Siglent Technologies SPD3303X-E Triple Output Power Supply

There are some good reviews of the features and performance of this supply, so I will just mention that Siglent appears to now be shipping a new version of hardware (and firmware) with the SPD3303X-E. Presumably this corrects the issues reported in some recent reviews with DOA or short-lived units that reboot continuously. I just received a new unit and the calibration date is Dec. 2023. The unit shows it has V6.2 hardware and a firmware release that is not even available for download yet on Siglent's website (as of March 2024). So I am going to ASSUME based on this that the issues reported with the older versions has been fixed. So far the unit has operated flawlessly, and the two main (32V) outputs are accurate to better than the stated resolution. The third output is very limited and I don't really see myself using it, but if you need a logic source it should work for that. The UI is perhaps a little unusual but in my opinion, it's very simple to learn and operate. I've used the series-output function to power 48V devices and it works well for that (note that it is limited to 60V in series, not the 64V that you might expect). I have not had a use for the parallel (higher current) function yet. I appreciate the variable-speed fan. With the outputs off and the unit powered on, the fan does not operate. It starts to spool up at around 30-40W of output, but it's not until you get above 50% of rated power that the fan noise becomes what I would describe as noticeable. This is replacing an older single-output linear supply that had very noticeable fan noise even at idle output, so I can live with the fan on this one. I haven't done anything fancy with it yet like control it remotely or save/recall setups, and not sure I'll need to as I'm not an engineer, I'm a telecom technician. It's pretty heavy, but all good linear supplies are. The leads, while decent and tight-fitting in the sockets, are only 1M in length so you'll need to be closer to the supply to use them, or you can do what I did and buy some 5- or 6-foot test leads on Amazon (they're out there). So far I'm pleased with this unit.

Product: Siglent SPD3303X-E Programmable DC Power Supply Use: for work lab setup at my house (work from home) Purchased: July 2022 (2-3 months of usage at the time of this review) Background/Usage: I am an engineer with 30+ years of post graduate experience with a focus of 25+ years in the design and development of medical imaging equipment. This is the 3rd piece of Siglent equipment I own, along with the Siglent SDG6022X Arbitrary Waveform Generator and the Siglent SDS2204X Plus Digital Storage Oscilloscope (many additional options purchased). My overall impression is that I like this power supply. I have been exposed to and used many other manufacture equipment from many of the top brands. Since I purchased this using my "dime", I tend to balance form, function, quality, price and several other factors. Value: I could have spent a lot less and gotten a lot less features and quality. For me, quality was a heavier factor that you just are not going to get with those sub $100 supplies. Quality: The build quality is very good. A bit noisier than what I personally like, however, not as noisy as some very expensive and most cheap counter parts. With this being in a lab bench setup with several other pieces of equipment, noise is noise. Screen display is sufficient for what is needed, showing what one needs to see. Buttons and knobs are more than sufficient, decent quality. My one "ding" (CON) is the banana plugs feel a bit cheaper than everything else on this piece of equipment and are non-standard size for a BNC dual banana plug adapter. This is a big oversight on Siglent's part and a common point of complaint. I overlook this and can easily work around it. Features: For the value, this is feature rich. I know the specs say this is 3 output, and technically it is... however, only 2 are IMHO independently controlled, those being the 32 volt @ 3.2 amp outputs. The 3rd one is a selectable 2.5/3.3/5.0 volts @ 3.2 amp output. So yes, technically 3. I do like and use the 3.3 volt or 5.0 volt output for small prototype boards. Adding a 12.0 volt selection would have been a win IMHO... but so be it. The 2 independent programmable outputs can be put into series for up to a 60 volt @ 6.4 amp max output. Something I won't need but nice. I utilize the minimum resolution of 1 mV and 1 mA setting ability. Although many may not need this fine resolution, it is very necessary in my line of work dealing with very small signals. I am happy with this supply and would recommend it.

Really nice power supply, I got one in undergrad and me and my professors liked it enough we replaced the ones in the school lab with these. Great for most projects, one issue I experienced is that the reverse current protection is less then one would hope, if you connect a power source the wrong way you can easily fry it, would add an ideal diode if planning to work with batteries. Otherwise very stable supply for motor controllers, and accuracy well beyond what anyone needs. Dials are all really smooth and feels very professional.

Pros: The voltage and current capabilities are well thought out, the main V/A/W display is clear and easily understood, the serial and parallel capabilities are great, and the network interface is both well documented and comprehensive as compared to the front panel controls. The "lock" function is great. It can save up to five "scenes" in memory that let you keep common setups handy. These are all good reasons to buy something like this, so the pros here, while shorter than the cons section below, are really what to focus on if you need a good dual power supply. Dual? Yep. This is really a dual channel programmable power supply. That third channel... well, see the cons below. Cons: 1) A Windows OS-based computer is required to upgrade the firmware. Should have been a slot where you could pop a memory card in it to make it platform independent, and given the price of the unit, I can't see that they had any decent excuse not to do it. Many people don't run Windows, and for very good reasons. Furthermore, the device has a network interface, and could upgrade itself over the network if it was simply designed to do so. A $20 IOT lightbulb can do this. There's no legitimate excuse for a $400 lab instrument to lack the ability. 2) There's no control over display brightness. There should be. It's VERY bright. 3) The graphing is extremely minimal; you'd be better off utilizing the network interface and tracking the state of the supply yourself. This will allow you to gather statistics, catch rare events, etc. 4) There's no built-in event catching/triggering: you could leave a device on there, not be in the room when something happens, and come back to no hint of, and no details on, the event if it has scrolled off the (very minimal and short-time) graph display. There should be settable alarm / catch parameters to flag/record events. Again, given the price of the unit, there's no good excuse not to have this. 5) The third supply is handy as far as it goes, but it's not much better than a wall wart. There's no current tracking, current limit control, or display of any kind for the third channel other than an off/on/overload LED. 6) As other have mentioned, the images in this listing are misleading: the unit sold here, the SPD3303X-E, offers two decimal digits of precision, not three. I doubt very much that this will make any practical difference for the vast majority of users. --- So. I like the unit. A dual channel programmable power supply is an extremely useful tool to have on the bench if you're doing engineering or are a maker type of person. I'm okay with the price, but would have liked some more features. Some of what is missing I will create by utilizing the network interface, but not every hardware person is a programmer, so just because I can do it doesn't mean some other person can do it. So for me, it's really been a very good purchase. For someone else, the caveats implicit in the "cons" section above may be significant. If they aren't, then I definitely recommend the unit.

I have used mine for 2.5 years now, powered it up over 250 times, and it is still like brand new. Let's start with the most important feature: voltage accuracy. I have a couple of Siglent SDMs, and they show the precise calibration of the voltage settings to be less than 0.016 % from 1.0 V to 30.0 V !! , with little or no drift. The residual AC must be very low, (the minimum I can measure is 0.5mV with SDM bandwidth ~600KHz ). I have not tested it yet under maximum loads. The Ethernet and USB interfaces work as expected and I was able to easily create several Python programs to run it thru its paces under Linux. The Windows software did not work and reluctant to install the bloated NI-VISA. The 10mA precision ammeter is a tiny bit disappointing, and the 'non-E' version of this supply with a 1mA display is $150 more! If you need to monitor small loads precisely you'll need to add an SDM to the measurement loop. Two years ago, I did a firmware update to improve the network capabilities and was forced to get the Windows software working. I had a bit of trouble and the Support Engineers were extremely helpful. There are several app notes and videos available. The firmware seems very stable now. The delivery was great, very good packaging, and reliability is good too. ...very happy with it.

It isn't cheap but I am very pleased with this unit. Very intuitive interface and very easy to use. Power outputs can be connected together to get a negative voltage reference. (As in +32 to -32) Note that earlier reviews mentioned how the banana binder posts don't properly hold a standard banana plug and the connections are very loose - to the point of falling out. Siglent evidently fixed this issue - mine fit perfectly and the connections are tight. It would be nice to have the higher resolution unit (1/1000 instead of 1/100) but I could not justify the substantial cost increase for my needs as a hobbyist. I would buy this unit again. Update: I have had this unit for 9 months and no issues. However, if I was buying it again, I would spend the extra money to get the SPD3303X for the higher resolution. Oh, I have read other reviews on Siglent equipment that the unit was believed to be out of cal when received. I thought the same thing because it is not obvious when the calibration was performed at the factory unless you look closely on the correct side of the calibration sheet. The calibration is good for one year AFTER YOU turn the unit on for the first time.

I've been looking at linear supplies for a long time. For my budget it came down to GW Instek, this one and Rigol 8 series. Rigol had tighter specs, but the feature list appeared to focus on industrial applications (like rapid product testing). Instek had quite possibly the worst interface in history. So I settled on Siglent. I just finished testing it. My unit was calibrated in July. Siglent states that after calibration, the power supply can sit on the shelf for 180 days before first use and remain in spec for another year. I suspect that what gets these units out of spec is the low end capacitors on the main side. So here is my report. All voltages are within spec, or at least equally wrong as my Fluke MM and Rigol o-scope. Channel 1 was below set voltage by 200uV at all ranges (100uV tested resolution). Channel 2 was about 100uV high. Logic channel was off by over 100mV on all settings, but who cares about that one anyway. All three channels are within noise spec. I tested using Rigol 1202 on Hi-res with 20mHz noise rejection, deepest memory setting and coil ground attachment on the probe. The advertised noise is 1mV RMS. I picked up 1.7mV RMS, but I was also detecting almost 1mV RMS background noise, so I'll give Siglent the benefit of the doubt. Overall, what sold me on this was the interface. I think it is the best one in this class. If you desperately need to use this for a production line testing, there is a timer setting.

Fantastic power supply for the price. Convenient having a dedicated output that is the voltage of typical MCUs.