Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Mars-Hall on October 18, 2012, 05:31:05 am

Title: Pilot/heater delay when powering up
Post by: Mars-Hall on October 18, 2012, 05:31:05 am
Hello,

I have a 66 Super Reverb that when I flip the power switch on, the pilot light and heaters don't light up for several seconds.  Is the power switch going bad, not making good contact? 
Title: Re: Pilot/heater delay when powering up
Post by: HotBluePlates on October 18, 2012, 07:09:59 am
If the pilot light doesn't light immediately, and and the amp is bone-stock, then there is a problem with either the power switch or a intermittent connection in the filament wiring. Alternatively, there could be intermittent connection related to the power cord, whether that's at the plug/outlet, at/inside the amp, or along the length of the cord.

Clip your meter leads to one side of the PT high voltage secondary winding and ground, and see if it appears as the switch is thrown. If so, the switch is functioning correctly.

If it works, you'll have to manipulate the power cord to see if you can induce a loss of a.c., and prod the heater wiring with a chopstick to see if you can locate the intermittent connection.



(As an aside, my dog's name is "Marshall" and my son's initials turned out to be "JMI" (not planned that way). However, all my amps are copies of American amps. Hmm...)
Title: Re: Pilot/heater delay when powering up
Post by: Mars-Hall on October 18, 2012, 08:07:34 am
Thank you, I will trace down those items.
Title: Re: Pilot/heater delay when powering up
Post by: stratele52 on October 20, 2012, 03:37:32 am
Put an AC voltmeter on pilot light socket to "see' if power is there right after you power ON. You 'll will know what to check.

Heater are not fast as pilot light .

Pilot light's contact in socket could be "dirty" . Just unscrew / screw  few times the bulb will clean them.

If AC on voltmeter is "slow" check transformer heater 's green wires like HotBluePlate write. Check their connexions at pilot light , This is the heater starting  point too.
Title: Re: Pilot/heater delay when powering up
Post by: PRR on October 21, 2012, 12:08:42 am
Is there any chance it has a starting surge limiter?