basey Posted March 4, 2007 Report Share Posted March 4, 2007 Hi I have put fiber optics into my latest bass,which also has a Aguilar OBP-1 preamp. I have it wired right now with 1 9v with a resister powering the LED and 1 9v powering the Preamp. They are both switched by the TRS jack. My problem is I'd like to get more voltage to the preamp (18v recommended) but I dont have any more room for batteries. nor do I want to put 3 in it. Does anyone have any tips on how to get more power to the pre? Any help is greatly appreciated. Quote Link to comment Share on other sites More sharing options...
curtisa Posted March 4, 2007 Report Share Posted March 4, 2007 What's wrong with running the preamp and LED off the same 18V supply instead of 1 9V battery each? Just double the value of the resistor feeding the LED and you're good to go. Cheers, Curtis. Quote Link to comment Share on other sites More sharing options...
basey Posted March 4, 2007 Author Report Share Posted March 4, 2007 I'll try that. thanks. Just to be clear, do you mean hook them both up parallel to th 18v, or series? Quote Link to comment Share on other sites More sharing options...
curtisa Posted March 4, 2007 Report Share Posted March 4, 2007 Both in parallel will do the trick. Quote Link to comment Share on other sites More sharing options...
Maiden69 Posted March 4, 2007 Report Share Posted March 4, 2007 Both in parallel will do the trick. In series!!! In parallel will vive you 9V with more current. I don't know about the resistor for the LEDs. Never palyed with them before. Quote Link to comment Share on other sites More sharing options...
basey Posted March 4, 2007 Author Report Share Posted March 4, 2007 Both in parallel will do the trick. In series!!! In parallel will vive you 9V with more current. I don't know about the resistor for the LEDs. Never palyed with them before. I meant the two devices running parellel to each other, not the batteries wired parellel. Sorry about the confusion. Quote Link to comment Share on other sites More sharing options...
Maiden69 Posted March 5, 2007 Report Share Posted March 5, 2007 The devises can be run in parallel, I would even run the LEDs out off one 9V instead of using a resistor... I don't think that the voltage-current drawn would make a big difference in the life of the batt. You can get creative and use a voltage regulator to bring the voltage down to 5,12 or use an adjustable to set it to your liking. http://www.radioshack.com/search/index.jsp...lators&sr=1 I have used the fixed ones, very easy to connect. Quote Link to comment Share on other sites More sharing options...
curtisa Posted March 5, 2007 Report Share Posted March 5, 2007 The devises can be run in parallel, I would even run the LEDs out off one 9V instead of using a resistor... I don't think that the voltage-current drawn would make a big difference in the life of the batt. You can get creative and use a voltage regulator to bring the voltage down to 5,12 or use an adjustable to set it to your liking. http://www.radioshack.com/search/index.jsp...lators&sr=1 I have used the fixed ones, very easy to connect. You have to use the resistor to limit the amount of current passing through the LED. The LED will typically only survive 20mA of current at the most, and the resistor is there to prevent the current from rising beyond what the LED can handle. No resistor = no current limiting = burnt out LED. You can make all sorts of current regulators out of those voltage regs, but it's overkill in this application - why spend extra time and money buying/wiring up a regulator when you can hook the LED to a 5 cent resistor instead? 9V or 18V, probably doesn't really matter. The current draw isn't excessive like you say. My only preference for using the full 18V is that the load from the LED (or LED's if there's more than one) is shared equally across both batteries - there may be other sonic ramifications to running with one battery gradually running flatter than the other that I don't know about with that preamp. Quote Link to comment Share on other sites More sharing options...
basey Posted March 5, 2007 Author Report Share Posted March 5, 2007 You have to use the resistor to limit the amount of current passing through the LED. The LED will typically only survive 20mA of current at the most, and the resistor is there to prevent the current from rising beyond what the LED can handle. No resistor = no current limiting = burnt out LED. I can testify to this statement. I went through a few LEDs very fast when I was first messing around with them. At 4$ a pop. I like the idea of them running off the same power source. Hopefully the LED will work somewhat like a battery power indicator. Well, Here I go. wish me luck! Quote Link to comment Share on other sites More sharing options...
curtisa Posted March 5, 2007 Report Share Posted March 5, 2007 I like the idea of them running off the same power source. Hopefully the LED will work somewhat like a battery power indicator. Maaaaaybe. LED light output tends be pretty non-linear with respect to applied voltage. You'll probably find that the LED bightness will only start to noticably dim when the battery voltage gets critically low, by which time it's probably too late anyway! You may be able to "fudge" it slightly by using a larger-than-normal value resistor so that the LED current is only just above the minimum needed to light the LED when the battery voltage is healthy - experiment with different value resistors. Well, Here I go. wish me luck! Good luck! Cheers, Curtis. Quote Link to comment Share on other sites More sharing options...
basey Posted March 6, 2007 Author Report Share Posted March 6, 2007 I appreciate the help. It worked like a charm. I posted a sound sample in the progress section. You can really here a difference between 9 and 18v. Thanks again. Quote Link to comment Share on other sites More sharing options...
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