Power Switch LED Upgrade For Parasound Halo JC 1 Power Amplifier

Rutgar

Hi DarqueKnight. I looked around for a replacement LED that wasn't quite as brite as the one's you used, but a little brighter that the stock ones. I think these will work:

http://www.marktechopto.com/Products/ultra-bright-leds-features.cfm?Part_Number=LC503PBL1-30Q-A

If you would, please let me know if you think there is a problem with this particular LED. Sorry to keep asking all of these questions, and I appriciate all of your help.

DarqueKnight

That LED is actually 7.6 times brighter than the stock LED and is 1.8 times brighter than the replacements I chose.

You can't just go by the luminous intensity in millicandela (mcd). You also have to consider the radiation angle (in degrees) in addition to the intensity.

The luminous flux, in lumens, is the perceived brightness of a light source by the eye. In order to compare the relative brightness of two light sources, we need to calculate their luminous fluxes.

The luminous flux is calculated by dividing the luminous intensity (in candelas, or cd) by the scaling factor that corresponds to the LED's radiation angle (see Table 1).

For example, the blue LED's that came with my JC 1's were 5mm diameter with a luminous intensity of 300 mcd and a radiation angle of 25°:

300 mcd = 0.3 cd and the scaling factor at 25° is 6.71,

0.3/6.71 = 0.045 lumens.

The replacement LED's I chose had a luminous intensity of 3460 mcd and a radiation angle of 15°.

3460 mcd = 3.46 cd and the scaling factor at 15° is 18.50,

3.46/18.50 = 0.187 lumens.

The relative brightness of the replacement LED to the stock LED is:

0.187/0.045 = 4.16. Therefore, the replacement LED is a little over 4 times as bright as the stock LED.

Table 1. Luminous Intensity Scaling Factors

Radiation angle 5° -- Divide by 167.22
Radiation angle 10° -- Divide by 41.82
Radiation angle 15° -- Divide by 18.50
Radiation angle 20° -- Divide by 10.48
Radiation angle 25° -- Divide by 6.71
Radiation angle 30° -- Divide by 4.67
Radiation angle 35° -- Divide by 3.44
Radiation angle 40° -- Divide by 2.64
Radiation angle 45° -- Divide by 2.09

[Source: Wikipedia article on "Candela".]

Assuming the blue LED's in your JC 1's have the same intensity and radiation specs as mine, then your stock LED's when new had a luminous intensity of 300 mcd and a radiation angle of 25°:

300 mcd = 0.3 cd and the scaling factor at 25° is 6.71,

0.3/6.71 = 0.045 lumens.

The replacement you are considering has a luminous intensity of 1600 mcd and a radiation angle of 30°:

1600 mcd = 1.6 cd and the scaling factor at 30° is 4.67,

1.6/4.67 = 0.343 lumens.

The relative brightness of your proposed replacement LED to the stock LED is:

0.343/0.045 = 7.62. Therefore, the proposed replacement LED is a little over 7 times as bright as the stock LED.

Compared to the LED replacement I chose, the relative brightness of your proposed replacement is:

0.343/0.187 = 1.82. Therefore, your proposed replacement LED is almost twice as bright as the replacement I chose.

If you want a replacement that is only a little brighter than the stock LED, I would suggest avoiding any LED series that uses the term "Ultra Bright" in the title.;)

disneyjoe7

^^ WOW:D deep

Rutgar

Wow! Who would have ever thought that LED's are so complicated! I'm glad I didn't order that one.

I am currently working on seeing if Parasound will send me a couple of replacements. And like I said earlier, I have already ordered some of the same LED's that you are now using. So if worse gets to worse, I can still put those in.

DarqueKnight

One more thing to consider when you are replacing LED's: they are very easily damaged by excessive heat to the leads. Overheating can cause immediate or premature LED failure.

You will be placing the soldering iron tip only a few millimeters from the light emitting elements inside the LED body. You will not be able to place a clip-on heat sink between the soldering point and the LED. The next best thing is to clip the heat sink across the ends of the long leads after insertion on the board. Melt solder on the tip of your iron and then apply the tip to the board holes just long enough to form a good joint. This should take no longer than 1 second with a 40 watt iron.

If you melt cold solder into the board hole/LED lead joint, the iron will be in contact with the lead for a longer time and will transmit more heat to the the light emitting elements.

madmax

Should have used lasers that cut into anyone walking too close.

I like all the same color, hopefully blue. I have two little red leds on my amps. They really annoy me. Actually, they down right piss me off. Damn those little bastages!

Rutgar

Well, I guess I'm not going to mess with my LED's on my JC-1's. My dealer said that when he talked to Parasound, they said that they wouldn't send out any replacement LED's, and that if I messed with the amps, it would void my warranty. They did offer to repair them for free under warranty. I would just simply have to send them in.

Although I could easily do the repair, I'm not going to take a chance with the warranty.

BlueFox

WilliamM2 wrote: »

Personally, I've always found bright LED's distracting, even down right annoying if they are blue.

I have several pieces that I have modified the LED's on, but to make them dimmer, and change the color to anything but blue. This includes both my power amps, both power conditioners, and even the LED on the front of my HDTV.

Whatever floats your boat.

Yes indeed. I enjoy listening to music in a darkend room, and the bright LEDs are like lasers to the eye. I put a piece of black electrical tape over the brightest, and put a pin hole in it to let the "correct" amount of light through.

DarqueKnight

Rutgar wrote: »

Well, I guess I'm not going to mess with my LED's on my JC-1's. My dealer said that when he talked to Parasound, they said that they wouldn't send out any replacement LED's, and that if I messed with the amps, it would void my warranty. They did offer to repair them for free under warranty. I would just simply have to send them in.

Just send them in, huh?

Wow...I don't know the reason for the current hard line from Parasound. They used to just send the LED's out. Maybe people were damaging their amps or the replacement LED's while attempting the repair. There are a lot of hacks out there in audio land.:)

Rutgar

DarqueKnight wrote: »

Just send them in, huh?

Wow...I don't know the reason for the current hard line from Parasound. They used to just send the LED's out. Maybe people were damaging their amps or the replacement LED's while attempting the repair. There are a lot of hacks out there in audio land.:)

You ain't just woofin'! I have more than the ability to do this. But I still have more than 5 years left on my warranty. So I'm just not going to take the chance. If I decided to let them do it, I really only have to send one of the JC-1's in. I recently had to send the other in for a problem in the protection circuit, and they replaced the blue LED at the same time. Which, of course, what started me down this path in the first place. Because now the other amp is notably much, much dimmer than the one they fixed.

DarqueKnight

One of the JC 1's designers, went on record to emphasize the his firm, CTC Builders, did not design the startup circuits :

JC 1 LED thread on Audio Asylum

I have a little over 7.5 years left on my JC 1's warranty. Prior to replacing my LED's, I did get an email reply from Parasound stating that this would not void the warranty.

Some other threads at audioasylum.com about the LED problem:

Audio Asylum JC 1 LED thread #2

Audio Asylum JC 1 LED thread #3

schwarcw

Raife, thanks for the post. This could be valuable information if my LED's in my Parasound equipment start to fail. I've got quite a few to deal with if they start to fail. Let me contribute a few pic's I've got the following Parasound Halo hardware in the stack: a C2 controller, A52 - 5 channel amp for the surround and center channels (SDA-2's, CSi40), and 2 - A21's to power the Polk 2.3's.


Lights On



Lights off:



Close ups:

DarqueKnight

That's a nice light show. I would like to see a pic of how things look from the listening position.

Rutgar

Yes, that is a nice light show. I guess while were at it, here is a pic of my JC-1's:



I also have a pair of A21's on order to drive the center and surrounds. Should possibly be here by this Friday!

Face

Nice setup!

schwarcw

Thanks guys!

I will try to get a pic from the listening position tonight. I will have my hands full with (4) eleven year old girls running around the house for New Year's eve. No party for me!:(

Rutgar

Okay, I got my Halo A21's, so I just had to post a pic!