What will raising the Va of atransformers provide?

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...

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 :)

I might add that I was one of the origional Krell dealers and have also sold Class A amps from Musical Fidelity and Stax. I had a preamp with a custom power supply using 2 Avil Lindberg torrodial transformers and very large caps built in the early 80s; my ASR Basis phono stage uses a 50 lb power supply and my MF Kw line stage weighs 50 lb or so and will put out 50 volts. I also use an aftermarket PS for my MF V-DAC. I am well aware of the importance of power supplies; my point was that JUST the subistution of bigger transformers in a design that already had adquate ones was not a guarentee of better sound. As Atmasphere points out it is a lot more complicated than just making a simple subistution.

Atmasphere is correct. I was describing transformers whereby you want the same rail voltages and are just swapping transformers with one with higher VA ratings, but the voltage in/out (turns ratio) is the same. If you change the turns ratio from the original transformers without playing with the power supply circuitry, your power supply rails voltages will be different. Guys, and ladies, "always on" describes that the device is always turned on. it does not mean that it is biased towards full output capability. You can bias where the devices are "just" turned on (class A) or you can bias where the devices are cooking at full rated current output (full power class A). If I bias a 100 WPC amp on at 25 WPC, it is biased class A at 25 WPC, but it is still class A. Just not 100 WPC class A.

enjoy

All:

Thank you for the much-appreciated in-depth responses.

I should have also indicated, in my very limited knowledge of the subject, that I am aware that it is not a simple swap-out of one pair of transformers for largers ones. This naturally

Ultimately, though, as I've learned from all of you, is simply trust one's own ears. My custom main speakers - Van L Speakerworks/Quartet - are absolutely wonderful and about as far as I could have them designed (Deuland VSF Copper caps/resistors/cast inductors/SilTech gold internal wiring/WBT connectors/Eichmann Toppers/Scan Speak Revelator tweeters & custom dual-motor 5.25" bass drivers. My 'sub-bass system' is a pair of REL G-1's. My apologies for the boasting. I'm just extremely proud of this set-up. The intent with this Q & A is to [hopefully] make sure I'm not leaving anything on the table when it comes to getting the fullest reproduction available.

Thanks to all again.

Scott

The intent with this Q & A is to [hopefully] make sure I'm not leaving anything on the table when it comes to getting the fullest reproduction available.

Well heck, you could try out some tubes in that system :)