A review of a LM3886 eBay amplifier is performed. Performance, efficiency, thermal, heatsink, design issues and possible modifications are discussed.
Пікірлер: 21
@briansilcox57207 ай бұрын
Great analysis. I have built several 3886 based amps recently, seriously heatsinked kit products, they work very well.
@DanPattenAudioG33k7 ай бұрын
Good to hear. The LM3886 does a decent job but they do need a decent sized heatsink.
@MichaelBeeny Жыл бұрын
Hi Don. I know you was laughing about adding those 2 extra heatsinks but that is exactly what is needed. Almost all the amplifiers from Ali/EBay etc are almost always under heatsinked. It is done like that to make it cheaper. The money in any amplifier is in the power transformer and good heatsinking. This amplifier suffers from both these limitations. If these things were addressed, it would cost double, and no one would buy it. You can get a similar module with fan cooling but it's quite noisy as the fans run flat out. Again a mod you can do it to wire the 2 fans in series, makes it quite a good little amplifier and fan noise is fine. Most of all it runs almost cold and stops the amp running into thermal limiting.
@DanPattenAudioG33k Жыл бұрын
I agree. Most of the amps I have worked with, the chassis, heatsink and power supply are a majority of the cost.
@Dazzwidd18 күн бұрын
30W input for 2W output? thankyou for alerting me to this monstrosity of an amplifier
@SachinB.A.20 күн бұрын
Is lm 3886 ic AB or Class D ? And also tell me which is best ic than lm3886 which delivers 100 watt output. Thanks
@DanPattenAudioG33k20 күн бұрын
@@SachinB.A. LM3886 is Class AB and I believe 68W rated. It is the highest power AB chip I have used. You could use 2 in BTL configuration and get 100W.
@ChicagoRob229 күн бұрын
Nice, if you like toy amps.
@hugueslecorre48936 ай бұрын
The ac fuse might be in the socket
@DanPattenAudioG33k6 ай бұрын
That is a good thought. If I recall, I checked for that but might have missed it.
@francescodileo835310 ай бұрын
But these IC 3886 are original or fake?
@DanPattenAudioG33k10 ай бұрын
Hard to say. The performance seemed ok, so there were no red flags about being fake.
@heryantochang5 ай бұрын
How many amperes is a good transformer for an LM3886 stereo amplifier?
@DanPattenAudioG33k5 ай бұрын
For a robust design, I think you want the secondary windings to be rated for 6 amps (for a stereo design).
@heryantochang5 ай бұрын
@@DanPattenAudioG33k in my country the average person sells 5A or 10A... 6A ones are rare.. Can a 5A transformer be used for this amplifire?
@wcovey94053 жыл бұрын
There must be something wrong with the circuit used or parts used.
@DanPattenAudioG33k3 жыл бұрын
Are you referring to the thermal issues? The LM3886 has a quiescent current of 0.050A to 0.085A. I have typically measured the device at 0.065A. 0.065A x 72V x 2 (stereo) = ~10W of power dissipation. This is just the two LM3886 while at idle. 10W is a fair amount of power to get rid of.
@wcovey94053 жыл бұрын
@@DanPattenAudioG33k I have built a number of LM 3886 power amplifiers, using a plus, minus 35 vdc power supply, and they work well. The IC does run hot when driven hard. The heat sink should be large. When driving just one watt of power, a little warm is all it should get, unless your driving a load of four ohms or less, then I don't know. The transformers I have used deliver plus minus 4 amps per side, and when driven into a 8 ohm load there was no loading down of the power supply voltages, how ever there was with a 4 ohm load the IC got hotter quicker and the PS voltage drop. To my way of thinking, the IC does not mind high voltages (within its limits), but it gets hot over delivering high current. From your video it sounds like the IC is using too much current for the load driven, and or the transformer is to weak, or maybe there is something else.
@DanPattenAudioG33k3 жыл бұрын
Thanks for sharing. I guess one of the points I was trying to make in the video is that the LM3886 can dissipate a fair amount of heat. A typical problem with implementing this IC is not using a large enough heatsink. Always seems to take a larger heatsink than anticipated. Thanks.
@Atelierul292 жыл бұрын
That transformer is a joke for two LM3886
@DanPattenAudioG33k2 жыл бұрын
I ran the amplifier to full power and did not recall seeing any droop in the voltage rails (which would indicate undersized transformer). FYI.