My Marshall MA100C 100 Watt All Valve 2 X 12 Combo Amp

Hi Guys,


Just thought I would start yet another thread, this time it's about my Marshall MA100C 100 Watt 2 X 12 All Valve Combo amp, anyway, about a couple of years ago, I bought the amp from Sounds Of Music, one of my local music shops here in Darwin, I had been having trouble with it blowing fuses ever since I bought it, it also had a problem with the Reverb not working, so I took it back to the shop to get it sent away to get fixed, got it back from the shops about a month later, the Reverb apparently had been fixed, not long after that the Reverb stopped working again, so, rather than send it away, I decided to fix it myself, turned out it was a broken wire in the Reverb tray that stopped the Reverb from working, later on that year the amp started blowing fuses randomly, eventually I ended up getting a mate of mine to do some tech work on the amp, a couple of days ago, I texted my mate doing the tech work on my amp and he said that he would do some work on it in the next few days, he's going to change out all the original power valves and the Output transformer, hopefully I should have the amp back home in a fortnight's time or so, I'm pretty excited to be able to use it again cause I have been missing it, when it was working well it did sound really good.


Here's a pic of my Marshall MA100C amp:

Attachment 12398

crikey Doc you got more build diaries than anyone on the forum at the moment, talk about keeping busy !
Should be good when the amp is running as it should

Quote:

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Originally Posted by wokkaboy

crikey Doc you got more build diaries than anyone on the forum at the moment, talk about keeping busy !
Should be good when the amp is running as it should

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I reckon mate, I like to keep my mind busy cause that way I stop myself from feeling bored and miserable, been getting into positivity lately, anyway, when the amp was going well it actually did sound great, I hauled it down to the Happy Yess Club and did manage to get through one gig without it breaking down on me, I'll see if I can record a new demo clip of it once I get it back home from being fixed.

I know that the pic of my Marshall that I posted is a bit grainy, so, once I get it back from being fixed, I'll post some hopefully better pics for you guys to check out, along with a new sound demo, in the meantime, here's a demo I recorded last year, if my memory serves me right:

https://dl.dropboxusercontent.com/u/...C%20Record.mp3

Hi Doc, just wondering if it is an open or closed back?

Back in the 1980's I bought a 50w 2 x 12 Marshall Combo as I was sick of lugging around a 100w head & 4 x 12 cabinet. Sounded rubbish with my Strat and a bit better on the Explorer but oh so awesome on a mates Les Paul to the point where he permanently borrowed it for about a year until I sold it to fund other acquisitions. Mine had an open back and was the main reason it didn't sound as good compared to the enclosed 4 x 12 cabinet which had a much fuller sound plus wider tonal range.

More recent Marshalls seem to have a bad reputation for reliability issues and hope it doesn't cost you too much to sort out.

Quote:

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Originally Posted by wazkelly

Hi Doc, just wondering if it is an open or closed back?

Back in the 1980's I bought a 50w 2 x 12 Marshall Combo as I was sick of lugging around a 100w head & 4 x 12 cabinet. Sounded rubbish with my Strat and a bit better on the Explorer but oh so awesome on a mates Les Paul to the point where he permanently borrowed it for about a year until I sold it to fund other acquisitions. Mine had an open back and was the main reason it didn't sound as good compared to the enclosed 4 x 12 cabinet which had a much fuller sound plus wider tonal range.

More recent Marshalls seem to have a bad reputation for reliability issues and hope it doesn't cost you too much to sort out.

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It actually has a semi-enclosed back in that there are some round holes cut into the back baffle near the bottom of the baffle, there are also some thin ventilation slots cut into the top of the back baffle, yeah I know it's a bit of a weird one, I'll see if I can post some better pics of my Marshall once I get it back home from being fixed mate, hopefully in the next couple of fortnights or so.

Update:


Just recently heard some news about the progress that the guy fixing my Marshall has made on fixing it, apparently he has found and fixed a couple more things that were wrong with it, so I was pretty stoked to hear that, hopefully when I get the amp back it'll be good as new and will sound great too, can't wait to play my LP Studio through it once it's back home.

back in action soon then mate

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Originally Posted by stan

back in action soon then mate

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Haha...yep, I'm pretty stoked cause I've just been through a long drought of not playing any guitar for a while and I'm just itching to do some serious playing, once I get the Marshall back home I'll have something to annoy my neighbors with, and if they object I will calmly point out just how much their noise has been annoying me....at 2:40am when I'm trying to sleep, and see what they have to say about that.....*cue evil laugh*.....lol.

Update:

I just got a txt message from the guy who is fixing my Marshall MA100C amp, apparently he's finished working on it and he reckons the amp is fixed and he's going to see if he can drop the amp at my home tomorrow, so, hopefully the amp should be a lot more reliable and I'll be able to do some serious gigging with it.

Oh, and the cause of the fuse blowing?.....apparently the power transformer was putting out HT which was too high for the power tubes to handle, one of the power tubes arced-over and it's socket carbonized, a couple of mosfet transistors also got damaged by the excessive HT.