[les_garten]

How do you guys do a start up delay to allow tube heaters to be on for x amount of seconds before the amp lights up?

Keeping in mind that the Tube heaters are driven off the same transfo as the amp power supply and 250v secondaries are involved?

 

[johnwmclean]

I'm interested in this circuit as well, but after much debating I'm settling on a manual delay.

 

[9pintube]

The Manual "switched" warm-up comes on most Tube Lamda power supplies....I hope many of you DIYs are grabbing these excellent power supplies up before they're gone or out of reach $$$$wise....I've been lucky enough to become best friends with one of the premiere builders/repair dude in the midwest....Google him CHRIS IVAN Audio/amp repair.. I hope this rant isn't to far off your subject les_garten , Tube heater warm up is obvious very important........

 

[les_garten]

Quote:

Originally Posted by 9pintube /img/forum/go_quote.gif The Manual "switched" warm-up comes on most Tube Lamda power supplies....I hope many of you DIYs are grabbing these excellent power supplies up before they're gone or out of reach $$$$wise....I've been lucky enough to become best friends with one of the premiere builders/repair dude in the midwest....Google him CHRIS IVAN Audio/amp repair.. I hope this rant isn't to far off your subject les_garten , Tube heater warm up is obvious very important........

A link would be good...

 

[johnwmclean]

Les have you seen these?

Power Supply Delay Action Board 300B 2A3 KT88 tube amp - eBay Single Disc Players, CD Players Recorders, Home Audio, Electronics. (end time 22-Dec-09 09:03:18 AEDST)

 

[les_garten]

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif Les have you seen these? Power Supply Delay Action Board 300B 2A3 KT88 tube amp - eBay Single Disc Players, CD Players Recorders, Home Audio, Electronics. (end time 22-Dec-09 09:03:18 AEDST)

Hey Thanx!
I'll hit him up for how to wire that. I'm assuming it interrupts the HV off the Transo to the PS?

 

[les_garten]

Hmm, found this one as well.

Tube Amp Power Delay Connection - Time Delay Board - eBay (item 260525815225 end time Dec-25-09 20:40:12 PST)

 

[spritzer]

The voltage these things can switch really depends on the relay, in the first link it can only handle 230VAC (i.e. no DC) and the latter can handle 400VAC (again no DC).

 

[fishski13]

i assume you're concerned about cathode stripping? i wouldn't personally worry about it unless you're using expensive tubes. the easiest way would be to wire the heaters on a separate "stand-by" switch from the main power switch that will just power the heaters.

 

[les_garten]

Quote:

Originally Posted by fishski13 /img/forum/go_quote.gif i assume you're concerned about cathode stripping? i wouldn't personally worry about it unless you're using expensive tubes. the easiest way would be to wire the heaters on a separate "stand-by" switch from the main power switch that will just power the heaters.

That was for sure Plan B. This looks pretty sweet though. Also a no brainer for anyone who I might let use it. Another point of failure though, that's a consideration. The first implementation will be the eXStata, cheap tubes there. This is DIY though, so some is the fun of doing it.

 

[dsavitsk]

Quote:

Originally Posted by fishski13 /img/forum/go_quote.gif i assume you're concerned about cathode stripping? i wouldn't personally worry about it unless you're using expensive tubes.

Cathode stripping is a bit of a myth. It happens, but only at several thousand volts. Start up delays are a solution in search of a problem. But, if you must, why not just use a tube rectifier?

 

[Rescue Toaster]

Yeah the simplest method is to use a nice slow warm-up tube rectifier. Damper diodes are especially good.

 

[fishski13]

Quote:

Originally Posted by dsavitsk /img/forum/go_quote.gif Cathode stripping is a bit of a myth. It happens, but only at several thousand volts. Start up delays are a solution in search of a problem. But, if you must, why not just use a tube rectifier?

i agree with this, but would probably sleep better if using expensive tubes

. i wouldn't worry about uneven wear with DC heaters either.

 

[les_garten]

Don't know how much of a difference this makes, but these heaters I'm looking at are AC heaters.