Isolation transformer

[JOEJAZZMAN]

Because of dirty mains power and increased safety considerations, I want to use an isolation transformer on a new guitar amp I am building. My power transformer is a 250 VA rating. Should the isolation transformer also be 250VA, or for some reason I'm not aware, it can be less. Thanks to all of you for your generous spirit in sharing info.

 

[AllenB]

Normally it would be chosen to be larger. Your concerns about safety and noise can be dealt with without going to this extent. Either way I'd think it is best to address the safety concerns in the unit itself.

 

[TonyTecson]

the power traffo in the amp itself is an isolation transformer, better to solve the issues within the amp itself...

 

[nigelwright7557]

You could try an IEC mains filter on the mains input.

 

[Speedskater]

Safety should be addressed with a GFCI receptacle.
Isolation transformers should always be oversized.