LEPA G700-MA Power Supply Review

[nextpage title=”Introduction”]

LEPA is a newcomer to the power supply market, established by Ecomaster, the official distributor of Enermax power supplies in the United States. The LEPA G series is the Enermax MODU87+ series with a different name, and we don’t understand why the same distributor offers the same power supplies under two different brands. We’ve already reviewed the LEPA G500-MA and the Enermax MODU87+ 700 W, and both proved to be excellent products. Let’s see if the LEPA G700-MA is also a good option.

Figure 1: LEPA G700-MA power supply

Figure 2: LEPA G700-MA power supply

The LEPA G700-MA is 6.3” (160 mm) deep, using a 140 mm twister bearing fan on its bottom (Enermax EA142512W).

This unit has a modular cabling system with seven connectors (two red for video card power cables and five black for SATA and peripheral power cables), and three cables are permanently attached to the power supply. This power supply comes with the following cables:

• Main motherboard cable with a 24-pin connector, 23.2” (61 cm) long, permanently attached to the power supply
• One cable with two ATX12V connectors that together form one EPS12V connector, 23.2” (61 cm) long, permanently attached to the power supply
• One cable with one EPS12V connector, 23.2” (59 cm) long, permanently attached to the power supply
• Four cables, each with one six/eight-pin auxiliary power connectors for video cards, 19.7” (50 cm) long, modular cabling system
• One cable with four SATA power connectors, 18.1” (46 cm) to the first connector, 5.9” (15 cm) between connectors, modular cabling system
• Two cables, each with two SATA and two standard peripheral power connectors, 18.1” (46 cm) to the first connector, 5.9” (15 cm) between connectors, modular cabling system
• One cable with three standard peripheral power connectors and one floppy disk drive power connector, 18.1” (46 cm) to the first connector, 5.9” (15 cm) between connectors

All wires are 18 AWG, which is the minimum recommended gauge, but the main motherboard cable uses thicker 16 AWG wires, which is nice to see.

This configuration is good enough for a 700 W product. It is important to understand that while the modular video card cables are wrapped in the same nylon sleeve and share the same connector on the power supply side, they are separate cables.

Figure 3: Cables

Let’s now take an in-depth look inside this power supply.

[nextpage title=”A Look Inside the Enermax MODU87+ 700 W”]

We decided to disassemble this power supply to see what it looks like inside, how it is designed, and what components are used. Please read our Anatomy of Switching Power Supplies tutorial to understand how a power supply works and to compare this power supply to others.

On this page we will have an overall look, and then in the following pages we will discuss in detail the quality and ratings of the components used. As already explained, this power supply is an Enermax MODU87+ 700 W with a different name.

Figure 4: Top view

Figure 5: Front quarter view

Figure 6: Rear quarter view

[nextpage title=”Transient Filtering Stage”]

As we have mentioned in other articles and reviews, the first place we look when opening a power supply for a hint about its quality, is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil. 

This power supply is flawless on this stage, with two Y capacitors and one ferrite coil more than the minimum required, plus one X capacitor after the rectifying bridge.

Figure 7: Transient filtering stage (part 1)

Figure 8: Transient filtering stage (part 2)

On the next page, we will have a more detailed discussion about the components used in the LEPA G700-MA.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the LEPA G700-MA. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBU2006 rectifying bridge on its primary, which is attached to an individual heatsink. This bridge can deliver up to 20 A at 100° C if a heatsink is used, which is the case. At 115 V this unit would be able to pull up to 2,300 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,840 W without burning itself out. Of course, we are only talking about this component. The real limit will depend on all other components from the power supply.

Figure 9: Rectifying bridge

On the active PFC
circuit, two TK20J60T power MOSFET transistors are used, each one capable of delivering up to 20 A at 25° C in continuous mode (unfortunately, the manufacturer doesn’t state the limit at 100° C) or up to 40 A at 25° C in pulse mode. These transistors present a resistance of 165 mΩ when turned on, a characteristic called RDS(on). This number indicates the amount of power that is wasted, so the lower this number the better, as less power will be wasted, thus increasing efficiency.

Figure 10: Active PFC transistors and diode

The active PFC circuit is controlled by a CM6502 PFC controller.

Figure 11: Active PFC controller

This power supply uses a Japanese capacitor, from Rubycon, labeled at 85° C to filter the output from the active PFC circuit. For a “Gold” power supply, we expected to see a 105° C capacitor here.

In the switching section, two SiHG20N50C power MOSFET transistors are used. Each of the transistors is capable of delivering up to 20 A at 25° C or 11 A at 100° C in continuous mode or up to 80 A at 25° C in pulse mode, with an RDS(on) of 225 mΩ.

Figure 12: Switching transistors

The switching transistors are connected using a design called LLC resonant, controlled by a CM6901 integrated circuit, which operates under PWM (Pulse Width Modulation) mode when the power supply is operating under light load but under FM (Frequency Modulation) mode under other loads.

Figure 13: Controller

Let’s now take a look at the secondary from this power supply.

[nextpage title=”Secondary Analysis”]

This power supply uses a DC-DC converter design in the secondary, meaning that this is basically a +12 V power supply where the +5 V and +3.3 V outputs are produced by two separated power supplies connected to the +12 V output. This design is proving to be the best solution for achieving high efficiency. Furthermore, the +12 V power supply uses a synchronous design. In this kind of design, the rectifiers are replaced by transistors (MOSFETs) in order to increase efficiency.

The +12 V output is rectified by four IRFB3206 MOSFETs, two for the direct rectification and two for the “freewheeling” part of the rectification. Each transistor has a maximum RDS(on) of only 2.5 mΩ and can deliver up to 270 A at 25° C or 190 A at 100° C in continuous mode or up to 1,080 A at 25° C in pulse mode. This would give us a maximum theoretical current of 266 A for the whole +12 V bus; if all this current would be pulled from the +12 V outputs, this unit would be able to deliver up to 3,192 W! Of course, other parts of this power supply would burn way before we could get even close to this theoretical value.

Figure 14: +12 V transistors (the diode on the right is used for the +5VSB output)

Like all other members of the MODU87+ family, the filtering stage of the +12 V line uses a mix of solid capacitors and Japanese capacitors, from Chemi-Con, installed on small printed circuit boards attached to the main power supply board.

Figure 15: Filtering circuit

The +5 V and +3.3 V outputs are produced by two separated DC-DC modules, which are connected to the main +12 V line to produce these two voltages. Each module uses three APM2556 MOSFETs, controlled by an APW7073 integrated circuit, and has solid capacitors.

Figure 16: One of the DC-DC modules

Figure 17: One of the DC-DC modules

The secondary is monitored by a PS231S integrated circuit, which supports over voltage protection (OVP), under voltage protection (UVP), and over current protection (OCP). This integrated circuit has five OCP channels (+3.3 V, +5 V and three +12 V), correctly matching the number of +12 V rails advertised by the manufacturer.

Figure 18: Monitoring circuit

[nextpage title=”Power Distribution”]

In Figure 19, you can see the power supply label containing all the power specs.

Figure 19: Power supply label

This power supply is sold as having three +12 V rails, which is correct, since this unit has three +12 V over current protection circuits (see previous page), and we could clearly see one “shunt” (current sensor) for each +12 V “rail” see Figure 20). Click here to understand more about this subject.

Figure 20: Shunts

The three +12 V rails are distributed as follows:

• +12V1: Main motherboard cable, ATX12V, and EPS12V connectors
• +12V2: The two peripheral connectors of the modular cabling system that are close to the video card power connectors, and two of the video card power connectors
• +12V3: The first three peripheral connectors of the modular cabling system, and two of the video card power connectors

This distribution is perfect, as it keeps the CPU (ATX12V/EPS12V connectors) and the video cards in separate rails.

There is one interesting point. Each red connector of the modular cabling system, which is used to connect the video card power cable, is half connected to the +12V2 rail and half connected to the +12V3 rail. When using two video cards that require only one power connector each, the best method is to use only one cable. This way you are ensuring that one of the video cards is installed on the +12V2 rail, and the other one is installed on the +12V3 rail. If you use the two cables, you may end up connecting the two video cards on the same rail.

How much power can this unit really deliver? Let’s find out.

[nextpage title=”Load Tests”]

We conducted several tests with this power supply, as described in the article Hardware Secrets Power Supply Test Methodology.  

First, we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching the behavior of the reviewed unit under each load. In the table below, we list the load patterns we used and the results for each load.

If you add all the powers listed for each test, you may find a different value than what is posted under “Total” below. Since each output can have a slight variation (e.g., the +5 V output working at +5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. In the “Total” row, we are using the real amount of power being delivered, as measured by our load tester.

The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test, the +12VA input was connected to the power supply +12V1 and +12V2 rails, while the +12VB input was connected to the power supply +12V1 rail.

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	4.5 A (54 W)	9.5 A (114 W)	14.5 A (174 W)	19 A (228 W)	25 A (300 W)
+12VB	4.5 A (54 W)	9.5 A (114 W)	14.5 A (174 W)	19 A (228 W)	25 A (300 W)
+5 V	2 A (10 W)	4 A (20 W)	6 A (30 W)	8 A (40 W)	10 A (50 W)
+3.3 V	2 A (6.6 W)	4 A (13.2 W)	6 A (19.8 W)	8 A (26.4 W)	10 A (33 W)
+5VSB	1 A (5 W)	1.5 A (7.5 W)	2 A (10 W)	2.5 A (12.5 W)	3 A (15 W)
-12 V	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)
Total	138.1 W	279.3 W	419.3 W	545.6 W	706.2 W
% Max Load	19.7%	39.9%	59.9%	77.9%	100.9%
Room Temp.	46.1° C	45.5° C	46.3° C	48.0° C	46.3° C
PSU Temp.	50.6° C	50.5° C	50.5° C	51.0° C	52.6° C
Voltage Regulation	Pass	Pass	Pass	Pass	Pass
Ripple and Noise	Pass	Pass	Pass	Pass	Pass
AC Power	154.2 W	307.2 W	465.5 W	618.4 W	818.0 W
Efficiency	89.6%	90.9%	90.1%	88.2%	86.3%
AC Voltage	119.4 V	118.9 V	117.5 V	116.0 V	113.5 V
Power Factor	0.983	0.981	0.989	0.994	0.995
Final Result	Pass	Pass	Pass	Pass	Pass

The LEPA G700-MA can really deliver its labeled wattage at high temperatures.

Efficiency was always extremely high, above 90% when we pulled between 40% and 60% of the unit’s labeled power (i.e., between 280 W and 420 W). At full load (700 W) efficiency, it dropped a little below the 87% minimum required by the 80 Plus Gold certification, but this is normal as Ecos Consulting, the company behind the 80 Plus certification, tests power supplies at lower temperatures.

Voltage regulation was very good, with all voltages within 3% of their nominal values, except the +3.3 V output during tests one and two, and the -12 V output during tests four and five. They were, however, still inside the allowed range. This means that voltages were closer to their nominal values than required by the ATX12V specification most of the time. The ATX12V  specification says positive voltages must be within 5% of their nominal values, and negative voltages must be within 10% of their nominal values.

Noise and ripple levels were always very low. Below you can see the results for the power supply outputs during test number five. The maximum allowed is 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V, +3.3 V and +5VSB outputs. All values are peak-to-peak figures.

Figure 21: +12VA input from load tester during test five at 706.2 W (45.6 mV)

Figure 22: +12VB input from load tester during test five at 706.2 W (43.4 mV)

Figure 23: +5 V rail during test five at 706.2 W (17.4 mV)

Figure 24: +3.3 V rail during test five at 706.2 W (26.4 mV)

Let’s see if we can pull more than 700 W from this unit.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. We couldn’t pull more than that because the power supply shut down, showing that its protections were working just fine.

Input	Overload Test
+12VA	33 A (396 W)
+12VB	33 A (396 W)
+5 V	20 A (100 W)
+3.3 V	20 A (66 W)
+5VSB	3 A (15 W)
-12 V	0.5 A (6 W)
Total	982.6 W
% Max Load	140.4%
Room Temp.	45.7° C
PSU Temp.	54.4° C
AC Power	1,184 W
Efficiency	83.0%
AC Voltage	111.4 V
Power Factor	0.997

[nextpage title=”Main Specifications”]

The main specifications for the LEPA G700-MA power supply include:

• Nominal labeled power: 700 W at 50° C
• Measured maximum power: 982.6 W at 45.7° C
• Labeled efficiency: 87% minimum, 80 Plus Gold certified
• Measured efficiency: Between 86.3% and 90.9% at 115 V (nominal, see complete results for actual voltage)
• Active PFC: Yes
• Modular Cabling System: Yes
• Motherboard Power Connectors: One 24-pin connector, two ATX12V connectors that together form an EPS12V connector, and one EPS12V connector, permanently attached to the power supply
• Video Card Power Connectors: Four six/eight-pin connectors on separate cables, modular cabling system
• SATA Power Connectors: Eight on three cables, modular cabling system
• Peripheral Power Connectors: Eight on three cables, modular cabling system
• Floppy Disk Drive Power Connectors: One
• Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over power (OPP), over current (OCP), over temperature (OTP), and short-circuit (SCP) protections
• Are the above protections really available? Yes.
• Warranty: Five years
• Real Model: Enermax MODU87+ 700 W
• More Information: https://www.lepatek.com
• Average Price in the US*: USD 150.00

* Researched at Newegg.com on the day we published this review.

[nextpage title=”Conclusions”]

The LEPA G700-MA is a terrific power supply, with outstanding efficiency above 90% if you pull between 40% and 60% of the unit’s labeled power (i.e., between 280 W and 420 W), good voltage regulation, and very low noise and ripple levels. And we could pull up to 980 W from it with 83% efficiency, which is simply amazing.

The good news is that you can buy this unit for USD 150, which is a fantastic price for a power supply with such high efficiency. The Enermax MODU87+ 700 W was sold for USD 220 when it was released, but now it is sold for USD 180. The LEPA G700-MA is identical to the MODU87+ 700 W and costs less, making it a no-brainer.