Introduction

We would like to thank Antec for supplying the review sample.


The legendary Antec Signature line has been brought back to life. Only this time, the OEM is Seasonic and not Delta, and efficiency and wattage are much higher. The new Signature units with model numbers SP1000, SP1300, and ST1000 use Seasonic's Prime platform, and the MSRP of these PSUs is set to $230, $270, and $280 respectively. They are pretty expensive, but address extreme enthusiasts who are willing to spend a lot to get a topnotch power supply.



The most efficient model of the line, the Signature 1000 Titanium, will be the main subject of this review. It is a fully modular 80 PLUS Titanium efficiency PSU with the ETA-A+ (91%–94% overall efficiency) and LAMBDA-A (20–25 dBA) efficiency and noise certifications on the Cybenetics scale. It is difficult for a high wattage PSU to remain quiet, especially at heavy loads, but the more efficient the platform, the lower the thermal loads, which means a more relaxed fan-speed profile can be used.


In the bundle, you will also find three Velcro straps and the usual zip ties. Some included thumb screws would have also be nice.


The PSU comes in a pouch instead of a plastic wrap. This is a nice detail, especially for such an expensive product.

Specifications

The warranty is set to ten years—Seasonic offers two more years for its Prime models. In any case, both are long, and the two-year difference is not a deal-breaker for someone who prefers the Antec model in terms of looks or for the OC Link feature, which allows two Signature PSUs to operate in tandem for a truly power hungry system. This is a cool feature, but efficiency at light loads goes south if you use two PSUs for the same system, and you will need a large chassis to accommodate both PSUs. I prefer a stronger PSU instead of two with a lower capacity for normal situations outside of extreme overclocking.

Cables and Connectors

It is strange to find 18AWG gauges in a high-end PSU with 1 kW power output. Load regulation could even be better with thicker wires, and there would also be a small efficiency boost, mostly at high loads. However, thicker gauges lead to less flexible cables, which can be a major headache. A strong advantage of this PSU is that it doesn't use any in-cable caps.


There are a huge number of connectors, including two EPS, eight PCIe, 14 SATA, and five 4-pin Molex connectors. Unfortunately, the 4-pin Molex connectors are only 120 mm apart.


There is also a 4-pin Molex to SATA adapter, compatible with the SATA 3.3 (announced on February 16, 2016) and SATA 3.2+ specifications, which introduced the power disable (PWDIS) feature. This feature utilizes the third pin (P3) of the SATA connector, which in the older SATA specifications is tied to the first (P1) and second (P2) pins, and all of them take the 3.3 V rail for the attached drive. According to the newer SATA specification, P3 is now independent and transfers the power disable signal. This means a new HDD that supports the power disable feature will not start if combined with a PSU with the older SATA connectors featuring 3.3 V at P3 because the HDD will see a continuous high-state signal on P3. It will get stuck in a hard reset condition, which will prevent it from spinning up.

Component Analysis

The PSU uses Seasonic's Prime platform, which is among the best. The design is cutting edge, and the build quality is great. Seasonic uses good (and expensive) parts to achieve top performance and high reliability. Most of the filtering caps belong to good Japanese lines, and the Hong Hua fan with a fluid dynamic bearing has proven reliable and, best of all, doesn't notably increase the production cost.


The first part of the transient filter is on the PCB that holds the AC receptacle, while the second is on the main PCB.


This part (MOV) provides protection against voltage surges. The platform also has an NTC thermistor, which is supported by a bypass relay to restrict inrush currents during the start-up phase.


Seasonic used two bridge rectifiers, which can handle up to 50 A combined.


This is the APFC converter. It uses quality parts, including Infineon FETs and Rubycon bulk caps rated at 105 °C and a lifetime of 2,000 hours. My only objection here is the low voltage rating of the bulk caps. 400 V is very close to the APFC converter's DC bus voltage (385–390 VDC).


The PFC controller, an NPC1654 IC covered in black tape to make it more resistant to EMI noise, is installed on a small daughter board.


The main FETs are arranged into a full-bridge topology. An LLC resonant converter is also used for higher efficiency.


The drivers for the main FETs are installed on the solder side of the main PCB.


The LLC resonant converter is a Champion CM6901T2 IC.


The heatsinks on the secondary side are used to cool down the FETs installed on the back of the main PCB. These handle the +12 V rail.


Two DC-DC converters generate the minor rails.


Both the electrolytic and polymer filtering caps are by Japanese manufacturers, and most belong to good lines.


The board shown in these photos hosts the supervisor IC, a Weltrend WT7527V.


The PWM controller of the 5VSB circuit is a LSP5523 IC.


There is a dedicated board for the -12 V rail.


The modular board uses bus bars to transfer power to the sockets without major energy losses.


Soldering quality is satisfactory, although this is not the best I have seen from Seasonic.


The Hong Hua fans offer good performance and reliability without breaking the bank, which is why most PSU manufacturers prefer them.