power LED

[adamct]

Use a red one - they have the lowest voltage drop

It is probably just the luck of the draw and the specific LEDs used (which presumably aren't representative and therefore shouldn't be relied on), but see the empirical test results at the bottom of this page. The green and yellow LEDs both had lower voltage drops than the red.

 

[2wo]

Most important, is you need to find an LED that you can live with, not some semi Laser beam, that will turn you into an Ax murderer.

I once wired, one of the  nifty new high output blue LED's into my CD player.

terrible decision.     

 

[adamct]

So...I completed my Quickie build this weekend. It turned out VERY nicely, if I do say so myself.  ;D

The deviations from stock are as follows:

1. I mounted the batteries on the underside
2. Installed a "ladder-style" stepped attenuator,
3. Installed 2.2uf ClarityCap ESA caps on the outputs,
4. Replaced the 1,000uf electrolytic caps with 100uf ClarityCap SAs,
5. Installed "upgraded" RCA jacks, and
6. Installed a power LED.

I used this LED. It only draws 2mA, and the luminosity is 1.2 to 2.0 mcd, so it definitely isn't bright at all. The forward voltage drop is 1.9V.

Funnily enough, this might be one of those rare instances where a modification made it easier to identify a problem in the circuit, rather than harder. When I first put the Quickie together, I couldn't get it working. After running various tests, I decided to try Paul's patented "chopstick" test. I poked around at various places in the circuit, and the LED immediately went on when I poked one solder joint in particular. It make it a piece of cake to identify the issue (it turned out that when I soldered one of the wires, it was inserted too far into the terminal hole, so that the solder flowed around the insulation, rather than onto the wire itself - I didn't notice this immediately, because it was a relatively crowded terminal with other wires that were correctly soldered at the same hole).

I'm very glad I installed the LED. Recently I've forgotten to turn off my tube amps a couple of times. While that's not a catastrophe, it's not ideal. At least those amps were wall-powered. If I do that with the Quickie, I'll need to swap the batteries, and given my mods, that is a relatively painful process.

I'll post pictures once I've finished the base. I also have a PJCCS on the way...I'm just hoping my mods don't make that a pain to install...

Best regards,
Adam

 

[4krow]

Of course you realize that photos are required now. How can I brainstorm new ideas all by myself?

 

[adamct]

LOL. I'll take pictures tonight. But you will have to excuse the unfinished base...

;-)
Adam

 

[adamct]

Greg,

Pics posted here. Enjoy!

Best,
Adam

 

[Paul Birkeland]

It is probably just the luck of the draw and the specific LEDs used (which presumably aren't representative and therefore shouldn't be relied on), but see the empirical test results at the bottom of this page. The green and yellow LEDs both had lower voltage drops than the red.

This is a pretty bizarre table with the voltages.  You can get a red LED with a forward voltage drop of 1.6V to 12V (easily, there may be other obscure special order choices), whereas yellow LED's range from 1.8V to 12V (hence you can get a red LED with the lowest drop).  The table is likely an amalgomation of random junk box LED's, where the actual forward voltage would be better determined by varying the current through the LED and creating a voltage vs. current curve to visualize the nominal drop.

-PB