120V LED vs. 6.3V lamp: Pros / Cons?

Interesting, didn't know that existed. They must have a diode and current limiting resistor built-in, right?

Sorry, I don't have a direct response to your question. I usually go by price and ease of install. I have a standard LED in a D-style build that I really like. It was obviously cheap and easy to put in because the relays already had to have DC to them, so it's just tapped off that.

 

The only thing I can think of is a small point against the incandescent in that it adds a little bit more current draw to your PT heater winding, so dropping it in favor of the 120 volt indicator on the primary side of the transformer would allow your amp to run ever so slightly cooler.

Personally, I've come to prefer using LED indicators run off of the heater winding. Cheap and easy with a low current draw, it's the best of all worlds if you're drilling your own chassis. If you are using a chassis drilled for a traditional indicator you would have to make some kind of adapter for the hole though and that obviously isn't going to be a great option if you are trying to match a vintage aesthetic.

 

The diode is built into the name LED - light emitting diode. Really just need the appropriate dropping resistor. And lots of insulation material.

Someone probably makes an led replacement for that 6.3v bulb that goes into the standard socket.

 

Could also increase the heater voltage, not a good thing. Just something to keep in mind.

 

I tried one a few years back. It just doesn't look right in a blackface amp. It was too bright. By the way, that was using a red LED bulb with a red jewel. Trying to use white looks even worse.

 

They actually just came out with a new line of LED replacement bulbs that come in various colors and diffusion settings. (no affiliation, etc)

https://www.amplifiedparts.com/products/dial-lamp-led-version-47-or-44-t-3-63v-bayonet-base

 

I get that but don't you need at least half-wave rectification? There has to be a diode in there too, other than the LED, right? Not that it matters, just curious.

 

An led really is a diode and only passes current in one direction. That is why people replace the diodes in distortion pedals with LEDs sometimes - the work the same. LEDs have a higher forward voltage than normal signal or rectifier diodes but don't handle as much current unless they are meant for room lighting.

 

Is this a new incoming trend?
I just looked for a bulb a few days ago and have none left, should I stock up on NOS vintage lamps?

 

Stocking up on vintage lamps is not out of the question...

Of course, your amp will sound better with NOS lamps than with those new ones.

 

I put an LED in my DRRI instead of the standard bulb. The main reason was the flimsy bulb holder. It bends extremely easily. I wanted to put an LED in and be done with it. So far so good after 10 years.

I put in a white one and change jewels out now and then.

 

The only requirement is that the LED can handle the current. Since an LED lights only on forward voltage, it's lit during half the AC sine wave--meaning it blinks at the frequency of your AC mains voltage (50 or 60 Hz).

You can run pretty much any LED on mains voltage so long as you limit the current with a resistor of the proper value & wattage dissipation rating.

 

Using the led, you can keep the (high current and magnetic field) heater wiring shorter, hopefully limiting hum. Electric fields from the 120V are more easily shielded.