chilipeppermaniac
Ambassador of Decibels
As I finished my above message, I see Sysco basically brought my message to reality, and he is no DUMMY,. BUT HE WAS--- 4TIMES that day.
Dig it man. I don't want to hurt the amp any more. Especially if it's popping fuses, or refusing to stay operational at normal volume levels, it's best not to play it until it gets fixed.Sysco, at least I can say this about you and 99% of the regulars in here. We all range from just getting by, to fairly comfortable income, home and family life wise. But the reality of it is, whatever our story, these 99% will be the first to reach out to help those who are up against it. Whether it is fixing someone's TS9 Pedal, offering to buy a guitar or amp etc to infuse some funds into a low funded member's need, or tech help on amps, cars, houses, health issues etc, we have a pretty knowledgeable, resourceful and good bunch here.
Having read his situation, plus his experience with his JCM800, I would express my biggest word of advice to Bluesman regarding his Jonesing to use the amp vs. getting it fixed right.......
First, My advice is the same as AMPMAD said. DO NOT play the amp until it is fully checked and gone over by Tech of choice. No matter how good the new Tubes make it sound NOW, you run the risk of ruining them and other more costly fixes to the amp. In doing so, you set yourself up to risking more of your already thin finances.
2nd, I know you say it has been 6+ years...
In 16+ years time for me, I have owned my 1972 Marshall JMP 50 watt head, and in my lack of experience/amp education, I did the thing I knew best to do. Asked a more experienced guitar playing friend who to go to for repairs here in Maryland. The guy had a decent reputation but some things about him during the initial consult and subsequent repairs rubbed me wrong. In the end I feel as if I lost a perfectly good OEM transformer that later became his stash or sold for profit,,,, because the amp still failed me after his 2 repair trips and even my own later learned amp checks and setting things right that he missed.
Ya see, after the amp still acted up on me once he " fixed" it, I decided to take a step back and see what I could learn to fix it myself or find a more knowledgeable and thorough tech to do it right. That is when I found some really sharp members here and on the Marshall amp forum. These guys can look at pictures and see things even better than I can looking in person with my untrained naked eye. They also know how to make sense of the schematics, expected values and specs of the components and how to test and verify that things are either within spec, or on their way out or already failed.
Third, I took the time I really would have loved to be playing the amp to learn as much electronics and amp theory, testing, study as I could immerse myself in till I got to the point of understanding what our " experts" were telling me.
You see, a 72 JMP that works as it should is a wonderful thing, but a dead amp or dead me was the downside I wasn't wanting to see happen. In all my learning, I stress safety as number 1. ( it troubles me that 218 221---- 220K etc statement you made.) This is because how do we know you were in your amp as safely as possible if their was any confusion as to what reading you were actually getting?
This is why I stated that in my own amp diagnosing sessions, I would proceed to make any test lead connection, any Multimeter setting, any tubes in- tubes out, fuse blows etc scenarios ONLY after confirming that I understood precisely what the experts were telling me and they understood what I was proposing to do.
In fact one member here even brought up such a level of concern that I was pretty sure I had covered. I cannot stress this was the most important concern and surely glad he voiced his thought for me to verify my equipment with him.
He said he wanted to make sure my test leads and the Volts ratings of them plus my Meter could handle the potential volts amps put out. He said to be safe in a live amp that needed to be like 600V.
Having said all that, I am sure I will come up with other advice. BUT that is a good start other than to say LISTEN to Ampmad. He will not steer you wrong, and if you want to stretch your skills before you get a complete understanding, I would only do so on useless sacrificial and non lethal components such as Scrap electronics, scrap pcb boards etc. DO not RISK your LIFE or RUIN a perfectly good JCM800 by your own limits of experience, patience or ability to fully concentrate and be organized in your repair bench/tool setup, and physical dexterity with test tool or hot soldering iron.
You're very fortunate to have a perfectly normal boy there...My son did exactly this in his bedroom a while back. Then he wondered why the lights turned off...thank God for breakers...
Once, he turned on a baseboard heater and stuck an action figure in it, and then left it there until it was literally ON FIRE
Another time he took a pair of scissors and cut the entire backside of my couch open because he "wanted to see what was in there"
He once jabbed a meat thermometer into my 4x12 and right through the grillecloth and into a speaker cone
Oh and he once peed in a wall heater and it stunk up the entire house
....among other things.
He's only 7, we've got a long way to go, and I just don't have nice things anymore
He's a good kid with a great big kind heart though, and I love him.

I'm disabled mostly from back pain and depression. My foot is better, pretty much fully healed. I can walk good again, no problem. But the damage has been done to the home, it's like I have fallen and I can't get up.
When you are chasing the most important projects, and probably winning, it dwarfs other things in ways that is hard for most people to understand. You speak as though you could understand, so because I believe I am not the only one designing great things like this, you may understand what it's like to have a world class idea, but the world is, as you say, not ready for it yet.
Last month, I walked 5 miles for my medicine. Same for the last three or four months. They stole my bike, when I broke down to get a shower at the local homeless shelter. It was the best bike I ever owned, and had an electric motor for it. I was converting it to recumbent, so it was perfect for my back and disability. Schwinn Twinn, got it on sale during the holiday season. So low priced I thought it was a rip off. Now I can't seem to replace it for 650 and a trip from the far east.
It just took me 7 years to finally reduce my monthly medicine expenses from nearly 700 a month, to nearly half that, as the black market had me all pinched in while the compassion clubs were non-existent in my area until recently. That's right, I'm very possibly loosing my house to back taxes I can't afford to pay because this is one heartless city. I will be surprised if I'm not homeless again as a result of this. My family said they were coming back as soon as the weather clears after wintertime, to finish the cleaning job. That was last year. We've been through another winter and still no family to help.
It's kinda like I've fallen, and I can't get up.View attachment 44532
You're very fortunate to have a perfectly normal boy there...![]()
Your right. He should have used one of his dad's guitars!NO NORMAL boy puts a meat thermo thru a Marshall cab
Your right. He should have used one of his dad's guitars!
And it's never too late to keep that "certain British guitarist" away from little boys...Too Late, that trick was done by a certain British guitarist before.
Science discovered that we are essentially cannabinoid critters with an ECS or Endogenous Cannabinoid System. It's function is to keep our body's systems in running properly, and when used in plant based form can be thought of as a second immune system, and does great helping to detox the body.Drugs and alcohol: It lets you - be you again !
Milk and Cookies does that for me. Not much good on the back pains, but I never get a hangover.
Are you crazy, Sysco., NO NORMAL boy puts a meat thermo thru a Marshall cab. McB needs to return that one for warranty repairs. In my case, I was a pyro and once lit a small fire on my school friend's mom's 60's mustang convertible top back around 1974



He just wanted to verify my hot licks! LolNO NORMAL boy puts a meat thermo thru a Marshall cab.
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Dig it man. I don't want to hurt the amp any more. Especially if it's popping fuses, or refusing to stay operational at normal volume levels, it's best not to play it until it gets fixed.
I was kinda hoping to put it back to, no more popping fuses state, it was in 3 weeks ago. But that seems like a no go, so I have to wait for the local repair tech to have an opening for me. I think he just works from home. Lucky dude. He really liked hearing about that speaker attenuator bit. And that my amp was full of Telefunkin's, he was nearly started shouting, you mean Telefunkin puts out new production parts? I need more myself, but can't hardly afford it. I love the preamp tubes but the power tubes seem great too.
No worries about not playing the JCM 800 until it's fixed. I have a transistor Marshall Lead 12 that gets me by during times like these. That's the only way I could survive 5-6 years without without my tube amp. Not a terrible amp for not being tube. I appreciate all the support. You did great fetching me such a great tech lead. I appreciate the time and effort.
I have Elderly's 25 year amp tech. R U kidding me!!! He's probably done more of my amp than any other around. Elderly, is like the best music stores in the state. Certainly one of the best. I can tell by talking to this guy, he seems sharp and capable and friendly, plus he really knows his stuff. I figure give me 5-6 weeks and the amp will be in peak shape, and I will be posting a video of my entire rig, including greenback clones and the eminence attenuating speaker, the ReignMaker.
FixedI think you should get the LRT (local repair tech) to build yer bias probes.
Dude, just to be safe you should NOT run your nice Marshall amp without testing it first.
There's no point in wrecking the brand new tubes, or anything else.
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