Marshall = Unreliable , is there creedence in this opinion ?

From 20 years of repair experience, I would guess that all the examples you've listed apart from the 900 and DSLs were the result of poor maintenance or 'user error'.

The only other one which might not be is the old amp that kept blowing fuses - could have been the crappy impedance selector - but any decent tech could have fixed it permanently. The older ones in particular are all at the mercy of the sort of "repairs" I've had to remove and redo properly ever since I started work. Using substandard tubes was a big problem until recently too - some of those older amps are pretty hard on them, and if you fit some of the crap that was common especially in the later 80s and early 90s, expect trouble.

All tube Marshalls from 1967 (introduction of the steel chassis and full-scale mass production) to 1990 (end of the JCM800 series) are extremely reliable. The later 70s and JCM800 models with proper rotary impedance selectors are almost bomb-proof. The 80s solid-state amps are the same - in fact, they're some of the only solid-state amps ever made that are equivalent in quality to the matching tube amps of the time - it even goes down as far as the little Lead 12 which is built using precisely the same components and materials as their most expensive tube amps.

JCM900 was the start of the rot - their first amps that were obviously designed with an eye as much to cost as build quality. While the evolution from '67 to '90 was slow and steady, with no really major changes, the 900s were new from the ground up and suffer from a lot of problems that happen under these circumstances (especially combined with cost-cutting). Although the DSLs don't look much better, from experience I would say the failure rate is actually lower, so they've clearly learned.

However, the Reissues are excellent amps, built almost as well as the later 70s models, although there is a little question over the transformers - I've seen a few blow for no apparent reason.

I would count the Standard Lead and Master Volume amps made from 1976 to 1990 as some of the most reliable amps ever made by any company though. Just make sure they are to factory spec, with good tubes, and biased correctly (ie conservatively as they were designed, not how current fashion dictates) and they'll work as well now as for the thousands and thousands of bands who toured with them in the 70s and 80s.

Just my opinion.

 

NAILED IT!

 

Part of the Marshall mistique is that they are roadworthy.

It may be easier to run into a bad Marshall because their are so many out there. That is about percentages.

I do agree that many Marshall's that do go down, are due to poor maintenance. If you have a 30 year old Marshall, get it serviced.

I also agree that Marshall could do a little better job on some of the 2000's.

 

I've played hundreds of gigs with Marshalls. The only problems I've encountered were standard maintenance stuff you'd expect with 25+ year old amps, things like tubes and filter caps.

I bring a back up amp no matter which company manufactured the amp that will be my main one for the evening. Marshalls are no less reliable than any other manufacturer as long as you maintain them properly.

 

Marshall circuits are far from "high tech" by today's standards. I would think that it would be hard to mess it up, unless built with substandard parts. I know many people who swear by old Marshalls.

If they had reliability problems, I don't think they would have lasted 30+ years in the business

 

I've been gigging a DSL 100 for two years now+bedroom jamming too. no problems other than replacing power tubes. I like the SED's the best. I do carry a Valvestate head for backup just in case. .




I can't speak for the TSL though

 

There was a lot of talk back in the '70s about Marshall heads that caught on fire. Because this was before the internet, there wasn't a lot of information available about what was actually going on. Was it bad impedance mismatches? User error? Bad OTs? Bad user mods like master volumes? But there was a reliability knock on Marshall (fair or unfair) going way back.

Part of the issue is that the only comparison a lot of people had were blackface and early silverface Fenders and those would definitely take a lickin' and keep on tickin'. Whether you wanted them to or not.

 

My tech is of the opinion that a lot of the people attracted to Marshalls are "rawk dudes" who don't take the best care of their stuff. I've seen tons of 'em just sort of tossed into the back of a van at the end of the night.

Also, people that like Marshalls tend to run 'em pretty high, which may put more strain on the components.

I've had a bunch, and never really had any problems with any of them...

Loudboy

 

I'm a "RAWK dude"

 

my JCM 800 2203 has been the most reliable amp i've ever had. it's gotten dropped down steps, off the back of a van, had beer poured on it, and been knocked from on top of a full stack to the floor by my idiot bassist friend yet it has never stopped working, except when the tubes shattered. it's biased to take KT-88's and it's never malfunctioned.

my 1959slp reissue however, has failed on me several times. i had a lot of problems with a JCM2000 DSL 50 too, but i sold that a while ago.

in conclusion: old marshalls=reliable, new marshalls=not so much.

 

Back when I started repairing amps (1985), a "good trick" with your non-MV Marshall was to set the amp to 4 ohms when running a 16-ohm cab. This gave "more distortion at lower volume". It certainly did... right up to the point where the volume went right to zero because the OT burned out. Connecting them to cabs with guitar cables worked quite well too - I once saw a coiled cord that actually caught fire when run between a Super Bass head and the cab...

Prior to the mid-70s, Marshalls had crappy impedance selectors that often fell out (or just went intermittent) and fried OTs too - I actually think that their reputation for having 'weak' transformers is because of this, not the transformers themselves. And they had mains voltage selectors that did the same thing, and got put back in wrongly, either accidentally or on purpose to 'increase power' or 'get more distortion' .

There were also a lot of bad mods, often poorly done or downright dangerous (EVH's 'magic' Marshall is a classic example, no matter how it sounded), and a lot of techs that were either self-taught DIY'ers with little or no idea of good workmanship and reliability, or "proper" electronics engineers that didn't understand distortion or how guitar amps were really used - driven flat-out, in most cases .

That's why I built my first dummy load/attenuator - to be able to test amps continuously at absolutely full crank without going deaf (and in my student apartment, with neighbors). I soon found out how to make amps reliable, simply by watching how they failed under that sort of treatment... and I still do the same thing today.

Part of Leo Fender's genius was to understand how real musicians used his gear - possibly because he was a self-taught repairman, not a trained electronics engineer. BF Fenders were built with one impedance setting only, and robust enough to take any combination of cabs in normal use... and even protected with a shorting switch in the main speaker jack. They're almost idiot-proof, which eliminates the most common cause of trouble in most things...

 

I can't imagine a more abusive group of customers than rock musicians. The majority of the used Marshall gear I've seen was chipped, cracked, bruised, torn and ugly to boot. When that level of abuse is directed at electronic equipment failure is inevitable.

I think quality control is an issue many manufacturers should address, but in the current world economy price prevails over performance. FWIW, I don't think inherent flaws are a factor in Marshall amps, but like any complex device, a Marshall amp is the sum of its parts and workmanship, both of which are inconsistent at times.

If I take my DSL50 and throw it into the back of my truck, or bump it hard against doorways and walls everytime I move it, I would expect problems with it, but no more so than I would with my color tv or computer. My DSL50 is a 1998 model that ran for years with the tubes running way too hot due to the bias settings, and other than a loose connection caused by jarring the head, I've had no problems despite the abuse it was subjected to due to excessive heat.

I had a friend with JCM900 100-watt head and matching cab that ran it for 5 years at near full power for hours almost everyday using an instrument cable as the speaker cable. He ran it like that until one of the tubes blew, then had it retubed and was up running again at the cost of $150. Only a tough product could take that kind of abuse.

 

Good advice! I have used a JCM 2550 for hundreds of gigs with zero problems, and I run it hard. Proper maintenance is important, and don't knock 'em around too much, take care of them! (that said, I do bring a spare 2555 with me just in case!). If you're good to them, they'll be good to you.

 

Maybe I'd better be quiet, before my DSL 100 breaks down.

 

Don't worry too much, not all of them do . Like anything that techs love to hate, but which are pretty successful commercially, the vast majority of them don't break. But there's a HUGE difference between a failure rate of 1% and one of 10% - even though 90% of the users won't notice, since their amps are fine.

The problem for me is that I believe that amps which are marketed as 'professional equipment' should be capable of being used like that - including some fairly rough treatment - without the failure rate rising significantly. The 900s and DSL/TSLs just don't quite meet that standard - the 800s and JMPs did - easily, with the 800s. I have no problem with any company making a cheaper range - eg Valvestate, or the JTM30-JCM600s - and not building them to the highest standard. That's what cheaper ranges are for. But I don't think something which is marketed as a fully-professional amp should have some of the design "features" of the 900s and DSLs, when these are well-known to be failure-prone if the amp isn't babied. Or, like the use of MDF for the 2x12" cabs, just cheap for the sake of it.

Yes, musicians are abusive, but it's quite possible to build gear which will take it, simply by recognizing that there are some parts and methods which are better than others, even in a mass-produced amp. All you have to do is ask someone who repairs them.

I could criticize Fender in exactly the same way BTW, it's not that I have anything against Marshall particularly. It's also good to see both companies returning to building amps worthy of their great name (Fender have had the Custom Shop for a while, and Marshall's new Hand-Wired series), and built the way that name was established... now what would be really nice is to see Marshall build a modern amp to at least Reissue standard, even if not HW.

 

Amen JP, someone should poke Marshall with soft cushions until they confess! (and agree to do this)

Marshall should hire you to develop this project.

 

I had 2-3 JCM 800s (one pre channel switching) that gave me nothing but headaches. My best friend now owns three of them, and only one seems to work at a time. How these have gotten a reputation as reliable, I have no idea. Thin buzzy overdrive as well. You NEED a box with them. My 70s seemed to be much more reliable.

 

I've worked on many vintage Marshalls,
and still do weekly.
If setup correctly they're just as reliable as anything else.