UNPLANNED DOWNTIME: 12th Oct 23:45
The most unreliable amplifier ever….
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The Vox T60 transistor head for bass in 1964 is a clear winner for this title.
Excellent concept let down by its circuit design which led to thermal runaway of the output stage.
ie Too hot results in more current which results in more heat which ends up with smoke, possibly flames and no sound.
The Burns Orbit range, another early 60s tranny design.
Sounded ok in the shop, on stage once the drummer started they were inaudible.
Turning them up, usually to full, didn’t improve the situation much, they just sounded worse rather than louder.
Inevitability they blew up …
Let’s hear your stories guys…….& gals of course !!!
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Flawed maybe but unreliable not so, but of course being a valve amp they required some respect in transportation etc.
We used a non top boost AC30, a Supertwin AC30 and an AC30 head with a T60 cab from 1962 to 1966 with no issues….all bought new from Barratts of Manchester.
End of.
The mid-70s Marshall 'flat' lead and bass 100W heads are less forgivable, they're almost as prone to power transistor failure but were more than ten years later.
And TSL100 (same main PCB) and TSL60 (worse!). I'd be interested to know the proportionate failure rate, but they certainly do have several serious design flaws that can't be fixed completely.
The Mode Four is *much* worse though - whoever had the idea of building an amp using not one but *four* of the already notoriously unreliable AVT100 power modules, wired up in a way that almost guarantees cascade failures...
The Mode Four takes it, for me. When I was doing repairs I had a point-blank refusal to ever accept one for work after I saw the first one - they simply could not be guaranteed, and I didn't want the comeback.
There was something deeply wrong at Marshall in the 90s and early 2000s - a whole succession of flawed designs with serious reliability problems that should have been obvious to anyone with real-world repair experience before they were even put on the market. Thankfully, they seemed to have improved after that.
Several Trace Elliot valve guitar amp models from the 90s aren't good either.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Just because I don't care, doesn't mean I don't understand." - Homer Simpson
But yes, you are right the Mode Four was awful.
Most recently I’ve had 2 brand new Oranges with exactly the same rattle, a buzzing Hook Little Lenny, and both a Suhr Hombre and a 68 custom pro with rattling output tubes.
I’ve also this year tried in shops a 68 custom twin where the reverb was faulty and the amp had an unexplained loud hum and a Marshall Astoria that was basically dead and crackling on power up.
I think it might be me…or maybe just that tube supply issues are causing issues in modern production valve amps.
Also...
I thought everything was better in the olden days?
Lucas - Prince Of Darkness
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Just because I don't care, doesn't mean I don't understand." - Homer Simpson
When it's working it does sound really good though.
EDIT: Googling for pictures, I think it's probably an EB 12 150
@Voxsupertwin
I think maybe Vox AC30 amps in the sixties were more reliable in the sixties due to the higher quality of the valves available back then. I don't know any owner of a Vox AC30 now who hasn't had some issues. I've just done 3 AC30's belonging to one owner.
Shame because it's a great sounding amp when it's on form and nothing else really sounds like it.
Finally went back to get one about ten years later and it's still going fine now with just a bit of servicing.
I threw a fortune at that bastard,
Never could get it to work properly.
(I’m just guessing about the failure rate, but I wouldn’t be surprised if it’s in that ballpark.)
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Just because I don't care, doesn't mean I don't understand." - Homer Simpson
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Just because I don't care, doesn't mean I don't understand." - Homer Simpson
They do have problems - largely caused by the poor layout, which puts the heat from the power valves straight into the chassis - but compared to the DSL/TSLs they aren’t actually that bad.
The MG100DFX and the AVT100 are worse too.
I’ll say it again, but the Mode Four beats any of them.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Just because I don't care, doesn't mean I don't understand." - Homer Simpson
(but as I said, most of the time it sounds really good - just never know when it's going to sulk)
I had a similar experience - when eventually it was "working as designed" it sounded fucking awful so I sold it on. I don't miss it.
I thought the DSL40/DSL40CR were quite well regarded...
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Just because I don't care, doesn't mean I don't understand." - Homer Simpson