I had the same problem years ago with a Peavey. I sprayed the send n return and plugged a jack in n out few times and solved the problem. Great video. God bless.
Stuart, I have seen this same issue on my Peavey Bravo. I keep the jumper in but, noticed issues when it was out. A quick clean took care of it it as well. This must be a common issue across different brands. It's good to know to look for this. I appreciate the schematic and explanation of function as it helps to understand what is going on in there. Once again you've produced an excellent video to teach and entertain at the same time.
Thank you so much for this. I have a Subway Blues with the same issue. I’m on a business trip right now can’t wait to get home to try this fix on mine!
I had the same symptoms on my fender "68" custom twin reverb reissue. Powers up just fine. After it gets really warm, there's a obvious drop in output with some nasty distortion. I replaced the valve tubes, same thing. I am not a technician. However being a genius, I replaced the output Transformer. Miraculously it PERFORMED great. Put the amp all back together and the next day the same problem resurfaced but worse. Now its just a mess. Time to find a good tech. I wish I would have discovered your channel before I started taking on a project that I was not qualified for.
Hi Mike. DOn't be too hard on yourself. If you're interested in learning to repair amps, this is exactly the way to do it. Have a go and get some experience. I hope you get it fixed. I can;t recall if your amp has FX send/return jacks. If it has, try cleaning the contacts. (Just spray some cleaner into the socket and work a jack plug in and pout a few times.) Long shot, but it could be that.
Nice easy one, love your surprise when you plugged in the blue lead..! Great video and as you've said before, send & return sockets can be the culprit..Ed..uk..😀
Paper usually contains a minor amount of gritty silica and so even without using contact cleaner the strip of paper tends to polish or burnish the contacts as you pull the paper between them. If you do use Deoxit or similar lubricating contact cleaner on the paper strip, it's a good idea to flush the contacts with alcohol afterwards to degrease them. Actually, if the jacks are old and particularly oxidized/intermittent, a thin strip of ultrafine *plastic-backed* sandpaper, like that used for polishing fiber-optic connectors, works well with just one pull; or you can use an ink eraser shaved very very thin with a razor blade.
@@1Dougloid , I've got a stash of Japanese made NOS plastic 1/4" jacks from the late 70's/early 80's (I think they were made for/ used by Nakamichi) and they're decent quality, better than most modern Asian made jacks anyway. The real problem with that style of connector in general appears to be that the contact pressure is weak because it's spread out and diffused over a wide area; instead of having a very small contact nub that has high contact pressure, like what you'd see on old open-frame Switchcraft jacks.
Good catch. You got off easy, not having to do the dreaded Mesa board dive. Make sure and report this to your parole officer. I've got a Splawn waiting for me with a similar stated problem.
I am eyeballing one of these amps locally. Is the Mesa Boogie Subway Rocket Reverb one of the Mesa models that are expensive to troubleshoot/repair due to the design under the hood?
My brother has had this amp in his local USA Mesa shop, who said it needs to go back to the factory for service. Freight and service charges are difficult to justify. He has a floorboard multiFX unit. If we pull the Mesa amp chassis, do you know of a 1U/2U power amp that could be inserted that might be modified to fit reasonable well? The thought being to use the multiFX as a preamp, fed to the Mesa populated with a poweramp.
All the old 1960's amp with point to point wiring. It's pcbs which are the main problem - you can;t get to the other side to check things out without major work.
Hi Stuart, really like your channel and the projects you get into. I have this exact amp, have had it for almost 20 years now and I need to clean the pots specifically around the volume knob as it cracks unbearably loud. I was wondering how you removed the chassis from the casing as you just indicated it was a pain, and yes you're right it is!? I took the 4 screws out from the top but I can't seem to get the chassis to move, it's like it's stuck on something with the front panel and I can't tell what it is thats blocking it. I was wondering if you had any insights as the discussions I am finding online seemed to indicate similar issues with this and similar amps. Thanks in advance and keep up the great work!
Hi Gary I can;t recall on this particular amp but sometimes the chssis can get stuck either on some creased up tolex or on aluminium plate/foil they put on the top surface for hum reduction. If so it can be a TOTAL PIG to get the chassis out! Good luck.
@@stuartukguitarampguy5830 Hi Stuart, just a heads up I finally figured this out. I had to remove the amp mesh / speaker cover to get the chassis to come out easily. Once removed the chassis just fell out.
My Rocket 4Forty just began doing this. But it doesn't take any time for it to happen, it happens right as it's turned on. Any ideas? Same circuit design as the other rockets I believe.
I used to be an authorized Mesa repair tech and I wrote them off years ago. They are a disaster in design. Excellent video, interesting twist towards the end.
Interesting thanks David. I have a friend who is an authorised repairer and feels the same. Mesa have just been taken over by someone (I can't recall who) and they've stopped paying his invoices!
@@stuartukguitarampguy5830 That's interesting. They were acquired by Gibson because Gibson has done so well making amps, viz., trace elliot disaster goldtone shite and those awful SG amps from the old Standel factory that used 8417 power tubes. Grenade city. After having my arse kicked by the last two mesa amps through here I swore off. No more.
@@stuartukguitarampguy5830 I have a theory about this. How does a guitar company recently out of bankruptcy finance this deal? Answer: With other peoples' money. Who are they? VC types, aging hippies who have expensive Gibson guitars but can't really play all that well because they haven't learned their craft. Jeez, it would be cool to have an amp company! What will happen? Well, the argument's a little convoluted but I figure there's a lot of talk around the office-God forbid any of these guys would work in the repair depot or on the sales floor-about "synergy" and "merging resources and working together to create a great new thing" and similar bizspeak chatter. In reality, the people who put up the money are going to want to see a substantial ROI sooner than later-the people who actually are the investors will demand it. So where do the payments start coming from? I believe Mesa sales are static-growth is lof limited potential. Mesa sells communion wafers to the already converted. So: Let's broaden the base and cheapen the product to get the prices down and bring in the dough to pay the VCs. Answer: Cooking grade new, less complicated designs will be farmed out to China or Viet Nam and Petaluma will exist only as a rump custom shop and repair depot. Coming soon to a Walmart near you, trading on brand name recognition. Why do I think this? Marshall Laney Fender Acoustic Vox and on and on and on.
Considering the hassle of removing the chassis, I would have tested the repair by tapping and then alternately blowing coolant spray and hot air on the effects/headphone jacks just to ensure the problem is resolved. Nothing worse for a tech than to put everything back together and have the problem show up again.
@@stuartukguitarampguy5830 , check out the Brads's Guitar Garage channel from Australia, it's "Mess-uh" to him; he posted several Mesa repair videos recently. Also, Psionic Audio is doing an ongoing major redesign on a Mesa Dual Rectifier amplifier. He's way braver than I, I'm not that fearless!
That must be the only Mesa amp that looks serviceable. It's surprising that Randall Smith went down the road of practically unserviceable amp design considering he started hot rodding turret board Fenders which gave him the inspiration to make and sell his own amps. Pre 80's Fenders are a relative breeze to repair/service compared with his designs. Perhaps he didn't want another 'upstart' doing what he did !
A view of the innards of a Mesa is always the same; 6 pounds of shit in a 5 pound box. They are overbuilt for the sake of overbuilding, in order to overcharge cost. Nevertheless, the solution was well spotted, Stuart. Quite a good episode; including tech tips as well. Try to stay in from the blustering, numbing, cold. Cheers!
Mesa should be pronounced Gar-bage. I have yet to read about a single amp manufacturer that is more despised than Mesa. Even I, as someone who isn’t into electronics repair, can tell that those amps are a complete nightmare for any tech.
@@stuartukguitarampguy5830no doubt they sound great but speaking from perspective of an engineer, these are the amplifiers that are great while they work and when they go bad they become a serious issue. I was always told by one of my professors back in university that beauty of engineering is in simplicity and that is exactly why I love the old school amplifiers like Fender, Randall, Laney etc. People who are swearing into Mesa are just like Gibson people, they give off such a cult-like vibe. It’s a great piece of gear but there is many amplifiers and guitars out there that do the same thing just as good or even better for much lower price and with much better repair options. I can’t imagine buying a 3000€ amplifier that no one wants to repair in my area so I have to send the whole thing half way across the globe for repairs and pay another 1000€ for shipping and import fees. A bloody nightmare.
I had the same problem years ago with a Peavey. I sprayed the send n return and plugged a jack in n out few times and solved the problem. Great video. God bless.
Thanks for sharing
Great job….customer must be happy…..and I can confirm…he is!
Yes he was a really great guy! :)
Stuart, I have seen this same issue on my Peavey Bravo. I keep the jumper in but, noticed issues when it was out. A quick clean took care of it it as well. This must be a common issue across different brands. It's good to know to look for this. I appreciate the schematic and explanation of function as it helps to understand what is going on in there. Once again you've produced an excellent video to teach and entertain at the same time.
Cheers Michael I'm glad you enjoyed it.
Thank you so much for this. I have a Subway Blues with the same issue. I’m on a business trip right now can’t wait to get home to try this fix on mine!
I had the same symptoms on my fender "68" custom twin reverb reissue.
Powers up just fine. After it gets really warm, there's a obvious drop in output with some nasty distortion. I replaced the valve tubes, same thing.
I am not a technician. However being a genius, I replaced the output Transformer.
Miraculously it PERFORMED great.
Put the amp all back together and the next day the same problem resurfaced but worse. Now its just a mess.
Time to find a good tech.
I wish I would have discovered your channel before I started taking on a project that I was not qualified for.
Hi Mike. DOn't be too hard on yourself. If you're interested in learning to repair amps, this is exactly the way to do it. Have a go and get some experience. I hope you get it fixed. I can;t recall if your amp has FX send/return jacks. If it has, try cleaning the contacts. (Just spray some cleaner into the socket and work a jack plug in and pout a few times.) Long shot, but it could be that.
Nice easy one, love your surprise when you plugged in the blue lead..! Great video and as you've said before, send & return sockets can be the culprit..Ed..uk..😀
Paper usually contains a minor amount of gritty silica and so even without using contact cleaner the strip of paper tends to polish or burnish the contacts as you pull the paper between them. If you do use Deoxit or similar lubricating contact cleaner on the paper strip, it's a good idea to flush the contacts with alcohol afterwards to degrease them. Actually, if the jacks are old and particularly oxidized/intermittent, a thin strip of ultrafine *plastic-backed* sandpaper, like that used for polishing fiber-optic connectors, works well with just one pull; or you can use an ink eraser shaved very very thin with a razor blade.
One of the things you find is the spring leaves lose tension over time. I just shit can 'em and replace with genuine Cliff jacks when I can find them.
@@1Dougloid , I've got a stash of Japanese made NOS plastic 1/4" jacks from the late 70's/early 80's (I think they were made for/ used by Nakamichi) and they're decent quality, better than most modern Asian made jacks anyway. The real problem with that style of connector in general appears to be that the contact pressure is weak because it's spread out and diffused over a wide area; instead of having a very small contact nub that has high contact pressure, like what you'd see on old open-frame Switchcraft jacks.
Good catch. You got off easy, not having to do the dreaded Mesa board dive. Make sure and report this to your parole officer. I've got a Splawn waiting for me with a similar stated problem.
Chortle!
Nice one, thank you. I have one of these so I'll keep this in mind. - amazing lead tones with this wee amp on the Countour setting with a Les Paul
Glad you enjoyed it!
I am eyeballing one of these amps locally. Is the Mesa Boogie Subway Rocket Reverb one of the Mesa models that are expensive to troubleshoot/repair due to the design under the hood?
Hi. In my opinion all Mesa are hard to repair and few techs will take them on.
😂 it take years to hit an amplifier correct 👍🏻😂
Great video 👍🏻
Yeah these newbies just bang and thump in any old place. Little do they realise the exquisite subtlety of a true master...
Nice one Young Stuart. Cheap crap sockets!!
Another awesome video, great job...love from the sunshine state..
Thanks John. We could do with some sun here. Brrrrr.
Good repair Stuart.
Cheers Zack.
My brother has had this amp in his local USA Mesa shop, who said it needs to go back to the factory for service. Freight and service charges are difficult to justify. He has a floorboard multiFX unit. If we pull the Mesa amp chassis, do you know of a 1U/2U power amp that could be inserted that might be modified to fit reasonable well? The thought being to use the multiFX as a preamp, fed to the Mesa populated with a poweramp.
Mesa are a bit of a nightmare to work on I'm afraid. Unfortunately I don;t know of anything that can help you. Good luck!
@@stuartukguitarampguy5830 I understand. Thanks for the quick reply. Cheers.
Great video, Stewart. What, in your opinion, is the easiest amp to repair?
All the old 1960's amp with point to point wiring. It's pcbs which are the main problem - you can;t get to the other side to check things out without major work.
Hi Stuart, really like your channel and the projects you get into. I have this exact amp, have had it for almost 20 years now and I need to clean the pots specifically around the volume knob as it cracks unbearably loud. I was wondering how you removed the chassis from the casing as you just indicated it was a pain, and yes you're right it is!? I took the 4 screws out from the top but I can't seem to get the chassis to move, it's like it's stuck on something with the front panel and I can't tell what it is thats blocking it. I was wondering if you had any insights as the discussions I am finding online seemed to indicate similar issues with this and similar amps. Thanks in advance and keep up the great work!
Hi Gary I can;t recall on this particular amp but sometimes the chssis can get stuck either on some creased up tolex or on aluminium plate/foil they put on the top surface for hum reduction. If so it can be a TOTAL PIG to get the chassis out! Good luck.
@@stuartukguitarampguy5830 thanks for your response Stuart, I’ll keep at it 😊
@@stuartukguitarampguy5830 Hi Stuart, just a heads up I finally figured this out. I had to remove the amp mesh / speaker cover to get the chassis to come out easily. Once removed the chassis just fell out.
@@garywaddell6309 Ah okay well done!
@@stuartukguitarampguy5830 Assuming your got it out by now but yes...mine was a bear to get out too!
My Rocket 4Forty just began doing this. But it doesn't take any time for it to happen, it happens right as it's turned on. Any ideas? Same circuit design as the other rockets I believe.
H. HArd to say at a distance I'm afraid. I hope you get it sorted.
I used to be an authorized Mesa repair tech and I wrote them off years ago. They are a disaster in design. Excellent video, interesting twist towards the end.
Interesting thanks David. I have a friend who is an authorised repairer and feels the same. Mesa have just been taken over by someone (I can't recall who) and they've stopped paying his invoices!
@@stuartukguitarampguy5830 That's interesting. They were acquired by Gibson because Gibson has done so well making amps, viz., trace elliot disaster goldtone shite and those awful SG amps from the old Standel factory that used 8417 power tubes. Grenade city. After having my arse kicked by the last two mesa amps through here I swore off. No more.
@@1Dougloid Ah yes, Gibson. I had forgotten. It's not looking good so far!
@@stuartukguitarampguy5830 I have a theory about this. How does a guitar company recently out of bankruptcy finance this deal? Answer: With other peoples' money. Who are they? VC types, aging hippies who have expensive Gibson guitars but can't really play all that well because they haven't learned their craft. Jeez, it would be cool to have an amp company! What will happen? Well, the argument's a little convoluted but I figure there's a lot of talk around the office-God forbid any of these guys would work in the repair depot or on the sales floor-about "synergy" and "merging resources and working together to create a great new thing" and similar bizspeak chatter. In reality, the people who put up the money are going to want to see a substantial ROI sooner than later-the people who actually are the investors will demand it. So where do the payments start coming from? I believe Mesa sales are static-growth is lof limited potential. Mesa sells communion wafers to the already converted. So: Let's broaden the base and cheapen the product to get the prices down and bring in the dough to pay the VCs. Answer: Cooking grade new, less complicated designs will be farmed out to China or Viet Nam and Petaluma will exist only as a rump custom shop and repair depot. Coming soon to a Walmart near you, trading on brand name recognition. Why do I think this? Marshall Laney Fender Acoustic Vox and on and on and on.
@@1Dougloid Hi Robert. You could well be right. I'll be intrigued to see what they actually do with the brand.
Interesting and very helpful. I should mention however, it's pronounced "MAY-SA" or "MESS-AH" Boogie.
Hi Jim. Yes got that now!
Considering the hassle of removing the chassis, I would have tested the repair by tapping and then alternately blowing coolant spray and hot air on the effects/headphone jacks just to ensure the problem is resolved. Nothing worse for a tech than to put everything back together and have the problem show up again.
Excellent.
Glad you enjoyed it.
"You say Meeza, the Aussies say Mess-uh/ let's call the whole thing off...." 🤣. Here in the States it's pronounced May-sa.
Ha ha! Soo comment from the ex mesa engineer. Nightmare amps. I rarely take them on.
@@stuartukguitarampguy5830 , check out the Brads's Guitar Garage channel from Australia, it's "Mess-uh" to him; he posted several Mesa repair videos recently. Also, Psionic Audio is doing an ongoing major redesign on a Mesa Dual Rectifier amplifier. He's way braver than I, I'm not that fearless!
When you said "Mesa", I immediately came to the correct diagnosis and fix: trade it in for a Fender.....
Yes not my favourite amps tbh.
they use good parts
Same as my Laney GC50.
I want to change the valves on my subway rocket but does anyone know which valve the balanced position V4 phase inverter is ?????
I Can;t remember on this amp particularly, but in general it's always the one closest to the power valves and furthest away from the input jack
That must be the only Mesa amp that looks serviceable. It's surprising that Randall Smith went down the road of practically unserviceable amp design considering he started hot rodding turret board Fenders which gave him the inspiration to make and sell his own amps. Pre 80's Fenders are a relative breeze to repair/service compared with his designs. Perhaps he didn't want another 'upstart' doing what he did !
Hi Pete YEs they have been designed without the slightest thought for fixability. Highly annoying.
A view of the innards of a Mesa is always the same; 6 pounds of shit in a 5 pound box. They are overbuilt for the sake of overbuilding, in order to overcharge cost. Nevertheless, the solution was well spotted, Stuart. Quite a good episode; including tech tips as well. Try to stay in from the blustering, numbing, cold. Cheers!
Thanks Alex.
Mesa should be pronounced Gar-bage. I have yet to read about a single amp manufacturer that is more despised than Mesa. Even I, as someone who isn’t into electronics repair, can tell that those amps are a complete nightmare for any tech.
Yet the owners adore them! Go figure...
@@stuartukguitarampguy5830no doubt they sound great but speaking from perspective of an engineer, these are the amplifiers that are great while they work and when they go bad they become a serious issue. I was always told by one of my professors back in university that beauty of engineering is in simplicity and that is exactly why I love the old school amplifiers like Fender, Randall, Laney etc. People who are swearing into Mesa are just like Gibson people, they give off such a cult-like vibe. It’s a great piece of gear but there is many amplifiers and guitars out there that do the same thing just as good or even better for much lower price and with much better repair options. I can’t imagine buying a 3000€ amplifier that no one wants to repair in my area so I have to send the whole thing half way across the globe for repairs and pay another 1000€ for shipping and import fees. A bloody nightmare.
@@starscream007 I agree with every word of that and could have writen it myself.
Hey Stuart. Its
pronounced May Sa. Your welcome.
Hi JAck. Probably depends where you come from!