Troubleshooting Your Tube Amplifier

[@THEQueeferSutherland]

I like how this feels like a very dry video you watch in school. It's comforting to me.

[@Cam_B]

or like a new work orientation video. I immediately get tired.

[@jarveysorensen5502]

Educational though

[@JensenDKMG85]

FYI suggesting to wear rubber gloves is terrible advise. I'm an electrical engineer and I can tell you that unless those rubber gloves are electrically rated you are asking for major issues. Something like latex gloves will MELT TO YOUR SKIN. Please, for the safety of others, change or remove your statement

[@drabbster]

put socks on your hands to replace tubes or wear cotton gloves. they're not meant to be touched by skin because of the fat fingerprints you'll leave.

[@2beJT]

Not true. Touch the tubes and save yourself wearing socks on your hands for no real reason other than old misinformation that continues to spread from old pre-internet days when it was hard to ask a real amp tech. Even in this video you see the man changing tubes without covering his hands.

[@krito2thegreatest38]

You a Gaylord you think you know I e but you pretend

[@TunnelSnake-es7tu]

Shut up I’m smarter than you lmao

[@BrewReview]

This advice comes from the knowledge that oils on skin negatively affect car headlamp bulbs. Tubes are not subject to these issues since the glass surrounding the filament is thicker and also not made of the same type of glass. You’re safe to handle tubes without protection assuming they’re cold. When dicking around INSIDE a tube amp however, different story.

[@patwilson5965]

"keep amplifier turned off and unplugged when touching anything inside the amp" First instruction: tap on the inside of the amp with the amp on.

[@SuperSayinSolidSnek]

inside is the key word, the tubes aren't really 'inside' the amp

[@keithdarling8290]

@@SuperSayinSolidSnek To a certain extent, you're correct.......the Tubes, although not "IN THE AMP, " what you have to be aware of is the Heat from the Tubes, Oils from your skin can, although rarely, help to speed up the aging of your tubes and WILL DETERIORATE the Glass surrounding the Plates inside your aTubes then, MOST IMPORTANTLY, THE CAPS......OR CAPACITORS LOCATED INSIDE. These Capacitors, can and will hold an ELECTRICAL CHARGE powerful enough to knock you across the street, make your Hair as Curly and Frizzy as mine not to mention, if not given enough time to TOTALLY DISCHARGE, NOT ONLY AFTER YOU TURN THE AMP OFF BUT ALSO UNPLUG FROM THE WALL, there is a very good chance of this Organ/Muscle inside your Chest, called YOUR HEART, WILL ALLOW ENOUGH CURRENT, VOLTAGE OR A COMBINED AMÒUNT TO PASS THROUGH. Thuss making your Heart..........well, you can figure it out......if you live!! MOST Tube Amps are designed and built to not only operate here, in the USA off of 120 Volts, if you read your manual these Amps and their Components like the Power Transformer can withstand the 220 Volts required overseas!!! Thank you for taking the time to read this. It could save your life!!!!

[@hansfranz8795]

Also: "Wear rubber gloves for extra protection" - continues to not wear rubber gloves

[@BentGear]

Pat Wilson that had me scratching my head swell

[@Azarie03]

Just enjoy the free tutorial, ingrate.

[@pippafoxglove393]

I'm an absolute beginner in this area. The video was very informative. But, I will leave this type of work to the pros.

[@abramtreadwell722]

After watching your video I now know I have a blown preamp tube. Thank you!

[@D0KS1]

sound gets down and up?

[@JIMJAMSC]

My 2 cents when dealing with snap crackle pops noise etc. May seem like Duh but its common. Plug directly into the amp. Try 2-3 different cords. I don't care if they are brand new $60. Try 2 guitars. Plug amp directly into the wall with nothing else in the outlet. Try different outlets.Many warranties are generous so do not void it. Check first before replacing things.

[@LanzDeVayn]

Best 6:20 minutes I've spent recently. Thanks for the crash curse!

[@fatwillie7854]

Follow the advice in this video and you'll crash for certain.

[@effdpaul1815]

In all my years of playing fulltime through tube amps, the only tubes that failed on me were preamp tubes. The other tubes were routinely checked during maintenance with no sudden surprises during a performance.

[@umialien]

This helped me diagnose and fix my Randall RD45H. Luckily, it came with a spare power fuse . Cheers!

[@Strotophonic]

Very useful, helped to diagnose a faulty tube on the preamp of my amplifier. Save myself a lot of money.

[@basketballjones6782]

1:24 dude... you might want to turn the amplifier on before running the volume control up or down listening for noise. Just a thought.

[@circuitmonkey6653]

Stop. "Wait 15 minutes to discharge your amplifier". That is a pretty good way to get zapped. Capacitors in amplifiers can store high voltage for weeks. You need to properly discharge all the capacitors before poking your bare fingers in the chassis. This is pretty basic protocol and if you question how or why it needs to be done, please take your amp to a professional. This video does not apply to all amplifiers. If you are using this to troubleshoot a vintage amp, the information in this video will more than likely result in you damaging your amp, yourself, or your wallet by paying way too much in new vacuum tubes. I have no idea why Sweetwater would put this out or why it has been up this long. It takes a lot of study and work to get to a point where you can safely repair an amplifier correctly. Not saying you might not luck out and fix it replacing a tube, but without proper diagnostics(that don't include repeatedly blowing fuses until you figure it out) you could make your problem a lot worse. What caused your tube to fail in the first place? Do you know what a bias setting actually is? Are you using a current limiting device? Are you using an isolation transformer? Curiosity is good, but it also killed the cat. This endeavor should be approached with a lot of caution that does not seem to be addressed in this content. Learn the basics before you attempt repairs on a device that can stop your heart.

[@jamesball5743]

Okay boomer

[@TomaszGutka]

Thank you! It was even more helpful for me, because I needed to diagnose Mesa Boogie Mark V head :D In my case, the problem were 2 capacitors that were bulked and had to be changed, but the video helped me realize that the tubes weren't causing the hiss (it kinda seems rare that problem was not tube-related, don't you think?). And if Mark V users have any electronics-related problems, I advise that you try to isolate the problem with Triode/Pentode switch, Hard Bypass switch, EQ, Reverb and FX Loop switches and check if the problem still occur after switching those parts of the circuit off.

[@blazerMcfly]

No volume but I had power. Turns out I had a blown HT fuse, thanks for the help!

[@funkybee6506]

What does it mean when there is a hissing/crackling sound when the amp is on standby but it goes away when you start playing?

[@manicmurph]

How long do tubes usually last on average? I have an EVH 50 watt and yesterday so all 3 channels were working and now today the first channel that has the green and blue channels combined isn't working but the red high gain channel is working. I think though when I was playing that the sound on the red channel was lowering.

[@Somchiman]

Excellent demo. It is really useful!!!!

[@TributeHurrikane]

Very informative and detail explanation, I have a Carvin power amp TS100, and the volume drops when playing, it's good then suddenly volume gets less, any idea you think is causing this, Thanks for your time and hope to hear from you!

[@mrcoatsworth429]

Can somebody explain 3:30 to me? He says "and the signal will be weak," but if you plug into the FX return (straight into the power section), shouldn't the signal be really loud, since that's what the power amp's purpose is?

[@slavesforging5361]

a power amp running a signal that doesn't have a pre amp will be very weak. there are 3 levels of electirc signal: Insturment level (weakest and what a guitar puts out), mic level (mid level and what mics put out), and line level (strongest and what cd players/keyboards/cell phones etc put out). power amps are built to work from a line level input only. if you send them an instrument level signal, they won't do much with it. plugging into the send bypasses the preamp, sending your instrument level signal directly to the power amp. hence weak.

[@robert1969woodstock]

Im back watching this video once again... 🤦🏼‍♂️

[@DS-nw4eq]

Lol

[@Pamahana]

So I've stopped playing for awhile and have a Peavy 6505 112 combo turned it on and it's just static, plug my guitar in and you have to turn post and pre up stupid high to actually get sound and when you do it's just the most dull strumming sound ever. Anyone have suggestions?

[@kittyvlekkie]

really cool video, very helpful and also some repitition to make exactly sure what youre talking about, learned a lot from this!

[@ironwolg]

I've been having a problem with my Dual Rectifier amp and I believe it's a tube issue but I'm not sure. When I turn on the clean channel I get breakup in the signal way too early. I've tried adjusting the gain and master volume settings as well as the EQ to try to get rid of it but it yields minimal results. A friend of mine suggested that perhaps it's the preamp tube rather than a damaged speaker as I previously thought. I was just curious if a bad preamp tube could cause early breakup in a signal. It's only noticeable in the clean channel but it could likely be happening in all the others as well, it's difficult to tell.

[@randolphpatterson5061]

+Perry D I suspect you may have a bad tube or a bad tube connection, or even a bad switch. I suspect that the symptom is there only when you are in tube mode, and not solid-state mode. You might have a malfunctioning rectifier tube, or the tube sockets may need cleaning and/or retensioning, and may be causing a tube to not operate. This model of amp has been produced for twenty years, and it started as a rather less complex design, so I can't be sure which features yours has. But if you can switch power and are running at fifty watts and a rectifier tube isn't operating, you won't have as much headroom as when both rectifier tubes are functioning. Perhaps your amp automatically switches to a low-power mode when you switch it to the clean channel? I honestly know know, but for the purpose of this fix, it's largely irrelevant. You'd have less power & headroom in 100-watt mode as well, but you may not notice unless you're playing at a higher volume setting. Over time, tube socket contacts can develop both corrosion on their contact surfaces and looseness, "losing their grip" on the pins of the tubes and in some cases breaking the connection between the tube pins and the contacts altogether, mimicking a failed tube. Operate the amp in full-power mode using the tube rectifier and try to determine that you are, or are not, hearing the problem. Try it in 50-watt mode, if you have that feature. Give the amp about 15 minutes to warm up, and then try to see if both 5U4 tubes are hot and slightly glowing. There's a quick-and-dirty method that isn't thorough, but it may help. Here's what you can try if one of the tubes looks dead, or even if you suspect it is (you can do this with all the tubes, as a regular yearly or twice-yearly maintenance step): With the amp in tube recto mode, using a clean cloth for burn prevention, grasp the top of the tube and CAREFULLY rock it in a circle, but don't tilt the tube very much, so as to avoid bending (or breaking) a tube pin or a socket contact. You're trying to loosen up any corrosion and/or dirt between the tube pins and the socket contacts, and hopefully restore a secure metal-to-metal connection. You might hear some loud noises when you do this, especially if you indeed have a dirty socket. Try to see if you can hear any difference when you resume playing. If the symptom seems to have vanished, you just may have temporarily cured the problem. If not, go ahead and try a substitute 5U4 tube. If you have a spare pair, replace both tubes. If you only have one spare, try it in both positions and test it each time for the symptom. It's also possible that you do have a bad preamp tube, and you can substitute a new one (or a known good one) in each location, one at a time, and see if that resolves anything. A 12AX7 will work as a TEMPORARY substitute in about every preamp-tube location in the amp. So will a 12AT7, 12AY7, 7025, 5751, ECC81, ECC82, and ECC83. But if you find a bad preamp tube, you must then install the recommended tube for that socket for best performance. This is most critical for the first tube in the signal path, usually either a 7025, a 12AX7 that is suffixed with one or more letters (12AX7A, 12AX7WB, etc.), or an ECC83, followed by the preamp socket located closest to the 6L6 (or EL34) output tubes, which is actually the driver in the output section and is sometimes a 12AT7. You need a high-quality preamp tube in the first position for low noise and lack of microphonics. This is only one basic step in determining if there's a "mechanical" cause for the symptom you've described. If all the connections in the circuit are known to be clean & tight, they can be ruled out as causes. It does no good to replace good tubes with more good tubes, if a bad contact is the problem. If you want me to discuss additional options, please feel free to reply, or just reply to let me know if you already know this stuff, and I'm all washed up or something. Either way, I'll be notified in my email and can then respond. If you want, I can give more details on how a more complete tube socket servicing is done. Finally, for safety's sake, you must be aware that LETHAL VOLTAGES are present at certain places inside the amp, whether it is plugged in or not. Try to work with only one hand, and keep the other away from the amp, or any grounded surface. Stand on a thick rubber mat or rug, and don't wear any metal jewelry or anything that might snag or dangle on any part of the amp. And keep pets and children out of the room. I hope to hear from you.

[@captainamerica9353]

Perry D, problem is, you need to upgrade to a Triple Rectifier.

[@petemitchum3198]

I understand that you explained the power tubes is that if one tube is bad, you must replace all four that have been matched? I have a Mesa Boogie California 6V6 40 watt that has four 6V6 power tubes. That's going to be really expensive repair. I guess the other three tubes are just trashed?

[@bertponjee8628]

Great! Clear deductions where the problem area lies. But what if this is the scenario:my Blackstar HT-5 (only 1 preamp tube, and only 1 power amp tube) makes funny noises when playing over the clean channel. Additionally, the amp seems to have lost both some highs and some lows, some punch, too, particularly when playing through the clean channel. The volume of the noise increases when turning the volume pot up. When playing through the overdrive channel, there is less funny noise, and the amp seems to have some more "life" in it. What is most likely the problem? Best regards from The Netherlands.

[@evanobrien8662]

Really cool that Mike Pence knows so much about guitar amps.

[@danielwelsh]

Look at your fuse.....you'll see if it's blown

[@davidmuoio8886]

I have one blown power tube mesa now down to 3 mesa tubes. Can I put 1 tung sol power tube in or I need to take another mesa power tube out and replace it with another tung sol.

[@middle_pickup]

Very helpful information! Thanks @SweetwaterSound!

[@BRG13DEAN]

I have an OR15 head that I haven't played in over a year. Last time I played it, it was doing fine, not really playing loud at all, but then it started to get quiet. Slowly it would get quiet, until there was no more sound coming from the amp. In both 7 and 15 watt mode it was doing the same thing, and nothing changed after turning it off and trying again later. I cannot remember if there is a hum now or not. The fuse is not blown. It powers up just fine, just no sound coming out. Does this mean my power tubes are bad?

[@Migler1]

You said “replace the fuses”. Which fuses are you referring to?

[@Hagstrom4ever]

It's beautiful to see the amp on and powertubes 3 mm out of the socket

[@comicblueswithjonygitar36]

Those tubes are usually inside and outside pairs?

[@luisytomy64]

Hi, my DCM 40 transistor amp makes a pop noise when i push the power button on or off, any ideas? Thanks!!! Great Videos.

[@ismorenfors2745]

Can I test my Peavey ValveKing tubes with this techinque: one at the time, or is there different kind of circuitry in ValveKing which would damage the amp if I try to narrow down the valve problem like this? Thanks!

[@nickjimenez6138]

I've got a monoprice tube amp with 5 tubes. 2 large and 3 smaller. I play 1 to 3 hrs a day. I recently started using the effects loop and a couple days of playing I turned it on one day to zero volume. I can turn on my op amp pedal and crank the volume and you can barely hear the guitar. Anyone have any ideas? Should I just swap them all out and if so what tubes does anyone recommend? I play blues classic rock, get a little dirty Jimi in there as well. Thanks for any advice.

[@poit57]

Did you get your amp repaired? I have a Monoprice tube amp as well and found this video looking for a way to diagnose my problem. I tried the effects loop for the first time last week. After about 15 minutes of playing, the main fuse blew. Now the fuse blows immediately every time the amp is turned on with no guitar or effects pedal connected to any input. It does the same with all tubes removed, so I don't think any of the tubes are the problem. I'm guessing I'll have to track down a local amp repair shop.

[@nickjimenez6138]

@@poit57 TN, I have always used solid state amps and this Mono was my first toe in the tube amp pool. I rarely used the effects loop on the SS so I wasn't sure about using it. I've read that the Mono is the same wiring as the Laney Cub. I upgraded the tubes and swapped them out with the old ones when they arrived. Have not had any problems since I put them in. I'm buying a Fender 68 custom twin in a couple months so I'm truly upgrading in the tube amps dept. Just bought a Peter Frampton LP copy so I'm using that through the Mono and it sounds great. Am also using the loop and have zero problems with the amp.

[@411Soulman1]

I have a tube amp that produces a raspy bass sound if I turn the bass control up. I'm using 6L6 tubes. Could it be because the screen grid and the center tap on the output Transformer primary are hooked up together? What if I hook the two screen grids together and then put an electrolytic capacitor between the screen grids and the ground, then between the screen grids and the power supply a 1500 Ohm resistor?

[@gmzfabian]

I have a question! I have a marshall jvm210H and when I wait 15 minutes to active the standby it makes a lot of noise and louder but sometimes it is fine and works perfectly but most of the times I can't use it because of that, any idea what is the problem? And what is the of the valves? Blue with red and something like that?

[@WillemDekeyser]

My HT fuse keeps blowing. I'm using a Marshall Bluesbreaker 2017 Reissue, volume on 7, with an attenuator on -16dB. Is this problem due to the attenuator? If I turn on the amp, while the settings are as described above, the HT fuse blows immediately. But when I turn on the amp when its volume is on 2, and the attenuator is on -4dB, it doesn't blow... When I keep turning the volume and attenuator up until it hits volume on 7 and attenuator on -16dB, I also doens't blow. But when I then put my amp in standby, I hear a crackling sound. When I then check my HT fuse, it's blown.

[@the_simulacra]

I have Orange Dual terror head, pracicaly new and I think the gain is weaker last days, I could be biased. Also I hear considerable hum when amp is on, on one channel louder than the other. And I think it's getting louder when I crank up the volume. I thought it was because guitar but seeing thi video makes me think of it as a malfunction right?

[@edippoliti4531]

Thank you, very helpful,now i know it's my preamp ,two tubes not lighting up ,I've switched them out ,but still no go ?

[@slangdoll]

Any idea what it might mean if the STANDBY doesn't actually mute the sound? All the sudden today my STANDBY position isn't muting my sound. I have a Hughes & Kettner TubeMeister18 and the TSC LEDs on the back are normally on when in standby and turn off when switched to play but now when in standby the lights are now off and I can hear my guitar. Actually, TSC indicates a tube needs to be replaced because one LED is on so I'm figuring I just need to replace the tubes but with the standby not working, it makes me think something else is going on...

[@sweetwater]

Hello, Norman! That doesn't sound normal at all! The Standby switch should mute the speaker level output of your amp (it may not mute other things like the silent recording output). The good news is, if you bought your TubeMeister from us here at Sweetwater, you're entitled to free Technical Support from our dedicated team of in-house technicians. Give me a call if you'd like as, I'd be happy to help any way I can. Thanks for the question! Brandt Miller, Sweetwater Sales Engineer, [phone] ext. 1628, [e-mail]

[@smokinone951]

i have a question i hope you can help me with. i have a kustom hv65, its a great lil amp and i only paid 100 for it. problem is when i turn on power sometimes immediately turns on other times it can sit for up to 30 min before it pops and turns on. didnt do this before, any ideas what could be? im thinking power supply because once amp is on everything works great

[@budmeasap]

Running a Carvin X-100B through a Crate half stack. Noticed the two right speakers are out. Any solutions...where do I start looking?

[@MysteriousPostbox]

im running through a marshall Ma50h, was playing and all of a sudden there was a pop and no more sound was coming out, all the lights are still coming on fine, i've changed the power tubes and still nothing, is this a fuse problem, or the pre amp tubes? any feedback is much appreciated!!!!!!!!

[@Mole_King]

That's satisfying. I am Sweetwater's 200,000th subscriber.

[@rufiopan1]

So I have crackling and the crackling gets louder when I turn it up. I replaced all of the preamp tubes and still have the same problem. Thoughts?

[@georgehutchinson527]

Hey. I own a 50 watt HIWATT custom signature series. After warming up my amp and switching on the amplifier, I heard a loud popping sound and one of my powertubes lit up. Since then I have had no sound coming from the amp. I worried that it might be a circuit board problem, but all of the valves still warm up and the power switch still lights up. Ive just noticed the Ht switch has also blown. Can you give me any advice on how to solve this problem.

[@Jamie7-w]

indeed. good info, and not trying to be a "chop buster". however, there are certain kinds of "hum" and crackle caused specifically by capacitors. of course, replacing a cap can be dangerous, and the user may want to refer to a pro amp tech.

[@ChrisNash]

I've been having problems with my AC 30 completely shutting down and blowing tubes when switching on the Standby switch ... any thoughts? Is this a common problem ?

[@captainamerica9353]

Amazing, there are 49 switches, jacks, knobs on the front and 28 in back, that's 77 total. And I'm getting by with 13 on my Princeton Reverb.

[@ebowdan3138]

Hi, I have a fender super sonic 22 and it has a noise, it sounds like rain, it's not to loud, but I went to this studio record and when they set up all the mics the noise was just loud to record. Please tell me what can I do. By the way, it still make the noise with the reverb off.

[@LeoTorresGuitar]

Help Please; I found the microphonic valve, replaced it but the new one was microphonic as well. Then just to doublecheck, exchanged the placing of them preamp valves to find that any valve that I placed on the top right would become microphonic. It's a Fender Blues Deluxe 92' Any advice or help would be greatly appreciated !

[@LeoTorresGuitar]

@Luke Robinett yep, dazed and confused by the fact that a 80's fender amp I had just bought had problems did cloud my judgement. So that was the case and has been fixed now. Thanks for the statement of the obvious to which I was oblivious back then !

[@1thess523]

So i laid down my blackstar HT 60 2x12 down gently on it's face to change out the speakers and when I put everything back together and turned it on it started humming which it never did before and now the clean channel's volume is low but the overdrive channels seem to have their same volume but it feeds back like crazy now. It only hums when I have my guitar plugged in , if the amp is just on with no guitar I can crank up each channel volume but there is no humming or sound only when guitar is plugged in .

[@matthewJ142]

Did you ever find out what it was? A loose bolt or piece in your amp may be the culprit 😊

[@hatespirit]

Hello there, for whoever that can help me please, I have a Peavey JSX, recently i was playing my guitar at a moderate volume (not more than 2) and it was all fine but suddenly sound volume went to almost silent, i can still get sound but i have to crank it up and i get noise... is this pre-amp tube issue or power tube issue?

[@tusharkakshapati7610]

Leaving a comment in case someone answers, cuz I've got the same problem. The thing is if i crank up the gain, it sounds fine, i dont know what's wrong. Amp doesn't play clean anymore.

[@tusharkakshapati7610]

Found the solution: found a local amp tech, he said there was an issue with the carbon flim underneath the volume, reverb and gain knobs. He replaced those films. Amp sounds just as it did new. Didn't charge much. Great guy.

[@hatespirit]

@@tusharkakshapati7610 I took mine to a tech yesterday, hope it will be something easy too, doesnt look like mine is having tour issue but we will see, enjoy your amp!!!

[@tusharkakshapati7610]

@@hatespirit good luck!

[@rich1051414]

Should you turn the amp on again after it is unplugged, and wait for the power LED to fade out? That will discharge most of the capacitors, and prevent yourself from getting bit. Of course, they may not discharge all of them, but it would discharge most of them.

[@SuperJiggawhat]

All this talk about getting your amp biased as he works on a mesa, ironic.

[@biglou2385]

I have a fender super 210 (red Knob )amp.was playing one day and it just went dead with no signs of anything wrong. replaced fuse and all tubes and still no power. any suggestions..please help

[@Audioman45]

Great video, but what a pain! I'm going back to modeling amps.

[@Superxpninja]

Audioman45 why😂 it's like changing a lightbulb

[@godmode3359]

Yeah $128 worth of light bulbs lol

[@asr1143]

i wouldn't say modelling amps but solid-states are almost like tube amps nowadays.

[@keithdarling8290]

I have an old Line 6 Flextone lll that is my " GO TO " BACKUP Amp. I'm also preparing to purchase a New Orange Crush Pro CR60C SOLID STATE AMP as my primary. Side by side with my Blackstar and Marshall DSL, there is VERY LITTLE difference in tone when it comes to comparing Solid State Tone to Tube Tone....the Amps sound totally different as they are all DEFINITLY DIFFERENT AMPS AND CIRCUITRY!!! Tone wise though, plenty of Low End, Great Mids and the Clean Channel is incredibly, sparkling CLEAN!!!.....Not to mention, having only 1-12 inch Speaker, compared to a 212 Combo and a Half Stack, my Spine is loving me for it!!! My Line 6 Flextone lll Amp is now over 15 years old and the ONLY ISSUE I've ever had, actually had nothing to do with the Amp. The FBV Shortboard was the problem. The Display Screen went bad and when that happens, it SCRAMBLES every saved Preset you've created, hence losing ALL of your sounds!! Unfortunatly, they no longer make replacement parts for the ORIGINAL Shortboard and the newer Mark ll and Mark lll Shortboards WILL NOT WORK WITH THE FLEXTONE!!! I've spoken with Line 6 about this issue and they have NO PLANS WHAT SO EVER to resolve this by re-issueing the Screen.......BUMMER!!!! This, of course, has sent the prices of USED ORIGINAL FBV Shortboards sky high. In the over 15 years I've owned this amp, the Screen has only failed me twice....twice too many times, as I had to spend a fortune to purchase on online, 1 from OVERSEAS, WAIT FOR CUSTOMS TO DO THEIR JOB, PAY THE IMPORT DUTIES NOT TO MENTION THE INTERNATIONAL SHIPPING ON AN EXTREMELY HEAVY PACKAGE!!!! The Shortboard is light but by the time you have to OVERPACK for shipping to keep it safe, then go throught all the Import stuff, It cost me MORE than what they cost BRAND NEW.....nearly $275. If you can find one here in the states, HOPEFULLY the seller has a video or picture showing the unit working. Otherwise, you'll be paying about $100 or more for a DOA product.....that is unless you get it off of eBay where eBay WILL REFUND YOUR MONEY if the Seller shows it as a WORKING UNIT on their listing. A Seller can list the item " AS IS, NO REFUNDS, " but if shown working or they state in their listing that the unit ....Screen works as it's supposed too, the Seller has ZERO recourse and eBay will AUTOMATICALLY WITHDRAW FUNDS FROM THEIR ACCOUNT AND REFUND YOU. Lucky for the Buyer; eBay saves ALL LISTINGS, PHOTO'S as well as COMMUNICATIONS between Buyer and Seller just for this issue and others like it for quite a while or until the issue has been resolved to both parties satisfaction!!!! OK, enough about eBay. The PLUS SIDE, if and when you DO find a WORKING DISPLAY SCREEN, the moment you replace the Screen and test your Amp befor putting the Shortboard back together, ALL OF YOUR SAVED PROGRAMS WILL RETURN!!!! That's been my experience....TWICE!!!! The only things I had to re program were the Titles of my Presets but all of my Presets I created returned to their ORIGINAL way I set them up....so KUDOS to Line 6 for, at least, designing this Amp in a way to store your Presets should the Short or Longboard crap out on you!!!

[@keithdarling8290]

You are correct...it is like changing Lightbulbs......VERY EXPENSIVE LIGHTBULBS...LOL... Lucky, Preamp Tubes are not that expensive, $10-$25 each, depending on the brand. It's the Power Amp Tubes where the Wallet starts taking a hit. Power Amp Tubes MUST be sold in MATCHED SETS, wheather it's a Matched Pair or Quads. You cannot replace just 1 Power Amp Tube at a time unless you wish to start replacing your Tubes every Month or so. Very few Amps are " Self Biasing, " even if yours is a Self Biasing Amp, I would NEVER TRUST one that states that. You absolutely HAVE to have your Power Tubes Biased EVERYTIME they are replaced or again, be prepared to start replacing your Tubes on a regular basis unless you are replacing the Power Amp Tube with THE EXACT BRAND, MODEL AND POWER RATING. That is the 1 and only time you don't have to have your Amp Biased. Unless you just got a bad Tube, even after replacing the 1 Power Amp Tube, personally, I would still pay the price to have my Amp checked out to make sure ther's not something else going wrong in that 1 V Section....such as a bad Socket or a Capacitor going bad.....with Tube amps, you just never know. Tha's why they are so expensive compared to Solid State. There is so much more that goes in to a Tube Amp than a Solid State which is why Tube Amps cost so much more to repair as well as make. I'm sure you know about Biasing, for those who may not, you have to make sure that the Current being drawn across the Power Amp Section is within Specifications or 1 or more Tubes will start working harder to draw the correct Current all the way across your Curcuit Board. This makes your Tubes work at more than double their intended consumption which starts a Chain Reaction causing the other Tubes to start getting weak or to fail all together. This will start to COOK EVERY TUBE IN YOUR AMP!!! I own Tube Amps with my Blackstar and Marshall DSL and it's not cheap to replace the Lightbulbs and have them Biased!! Lucky, Preamp Tubes DON'T HAVE TO BE BIASED.....they are truly like replacing a little more expensive LED or Compact Flourescent Lightbulb!!!!...LOL.... Please understand, I'm in NO WAY trying to BASH you or MAKE FUN of you in any way. Your comment just gave me the platform to educate those who don't know the process of replacing Tubes and why Tubes have to be done a certain way and Biased. If you feel, in any way, I'm trying to be mean or rude about your comment, PLEASE DON'T.....THIS IS CERTAINLY NOT MY INTENTION!! Take care and Play On!!!

[@jond3929]

Do old tubes affect the tone of the amp even if the tubes haven't necessarily failed? My amp hasn't had new tubes in 4 years and there's nothing specifically wrong with the amp like described in the video but it seems like the tone has changed recently (less gain and the tone has gotten colder). Does the amp need new tubes or am I just imagining that the tone has changed?

[@sweetwater]

Hi, Jon. Great question! It does sound like you need a tube change. I would compare it to an oil change on a car - even if you don't drive the car very often, it is a good idea to get the oil changed once or twice a year. If you have any other questions feel free to reach out. Thanks! Jason Filloramo, Sweetwater Sales Engineer, [phone] ext. 1281, [e-mail]

[@robertopizzamiglio5078]

Great video! But what if my amp makes no sound at all in the distorted channel but sounds fine in the clean channel? What do i have to check?

[@harpham13]

i have the same issue. xlean channel is fine but dirty channel needs to be on full. with gain all the way up to be heard at all. changed the tunes but no luck still ;(

[@steeveejay]

Each pre amp tewb has two triode sections eg section A and section B.. if the distortion channel and clean channel share the tewb , like , clean on B, distortion is usually A and B ,then 1 side of the tewb is faulty..change the tewb, (chuckle ) . If that dosnt fix it, you have a fault in the signal path , eg bad solder, (sodder) joint or faulty component..

[@epicdailyshow8569]

steeveejay My twin reverb makes a popping noise every time i turn it off of standby. But mine still works fine.

[@steeveejay]

EpicDailyShow Could be a few things, If it only started popping like, recent it could be a sign of a bad switch contact . soon as you flick tha switch , theres like 520 volts blasts its way to the choke and evens out at 460 volts.. if the switch has any corrosion from arcing it may be the cause.. If you replace the switch , solder a 20 or 30 uF cap across the switch terminals and it will last way longer .. Make sure its plastic and rated for 630 volts.. The cap changes the rate of charge so reduces arcing.....Hope that helps..

[@ottolehmann5286]

Hi so I have a Fender Blues Junior, it’s my practice amp and has been working great for two years however now when I turn it on it makes a really loud hum/distortion noise, none of the eq setting do anything (for example with everything on 0 including the master and volume it still makes this noise) in the back there is one tube which is glowing white and popping and going crazy inside, all the other tubes glow with a low red. Would the solution be to simply replace the damaged tube or is it more serious. Help please!

[@ottolehmann5286]

Dean ok so should I buy another power matched pair and replace the faulty tubes? Thanks for the help man

[@xReelox]

The valves don't light up in my amp (Hiwatt custom 100 dr103), I have changed the fuse that was blown, it turns on but the tubes don't warm up (light up). What could the problem be? should I send it to a professional to get it repaired? I got the amp from my dad and I know he's had problems with the amp before but no one really knew what the problem was and now it just "died"

[@jaychen2000metal]

My amp is super dark unless the presence in cranked but you can still hear it unless i eq like - 8 db of 400hz and also boost the 1.6 and 3.2 also by like +8. I'm lost. Tried 100 different eqing options all moderate loudness

[@reevesanglin1891]

Hi, I have a 65 Princeton Reverb Amp which does not power up. the mains fuse is ok and the fuse at the back of the amp. can any help with this issue? Reeves

[@rollo316]

I've got a vox night train g2 15w works great but I can't get it to turn off lol any suggestions why this might be happening ?

[@timmcclements7657]

i have a mesa boogie nomad 100...i get this crackling sound out of it after i warm tubes up...my tubes are new...its not my cords nor is it my effects...what is causing this?

[@jarredgraffiti]

Thanks guys.

[@REKApollo]

My tube amp is fine, but plugging the guitar into the send input on the back is the only way i can get sound out of it. the input on the front isn't working, but the input looks and feels fine when plugging in the chord. I'm not sure what's up with it. It's a really old marshal amp and the tube and fuse are both fine

[@dfoe108]

Where do I find the fuse of my amp if it is not on the back panel?

[@tedcabana]

I was searching, Why is the clean channel so much louder than the lead channel on my tube amp? Best I got was this video. Any ideas how to adjust that? I was thinking of a lower gain preamp tube in V1 slot. Any tech-heads out there?

[@ЙорданУшев-в5э]

Hi, I'm using Marshall JVM 410C It sounded good yesterday and now when I start it ( overdrive 1,overdrive 2 and grunch ) it sounds very weak. and in clean mode it is not heard at all. Please advise me what is the possible problem.

[@nikoladjikic9758]

Have you solved your problem?

[@ЙорданУшев-в5э]

No

[@ecko911]

Hello there, here's my situation, It might be nothing but coincidence but I believe I blew something by plugging in the footswitch of the amp while the amp was warming up on standby mode. Now I can't hear my guitar on both channels, all tubes seems to light up still, I changed both power fuses, still nothing. Any clue if I damaged it by myself? My amp is a Orange Rockverber 50 MK1

[@randolphpatterson5061]

+ecko911 Sometimes, the footswitch itself is the problem, and a wire often seems to break right at the spot where the footswitch cord goes into the footswitch housing, directly underneath the grommet/strain relief. If this is the case, your amp should be okay when the footswitch is disconnected, but the symptom appears when the footswitch is connected to the amp. If this sounds like the way your amp is behaving, you'll need to take the footswitch apart and inspect the wiring right where the cable comes into the housing, and perhaps check the solder connections on the other end, where the cable plugs into the amp. The simple act of plugging in the footswitch while the amp was in standby should never, ever cause a failure or a malfunction all by itself. One caveat: this generally applies to mechanical footswitches, and everything I've said may go out the window if the switching is accomplished by digital means. Still, it won't hurt to look for a broken wire, a failed solder connection, or a worn-out switch assembly.

[@JimDanDeeBand]

Hi Sweetwater, I hope you can help me. I have a 71 Traynor YSR1, bought recently and gigged 2 or 3 times. Bought it from the original owner. After returning from a gig to the jamspace, it now only makes quiet electronic sounding fart noise, and has hardly any volume. Does this sound like a tube problem? Your help is greatly appreciated, thanks! JDD

[@randolphpatterson5061]

+Jim Dan Dee Hope you've gotten it fixed by now. If not, try substituting tubes, one at a time, using a known good tube, and see if you find the cause. Or else, you may have a bad capacitor in the power supply section of the amp. Does the amp do it all the time, or does it just make the noise as you play it? You may try it your self or get a tech to do it, but you may need to look at almost every connection on the amp to see if you have a bad solder joint somewhere. Don't do it yourself if you don't feel safe, you can die from lethal voltages stored in amps, even if they've sat unplugged for long periods. They don't need to be powered up to kill you. You can try running it through an external speaker that's known to be good, to rule out a bad speaker. I'm clutching at straws now, since I can't hear the amp. Plug the guitar straight into the amp with a known good cord, too, and you can rule out anything in your effects arsenal as a possible cause if the problem persists. Check to see if the speaker leads are securely attached to the speaker.

[@AMRsti93]

it's not recognizing that my guitar is plugged in and when it's powered on i just hear loud static and crackling any suggestions? it's a bugera 333 infinium

[@matttaylor1449]

Test the tubes

[@LosSebosFR]

Hi, cool video ! i'm having a problem with my Orange rockerverb 50W head, when turn it on in "standby" mode, it stays on, the amp light stays on. But when i switch to the "ON" mode (where sound should come out), there's a small flash from the back of the head and one of the fuses blowns. Could this come from the power stage ?

[@silasfatchett5693]

Remove the power tubes and if the fuse doesn't blow when it's switched out of 'standby' it's most likely a failed power tube. It could also be lack of negative bias, so that would need to checked before installing new tubes.

[@1952TeleDude]

I have an very old Boogie. 60 watts. Reverb. No graphic. If I play an E or Eb note I get a fluttering Sound. Any quick ideas as I'm gigging All weekend.

[@rich1051414]

+1952TeleDude Sounds like a tube is microphonic on a note disagreeable with the amp. That tube probably happens to resonate somewhere between E and Eb. Change the tubes to something not microphonic, or not microphonic in a range that effects the amp. I think nearly all of them are microphonic to some degree at some frequencies, and only when in certain amps, due to the amp itself resonating better at certain frequencies. Its really just a case of bad luck i think man. I had issues once with an amp playing a low E, which did turn out to be microphonics, but'fluttering' is an interesting description. Mine was better described as scratchy. It helped by not pushing the amp against the wall.

[@geet77777]

I'm not much of an amp tech. but my trainer tube amp just stopped making any nose. but if i plug headphones into the headphone jack, I can hear it and control it fine. it was working great and just cut out.

[@jjmora05]

Sweetwater: I have a fender twin amp and when I powered on the amp the red light is getting weaker until the light is gone but the amp is working but if I hit with my hand above the light then the light is on but quickly its gone off again. Sometime the sound of the amp change dramatically. I am a musician but a stupid with gears so I will aprreciate very very much your advice. Thanks!

[@sweetwater]

jjmora05 Hi, please call us toll free, 800-222-4700 and a Sales Engineer can help you out.

[@SONGSTICKS]

SweetwaterSound Hi, I recently bought a Fender Greta and it has a problem. When it's been on for a little while the volume drops or sometimes just fluctuates. Does this sound like a valve issue please?

[@RobertoTorao]

thanks, very helpful!

[@gbzoxxoo8585]

So I just got a tube amp. With the master volume on 8 I can barely hear my guitar. When i turn the amp off i can hear it really loud for a second then the amp is off. It does have a standby switch but it doesnt make any difference when I turn it off or on. It has two different channels and they dont change and light doesnt come on. It's a marshall and the cab I have is new and cords are new and guitar is good as well

[@bluelightningfilms57]

I have a Laney GC-30V. It is making a steady humming noise, and one of the tube heats up so all of the inside components are orange hot.

[@strontvliegable]

My Marshall amp makes a rapid ticking noise and when turned halfway open gives looooots of feedback, please help!

[@mauriciogambini]

Thanks for all the videos you guys release. They are very useful. I’d appreciate if you could give me a tip about tubes. I was removing a preamp tube from my guitar amplifier and one pin broken (the other 8 are perfectly on the tube). Can I just removing it with pliers or there is a risk for getting electrical shocking ? Ps: all other components are set in their places. Thanks !

[@heut4384]

There are always getting risk electrical shocking IF you don't remove the power cord 🤭. There's a electrical 101 training in KZbin. I recommend you understanding about electronics before you trying to touch anything that uses power equipment. 🙄

[@hellskreamer]

Sweetwater: I have some weird sound coming from my amp head (Dual rectifier old 3 channel) and one of my rectifier tubes are not glowing, the sound is like if you pour sand slowly on glass or something like that. I bought this amp second hand, 15 years old and never changed tubes, but also bairly used by it's owners, only low volume etc. I have only had this amp for something like 3 weeks or so, it's my first tube amp and i am confused :). Thanks in advance!

[@randolphpatterson5061]

+Heavy Metal For Life Your amp is well worth repairing, and can be made to sound as good as new. Rectifier tubes need not be a matched set, and one variety of 5U4 may glow more brightly than another. Still, it may be that you have one bad tube out the pair. Shut it down, let the tubes cool for at least five minutes, swap the positions of the two 5U4's, and power it up again. If the same tube appears cool when it's in the other socket, it's a good bet that you have the bad tube identified. Pull the suspect tube out entirely, and see if the amp behaves differently, or if it sounds pretty much the same. If nothing changes when you remove it, you have more evidence of a bad tube. Doing this will not harm the amp, but use a towel or something to avoid burns. If the cool tube is always the one in the left-hand socket, or always the right-hand socket, chances are that either the socket contacts are holding the tube pins too loosely, or are coated with dirt or a film, and are preventing the tube pins from making electrical contact. Or, a wire soldered to the socket may have overheated and needs to be resoldered to the socket. As far as the "sandy" sound, there are a few typical causes. For one, the 100kOhm (sometimes 82kOhm) resistors soldered to the plates and grids of the preamp tubes may have met their doom by being stored in a damp environment, and they are one of the chief causes of a hissing or sometimes a popping noise. If you know what you are doing, you can simply replace ALL the 100k and/or 82k resistors in the amp, to be certain. Another cause, especially for amps that haven't been used much, is the same damp environment allowing moisture to get into the transformer windings. Inspect VERY CAUTIOUSLY for any signs of rust or paint peeling on the surface of the transformers, but DO NOT attempt to clean it off. Note it as a possible sign of a decayed transformer. Was the amp stored in a basement, or any other damp area? Sometimes, this can be largely remedied by leaving the amp turned on continuously for several days, allowing most of the moisture to escape from the confines of the (heated) transformer housing, even if there's no obvious sign of moisture damage on the surfaces. Another thing you can do, provided you have a known good spare preamp tube, is to try the "tube substitution method". Be very careful if you do this, and don't ever put BOTH hands in an amp, powered up or otherwise. Use one hand only, as a critical safety rule, and keep your other hand from touching the amp, or anything else that may be grounded. Swap your good tube with each of the tubes, one at a time, and listen for any improvement each step of the way. Test all of the preamp tubes this way, and pay close attention for any improvement in the noise levels each time. Don't strike the tubes very hard, but use your finger to gently tap each preamp tube, while the amp is powered up & in full-on mode. You may need to pull the chassis from the cabinet to do this. If you don't hear a thing, don't tap harder, turn the amp up instead. If you still don't hear much of anything, that's good! The one that is the loudest through the speaker when you do this will be the most critical tube to replace. It's the first tube that your guitar signal encounters, and so any noise coming from that tube will be amplified more than the noise from any of the other tubes. It's almost always a 12AX7 variety, but a high-quality version, such as a 12AX7A, 12AX7B, 12AX7WB, etc, or a 7025 (military-grade 12AX7). These have been tested & chosen for their low noise and low microphonics, among other things. Finally, a normal tube gives off an emission of random noise, called "blow", which usually subsides after fifteen minutes of being turned on, but it may take even longer. It sounds a bit like the surf! It seems to be worse if the amp has been sitting a long time, for some reason. This can contribute to the noise you hear, even if it isn't the sole cause. The thing to keep in mind is that you can do all of these procedures with no test equipment and with little or no out-of-pocket expenses, except for a preamp tube, if you don't have one, some relatively inexpensive 1/2-watt resistors, and you may also be springing for a set of rectifier tubes in the end. Just keep that amp warm and dry!

[@theosas5267]

+randolph patterson hii have a amp and 1 tranformer is have some like orange paint like a small eye drop--anyidea what might can be ?

[@codyellis5348]

My amp doesn’t even power on how do I trouble shoot that? It’s not the outlet or the power chord. It powered off while playing it and I can’t get it to power back on. Help?

[@radakinryder2741]

so my amps light is on but none of my tubes are getting warm and i have absolutely no signal going to the speaker. Im certain my power outlet is fine, my guitar and cable are fine. Im at a loss.

[@noprayertodie6959]

Good day,I have question about Bulbs,İn case I was played my guitar for 3+ Hr I was awaited some Minutes open guitar and amp there is a come explotion sound But I didnt heared any diffrent in the Sound in amp What just happened to my Amp?

[@noprayertodie6959]

Just seems like weak on Master Settings in Ovendrive Channel

[@joshuang3919]

I keep getting power surges on my peavey 6505mh along with the crackling sound...Sweetwater, what can I do?

[@sweetwater]

We apologize for the late reply! If you haven't already, give us a call at [phone]. One of our techs can check it out for you!

[@USMC_BABE38]

my dad's old Fender amp, its been working for many years and its been an long time since it's seen any repairs since he's owned it I'm the only one who's been using it since he's owned it I did carry it over to my house and it still worked after I'd brought it inside from the backseat of my truck I don't think it fell when It was into my truck I can' t figure out why help

[@cloversgood_luck9290]

Any amp heads have a suggestion? My amp turns on but the jewel light won't turn on so I have to check manually to see if its on. anybody know whats the cause? I bought this amp about a month ago.

[@LanzDeVayn]

Problem is that I want a M/B amp even MORE, now! Is this tattered-and-torn, used, beat-up demo available?!?

[@rune288]

hi can anyone help me? i have just bought a 5150 mk2 and i'm running it at 8ohms to a two-notes torpedo live but i can hear my actual guitar signal coming from within the head itself. is this normal.?

[@taterfight]

The noise that you are hearing is coming from the power soak in the torpedo live. Completely normal.

[@juanvaldez6357]

No audio examples?

[@papahjoshscene4234]

I have a vox vt30, but now there is a problem. if I play for 30 minutes, the sound suddenly decreases and hoarse. what's the problem?? Please help me. Thank you

[@undyingv0id397]

What do i do if my tube amp isnt getting as much gain as it used to? Everything else is okay except for that one part.

[@sweetwater]

Hello, Chris! If it doesn't have as much grit as it used to, but your tubes have been changed recently, it could be that the amp was biased cold. Also, you might just want to check the bias if you play it a lot, but it doesn't yet require new tubes. A simple adjustment could be all you need if the manual for your specific amp has re-biasing instructions. If you purchased the amp from Sweetwater, feel free to give our Tech Support team a call, or reach out to your Sales Engineer. Or, take your amp in to a local guitar amp tech. I don't recommend poking around inside your tube amp if you don't have much experience, because they do carry a LOT of voltage. Thanks for the interest! Kevin Spunde, Sweetwater Sales Engineer, [phone] ext. 1732

[@solomonoh7769]

0:04 Everybody loves to scoop mids, although Colin hates that.

[@joshuang3919]

Just asking, why should power tubes be replaced all at once?

[@ryannunwick2328]

Joshua Ng they dont have to. its only for biasing reasons. However, use the same tubes as you wont need to re bias your amp. my rectifer HW amp is making a strange noise and im geussing its a power valve. so im going to replace one. once i find it

[@ianmacdonald6350]

In a 4 output-tube amp they are in pairs, and if one of a pair is dead the other works twice as hard. The sound may be normal but the good tube is going to overheat and be ruined.

[@pjn2432]

Hello. Can anyone help me? My Tube Amp suddenly stopped amplifying my guitar. It can be turned on and makes some noise because of the tubes (so thats how I know nothing is wrong with the tubes) I never dropped it and always turned it on properly. It never caught dust, water, moist, extreme weather changes, etc. It just that it doesnt amplify my guitar... If anyone can help I would apreciate it

[@andreasunsvag4493]

My amp plays, but at a point it just goes silent. And after a while the sound comes back. Please help.