Phanteks AMP Series 650W Power Supply Review

The Phanteks AMP Series model with 650W capacity offers high enough performance and features quiet operation.

Phanteks AMP Series 650W
(Image: © Tom's Hardware)

Tom's Hardware Verdict

The Phanteks AMP Series model with 650W capacity offers high performance and quiet operation.


  • +

    Full power at 47 degrees Celsius

  • +

    High build quality

  • +

    Satisfactory performance

  • +

    Quiet operation

  • +

    Fully modular (with 2x EPS connectors)

  • +

    Compact dimensions


  • -

    Low 5VSB efficiency

  • -

    Transient response at 3.3V

  • -

    Low efficiency with 2% load

  • -

    Small distance between the 4-pin Molex connectors

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The Phanteks AMP Series 650W offers strong performance, excellent build quality and silent operation. All the above are provided at a fair price, so this product follows keeps up with its direct competitors in this wattage category, namely the Seasonic Focus Plus Gold with similar capacity (GX-650) that uses the same platform and the Corsair RM650x.

The Phanteks Amps line consists of three models with their capacities ranging from 550W to 750W. All are fully modular and are certified by both 80 PLUS and Cybenetics, so besides the 80 PLUS Gold badge, the PH-P650G also has the ETA-A and LAMBDA-A+ efficiency and noise badges, respectively.

All Phanteks AMP models use the new Focus Plus Gold platform, which is also used in the fresh Seasonic GX models. This platform is reliable and offers good performance, so we have high expectations from today's review unit, the PH-P650G.

Despite the super-compact dimensions, the have PH-P650G is equipped with two EPS and four PCIe connectors, so it will easily keep up with a potent system, as long as you don't try to power a pair of previous AMD GPUs with it (e.g., VEGA 56/64). If you don't need a second GPU, the PH-P650G is able to handle extremely power-hungry processors like AMD's Threadripper CPUs, which can draw more than 250W of power, and this is why the corresponding mainboards require a pair of EPS connectors. 


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Manufacturer (OEM)


Max. DC Output



80 PLUS Gold, ETA-A (88-91%)


LAMBDA-A+ (15-20 dB[A])


✓ (Fully)

Intel C6/C7 Power State Support

Operating Temperature (Continuous Full Load)

0 - 50°C

Over Voltage Protection

Under Voltage Protection

Over Power Protection

Over Current (+12V) Protection

Over Temperature Protection

Short Circuit Protection

Surge Protection

Inrush Current Protection

Fan Failure Protection

No Load Operation


120mm Fluid Dynamic Bearing Fan (HA1225H12F-Z)

Semi-Passive Operation

✓ (selectable)

Dimensions (W x H x D)

150 x 85 x 140mm


1.55 kg (3.42 lb)

Form Factor

ATX12V v2.4, EPS 2.92


10 Years

Power Specifications

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Max. PowerAmps20205430.3
Total Max. Power (W)650

Cables and Connectors

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Modular CablesCable CountConnector Count (Total)GaugeIn Cable Capacitors
ATX connector 20+4 pin (610mm)1118-22AWGYes
4+4 pin EPS12V (650mm)2218AWGNo
6+2 pin PCIe (680mm+80mm)2418AWGNo
SATA (420mm+150mm+150mm+150mm)2818AWGNo
SATA (300mm+150mm)1218AWGNo
4 pin Molex (450mm+120mm+120mm)1318AWGNo
4 pin Molex to SATA 3.3V Adapter (150mm+150mm)1218AWGNo
AC Power Cord (1370mm) - C13 coupler1118AWG-

There are plenty of connectors, including two EPS, four PCIe, twelve SATA (with two of them supporting the PWDIS feature) and three 4-pin Molex.

Component Analysis

We strongly encourage you to have a look at our PSUs 101 article, which provides valuable information about PSUs and their operation, allowing you to better understand the components we're about to discuss.

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General Data-
Manufacturer (OEM)Seasonic
PCB TypeDouble Sided
Primary Side-
Transient Filter4x Y caps, 2x X caps, 2x CM chokes, 1x MOV, 1x Discharge IC
Inrush ProtectionNTC Thermistor & Relay
Bridge Rectifier(s)2x GBU1006 (600V, 10A @ 100°C)
APFC MOSFETS2x Champion GPT18N50D (500V, 18A, 0.27Ohm)
APFC Boost Diode1x NXP BYC8-600 (600V, 8A @ 109°C)
Hold-up Cap(s)1x Hitachi (400V, 470uF, 2,000h @ 105°C, HU)
Main Switchers4x Champion GPT10N50AD (500V, 9.7A, 0.7Ohm)

APFC Controller

Champion CM6500UNX

Resonant ControllersChampion CM6901T6
TopologyPrimary side: Full-Bridge & LLC converter
Secondary side: Synchronous Rectification & DC-DC converters
Secondary Side-
+12V MOSFETS2x Nexperia PSMN1R8-40YLC (40V, 100A @ 100°C, 3.25mOhm @ 150°C)
5V & 3.3VDC-DC Converters
Filtering Capacitors

Electrolytics: 6x Nippon Chemi-Con (4-10,000h @ 105°C, KY), 3x Nippon Chemi-Con (1-5,000h @ 105°C, KZE), 2x Nichicon (2-5,000h @ 105°C, HD), 3x Nichicon (4-10,000h @ 105°C, HE)
Polymers: 9x FPCAP, 2x NIC, 4x United Chemi-Con

Supervisor ICWeltrend WT7527V (OCP, OVP, UVP, SCP, PG)
Fan ModelHong Hua HA1225H12F-Z (120mm, 12V, 0.58A, Fluid Dynamic Bearing Fan)
5VSB Circuit-
Rectifier1xPFC P10V45SP SBR (45V, 10A)
Standby PWM ControllerExcelliance MOS EM8569

As we already mentioned, all AMP models are based on Seasonic's newest Focus Plus platform. The main PCB is compact but still has enough clearance between parts, to allow for proper airflow. The build quality is excellent, and all parts are carefully selected to offer the highest possible lifetime, without dramatically increasing the manufacturing cost. 

The transient filter is complete since it includes all necessary parts, along with a discharge IC for lower power losses on X caps.

Both bridge rectifiers are cooled down by a small heat sink. 

Right in front of the APFC converter's parts, we find the NTC thermistor with model number WMF21-5D-15M and its bypass relay. This specific thermistor has 5 Ohms resistance (+-20%) at 25 degrees Celsius, meaning that with this specific operating temperature, the inrush current at 230V can go up to 64.86 Amps (230V x 1.41 x 5 Ohm). Given the high 20% resistance tolerance, the inrush current with 230V can be as high as 81.075A, given that the thermistor's temperature doesn't go higher than 25 degrees Celsius. 

The four primary FETs are arranged in a full-bridge topology. A resonant converter is also used, to restrict energy losses. 

All FETs that handle the +12V rail are installed on the solder side of the main PCB. The two heat sinks right above them, on the top side of the PCB, help in cooling down those FETs. Finally, the minor rails are handled by a couple of DC-DC converters. 

The filtering caps are of good quality since most of them belong to mid and higher-end lines. Besides electrolytic caps, many polymers are also used.

The 5VSB circuit uses an Excelliance standby PWM controller and the rectifier, on its secondary side, is an SBR. 

supervisor IC

(Image credit: Tom's Hardware)

The supervisor IC is a Weltrend WT7527V.

There is space for much more polymer caps on the modular PCB, but this would increase the cost without reason since the ripple suppression is already quite good. 

The main PCB has good soldering quality. 

The cooling fan is by Hong Hua, and it uses a fluid dynamic bearing. This is a good fan, which will live for quite long if you don't expose it to harsh conditions (40 degrees Celsius) for prolonged periods.

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