|
|
Post by Chris on Jul 24, 2014 10:09:25 GMT
As noted before eduardwobblechops has kindly offered to help with my amp; In order to help with my pig ignorance I'm posting this up in order to try and get things clear.  So far I think the 3 round black things are capacitors,transformer? Top centre? Valve bases. That's it. Sorry. If anyone fancies pointing out what the other components are it'd be much appreciated. There's also a slight buzz to this amp that disappears with a light tap to the volume control and ruffles when you turn the volume up. That's bad right? |
|
|
|
Post by gazjam on Jul 24, 2014 11:13:31 GMT
Chris,
Do you get the ruffles even when the amp has been on a while?
Sometimes if the valve bases dont make a perfect connection with the valve pins a russling noise can be heard. Goes away when valves heat up and metal expands for a better fit.
Does it only happen when you adjust volume?
Ali's yer man btw, taught me a lot about valve amps.
|
|
|
|
Post by Eduardo Wobblechops on Jul 24, 2014 11:16:07 GMT
Blue things on the circuit board are capacitors, all the stripy things are resistors. Blue squares top left and right are the pots for adjusting the bias. The big black round things are the PSU capacitors. Sounds like the volume pot may need a squirt of switch cleaner.
|
|
|
|
Post by Eduardo Wobblechops on Jul 24, 2014 11:17:30 GMT
Blue things on the circuit board are capacitors, all the stripy things are resistors. Blue squares top left and right are the pots for adjusting the bias. The big black round things are the PSU capacitors. Sounds like the volume pot may need a squirt of switch cleaner.
|
|
|
|
Post by MartinT on Jul 24, 2014 11:24:46 GMT
I was about to say dirty tracks in the volume pot. Light squirt of WD40 in the pot while the amp is switched off, then exercise the control several times before switching back on.
In fact, try it without the WD40 to start with.
|
|
|
|
Post by pinkie on Jul 24, 2014 11:49:57 GMT
I was about to say dirty tracks in the volume pot. Light squirt of WD40 in the pot while the amp is switched off, then exercise the control several times before switching back on. In fact, try it without the WD40 to start with. Oh dear - the whole sorry saga of the self-destructing Pip started with too much noise on the pot, and squirting it with switch cleaner. Then the interconnecting ribbon cables powdered to dust, and it was all downhill from there. If it doesn't respond to switch cleaner its a fairly simple item to replace. Shall I be the first to do the safety bit? THERE ARE LETHAL VOLTAGES INSIDE VALVE AMPLIFIERS EVEN WHEN SWITCHED OFF AND DISCONNECTED FROM THE MAINS due to stored charge in capacitors. Before you take the lid off, you really need to understand how to safely discharge the capacitors.  |
|
|
|
Post by Firebottle on Jul 24, 2014 11:55:17 GMT
Good one pinkie. Don't touch ANYTHING in there if you don't understand it.
Alan
|
|
|
|
Post by MartinT on Jul 24, 2014 12:12:43 GMT
|
|
|
|
Post by walpurgis on Jul 24, 2014 16:22:21 GMT
I was about to say dirty tracks in the volume pot. Light squirt of WD40 in the pot while the amp is switched off, then exercise the control several times before switching back on. In fact, try it without the WD40 to start with. Not keen on WD40 cleaner. I prefer a non lubricating switch cleaner aerosol. Take care using these though, some plastics can react (dissolve!), so test on a small area first. |
|
|
|
Post by Chris on Jul 24, 2014 16:29:56 GMT
Cheers gents! Much appreciated.
I am well aware of the dangers of voltages inside an amp and WILL NOT go near one. I've been dieing to have a crack at biasing it but not a chance am I going near it myself.
I've got electrical contact cleaner there so will take that to Eduardwobblechops on Sat and zap it there under his guidance.
|
|
|
|
Post by Eduardo Wobblechops on Jul 24, 2014 17:05:38 GMT
I was about to say dirty tracks in the volume pot. Light squirt of WD40 in the pot while the amp is switched off, then exercise the control several times before switching back on. In fact, try it without the WD40 to start with. Not keen on WD40 cleaner. I prefer a non lubricating switch cleaner aerosol. Take care using these though, some plastics can react (dissolve!), so test on a small area first. Me either, it's not suitable for this application IMHO. It's good at displacing water, which is what it's for, or loosening bolts and the like, but it's not a lubricant, and it dries out. Great for taking tar off paintwork though! |
|
|
|
Post by MartinT on Jul 24, 2014 17:11:35 GMT
Not keen on WD40 cleaner. I prefer a non lubricating switch cleaner aerosol. Take care using these though, some plastics can react (dissolve!), so test on a small area first. In this case, I was trying to think of what Chris might have lying around the rig. |
|
|
|
Post by Chris on Jul 24, 2014 17:15:15 GMT
In hand mate. It's not lying about the rig anymore.  |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 24, 2014 17:27:30 GMT
WD40 might not be ideal but someone like me always has a can about whereas switch cleaner is not on my regular shopping list. Good old WD has solved problems on my REL Quake (ta Alan) and more recently on the A&R Alpha - volume and selector.
As in both cases it was probably lack of use, hopefully they will now be OK as they are active again.
|
|
|
|
Post by Eduardo Wobblechops on Jul 24, 2014 17:54:26 GMT
Not saying it won't work, but it may cause problems down the line.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 24, 2014 18:03:53 GMT
Not saying it won't work, but it may cause problems down the line. Yeah, my brother in law is a design engineer and he gives me hell when I use WD as lubricant when it nothing of the sort. It is however, for them as don't know, the absolute dog's wotsits for protecting and cleaning stainless steel kitchen bits like microwaves. i always used to give my customers a can when I finished their kitchens. |
|
|
|
Post by Dave on Jul 24, 2014 18:24:57 GMT
WD is also great for cleaning up the crud which collects around the bottom bracket on a bike over time, in fact it brings the paintwork up nicely too  |
|
|
|
Post by walpurgis on Jul 24, 2014 18:28:58 GMT
WD40 can work well for cleaning accumulated muck from vintage Japanese amplifier facias (front panels) and it won't take the lettering off either.
|
|
|
|
Post by Firebottle on Jul 24, 2014 20:02:59 GMT
A surprising application I found years ago for WD40 was as sealer/enhancer for a polished slate hearth.
You don't need to apply much but the end result was fabulous, really bringing out the grain of the slate.
Cheers, Alan
|
|
|
|
Post by Eduardo Wobblechops on Jul 24, 2014 20:05:28 GMT
Cheers Alan, I'll try it on my 401 slate plinth.
|
|
