Switching circuit load on PT bias tap question

[Ptron]

I may have asked a similar question here before but I don't think I got a response. Would your typical 50Wattish PT bias tap be too loaded down if it were also used to supply your typical JFET switching circuitry? I know, not very specific, sorry.

The reason I ask is I'm building a scaled down version of the Kevin O'Conner's "Standard" amp from TUT5(2xEL34, 4 or 5x12AX7). His design uses the 5V rectifier tap on a Hammond 272JX PT and steps it back up with another transformer to derive the bias/switching supply. It could just be that this was the only widely available PT that fit all the other needs of the amp.

This amp does have powerscaling circuitry which I suppose might cause the bias supply to draw more current than it normally would but still it doesn't seem like the the load of this stuff would be much compared to the PA anyway.

[Rob Mercure]

If by "typical" you refer to Marshall and Fender I seem to remember that at least one Fender PT having its bias supply rated at 10mA. Why not drop in on the Hammond website and see if they provide ratings for their replacement transformers. I believe that their info is pretty comprehensive.

Now if the rusty memory is correct 10mA may be sufficient for JFET switching - if you intend to use relays you probably don't have enough current.

Rob