Newbie L-Pad Problem for DigiStar

[computer bob]

Well, yup, another newbie question re: L-pads.

I've installed two L-Pads from Parts Express into my DigiStar pachi (one for front speaker, other for rear sub-woofer). During big bonus, the front L-Pad starts to overheat unless its set to full volume (and thereby nullifying adding the control in the first place.). I've swapped the two L-pads but the problem stays with the front speakers, not with the L-Pad. I'm pretty certain that I installed the L-Pads properly. Any idea how to tame this beast?

[alstonj1]

yes goto a higher wattage volume controll or resistor .

[computer bob]

Thanks, Jeff (and all)... I bought the 15 watt L-pads from Parts Express, but it looks like I probably should have bought the 50 watts instead. Isn't it possible to wire in a resistor between terminals 2 and 3 of the L-pads? Or would this only make things worse?

[arbycoffee]

do a serch for resitor ladder

[cwstnsko]

I would guess the L-pad is either wired wrong, or not properly impedance matched to the front speaker(s?) If the front speaker is a different nominal impedance that the L-pd, you could have issues. I've never seen a machine that was actually pushing more that 15 watts. most are probably only pushing a few watts at the most.

[alstonj1]

putting a resistor in parallel with the l-pad will either make it worse or work but eliminate the purpose of the l-pad (would eliminate the range for volume )your best solution right now would be to set the l-pad to a comfortable level and measure it with an ohm meter then go buy a larger wattage resistor in a higher wattage rating and replace the l-pad with it or buy one in a smaller ohm size and use it with the built in volume control to control the volume. it may just be you bought a controller thats at its limit when you needed a few watts more . how do you have it wired in ? it does sound a bit odd that 15 watts doesnt cover it .almost sounds like your shorting the speaker (wired in parallel with the speaker instead of inline) not adding resistance (in series with the speaker).

[cwstnsko]

L-pads are different than pots. L-pads should always measure their rated impedance. The theoretical advantage of an L-pad is that the amp doesn't see a change in the resistance, so it operates at the designed load even if the volume is turned way down. The L-pad has to absorb the difference in the energy.

Ever since I figured out that most of the manufacturers use resistor in series with the speaker in their built-in volume controls, I use fixed resstors or pots without worrying about the theoretical advantages of L-pads.