Tube Power Supply Question

[cpsmusic]

Hi Folks,

About 15 years ago my father built me a stereo LA-2A that runs off an external tube power supply. The unit has been in storage up until recently when my father passed away. I'd like to get the unit working again. I realise that it's not a good idea to plug it in and turn it on, but I'm unsure as to how to proceed. I thought that the first step would be to make sure the power supply is working. I have two questions about this. Firstly, is it advisable to replace the electrolytics in the power supply due to their age? Secondly, does a tube power supply require a load or can it be run without one?

I have medium-level knowledge of electronics - I've built a few tube guitar amps although in the past I've had my Dad around to keep an eye on what I was doing.

Cheers,

Chris

 

[emrr]

15 years, should be fine unless storage was a harsh climate. 

 

[cpsmusic]

Can I fire up the power supply without a load? If not, what sort of load would it need?

 

[CJ]

no problem plugging it in without a load,

do you have a variac?  if so, pull the tubes and bring up the voltage slowly to reform the filter caps,

start with 1/4 th the line voltage, maybe 30 volts if you are in the US, then 60, then 90 and 120,

 

[mjrippe]

no problem plugging it in without a load,

do you have a variac?  if so, pull the tubes and bring up the voltage slowly to reform the filter caps,

start with 1/4 th the line voltage, maybe 30 volts if you are in the US, then 60, then 90 and 120,

Unless one of the tubes is a rectifier    In that case I usually install a solid state replacement and slowly bring it up to about 110v as the SS rectifier has a lower voltage drop than a tube.

 

[emrr]

Most tube rectifiers come on around 1/2 voltage, I'll let one sit at 60V for a few minutes before starting to creep it up.