DC Load Regulation and AC Ripple
DC Output Load Regulation
To simulate real world and maximum loading conditions, the LEPA Gold 750W PSU was connected to the load testers and supplied with a constant 115 VAC. In this test we are interested in seeing how well a PSU can maintain the various output voltages while operating under different loads.
The ATX12V V2.2 tolerance for voltages states how much each output (rail) is allowed to fluctuate and has tighter tolerances now for the +12V outputs. I have also included a second table of expanded tolerances (±1% to ±6%) for reference.
The following tables list the DC voltage results for the PSU while operating on 115 VAC, 60 Hz.
As you can see, the LEPA Gold 750W PSU produced excellent load regulation on all of the outputs across a broad range of loads. The three primary outputs (+3.3V, +5.0V and +12V) stayed within ±2% of their target values – very good!
AC Ripple and Noise on the DC Outputs
The amount of AC ripple and noise present on the DC outputs was checked using a digital oscilloscope. This AC component may be present in the KHz range where most switching power supplies operate or it may be more prevalent at the 60 Hz line frequency. We adjust the O-scope time base to look for AC ripple at both low and high frequencies. The ATX12V V2.2 specification for DC output noise/ripple is defined in the ATX12V Power Supply Design Guide.
Ideally we would like to see no AC ripple (repetitive) or noise (random) on the DC outputs – the cleaner the better! But in reality there will always be some present. I measured the amplitude of the AC signal (in millivolts, peak-to-peak) to see how well the power supply complied with the ATX standard. The following table lists the ripple/noise results during all of the load tests for the main output voltages of interest.
The LEPA G-750 power supply exhibited very good AC ripple suppression on all of the primary outputs and stayed well below the recommended values, even at full load.
Seems like a very reasonably
Seems like a very reasonably priced contender in the 750W range of 80+ Gold PSUs. Have to say that because of this review I certainly would consider it as a replacement or upgrade [situation-pending]. & Thanks for the review.
The cooling is ridiculous
The cooling is ridiculous inside this one. The fan has to spin quite fast even at moderate load.
Add the fact that the fan itself is complete crap and you get one of the loudest PSU i’ve ever heard… It’s louder than an overclocked GTX570.
I’m really considering voiding my warranty just to change the fan and those cooling plates if the screws are accessible.
The screws ARE extremely
The screws ARE extremely easily accesable… to change the PSU fan, ALL you need to do is to unscrew 4 screws and take out the shroud… though, BE careful with that. Make pretty damn SURE you discharge the capacitors before you open up your unit. There’s deadly charge can that be hidden behind those two big primary capacitors.
Cant confirm that.
I have an
Cant confirm that.
I have an absolute silent machine (you cant tell if its on or off unless looking at the LEDs or monitor)
running watercooling with external fanless radiator, gtx670 with 3 92mm silent fans and MB controlled noiseblocker case fans 11dB, and i cant hear the psu fan.
I even unplugged all case fans and stopped the gpu fans manually and still nothing from the psu…
Of course running a cheaper/older case with top mounted psu (instead of bottom) and not enuf airflow in a cramped case would make any psu-fan turn up on rpm…