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ESPImperium
Bronze Member
United Kingdom
132 Posts |
 Posted - 04/21/2008 : 20:41:25
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I have a couple of pedals i would like to change the LED in as its either getting dim or i just want the red colour changed to a high lumiosity blue, red or clear LED similar to the ones i have on my MXR DC Brick and MXR EVH Phase 90.
Can anyone guide me thugh how i should do this.
Thanks again. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/21/2008 : 21:06:13
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It's pretty easy - are you OK with a soldering iron? Have you used desoldering braid before?
Laurie. |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 04/21/2008 : 22:53:54
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| Lowering the current resistor's value will make it brighter |
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DeFrag
Moderator
USA
3409 Posts |
Posted - 04/21/2008 : 23:36:22
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quote:
Originally posted by ChristoMephisto
Lowering the current resistor's value will make it brighter
AND increase the failure rate. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/22/2008 : 02:41:32
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quote:
Originally posted by DeFrag
AND increase the failure rate.
It shouldn't be too bad if the current is limited to 20mA? I looked at a couple of pedal schematics and they tend to have maybe 1k2 resistors, making the current in the LED something like 5mA or a bit less standard in a pedal (if you take into account the voltage drops). The spec sheets for the LEDs confirm that 20mA should be OK. Raising the current by lowering the series resister will make the LED 2-4 times brighter (depending on the resistor/current selected and the luminosity curve of the LED).
Of course, simply putting a bright-white LED in place of the old red one with no other changes will make a HUGE difference even at 5mA - I've done that to all the pedals I've modded as a sort of "mod signature". I even ordered a wholesale lot of 3mm bright white LEDS from Hong Kong because they are so expensive over the counter here in ones and twos (I paid $2.50 for one last time I bought one...).
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ESPImperium
Bronze Member
United Kingdom
132 Posts |
Posted - 04/24/2008 : 01:37:37
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Thanks for the replys,
I have put in pickups into guitars before and even made a EHX LPB-1 clone before so am not scared of a soldering iron.
Id probably want to change the LED in my SD-1 first, changing that to a Keeley Blue colour or a really high lumosity clear white.
What Resistors should i change, like what R number, R1 etc???
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 04/24/2008 : 01:46:04
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Still like the dim LED on the early MIJ DD3s
I have a Rotary pedal that I modded to flash to the speed,
that would be a cool mod for some Boss pedals like the chorus or phaser
If anyone has a Dano Rocky Road, I can send you the mod, its really easy |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/24/2008 : 02:21:06
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quote:
Originally posted by ESPImperium
Id probably want to change the LED in my SD-1 first, changing that to a Keeley Blue colour or a really high lumosity clear white.
What Resistors should i change, like what R number, R1 etc???
The LED resistor in an SD-1 is R30. It is 3k9 and will run the LED at a bit less than 1mA if I have the calculations correct. Change to either of the LEDs you mentioned, and they will be brighter than the red one anyway. To make them brighter still, change R30 to 2k2 or 1k.
FYI - I am using 5k6 resistor in my DS-1 to stop the super-bright white LED being blinding...
When you change the LED, it is important to not solder the new one in reversed - that will kill it. Take a note of the orientation of the existing LED - it will have a small flat spot on one side. Make sure the flat spot on the new LED is facing the same way.
SD-1 schematic is here: http://www.godiksennet.com/images/sch/SD1PG2.JPG
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Edited by - Laurie on 04/24/2008 02:23:18 |
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stinkfoot
Silver Member
Sweden
181 Posts |
Posted - 04/24/2008 : 13:38:14
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Keep in mind that lowering the value of the current limiting resistor (R30 in the SD-1, as mentioned) will raise the total current draw of the pedal, thus decreasing battery life.
I prefer doing it like Laurie - use an LED that is in itself as bright as possible, and use a bigger resistor to keep its brightness within reason. That way, you'll get to eat the cake and keep it... you'll have a brighter LED and a longer battery life!
/Andreas |
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ESPImperium
Bronze Member
United Kingdom
132 Posts |
Posted - 04/25/2008 : 00:57:37
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quote:
Originally posted by Laurie
quote:
Originally posted by ESPImperium
Id probably want to change the LED in my SD-1 first, changing that to a Keeley Blue colour or a really high lumosity clear white.
What Resistors should i change, like what R number, R1 etc???
The LED resistor in an SD-1 is R30. It is 3k9 and will run the LED at a bit less than 1mA if I have the calculations correct. Change to either of the LEDs you mentioned, and they will be brighter than the red one anyway. To make them brighter still, change R30 to 2k2 or 1k.
FYI - I am using 5k6 resistor in my DS-1 to stop the super-bright white LED being blinding...
When you change the LED, it is important to not solder the new one in reversed - that will kill it. Take a note of the orientation of the existing LED - it will have a small flat spot on one side. Make sure the flat spot on the new LED is facing the same way.
SD-1 schematic is here: http://www.godiksennet.com/images/sch/SD1PG2.JPG
Thanks for the info, that will be helpful in my mod of my modding of my SD-1 when i come to it.
quote:
Originally posted by stinkfoot
Keep in mind that lowering the value of the current limiting resistor (R30 in the SD-1, as mentioned) will raise the total current draw of the pedal, thus decreasing battery life.
I prefer doing it like Laurie - use an LED that is in itself as bright as possible, and use a bigger resistor to keep its brightness within reason. That way, you'll get to eat the cake and keep it... you'll have a brighter LED and a longer battery life!
/Andreas
As i generally run everything from my Dunlop DC Brick i wont need to worry about the current draw as i dont use a battery, infact i remove them from my pedals when i get em' and stock pile them, as if i left them in there, for years id probably start to get some battery leak imo.
Also another thing about the a LED mod, could you do a seeing eye mod on the SD-1 as well, y'know simmilar to the DS-1 seeing eye mod, can that be done???
Is there any other mods that can be done to change the OD from the stock layout to a higher gain, say by changing the clipping diodes at D4 or D6??? |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/25/2008 : 01:03:27
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quote:
Originally posted by ESPImperium
Also another thing about the a LED mod, could you do a seeing eye mod on the SD-1 as well, y'know simmilar to the DS-1 seeing eye mod, can that be done???
Now there's an interesting idea... just conjecture, but you could try replacing either D4 or D5 with a red LED. If it sounds OK, drill the hole and mount it so you can "see" it.
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 04/25/2008 : 02:38:07
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On the SD1, no, 'cause the led needs to be to ground to flash
I tried a while back with the leds in the standard fashion, hoping too it would be like a SEM.
As a thought, you could add a pair of clipping diodes to signal ground. Same orientation as the DS1's clippers, and the second one (neg to signal ground)your led to flash. Stick it between the tone pot and volume, and add a .0047uf cap to give a nice corner frequency of 7k, to the treble area, 0.0033uf for 10kHz. (3.3kHz sounded too muffled)
to make it easy, solder the diodes (wires/toggle) to pads 9 and 1
1 being the neg side for the flashing led.
again, just a thought
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/25/2008 : 15:56:44
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quote:
Originally posted by ChristoMephisto
On the SD1, no, 'cause the led needs to be to ground to flash
I tried a while back with the leds in the standard fashion, hoping too it would be like a SEM.
Hmmm... needs to be actual ground rather than "virtual" ground? (the opamp input). The opamp has the ability to drive the current to make it flash. Will have a look at it when I do the SD-1 lovepedal mod I'm planning.... Will let you know if anything comes of it. |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 04/25/2008 : 23:04:47
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| When I was experimenting with my ODrive, I tried to attach it to hard ground, bottom of R8. It seemed to turn it on, weak tho. No effect led lighting up. Still came out fuzzy in bypass |
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Laurie
Double Platinum Member
Canada
4854 Posts |
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ESPImperium
Bronze Member
United Kingdom
132 Posts |
Posted - 05/01/2008 : 01:02:18
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Thanks for the hint on the Braid, i will now have to go and get some of that now...
Im gonna have a look under the bonnet of my SD-1 tomorrow and see where it can be improved to my liking, i am wanting to see if the Seeing Eye thing works and if it does ill be really pleased, but i am also thinking aboout a switch for Asymetric and Symetric clipping as well for the "Ultimate OD for me". |
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Topic |
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Changing A LED
