Dcarol, it appears that you are not addressing Stanwal's point about a class A amplifier. I agree with him- if the transformer for such an amplifier is up to the task in the first place, a larger transformer is not going to make a difference, high end audio or no. If the transformer is not up to the task, then the amp is either not class A or its one with a reputation for eating transformers. In any case it may be moot as a class A amplifier is 'high end' anyway...
This comment is not entirely true. Power transformers can have voltage drops across their windings, a lot has to do with the internal temperature rise of the part during operation- transformers with more temperature rise have higher internal voltage drops. If you go with a transformer with more VA, you may well have to *reduce* the turns ratio to obtain the correct output voltages under load.
In any case, while on the surface it might appear to be a simple upgrade, the fact of the matter is that doing such a change is an R&D project and should be viewed in that light, especially when the initial results fail to satisfy :)
Unless you are upgrading and altering the circuit designs within your amp, the new transformers must have the same turns ratio for voltage in and out. In other words, whatever the original input and output voltages are in your current transformer, that is what it must be for your new transformers.
This comment is not entirely true. Power transformers can have voltage drops across their windings, a lot has to do with the internal temperature rise of the part during operation- transformers with more temperature rise have higher internal voltage drops. If you go with a transformer with more VA, you may well have to *reduce* the turns ratio to obtain the correct output voltages under load.
In any case, while on the surface it might appear to be a simple upgrade, the fact of the matter is that doing such a change is an R&D project and should be viewed in that light, especially when the initial results fail to satisfy :)