Shielding and regulator location in the KTA 26 preamp
The hot dht pre thread reminded me that I have had the parts to build one of these sitting around for a couple of years. I read some related threads here and most of my questions have been answered but I am wondering about the shielding of the parts on the signal chassis and the location of the regulator.
I plan on shielding the tubes with a piece of copper pipe with a copper screen top in a kind of chimney arrangement. As far as the transformers go I am not quite sure what to do. Aesthetically the transformers will probably work best mounted under the chassis top plate at 90 degrees to the tube which would put the ¼” aluminum top plate between the tube and the transformer. Another option would be to top mount the transformers and cover them with mu metal cans, aluminum tube or copper tube. And lastly, simply top mounting them which would entail painting them, I am a little leery of doing that considering the value of the transformers as collector items. In any case, the transformers probably need to be within 5” of the tubes on the chassis I am thinking of. Does anyone have an idea which approach will be better?
As far as the HV regulator goes, would it be okay to build it into the PS chassis or should it be built on the signal chassis? In either case I am thinking of bringing a single ground back from the signal chassis to the PS chassis with a single point ground at the bottom of the first filter cap in the ps chassis, any thoughts on this approach?
Thanks for reading along and thanks to Kevin for publishing his design.