CL-90 installation ?

[Shannon Parks]

(Oh, guess what......transistors fail too!!!)

And what a pain the repair is when they do. :o

[erichayes]

Standby switches not only added to the cost of an amp, but also went directly contrary to an amp's XX tolerance quotient. It was hard enough getting all that metal into a living room without hiding it in a cabinet. Throwing another switch into the turn-on sequence ("First you turn this switch on, then you wait about a half minute and then turn this switch on. No, the volume control doesn't turn it on. Why? Well . . .") was simply not an option if you wanted domestic tranquility.

[Wharfcreek]

You're exactly right Eric!! Too bad though!! What a commentary on the state of existance of our American Public!! I suppose this is why Sony, Pioneer, and Sansui (among others) all prevailed in displacing poor Dynaco, Macintosh, and Marantz (among others) in all our living rooms. Gee, does this remind you of anything? (Like perhaps why so many American garages have Toyotas, Hondas, and Nissans {among others} in them!!).

[hilldweller]

What about a seperate transformer for the fillaments and a power switch? Turn it on, heat up the tubes and then hit main power. This seperate transformer thing for the fillaments can be a remote thing not directly attached to the amp if desired, no? Would be relaxing for the main power transformer too. It sounds good to me, what do you all think? Yellow_Light_Colorz_PDT_12

[Ty_Bower]

Not a bad idea. I'm sure it's been done in many places before. The risk you run is that someone will flip on the heater supply, and forget to switch on the B+. Then you end up with "cathode baking", which is apparently as bad as cathode stripping.

Another tip I read was to install a solid state diode in the standby circuit so that the AC heater supply is only on for every positive (or negative, it doesn't matter) cycle when the B+ is switched off. You'll need a double pole switch on the main power (B+) to make this work. Obviously, this trick only works for AC heaters. This cuts the power to the heaters down while in standby so the cathodes don't "bake". Switching on the B+ shorts out the diode, and the heaters get full AC. Credit for this idea goes to Eric, here.

[hilldweller]

Thank you so much. That makes perfect sense and is so simple. Why didn't I think of that, duh! :) :)