Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Fresh_Start on January 18, 2016, 10:38:26 pm

Title: 5E3 Chassis Questions - Pilot Light, etc.
Post by: Fresh_Start on January 18, 2016, 10:38:26 pm

Anyone know of an alternative pilot light that fits (or could be adapted to) an 11/16ths inch hole?

I've been looking at various Tweed Deluxe layouts and gut shots.  There has to be some way to avoid running heaters that close to the Tone pot & board.

Alternatively, how about a light that would fit in the 1/2" (I think) Ground switch hole and a switch that could fill that 11/16ths hole? 

Yes, 10s of thousands of 5E3s have been built with the existing chassis layout. Just brainstorming right now.

Chip

Title: Re: 5E3 Chassis Questions - Pilot Light, etc.
Post by: sluckey on January 19, 2016, 12:26:31 pm

Here's one idea...

Use the same lamp holder assembly. There is a LED replacement for a #47 bulb. Designed to work directly from 6.3VAC. But... Just build a small dc supply with a 470µF cap. Run the LED with the DC.

http://www.ebay.com/itm/111335488111?_trksid=p2060353.m1438.l2649&var=410349460920&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/111335488111?_trksid=p2060353.m1438.l2649&var=410349460920&ssPageName=STRK%3AMEBIDX%3AIT)

Title: Re: 5E3 Chassis Questions - Pilot Light, etc.
Post by: Fresh_Start on January 19, 2016, 01:39:32 pm

Thanks!

Quote from: sluckey on January 19, 2016, 12:26:31 pm

Here's one idea...

Use the same lamp holder assembly. There is a LED replacement for a #47 bulb. Designed to work directly from 6.3VAC. But... Just build a small dc supply with a 470µF cap. Run the LED with the DC.

http://www.ebay.com/itm/111335488111?_trksid=p2060353.m1438.l2649&var=410349460920&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/111335488111?_trksid=p2060353.m1438.l2649&var=410349460920&ssPageName=STRK%3AMEBIDX%3AIT)

DC supply off of the 6.3 volt heater supply?

Alternatively, I ass-u-me that the LED bulb draws much less current than an incandescent.  Maybe a dedicated branch off the 6.3 with 22ga wire would be OK?  It's current more than voltage that causes noise, right?

IOW don't run heaters to pilot light, then to power tubes.  Split supply on terminal strip.

Thanks again,
Chip

Title: Re: 5E3 Chassis Questions - Pilot Light, etc.
Post by: sluckey on January 19, 2016, 02:38:38 pm

You've got the idea! The only amps I have that use a #47 pilot lamp are my TDR and 5E3. I don't like those big ole lamp assemblies. I run the PT filament wires directly to the first power tube. Then I run a twisted pair of 22 or 24 AWG from that tube socket back to the left end of the chassis (as viewed on the pics on my website), up past the PT, and passing under the fuse and power switch back to the lamp assembly. These lamp wires are bundled with the wires going to the power switch and fuse.

Look at my 5E3 pics. You can see my black twisted pair peaking thru in a couple places.

Title: Re: 5E3 Chassis Questions - Pilot Light, etc.
Post by: Fresh_Start on January 19, 2016, 02:41:25 pm

I like it!  Thanks very much for the advice.  That's a clean, simple approach.

Chip