Tube DIY Asylum

Posted by Eli Duttman (A) on August 24, 2015 at 16:03:13

In Reply to: RE:thankS TK posted by DAK on August 24, 2015 at 11:33:48

This seems to be another case of tubes being mechanically fragile and electrically tough, while SS is mechanically tough and electrically fragile.

Yes sir, be very careful about exposing SS parts to over voltage, lest they fail. The IRFBC20 and ZVN0545A MOSFETs are favorites of mine in the DC coupled voltage follower role. At this time, I would not call for either FET, unless a protective Zener diode, like that shown in the uploaded preamp schematic, is employed. FETs and other SS parts turn on instantly and voltages are "squirrely" before tube conduction starts.

Eli D.