Hello!
I just bought 2 L25D By LJM mono boards, and tested them out at 55v+- VDC(4 ohm speakers)..
nice sound but not much..i compared it with another amplifier from that's rated 60w at 8 ohm and 80w at 4 ohm.
at 80w rated, it produces more sound at the same speakers..
what's happening?
I just bought 2 L25D By LJM mono boards, and tested them out at 55v+- VDC(4 ohm speakers)..
nice sound but not much..i compared it with another amplifier from that's rated 60w at 8 ohm and 80w at 4 ohm.
at 80w rated, it produces more sound at the same speakers..
what's happening?
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What are the relative gains of the two amplifiers? The L25D needs 1.6V and has a gain of 40x. If the other amplifier is more sensitive it will sound louder, but it will 'run out of puff' much earlier than the L25D.
Well,,,thanx for the fast reply,,as input,im using a laptop that's 1v i think..ill try to find the sensetivity from the other amp and post it,,it uses 2 2N3055 transistors(MONO BOARD)
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l25d amplifier with Power supply +/- 70v
l25d amplifier with Power supply +/- 70v of how much current is needed to pull out 250watt of power ??? I don't understand how to size the transformer or smps power supply .... what is the calculation to know the current needed ??? and how to size fuses protection ????
l25d amplifier with Power supply +/- 70v of how much current is needed to pull out 250watt of power ??? I don't understand how to size the transformer or smps power supply .... what is the calculation to know the current needed ??? and how to size fuses protection ????
I see you've posted the same question in another thread too. Scratch that, two other threads. Ooops, I have just found another one so three. Naw, that's wrong make it four.
Assuming the amp is 90% efficient the power draw from the rails needs to be ~280W. So with a 140V total supply the average current is 2A. But your PSU should be able to deliver peak current, not just average. I'd go for 3A on each of your 70V rails.
Assuming the amp is 90% efficient the power draw from the rails needs to be ~280W. So with a 140V total supply the average current is 2A. But your PSU should be able to deliver peak current, not just average. I'd go for 3A on each of your 70V rails.
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I don't understand what you mean, you say that 300watt of transformer is enough? I thought that for normal operation, need 300watt and for the peaks, at least 600watt
I was talking about a SMPSU rather than a transformer. With a transformer you have to be concerned about how much the voltage sags under load - due to trafo regulation and also ripple. I'd say if you're making a linear supply with a transformer, 400VA would likely be sufficient.