ThSpeakerDude88 said:
jacking for a second here:
Wait so does breaking the CT cause major problems with certain trannys? I have always wondered this because one of my amps uses this type of interupt so as not to stress a standard switch with HV DC on its contacts. I see that it can cause arcing in rectifiers, would this be a good idea with any tube rectifier with a standby switch before the DC part of the tube?
Also a thougt to ponder....do we really need standby switches? It seems they cause more problems than they do good. If you have a tube rectifier you already have a soft start. I can see guitarists wanting their tubes to "last longer" (ignoring the muting part-that can be done other ways.) but in real world does it really make much of a difference to tube life?
I went through several rectifiers before I figured out the arc was coming from opening and closing the CT style standby switch. If you hear an audible pop, Chances are it is or will happen at some point.
On the CT interrupt standby switch I cleared it up by putting a .05/630V film cap across the switch. Knock on wood, after about 9 months of heavy use, no problems.
When I saw the diode solution it seemed like a convenient idea, diodes generally costing a few pennies instead of a $1.00 cap.
Added bonus was you can put them on the 5Y3 socket easily as shown in the picture below.
I have another phenomenon that has yet to be explained when using CT interrupt style standby circuits.
Power up delay from standby. Once the amp is in standby mode for any significant time (2-10 minutes) when you go live, there is a 3-15 second delay before sound comes out of the amp.
On a B+ interrupt standby circuit, you get near instant response, But for some reason beyond my knowledge the CT style has a delay, and output sounds distorted and rises slowly to normal operation.
This concerns me, but I have not had anything fail in any obvious fashion yet.
IMO, it is a good idea to have a standby switch under some applications, I use mine a lot when in the studio or playing out. If you have a solid state rectifier it is more likely an asset than in a tube powered circuit.
I guess it save a bit of tube life but more likely saves on the filaments. New tubes are as reliable as light bulbs , they only have so many cycles.