Question regarding wiring an LED as a power indicator for Crack

HF9 · 4806

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Offline HF9

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Might someone be able to recommend a good way to wire up an LED as a power indicator for the Crack kit? I'd like to add a pilot light to the chassis and was hoping a member of the forums here might be able to give me the rundown.

TIA!

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Offline Paul Birkeland

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I believe the easiest way would be to install a 6v AC pilot light, then power it off the tube heaters. 

This might work:

http://www.tubedepot.com/p-pl-marshall-1.html

One wire will go to pin 9 on the 9 pin socket, the other wire will go to pin 5 on the 9 pin socket. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline HF9

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Perfect, Thanks! :)

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Offline HF9

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Reply #3 on: October 02, 2010, 12:00:21 PM
Ok, I've got a pilot light with a 6.3V bulb and I've run wires to Pin 5 and Pin 9. There's 0 resistance between these two points FWIW. The pilot light has positive and negative terminals. Which end goes to which pin?

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Offline JC

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Reply #4 on: October 02, 2010, 12:41:15 PM
If it is an incandescent lamp, it shouldn't matter.  Incandescent lamps don't have polarity.

Presumably, you are measuring/referring to pins on the driver-tube socket?


Jim C.


Offline HF9

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Reply #5 on: October 02, 2010, 01:51:05 PM
Indeed, all wired up and works like a charm. Thanks!

My DIY Audio Electronics Blog: DIYAudioBlog.com


Offline Joshewah

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Old thread, I know, but for curiosity's sake, which pins in the 9 pin socket are the positive and negative pins between pins 9 and 5?

I'm about to wire my amp up for a 6v light and I'd like to color coordinate the wire to the appropriate pin; red to positive and black to negative. I know I don't need to do this for an incandescent bulb, but some day I might like to wire a 6v LED in there.



Offline Doc B.

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The heaters are AC powered in the Crack. You would have to create DCV for your LED. Not sure if anyone has noticed but there are already two glowing power indicators on the amp.

(https://www.head-fi.org/content/type/61/id/1130838/width/350/height/700/flags/LL)

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Joshewah

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Aw, Doc I know. I'm just adding unnecessary bling to the already sexy design.  :P

The light I'm installing is an incandescent bulb though.



Offline Nathan

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The heaters are AC powered in the Crack. You would have to create DCV for your LED. Not sure if anyone has noticed but there are already two glowing power indicators on the amp.

(https://www.head-fi.org/content/type/61/id/1130838/width/350/height/700/flags/LL)

yes, I also noticed the built in pilot light

Crack/Speedball, SEX 2.1/C4S, Bryston BHA-1

Sennheiser HD600/Cardas cable, Beyerdynamic T1 2nd Gen, Hifimam HE560/Hifiman balanced cable