For this reason, I despise anyone who is just blindly voting for whoever the tv tells them too while acting like they care the whole damn time.
Here's the thing...this customer ended up having to spend quite a lot to replace the power transformer, and he's asking me to go ahead and do the same for the OT, so by the time he spends all that money, he'll have a great amp, but it could have been great from the get go if it had been built properly to begin with!
Good catch. One thing I might do that you could try is when doing the initial troubleshooting I use one of those solid state rectifier plugins to eliminate the rectifier tube from the mix because theyt can't be tested at working voltage on yr average tube tester. It is rare to have the combination of problems that you found here and catch the power transformer in the act of failing-although I suspect that it was in the process of failing already. As to whether the amp was worth what MM charges plus shipping, if the owner loves the amp madly then it's worth it, but it's not that far distant from used prices on the Usually Overpriced Source. One recently sold on fleabay for $349 + shipping.
You’re correct on the expense. The owner and I had that conversation before going forward with repair. The bright side is, with the better transformer, this is actually a very decent amp. I think we raised its value beyond a normal one.
Hey dude, from 40years experience, do Not use negative feelings towards your task at hand, negative emotions make humans stupid. I have learnt to "just do it", because at the end of the day, that's your duty to others❤
You are man of many faces I love it when you look like a hippie now you look like a father. I love the trouble shooting all the patience Aloha from Hawaii
Brad, we love your work Buddy! Would you consider working on a Gibson G-20 solid state amp from early 70's? Still has a tube like tone! Thanks, BluesFully, DW🎶🎵🎷😎
Have you ever had a Soldano Designed Yamaha "T" (USA Built) series amp on your bench ? I had a few in my rehearsal studio rooms T 50s and T 100 s Don't recall having troubles with them
Here's a tip for those great Japanese solder suckers. When it slows down, a touch of silicone grease on the plunger will make the pump much faster again.
I just noticed that DYNACO amp cover you re-purposed as your dummy load. Gives me the happies. My first "component " power amp back when I still thought I had the cash flow to be an "audiophile " was a Dyna 120. I eventually had a Phase Linear 2000 preamp and a pair of Phase Linear 400 power amps (25 years later sold at thrift store) and Klipsch Heresy (30 years later gifted to me). NOT the "kick" I anticipated, but worth the $75.00 or so I have invested. Now if I can just find a JBL "EGG", I'd have everything I drooled over in high school . . .
Man I love watching you trouble shoot these amps man! & I have to confess your reaction to the switch failing made me laugh allot...in an empathetic ..."I know that feeling kinda way!:)" That is my favorite solder sucker to use...in fact its the only decent one on the market...its incredibly powerful & has lasted me 12 years now.
@Marc Christopher hi! I was just wondering why you would think the o.p.t. might also need replacing as well? I mean, the p.t.'s in epiphone & legacy amps are well known to be underpowered & unreliable as found in the cases of mine & Brad's amps. But I haven't heard of problems generally with their output transformers. Have you experienced or heard otherwise?
@@nevillegoddard4966 Brad stated the transformers were known to have problems. Being one transformer has already predictively failed & the owner has already paid for bench time and shipping… why not replace any part that has known issues? Otherwise the owner could end up having to pay again for shipping and bench / diagnostic work. We also don’t know if the original failed power transformer may have caused some undetected damage to the output transformer. IMO.. If the amp was something I was intent on keeping and using regularly, I’d rather replace the transformer now, than hope it doesn’t fail and maybe be at a gig and *poof*. Kinda like when you change the timing belt on a Honda. You replace the water pump regardless of whether it’s failed or not. You have the engine apart…. Replace the components that are known to fail. But hey, I’m not a professional amp tech… so I may be completely wrong. In the end, it’s up to the owner of the amp.
@@marcchristopher6009 Oh right! I thought Brad was referring to just the power transformers though. You could be right too about the problem with the pt causing a problem with the opt, particularly if the problem was shorts between 2ndary windings in the pt. I'm thinking that's less likely in this case, than shorted turns in a particular winding, or a winding with a short to earth. From memory with my amp, the pt was running stinking hot due to the filament winding being insufficient to supply the load that was required from it. Something like 40% underpowered which is purely a poor choice of pt. Also the in-line fuseholder for the filaments had a high resistance in it & had melted. I'm pretty sure (but not definitely!) that each 2ndary winding would have a layer or 2 of insulation between it & the other windings adjacent. Now I've forgotten - is there a standard layout or format as to whether the hv 2ndaries are wound first or last, whatever? Regardless of what I said, if you're gonna be doing actual gigs with your amp you're right - you'd be better off changing the opt anyway. No doubt the 'Mercury' opt's are gonna be of a higher quality than the oem ones, & are therefore gonna sound better ay! So that's a bonus. And isn't the opt one of the key contributors to the sound after all? - And the speaker of course! Hmm. Yeah my amp has a no name 12 inch speaker in it D'oh! I'd probably use a 'Hammond' brand transformer if I was gonna replace mine, as I think they may be easier to get down here in Australia. As a side story, my old boss, after he retired, was building & rewinding opt's to supplement his income, & of course valve gear was always his hobby. So he'd rewound a 'conniseur's' (sp?) opt for their amp after it had gone open circuit, reinstalled in their (hifi stereo) amp, & returned it to them. The customer was happy with the repair but complained that now, in comparison, the original 'good' channel sounded like crap! The amp was rechecked & found to be working just fine. So the customer, being well-to-do with his 5 or $10k amp asked my old boss to rewind their perfectly operational other channel's opt. This was done & the customer was wrapped. Over time he gained a reputation for his opt's to the extent that customers who had their opt's previously rewound by the current 'guru' at the time - a Polish guy I think - to be rewound by Bob. So it turned out that Bob wound his opt's in such a way that the turns were 'intimately' wound, input & output layers alternately, rather than in bunches. This resulted in much better coupling from input to output, & consequently a purer, or cleaner sound. After investigation, it was found that this Polish guy was an ex-electric motor rewinder, where the turns were wound in bunches! Bob's opt's were so loved, that he worked on opt's for John Mellancamp & the Seekers! (rip Judith!). These opt's were obviously time consuming to rewind his special way, & thus quite expensive, but people were only willing to pay for them at a rate that only earned him about 15 bucks an hour, which was understandably insulting to him. So he abandoned the enterprise, sadly. What a bloody waste I say, & a sad endictment on peoples' greed. I must give him a call actually & see how he's doing; it's been a while.
Thats what I like about the Mesa Boogie MK IV amps is they have the switch on the back to go between Class A and AB , aswell as having the eq and most other features you want built in without going overboard (Hughes and Kettner I'm lookin' at you!)
You absolutely CAN unplug those spade connectors from the switch. The trick is to use a pick, or small screwdriver to lift the center portion of the female spade connector to disengage the lock from the hole in the male part.
Moving the stand by switch AFTER the filter capacitors will prevent in Rush current surge spikes? The wattage switch was causing the HUM issues because it's putting the power tubes in triode mode which causes HUM issues?
i just got a guitar a builder made and shipped it in a plywood made himself especially box. Impressive but heavy :) last week i had an acoustic couriered in a hardcase and it arrived with a cracked top. Eye opener to me, hardcase is no guarantee for safety :)
Long and interesting video. I can say you have tremendous perseverance! I don't work on amps, but would have been cussing much earlier. I see no issue with your solution for the bad pot. Curious how much this would cost the customer?
Brad could you tell me what output is your variac?? I’m thinking of buying one but not entirely sure if guitar amp draws more than 5Amp when you gently power it up. Could you maybe create video/content that would explain??
Never understood why people still want a tube rectifier in their amps. It has nothing to do with the feel or tone of the amp. A rectifier simply converts AC to DC. Correct me if I'm wrong, Brad. Input always welcome.
A tube rectifier is less efficient at doing its job. So what happens is the available DC voltages fluctuate as a result of this inefficiency when you ask all the tubes in the amp to suddenly operate like when you hit a note. The caps all have to refill themselves and they suck this current through the rectifier. A tube rectifier has more trouble recovering from this demand than silicon diodes and this results in an effect called "sag". This effect is not as desirable for some styles of music, like modern metal, for instance, but for other styles, it can be part of the tone and feel of the amp.
If you listen closely in many old rock and blues records the tube rectifier sag can be heard. Neil Young is notable for this as the Tweed Deluxe 5E3 is notorious for sag at high volume. You hit the note and it compresses like crazy, then blows up, makes for a really cool sound. Also, since it's less efficient you can crank the amp more which can be desirable if you want more breakup. For example, a Deluxe Reverb which has a much more efficient GZ-34 tube rectifier than the Tweed's 5E3 has way more headroom, punch and volume to the point of being hard to crank in many small venues and even rehearsing if you don't like earplugs.
Great Video and thanks. I have exactly the same problem with the Epiphone Blues 30 on my bench blowing the receptacle fuse. Was hoping there was another way to get another transformer for less than $300 from Mercury.
I’d agree with u on the heat from the tubes but those combos are hated for the fan it’s so powerful and loud that it keeps the amp super cool but if u have any drives on u get a bit of hum
It sounds sweet. I doubt that the value of the amp justifies the cost of repair, BUT it is better than stock now, and the owner will know that. The waste of trashing it would have been in his head for ever.
For modern times it actualy looks very well made it isn't a cluster luck and apears easily modifiable. But what combo doesn't have tubes under the circuit board? Not very many don't.
The clear sheath covers the tabs, the middle and bottom ones are completely unreachable no matter what, but I think all but one were installed upside down anyway, so there's no way to press the tab. Wiggling them should get them out without removing the terminal from the switch.
Those engineer solder suckers are the only non electronic one I've ever used that's worth a damn. I'm not an amp expert but I would've tried a reflow and contact cleaner on that pot first. This isn't a criticism as you did a great job. A tool question. What kind of wire strippers did you use. What do you think of them rather as I was looking at a pair of klein ones last night online and I have every other type, from lesser brands.
Man! I really hope you can find a way to keep doing these videos! If RUclips continues to f*ck ya over, there's Rumble & Locals for the $. You're a Top Ten Channel dude! 🤜
I’ve created some of my intros. The one in today’s video was created by a viewer named Richard from the UK. He’s a super talented dude. There’s a linger version of this intro I cannot play anymore or they’ll try to copyright claim the audio.
Hope all is well. 2005 year of the mini stacks with basic internal layout. 5 watts, plastic switch construction and so forth. fender, Marshall,egnator, orange on and on same cost cutting imported equipment targeted as budget friendly. Unfortunately it mainly effects. the youth of our musical future.
![YoungBoy Never Broke Again - Catch Me [Official Video]](http://i.ytimg.com/vi/KxwEXXFQMTY/mqdefault.jpg)
Oh shut up and tell us about the amp
I think you're on the wrong channel. The ADHD tube amp tech is THAT way --------->
@@TheGuitologist what's this guy's problem?? Somebody must have dip their balls in his Cheerios.
@@TheGuitologist you're to drawn out with shit..don't take it personally you're far from the only one
@@TheGuitologist dats some funny shit, bruh! It's good to see that you still got it 👍
@@grandudetonesnob7107 tell me what's funny what he said? Tell me he still got what?
Thanks for continuing to support the channel, everyone. I couldn't do it without you. Here's the schematic on this one, if you want to follow along: images.gibson.com/Lifestyle/Support/Files/Schematics/EPIPHONE_BLUES_CUSTOM_30_SCHEMATIC_VER01-DPPT.PDF
Yikes, 22,000uf filter capacitor at the 11.5V winding? Not saying that it's a direct cause of the transformer failure, but that is a bit excessive capacitance for just filtering DC. There's a point of diminishing returns for filtering DC, and it probably only needs about a 6800uf capacitor at that spot. Much beyond that, and that winding will start seeing a "dead short" briefly at power up, as the cap charges up. Had an issue similar to this on a Marshall JCM600 combo, and I had to reduce the capacitance from 20,000uf to 6800uf to resolve the issue. No longer blew fuses, and had no noise increase in the preamp stages. Luckily, the power transformer did NOT short, and the amp will live on. I got lucky. GREAT video once again! Love your work!!
@Filthy Peasant wow. That would be the biggest cap I've ever seen.
@Filthy Peasant Hi! Four hundred & seventy thousand microfarads? Oh man that's just so over the top I nearly shat myself lol!
@ExitThirteen hi! Yeah, about 2,000uF per amp of load is usually a good rule of thumb to use.
You worked your butt off on that amp,I liked the way you changed out the volume pot. I hate pots hooked directly to board, they seem to always give trouble. Hats off to you Brad you most definitely earned your pay.
When to hold e'm.... and when to fold 'em ---> on that vol pot.
Also board mounted tube sockets and jacks. Pcb construction doesn't have to suck but board mounted parts are one way to make it will have problems at some point.
@@michaelknight4041 да, но ламповые панели очень греют плату, можно потерять контакты от температуры.
The owner of that amp was super cool to spend all that money shipping you that amp so we could get a free troubleshooting seminar…thank you both.
Brad, I am amazed at your abilities. Truly. You can repair amps through understanding how they work (not just a replacement guy. There is a huge difference), you can repair guitars (frets, boards, acoustic tops, etc) and you can actually play a guitar, drums and sing! Watching you go through a amp repair has a calming effect on me. I love to watch yuo walk through the process. Thanks for your channel. I appreciate you. You are the kind of guy I would enjoy living next door to. lol Thanks, dude!
I appreciate that. I try to learn how to do many things. It’s nice to be noticed.
Скажите, игра пальцами, без медиатора?
Thanks for letting us watch you troubleshoot the amp. Seeing how a good tech goes about finding the issues is the most valuable part for me. So many guys just post videos of them changing the bad parts, but don't clue us in to how they go about the sometimes long and frustrating process of finding the fault(s) to begin with!
You put a lot of work into this Brad and it shows, I don't just mean on the amp itself but the whole format and edits in the video. Really well executed, really interesting and informative. Thanx
A repair video is always appreciated, but the value of the troubleshooting in this one is priceless. Thanks Brad!
your serenades at the end are a nice relief to the tension of the repair!
Very illuminating Brad, the one thing I’ve always regretted not doing was taking up and learning to play a classical musical instrument, now after a couple of years watching this stuff & not understanding 90% of it, I also deeply regret not getting schooled in basic electrical engineering.
I can't wait to watch the entire video. It takes me several days when they are longer like this one, but I enjoy them. Thanks for all the work you put into your vids.
I've got one of these amps, absolutely love it. One of the best things you can do to it is add a master volume because they are crazy loud, even on the '15w' setting. Also moving the fan supply to the point by the 4 diodes and getting rid of standby switch
Have no idea why they have a standby switch on a valve rectified amp as it's the perfect soft start and no need for a standby switch at all.
That’s the secret cure to the hum of the fan😊 I love mine so much after I found those mods
Just love the playing in your demo.
Just so full of goodness!
And makes that signature model so worthy..
I agree. Nice design and sound. Cheap parts will kill it as well as bad solder flux eroding old connections if a little age.
Yep that's why it's always important to clean it off the boards after.
Glad to see you back at working on amps. I have been watching you for years and learned a lot.
Not enough though. Colourblind + high voltage equaled a trip to the ER.
Back to watching it is.
Hey mate I had one of these, that switch can short inside between poles when turned off and the only fuse behind it goes. They fixed it in the next revisions but best to just take the standby switch out of the circuit on these, as it can happen again.
Big ol pile of frustration here! Good on you for staying the course.
were all OCD cause were watching this channel but this packaging is next level
When you pulled that lead - yeah, I was cussing with you. I modified my '68 Custom Reverb Deluxe this week. New board with circus boards just aren't built to be worked on. I exhausted my entire collection of choice words this week.
Finally got a chance to watch a new Guitologist video :)
I tell ya every single section being fused is a troubleshooter/repair man's real dream I would think.
Of course the one time you come across something like this it ends up being the transformer before all the fuses.
And yes it is a nice design built by the lowest bidder.
Quick "Behind the scenes" question: Are all of the amps you feature on the channel these days from viewers? Or, do you find amps to work on through other avenues other than RUclips? Also, you must get a lot of requests to fix viewers' items. How do you make your selections? Thanks for the great video today. -Steve
Lately I'm fixing viewer amps. I have a ton of amps and guitars of my own I need to repair as well. I need to start peppering in some of my own stuff here and there too.
"We'll dial it up slowly on the variac'. Man its been a while since I heard that :) Great video
Looks like this repair will go sky high , he should have told you , take everything out and built me a real amp . I bet the cost would have been even at this point, super scary layout on this , love your videos , just keeps me updated on what NOT to buy , I can't believe the patience you have hats off to you. Alfred NYC/PR.
Loved it!!!! Every second, I paused to pee and get fresh beer and resumed. I liked all the fuses it helped you trouble shoot. When the pot issue came up my first thought was clip it out and wire to board! Great minds think alike! lol. Oh!, great playing. Thanks from a seventy three year old who lives to fix things. Z.K.
Great work. When the switch contacts pulled out I don't know how you stopped yourself from throwing it against the wall.
Could those slide-on 1/4" female terminals be the locking type? They look like it. Require releasing a small tab on the terminal, will pull the guts out of a device if not released.
@@richpayton7162 Hi mate! I'm pretty sure they're just your bog standard female quick connect terminals (q.c.), or sometimes called spade terminals. I've never actually seen them 'lock' onto the male terminals that strongly before. I've seen them sort of lock onto a hard plastic insulator though.
I'm pretty sure the problem is that it's just a crappy chinese switch.
Enjoyed this video Brad. Very entertaining for us guitar players and amplifier lovers. Thanks!
Glad you enjoyed it!
Another great repair - way to go Brad! - kind of a marathon but you had the stamina - nice jam at the end
Dude, this was like watching a horror movie. Armchairing this, I thought for sure there was going to be a short in the switch or flyback voltage from a relay had blasted through a diode and that Mercury was gonna be toast! Well done! The tone on that amp shows why the owner packed it like the crown jewels! One of your best demos. Both of those guitars are special.
I couldn't live without the digital multimeter on my Variac - thank you for that. FWIW, I have a 300 watt GE bulb on my C/L and it starts to light at almost exactly 500mA draw. Pretty handy when dialing up an amp and you're trying to watch four things at once. Seems to only suck 5-10% of the juice out of an average system.
JCM2000? More profanity incoming...
I have that 65W flood light and that bigger bulb is I think 150W, IIRC. Those two do ok, but they light up bright pretty early on in the process. Thanks for watching. Glad you dug the video, Timothy. You're one of my OG channel supporters! I appreciate that.
@@TheGuitologist only thing i wondered was if you tested the transformer to see if that was indeed the issue, i mean it obviously was, but was just a wild chase you were on . good video my dude. pretty nice demo at the end too.
Keep up the good work, Brad!
Thanks for the warning, and thanks for the French. I'd like to extend another warning on the Buggera v5. It sounds great, but the tubes are permanently installed (12AX7 and EL84).
Cheers!
Damn that's some face-meltin neck-work you're doing there at the end. Killin it!
Amp sounds amazing! Great job!
Nothing like a classic guitologist repair vid on a sunday mornin'.
Oh cool Brad! I've set the notification. I wanna see this one mate! I've got a 'Legacy Valve Edition 15' combo amp, which is identical, & made in the same factory as the 'epiphone valve standard' amp. I bought this new & had overheating pt, melted pt fuseholder, clicks, pops & noises!
I've added a separate 3.5A 6.3vdc regulated power supply, extra node caps, & shielded signal cables so far. The chassis you've got there looks similar, but not too different I'm sure. I'm excited!
Hopefully this helps you with your issue. It's no secret these transformers are not good. I can recommend the Mercury so far, if you have the money to spend on it to make it really right.
I knew a guy here in South Carolina that worked on amps years ago,and in this situation,I shit you not,
He would cut a piece of 3/16 copper tubing and put it in the fuse holder and replace whatever the smoke came out of. Lol. I quickly learned how to work on my own stuff.
Nice video Brad.. I always learn something new from you.🤘
I have one of these snd they are an Excellent Sounding Amp
Very Sweet Tone with Dynamic cleans
Great Drive channel and reverb
I love how he talks about the caps and that fact the amps 17yrs old I have a peavey deuce from 83 with the original tubes I plan to have it gone over because I have never cracked it open
Mr. Belov made amps for many folks.... you are correct. I own one of these amps. That FAMILY of Epiphone amps were a good value. I found the Blues Custom to be the least lively sounding of the batch though....... not that it's bad.
I rather enjoyed playing though this one.
@@TheGuitologist The Valve Senior... (14w 6v6 pp) is more my style. It seems a bit less common.
Brad, you had me screaming at the screen.. lol.. after one look at the schematic verifying the the only thing the fuse protects was the primary on the PT, the Diags should have been over... in like 45 seconds.. lol.. then again, the goose chase could be the plan all along.. wink.. I use Merc trannnys too.. when the build or repair can justify them.. you can buy the whole amp used for 300 bucks.. putting a $300 tranny in, the pot, bench time, crating, shipping, etc.. he's dangerously close to spending enough to get a decent amp.. for instance, i bought a good condition Silverface Pro reverb the other day for $600.. scratchy pots and a worn handle.. but fully functioning.. already capped and re-tubed then it sat a while.. it probably cost me less than this repair cost with shipping.. and this amp wont be sought after by collectors any time soon.. i'll never lose a dime on the silver pro.. but to each their own.. i've never played one of those.. personally, i didn't think it sounded good at all.. (your playing is always good.. and i sure dig that new fiddle) might be that Fender M series cab sounding like crap too.. then again, dont know what you have loaded in it. anyway.. thx for the content..
That was great man!! Felt like I was right there with ya!😂
Thanks William. Being right here with me unfortunately means also feeling my pain.
@@TheGuitologist That switch was hilarious.
I love how ocd the way it was sent to you . Thank god for people that smoke to much weed
jeeeeze that is so frustrating! perhaps it's clever editing, but you seem to have more patience than I would dealing with this crap, especially that damn switch! glad you were able to get it working again for the customer, but just another example of the negatives and extra price we pay for cheaper mass manufacturing overseas. seems like quality control today is more about checking things aren't obviously messed up and no one is bothering to go through things from a true perspective of quality when it comes to maintenance, longevity, and reparability. seems everything electronic has gone this way these days, not just guitar amps.
great video as always, Brad!
Not only will our kids have no future because of our selfish need for cheep stuff but they'll also inheret a bunch of broken down electronics they will have to pay to discard. Most Americans seem to really only care about themselves. Not the viewers of this channel though. That's why I'm here still. Many from the seventies and up inherited 60's strats and acres of land while their children get the junk that their selfish parents never got around to fixing. (The land was obviously sold so selfish Daddy can make pretend he's Jimi Hendrix and build a studio eventhough he can't really play).
It's really a messed up thing we're doing to our kids. For this reason, I despise anyone who is just blindly voting for whoever the tv tells them too while acting like they care the whole damn time.
Here's the thing...this customer ended up having to spend quite a lot to replace the power transformer, and he's asking me to go ahead and do the same for the OT, so by the time he spends all that money, he'll have a great amp, but it could have been great from the get go if it had been built properly to begin with!
@41:00 I knew I can relate to your videos. Great info. I am learning a lot, too.
Good job as usual Brad
Thanks man. Just trying to get back to churning out good amp content for y'all.
I admire you stick-to-itiveness. On a different not though, do you happen to know what speakers are in the Fender cabinet that you use?
Designed and engineered in a two car… car port. No cap. Nice work!
Good catch. One thing I might do that you could try is when doing the initial troubleshooting I use one of those solid state rectifier plugins to eliminate the rectifier tube from the mix because theyt can't be tested at working voltage on yr average tube tester. It is rare to have the combination of problems that you found here and catch the power transformer in the act of failing-although I suspect that it was in the process of failing already. As to whether the amp was worth what MM charges plus shipping, if the owner loves the amp madly then it's worth it, but it's not that far distant from used prices on the Usually Overpriced Source. One recently sold on fleabay for $349 + shipping.
You’re correct on the expense. The owner and I had that conversation before going forward with repair. The bright side is, with the better transformer, this is actually a very decent amp. I think we raised its value beyond a normal one.
@@TheGuitologist You certainly improved the power supply over the original part. The MM will last forever.
I love them spicy slow blues with that rig Brad!!!
Always a pleasure!
Hey dude, from 40years experience, do Not use negative feelings towards your task at hand, negative emotions make humans stupid. I have learnt to "just do it", because at the end of the day, that's your duty to others❤
You are man of many faces I love it when you look like a hippie now you look like a father. I love the trouble shooting all the patience Aloha from Hawaii
most finely pacckaged amp in the world 👍
Brad, we love your work Buddy! Would you consider working on a Gibson G-20 solid state amp from early 70's? Still has a tube like tone! Thanks, BluesFully, DW🎶🎵🎷😎
At least the amp sounded pretty damn good after considering the debacle! ;)
Have you ever had a Soldano Designed
Yamaha "T" (USA Built) series amp on your bench ?
I had a few in my rehearsal studio rooms
T 50s and T 100 s
Don't recall having troubles with them
New subscriber long time viewer I have a question in your opinion and experience what is the most versatile yet simple tube amplifiers ?
I have that same amp. Thankfully I haven't had any issues with it. Matt from Pennsylvania.
Transformers are the Achilles heel. A long gig and too much heat I think breaks down the winding lacquer.
Here's a tip for those great Japanese solder suckers. When it slows down, a touch of silicone grease on the plunger will make the pump much faster again.
Great Job,…….You stuck with it and as usual,….it paid off. 👍😎
I just noticed that DYNACO amp cover you re-purposed as your dummy load. Gives me the happies. My first "component " power amp back when I still thought I had the cash flow to be an "audiophile " was a Dyna 120. I eventually had a Phase Linear 2000 preamp and a pair of Phase Linear 400 power amps (25 years later sold at thrift store) and Klipsch Heresy (30 years later gifted to me). NOT the "kick" I anticipated, but worth the $75.00 or so I have invested. Now if I can just find a JBL "EGG", I'd have everything I drooled over in high school . . .
Man I love watching you trouble shoot these amps man! & I have to confess your reaction to the switch failing made me laugh allot...in an empathetic ..."I know that feeling kinda way!:)" That is my favorite solder sucker to use...in fact its the only decent one on the market...its incredibly powerful & has lasted me 12 years now.
Excellent work as usual Brad! Should have just replaced the output transformer while it was on the bench. One less possible issue to worry about.
The owner and I are talking about it.
@Marc Christopher hi! I was just wondering why you would think the o.p.t. might also need replacing as well? I mean, the p.t.'s in epiphone & legacy amps are well known to be underpowered & unreliable as found in the cases of mine & Brad's amps. But I haven't heard of problems generally with their output transformers. Have you experienced or heard otherwise?
@@nevillegoddard4966 Brad stated the transformers were known to have problems. Being one transformer has already predictively failed & the owner has already paid for bench time and shipping… why not replace any part that has known issues? Otherwise the owner could end up having to pay again for shipping and bench / diagnostic work. We also don’t know if the original failed power transformer may have caused some undetected damage to the output transformer. IMO.. If the amp was something I was intent on keeping and using regularly, I’d rather replace the transformer now, than hope it doesn’t fail and maybe be at a gig and *poof*.
Kinda like when you change the timing belt on a Honda. You replace the water pump regardless of whether it’s failed or not. You have the engine apart…. Replace the components that are known to fail.
But hey, I’m not a professional amp tech… so I may be completely wrong. In the end, it’s up to the owner of the amp.
@@marcchristopher6009 Oh right! I thought Brad was referring to just the power transformers though. You could be right too about the problem with the pt causing a problem with the opt, particularly if the problem was shorts between 2ndary windings in the pt. I'm thinking that's less likely in this case, than shorted turns in a particular winding, or a winding with a short to earth. From memory with my amp, the pt was running stinking hot due to the filament winding being insufficient to supply the load that was required from it. Something like 40% underpowered which is purely a poor choice of pt. Also the in-line fuseholder for the filaments had a high resistance in it & had melted. I'm pretty sure (but not definitely!) that each 2ndary winding would have a layer or 2 of insulation between it & the other windings adjacent. Now I've forgotten - is there a standard layout or format as to whether the hv 2ndaries are wound first or last, whatever?
Regardless of what I said, if you're gonna be doing actual gigs with your amp you're right - you'd be better off changing the opt anyway.
No doubt the 'Mercury' opt's are gonna be of a higher quality than the oem ones, & are therefore gonna sound better ay! So that's a bonus. And isn't the opt one of the key contributors to the sound after all? - And the speaker of course! Hmm. Yeah my amp has a no name 12 inch speaker in it D'oh!
I'd probably use a 'Hammond' brand transformer if I was gonna replace mine, as I think they may be easier to get down here in Australia.
As a side story, my old boss, after he retired, was building & rewinding opt's to supplement his income, & of course valve gear was always his hobby. So he'd rewound a 'conniseur's' (sp?) opt for their amp after it had gone open circuit, reinstalled in their (hifi stereo) amp, & returned it to them.
The customer was happy with the repair but complained that now, in comparison, the original 'good' channel sounded like crap! The amp was rechecked & found to be working just fine. So the customer, being well-to-do with his 5 or $10k amp asked my old boss to rewind their perfectly operational other channel's opt. This was done & the customer was wrapped. Over time he gained a reputation for his opt's to the extent that customers who had their opt's previously rewound by the current 'guru' at the time - a Polish guy I think - to be rewound by Bob.
So it turned out that Bob wound his opt's in such a way that the turns were 'intimately' wound, input & output layers alternately, rather than in bunches. This resulted in much better coupling from input to output, & consequently a purer, or cleaner sound. After investigation, it was found that this Polish guy was an ex-electric motor rewinder, where the turns were wound in bunches! Bob's opt's were so loved, that he worked on opt's for John Mellancamp & the Seekers! (rip Judith!).
These opt's were obviously time consuming to rewind his special way, & thus quite expensive, but people were only willing to pay for them at a rate that only earned him about 15 bucks an hour, which was understandably insulting to him. So he abandoned the enterprise, sadly. What a bloody waste I say, & a sad endictment on peoples' greed. I must give him a call actually & see how he's doing; it's been a while.
1:12:30 OH YEAH !!!!
That ZIO looks EPIC!
Thats what I like about the Mesa Boogie MK IV amps is they have the switch on the back to go between Class A and AB , aswell as having the eq and most other features you want built in without going overboard (Hughes and Kettner I'm lookin' at you!)
Brad, I really liked the video when you started to lose it. Landfill huh 🤣 hilarious 😂
You absolutely CAN unplug those spade connectors from the switch. The trick is to use a pick, or small screwdriver to lift the center portion of the female spade connector to disengage the lock from the hole in the male part.
Moving the stand by switch AFTER the filter capacitors will prevent in Rush current surge spikes? The wattage switch was causing the HUM issues because it's putting the power tubes in triode mode which causes HUM issues?
another one in the bag, nice work.
Really enjoyed this one Brad, thanks!
i just got a guitar a builder made and shipped it in a plywood made himself especially box. Impressive but heavy :) last week i had an acoustic couriered in a hardcase and it arrived with a cracked top. Eye opener to me, hardcase is no guarantee for safety :)
What if the volume pot was the problem the whole time? Love you brother!!
Long and interesting video. I can say you have tremendous perseverance! I don't work on amps, but would have been cussing much earlier. I see no issue with your solution for the bad pot. Curious how much this would cost the customer?
Brad could you tell me what output is your variac??
I’m thinking of buying one but not entirely sure if guitar amp draws more than 5Amp when you gently power it up.
Could you maybe create video/content that would explain??
5A is plenty for most tube amps.
Fantastic playing as always, Brad! 😎
42min... haha I feel your pain. Those damn switches!
Top work there Brad
That switch--wow! Did you end up replacing it?
No, I just pressed the terminals into the switch further and it worked after that.
Great video Brad !!
Thanks John.
Great video Brad.
I regard the jamming in the end as a reward for me seeing the whole video. I know nothing about electronics.
Never understood why people still want a tube rectifier in their amps. It has nothing to do with the feel or tone of the amp. A rectifier simply converts AC to DC. Correct me if I'm wrong, Brad. Input always welcome.
A tube rectifier is less efficient at doing its job. So what happens is the available DC voltages fluctuate as a result of this inefficiency when you ask all the tubes in the amp to suddenly operate like when you hit a note. The caps all have to refill themselves and they suck this current through the rectifier. A tube rectifier has more trouble recovering from this demand than silicon diodes and this results in an effect called "sag". This effect is not as desirable for some styles of music, like modern metal, for instance, but for other styles, it can be part of the tone and feel of the amp.
If you listen closely in many old rock and blues records the tube rectifier sag can be heard. Neil Young is notable for this as the Tweed Deluxe 5E3 is notorious for sag at high volume. You hit the note and it compresses like crazy, then blows up, makes for a really cool sound. Also, since it's less efficient you can crank the amp more which can be desirable if you want more breakup. For example, a Deluxe Reverb which has a much more efficient GZ-34 tube rectifier than the Tweed's 5E3 has way more headroom, punch and volume to the point of being hard to crank in many small venues and even rehearsing if you don't like earplugs.
Great Video and thanks. I have exactly the same problem with the Epiphone Blues 30 on my bench blowing the receptacle fuse. Was hoping there was another way to get another transformer for less than $300 from Mercury.
You might be able to find one. Or ask Edcor to build one maybe?
I’d agree with u on the heat from the tubes but those combos are hated for the fan it’s so powerful and loud that it keeps the amp super cool but if u have any drives on u get a bit of hum
It sounds sweet. I doubt that the value of the amp justifies the cost of repair, BUT it is better than stock now, and the owner will know that. The waste of trashing it would have been in his head for ever.
That's a nice sounding old Gibson, Brad!
For modern times it actualy looks very well made it isn't a cluster luck and apears easily modifiable.
But what combo doesn't have tubes under the circuit board? Not very many don't.
I like there are no molex. Connectors to melt. That's pretty sweet.
brad those spade clips have a little locking tab that needs to be pressed down to free teh spade clip from the terminal.
The clear sheath covers the tabs, the middle and bottom ones are completely unreachable no matter what, but I think all but one were installed upside down anyway, so there's no way to press the tab. Wiggling them should get them out without removing the terminal from the switch.
Wow bueatiful guitar ,nice blues too .
I have one of these! I had to get the rectifier changed in mine
Thank you Brad!😁
Those engineer solder suckers are the only non electronic one I've ever used that's worth a damn. I'm not an amp expert but I would've tried a reflow and contact cleaner on that pot first. This isn't a criticism as you did a great job.
A tool question. What kind of wire strippers did you use. What do you think of them rather as I was looking at a pair of klein ones last night online and I have every other type, from lesser brands.
Damn Brad !!! You’re gonna have to dip those fingers in some ice water and cool em down😮
Man! I really hope you can find a way to keep doing these videos! If RUclips continues to f*ck ya over, there's Rumble & Locals for the $.
You're a Top Ten Channel dude! 🤜
ES-225! Such an underrated guitar
This one is the 125, but very close model. Just without neck and pickguard binding.
Great sounding amp
So Brad, wouldn't be better to replace that switch with one that doesn't come apart? Could it not be a future point of failure?
The terminals are press fit in there. It’s how it’s made. I think it’s fine as long as you’re not removing leads from it.
Love your intros. Do you create them?
I’ve created some of my intros. The one in today’s video was created by a viewer named Richard from the UK. He’s a super talented dude. There’s a linger version of this intro I cannot play anymore or they’ll try to copyright claim the audio.
Hope all is well. 2005 year of the mini stacks with basic internal layout. 5 watts, plastic switch construction and so forth. fender, Marshall,egnator, orange on and on same cost cutting imported equipment targeted as budget friendly. Unfortunately it mainly effects. the youth of our musical future.
Yep. This was a bad era for Chinese electronics. High demand and low quality.
Love it! Rock the socket!