Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: daveyajd on April 20, 2012, 12:31:29 am
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I am thinking ahead to the combo cabinet I will build for my TOS project and wondering if it would be possible to run a second "power on" indicator bulb to backlight a panel. Similar to what you see on some Matchless, Badcat, and other amps. I will have a standard jewel and an LED for the OD on the faceplate. Can I power another bulb as well?
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> Can I power another bulb as well?
Depends what you have for power.
My brother's 1941 Plymouth is now up to 20 assorted 6V lamps. (In 1941 turn-signals were optional and 4-way-flashers were unknown. He's near NYC and this is 2012.... he NEEDS to warn-off modern dense drivers.)
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I am using a Hammond xformer 290DX. Same as Super Reverb. Actually, I will go from PT to faceplate jewel and then to my switching relay and LED.
Thanks,
Aaron
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Sure , pilot light need a very very low power. Any power transformer can drive some
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OTOH hand you could run 120VAC bulbs off the 120VAC in-coming line.
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OTOH hand you could run 120VAC bulbs off the 120VAC in-coming line.
One troubling issue with that: it's to backlight the control panel, which means placing the bulbs near the pots. I don't know if the higher-current 6.3vac plan is necessarily better or worse than a lower-current 120vac plan.
Do note that Matchless used something like 6 extra bulbs along the inside of the panel. That is, if I remember right from the Matchless Clubman I owned ~15 yrs ago. Might have only been 4 bulbs.
I am using a Hammond xformer 290DX. Same as Super Reverb. Actually, I will go from PT to faceplate jewel and then to my switching relay and LED.
What PRR is implying is what is the PT's rating vs all the stuff you intend to hang off each winding? I dunno if you're building a SR with the PT, but it seems like there are at least a few additions, if you're talking about LEDs and relays.
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The amp that I am building is the Tweed Overdrive Special from Geezer and Tubenit's design. Let me clarify how I will use this additional bulb. It will be used to back light a nameplate on the cabinet, not the lettering on the face plate. Similar to the Matchless picture below. I am thinking I can wire up my face plate jewel and relay + LED normally and then in addition run another 6.3v bulb out of the chassis and down into the cabinet.
Thanks,
Aaron
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Get out your old Christmas tree lights and hook them up inside the cabinet.
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You mean the lights that are still on my roof in April? :l2:
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> You mean the lights that are still on my roof in April?
Yeah, except the incandescents have a short life and the LED strings radiate hash into audio circuits.
If the amp PT's 6V winding can power more than a couple tube heaters, it won't notice a few extra #47 lamps; just like the Plymouth's generator hardly notices a couple extra #1154 (6V stop lamps) on top of battery-charge, headlight, and heater-fan loads.
You don't want to go crazy, like the people who run hundreds of holiday lamp strings on one extension cord and burn the roof. But I think you could have quite a lot of light on an amp without any strain.
Another idea for BIG mellow light, in 120V lands, is two 15W/40W _appliance_ (refrigerator) bulbs in _series_ across the 120V line. This gives a large light source at low intensity, and the bulbs will last almost forever on 60V each. Of course this depends on being able to route the AC power lines well away from inputs and preamp pots.