The L25D can't do that because it doesn't work well with 4 ohms, let alone 2. Yes, you can wire the 2 coils in series to get 4, but then bridging two output channels makes the load appear to the boards to be 2 ohms again. This is totally out of class for the L25D. Even driving the 4 ohm load with one L25D is out of its class. ljm_ljm has an amp9 clone that uses 2 irfb4227 transistors that can drive 2 ohm loads. There is also the iraud200 that can do this. However, the iraud200 will need some mods because the original circuit design sucks. I personally discovered the required mods for that and wrote a couple of iraud200 threads for them. However, in your case, if you are only using +/- 45 volts, you may not have to do all of those mods. ljm's board may not like the +/- 45 volts. Seems like I remember him saying it requires more. I haven't tried the iraud200 at that voltage. Those boards are really looking for something like +/- 60 or 70, and they can deliver a butt load of power. As much as 1kw into 2 ohms or 500w into 4 ohms. More likely around 700w/350w.
Thanks for the explanation. My apologies I had confused the model numbers, it is actually the L15D I was planning to use.
the l15d may be better suited for the +/- 45v however, it will not do either 4 or 2 ohm I am quite certain. Let ljm_ljm disagree if he wants.
Interesting, I knew 2-ohm was perhaps iffy but I was quite confident I had seen 4-ohms as being ok. Is it possible to swap in a different output transistor and reduce supply voltage? I don't mind limiting performance at higher impedance.
FIY : I use L25D on 4ohm subwoofer with no issue. Tested up to 300Wrms. SingleEnded, not bridged.
I don't own L15D myself, but know some people using it on 4ohm speakers with no issue; Bridged on 4ohms would be a challenge.
Thanks for the confirmation. Is there any modification that can be done to improve my chances at 2-ohms? Even if it means limiting performance at higher impedance.
If not, I'll go ahead and wire it up in series and just use one amp channel and save the other channel for another subwoofer.
If not, I'll go ahead and wire it up in series and just use one amp channel and save the other channel for another subwoofer.
I have no experience with dual coil speakers.
2 ohms is a challenge for these amps. Affraid you'll reach mosfet current limit. There are some other irs2092 amps with stronger transistors which can sustain more current.
The significant mod I made was to increase the power caps to avoid bus pumping. I use an SMPS power supply.
2 ohms is a challenge for these amps. Affraid you'll reach mosfet current limit. There are some other irs2092 amps with stronger transistors which can sustain more current.
The significant mod I made was to increase the power caps to avoid bus pumping. I use an SMPS power supply.
How much capacitance did you add? I am using two Meanwell 48V supplies wired in series. I can add capacitance to both the rails.
I replaced the L25D onboard power rail capacitors with the biggest I could find that fit on the board : 820µF/63V
Power supply is SMPS800R +-60V from connexelectonic which has big output capacitors. 8200µF x 2.
So the total per rail, smps+amp, in my case is about 9000µF.
Power supply is SMPS800R +-60V from connexelectonic which has big output capacitors. 8200µF x 2.
So the total per rail, smps+amp, in my case is about 9000µF.
Unless he has changed the design, L25D doesn't do 4 ohms with +/- 70 volt supply. It trips the protection circuit. However, a lower voltage supply might change that. Also, when I changed the gate drive resistors from 20 ohm to 10 ohm, it came close to holding up for low frequencies. I should have tried switching the gate drive to 5 ohm. In the end, I had to deactivate the protection circuit, and eventually one of the boards burned out. I realized at some point that there's a way to get more current out of that board. However, I wouldn't recommend it because it would require a lot of mods. Remember that the inductors are sized, and you would have to replace that as well as the transistors and more ... then wonder if the traces on the board can handle 20A. If you want 2 ohm service, you need a more potent board.
The friend who answer is very correct.
L15D can connect 2 ohm speaker, of course, you can even work properly, the output of music.
But it may reduce a lot of power, because the current is not very big.
Of course, you can try, maybe you used in the power is not big, can meet.
If so that is no problem.
If there is a problem, that is likely to be automatically cut off the output signal.
Or perhaps temporarily no sound. But should not be damaged.
You can try. Don't need to change the circuit.
L15D can connect 2 ohm speaker, of course, you can even work properly, the output of music.
But it may reduce a lot of power, because the current is not very big.
Of course, you can try, maybe you used in the power is not big, can meet.
If so that is no problem.
If there is a problem, that is likely to be automatically cut off the output signal.
Or perhaps temporarily no sound. But should not be damaged.
You can try. Don't need to change the circuit.
So I would probably be better off to connect the load a series load of 4 ohms and save one channel for another subwoofer instead? In the interest of allowing the most power delivery.
Hi,
I have two toroid transformers 200VA 2x30VAC (+/-42V).
Can I connect two L15D for each transformer to this voltage?
I want use these L15D to connect tweeter and medium speakers in active crossover.
Thanks for yours help.
I have two toroid transformers 200VA 2x30VAC (+/-42V).
Can I connect two L15D for each transformer to this voltage?
I want use these L15D to connect tweeter and medium speakers in active crossover.
Thanks for yours help.
You only need to pay attention to is that you can.
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