I've often heard the expression "I blew my amp" but never really understood what it referred to or meant.
What should I do about mine? Having not used it for about 3 months (I've been using a different amp) I carried it to a different room in the house this afternoon. I plugged it in to the wall/mains and without checking anything turned the switch on at the wall. There was an immediate almost explosive phut which was quite alarming and then a burning smell, so I immediately turned it off at the wall.
On checking the amp I could see that the On/Off switch was in the opposite direction to the Stand-by switch. For the amp to be On they both need to be in the same position. I can't tell or remember though which direction is On and which one is Off. It tripped one of the fuses in the house fuse box too. I also noticed (when I bothered to look) that the Vol., Bass and Treble were all maxed out (10) (could have been a child over Xmas?...) but I'm not sure that should make any difference should it?
There's a fuse on the amp and it says "3/4A SLO-BLO" - although there wasn't anything slow about how it blew
. The glass bit is kind of dangly and the spring bit inside is all at one end and unattached to anything at the other (I'll post a pic below).
The amp is American. Is this a vaguely normal thing that happens once in a while and it's just a matter of replacing the fuse? Or is this likely to be something serious and I should get it to a tech pronto?
Many thanks for your advice/help etc.
Comments
what amp is it ? is it a combo ? head ? was the head plugged into a speaker ?
Id wait for ECC83 or ICBM to pass professional judgement tho
just because you do, doesn't mean you should.
If it blew the main fuse immediately on power-up, regardless of which state the standby switch was in, it's probably not a valve fault - unless it has a valve rectifier.
So (please...) for about the hundredth time on threads like these, WHAT AMP IS IT? 'American' covers rather a lot of amps, and it would be extremely helpful to know what make and model it is, since that would save asking questions like whether it has a valve rectifier! Why does everyone seem to want to keep it secret?
The knob settings have nothing to do with it whatever though.
"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
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
just because you do, doesn't mean you should.
@BillDL thank you
OK, so it is valve rectified - the 5AR4/GZ34, which will usually be at the end nearest the power cable/socket. There is a reasonable chance that this valve has failed, and the burning smell was coming from the base of the valve, rather than the socket. A short in the rectifier can blow the fuse even before the valves have warmed up.
What to do is remove the rectifier valve, replace the fuse - you should be able to get the correct value on Ebay if you don't have one, you only need a couple - and power up again. If the fuse blows again with no rectifier in, it's a definite tech job.
If it doesn't, it's probably worth buying a new rectifier valve (spares are useful anyway, and these aren't too expensive) and try again - make sure the amp is on standby when you power up. If it now blows immediately it's still a tech job. If it works until you switch from standby to on, it needs further investigation - there's probably enough to be going on with here!
"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
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
If there's absolutely no information you can find at all, use a T1A. The US 120V value in the manual online is 2A, and the 230/240V value is usually half that.
I'm assuming there isn't a voltage selector on the outside and your helpful small assistant hasn't set it to 120V, by the way...
"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
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
just because you do, doesn't mean you should.
On the current fuse I've managed to read (just!) "A (funny symbol?)TDC 11750mA.
The more modern production Imperial manual says "A standard 2A slo-blo fuse (style 3AG)" should be used.
My Imperial is No.12 v.11 (Mark Bartel reflecting in an email to the previous owner that V.11 reflected he was making a lot of changes to the design at the time.) So it has 6 preamp valves rather than 5 for example. I don't know if that matters?
Would it be possible to post a link to the correct fuse I should buy? Only if it doesn't take up too much of your time, I'm slightly confused at this stage though.
If you can’t find one, T1A will be safe enough.
"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
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
"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
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Are these the right ones? They have a voltage rating of 250v. If you buy a pack of 10 though the voltage rating seems to be 500v. Not sure why or whether they're actually different?
https://uk.rs-online.com/web/p/cartridge-fuses/8527146
"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
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein