Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: uki on April 24, 2019, 07:00:16 pm

Title: Pilot light
Post by: uki on April 24, 2019, 07:00:16 pm
The pilot light in my amp burned 2 times in three years, does it burn that often? Last one was a GE47.
What should be the value on those little bulbs?
Title: Re: Pilot light
Post by: sluckey on April 24, 2019, 07:19:44 pm
The pilot light in my amp burned 2 times in three years, does it burn that often? Last one was a GE47.
What should be the value on those little bulbs?
I highly recommend using a LED replacement such as this...

https://www.amazon.com/RetroArcade-us-ra-pb-led-ba9s-fr-w-10pk-Frosted-Pinball-Replacement/dp/B07PR5WKP5/ref=sr_1_6?keywords=%2347+led+bulb&qid=1556151314&s=gateway&sr=8-6

Never change a #47 bulb again.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313.TR1.TRC0.A0.H0.X%2347+led+bulb.TRS0&_nkw=%2347+led+bulb&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=%23ge47+led+bulb&LH_TitleDesc=0

Title: Re: Pilot light
Post by: PRR on April 24, 2019, 10:19:12 pm
Alternatively put a 10 Ohm 1/2W resistor in series to drop it to more like 4.8V. It will be dimmer and redder but about 30X the life or about 50 years. You might compromise with a 5 Ohm resistor.

This assumes "no shocks". If you drop the amp off the truck a lot, the filament will break.

It also assumes "good quality" lamps, and they are getting hard to find these days. Nobody cares. Incandescents are a dying industry, and they make them as cheap as possible.

Agree that I have gone LED almost everywhere. Even the 500 foot throw down my driveway, which I used to do with halogen and monster CFLs, is now LED.
Title: Re: Pilot light
Post by: shooter on April 25, 2019, 07:40:33 am
Quote
I have gone LED almost everywhere
agreed, use a power switch with them built in, pitched the sodium vapor, garden didn't complain  :icon_biggrin: