Amps dangerous bits

lorez · Post by **lorez** » Sun Sep 22, 2013 8:57 pm

If I was to take apart my bassman to sort out the crappy tolex/grill/speakers what should I be careful of? Which bits are the dangerous bits I keep hearing about that I shouldn't touch (capacitors if I'm not mistaken?) or are there ways of dealing with them?

George · Post by **George** » Sun Sep 22, 2013 9:13 pm

filter caps

they can be discharged but I'm not really sure how and do to want to recommend something that may kill u

benecol · Post by **benecol** » Sun Sep 22, 2013 9:15 pm

The filter caps are the ones that'll kill you. There are various ways of discharging them. Here's a link. I only take amps apart once my kids are in bed, as the thought of one of them wandering up and prodding something terrifies me.

Also, keep one hand in your arse pocket - the theory being, if you do get a kick, it won't go across your chest and hit your heart.

ekwatts · Post by **ekwatts** » Sun Sep 22, 2013 9:18 pm

Run your hand over all of the electronics lovingly. If you really love the tone of your amp, and you show it, then it will never hurt you and always give you the best sounds.

But yeah, it's the capacitors. Depends how long it has been since the last time you played it as to how dangerous they are, but the best advice is DON'T TOUCH ANYTHING AT ALL, EVER. Just make sure that you grab the chassis safely in the corners whenever you move it. I have a big roll of jumbo bubblewrap that I wrap amp chassis' in when I'm doing something with the cabinet so 1: nobody, including me, can accidentally poke my finger into a piece of electronics that is going to blow my arms and face off and 2: it's nice and safe.

Something else to watch out for is reverb. When I broke the handle on my Classic 30 I had to take the amp out of the cabinet so I could install some T-nuts underneath to hold the new handle. I thought I could do this without removing the reverb tank, but the wire was pretty short, and I must have broken it because now the reverb doesn't work. Which is really quite fucking annoying, because I really don't want to have to disassemble the damn thing again. But yeah, watch out for that. If necessary, remove the reverb tank along with the rest of the gubbins.

ekwatts · Post by **ekwatts** » Sun Sep 22, 2013 9:20 pm

benecol wrote:The filter caps are the ones that'll kill you. There are various ways of discharging them. Here's a link. I only take amps apart once my kids are in bed, as the thought of one of them wandering up and prodding something terrifies me.

Also, keep one hand in your arse pocket - the theory being, if you do get a kick, it won't go across your chest and hit your heart.

Does that not come from old computer technicians that used jumper leads for everything? Always fold one arm behind your back so as not to be tempted to change a bunch of things quickly using both hands, thereby creating a circuit across your body that will kill you?

George · Post by **George** » Sun Sep 22, 2013 9:26 pm

It comes from science

laterallateral · Post by **laterallateral** » Sun Sep 22, 2013 9:48 pm

This is the no fanfare way to discharge a filter cap

[youtube][/youtube]

If you're not game to touch the cap terminals (after you've done this) to make sure that it is completely discharged, you can short it out by taping a 20k OHM 5w resistor to the end of a chopstick and touching the resistor leads to the capacitor's terminals.

Chris Fleming · Post by **Chris Fleming** » Sun Sep 22, 2013 11:40 pm

Only go messing with things like that after you've checked that Cato isn't about

NickS · Post by **NickS** » Mon Sep 23, 2013 11:28 am

He might leap out of the wardrobe just as you're about to discharge the capacitor, yelling "Carthago delenda est!"

lorez · Post by **lorez** » Mon Sep 23, 2013 6:42 pm

Thanks for the tips.

So if I take the amp out of the chassis so I can retolex the chassis should I discharge the caps?

Also any tips on retolexing?

benecol · Post by **benecol** » Mon Sep 23, 2013 6:54 pm

The chassis is the metal bit the electrics live in. It's the cabinet you re-tolex.

</pedant>

lorez · Post by **lorez** » Mon Sep 23, 2013 10:47 pm

benecol wrote:The chassis is the metal bit the electrics live in. It's the cabinet you re-tolex.

</pedant>

Yeah yeah so do I need to get my brave on or can I get my Lawrence Lewellyn Bowen on without a care?

Also open to thoughts on what colour scheme to decorate? Toying with tweed but I could easily be persuaded to scumbag sparkle snack skin

bluesngrunge · Post by **bluesngrunge** » Thu Oct 17, 2013 3:43 am

Just wear rubber gloves

Stuart · Post by **Stuart** » Fri Oct 18, 2013 5:17 am

lorez wrote:
benecol wrote:The chassis is the metal bit the electrics live in. It's the cabinet you re-tolex.

</pedant>
Yeah yeah so do I need to get my brave on or can I get my Lawrence Lewellyn Bowen on without a care?

What I'd do is just whip the chassis out and put it to one side without messing with the caps. Then bung it back it when I'd finished the tolex ( I keep meaning to get round to doing up my 70s Twin Reverb in a surf green-ish colour).

But I've never actually done this and certainly do not hold my self out as an electronics safety expert.

Sloan · Post by **Sloan** » Sat Oct 19, 2013 4:04 pm

as long as you don't die, you'll be perfectly fine.

lorez · Post by **lorez** » Sat Oct 19, 2013 6:55 pm

Sloan wrote:as long as you don't die, you'll be perfectly fine.

I've followed that maxim so much in life