Fwd voltage question

[fasteddie455]

Howdy, I am attempting to build the Twin Peaks Tremolo by David Rolo and in the notes he states "LED1 is there to increase the output of the voltage regulator (5V + the Forward voltage of the LED). Try to find a LED with no more than 2V FWD voltage to make sure the voltage regulator still has enough drop out voltage to operate correctly."
now I am having a devil of a time finding a LED of any color whose max Fwd voltage is 2 or less. Am I misunderstanding something? what should I do? Any help would be greatly appreciated1 Thanks!
fasteddie455  

[somnif]

Diffuse reds tend to be in the 1.8-2v range. Or at least those I picked up from Tayda are.

[fasteddie455]

Is this something I have to measure on each actual LED or is this something that you just read the range in the info provided by the seller ? The 5mm red super bright one that I see on Tayda's site lists a range of 1.9 to 2.1 V.  The water clear ones are even more. Thanks for the help and for putting up with my ignorance.

fasteddie

[somnif]

The data sheet will give you the general range, but you can measure them directly easily enough with a DMM (though some cheap DMMs have trouble with diodes above a certain vf, mine will tell me up to about 1.9v). Most layouts of this circuit I see use a 3mm diffuse red LED. 

[fasteddie455]

Cool. I measured one of mine today and it was 1.78.so I reckon I'm in business! Thanks for the help!
Fasteddie455