Tech: Discharging Capacitors

I'm a newbie as far as rebuilding an amp is concerned. I have a 1966
Wurlitzer 3010 that needs to have the amp rebuilt. I bought the amp
rebuild kit from Victory Glass that I am going to attempt to install.
I understand that the old existing caps need to be discharged before I
desolder and remove them to prevent me from getting an electrical
shock. If this is true, what is the procedure for discharging these
old caps and is it necessary to discharge the new caps before
soldering them into my amp?

Thanks in advance,
Larry

On Nov 6, 10:37*pm, wedgehead3 wrote:
I'm a newbie as far as rebuilding an amp is concerned. I have a 1966
Wurlitzer 3010 that needs to have the amp rebuilt. I bought the amp
rebuild kit from Victory Glass that I am going to attempt to install.
I understand that the old existing caps need to be discharged before I
desolder and remove them to prevent me from getting an electrical
shock. If this is true, what is the procedure for discharging these
old caps and is it necessary to discharge the new caps before
soldering them into my amp?

Thanks in advance,
Larry

Can short their terminals together with test leads or similar.

Ideally a large value resistor should be used to discharge the caps. a
100k resistor (carbon only) on test leads is probably good value for
caps (and voltages) found in valve circuits. This should be held
there for a short time.

On Nov 6, 7:37*am, wedgehead3 wrote:
I'm a newbie as far as rebuilding an amp is concerned. I have a 1966
Wurlitzer 3010 that needs to have the amp rebuilt. I bought the amp
rebuild kit from Victory Glass that I am going to attempt to install.
I understand that the old existing caps need to be discharged before I
desolder and remove them to prevent me from getting an electrical
shock. If this is true, what is the procedure for discharging these
old caps and is it necessary to discharge the new caps before
soldering them into my amp?

Thanks in advance,
Larry

The W3010 is solid state, the voltages are probably not much more than
50V and will have bled away in a few minutes after the plug is pulled.
The small coupling caps are also no issue on these sorts of units.

Tube amps are another matter both because of the -much- higher
voltages and the fact that tubes stop conducting as they cool, often
before they bleed down the charge in the caps. "Kreed"'s advice is
best there.

Rob

On Nov 7, 6:39*am, Rob in NYC wrote:
On Nov 6, 7:37*am, wedgehead3 wrote:

I'm a newbie as far as rebuilding an amp is concerned. I have a 1966
Wurlitzer 3010 that needs to have the amp rebuilt. I bought the amp
rebuild kit from Victory Glass that I am going to attempt to install.
I understand that the old existing caps need to be discharged before I
desolder and remove them to prevent me from getting an electrical
shock. If this is true, what is the procedure for discharging these
old caps and is it necessary to discharge the new caps before
soldering them into my amp?

Thanks in advance,
Larry

The W3010 is solid state, the voltages are probably not much more than
50V and will have bled away in a few minutes after the plug is pulled.
The small coupling caps are also no issue on these sorts of units.

Tube amps are another matter both because of the -much- higher
voltages and the fact that tubes stop conducting as they cool, often
before they bleed down the charge in the caps. "Kreed"'s advice is
best there.

Rob


Rob and Kreed,

Thanks so much for the advice. You both were right on the money. No
charge was found in the old caps.

Larry