This is great. Works well. Regulates well, While a vernier would be nice as others have said, it adjusts well enough. I have used all three supplies in constant current as well as constant voltage. I have used them independently as well as bipolar. I did not bother with the switch. I just shorted one positive to one negative. I left them floating. I assume the ground is fine, I did not test it.

I've now had this power supply for about 5 weeks, using it almost daily, and in the main it has worked very well.It comes with 3 test leads with alligator clips in the box: 1 set up for powering a high-amperage load using both main outputs in parallel, and 2 single leads (one red, and one black). All of these seemed to be okay except for the black one, which had a cold solder-join at the alligator clip (fixed by re-flowing the solder). (I rarely use these leads anyway, having replaced them with a nice set of Pomona leads with Mini-grabbers, which suit my application better.)Pros:------------1. Price.2. Rugged construction.3. From the other reviews (and ones I have seen on YouTube) a good internal electrical design, although other reviews here with this product are much better at dissecting that part of the product, so take this comment "with a grain of salt". (This is me talking about what other people have said about this power supply.)4. Settings are made with potentiometers, so as long as you know no one has fiddled with the knobs since you shut it down, you can have a high confidence level that it will power up with the same settings it had when it was powered down. (I like this better than other power supplies with digital input with diaphragm buttons [I have not had good luck with diaphragm buttons in the past], because I like to keep my [expensive] circuit boards connected between sessions, where I might power off at night to continue where I left off the next day.)5. Voltage ramp-up is predictable with no overshoot that I saw on my oscilloscope during testing (observed in trigger mode so I could see repeated ramp-up patterns during testing).6. Outstanding customer service (from the supplier: Electronnix).7. For sensitive electronics, there seems to be little or no need to have fused power leads, since the current-limiting function appears to kick in extremely fast -- I speculate: faster than a fuse could blow. (Though for very expensive electronics, a fast-blow fuse in the leads might be good insurance, "just in case".)Cons:------------1. I will confirm that the leads are cheap: I suggest testing them before assuming they are good.2. On the unit I got, I originally found it exceedingly difficult to dial in an exact voltage for the right-side voltage output when it was in the range between about 9.5V and 13V (the range I use most frequently). The left-side output has no such problems, and has always been stable and voltage progressed smoothly throughout its range. I contacted the supplier (Electronnix) even though it was 7 days after the "free return period" and asked about this behavior of the right voltage knob. We agreed that it was likely to be a potentiometer problem, likely damaged in shipment. They agreed to send me a new part (service and tech support were excellent), and I agreed to install it, and if this fixed the problem, then we would save a lot of shipping costs. If not, the Electronnix tech support person (Jesus) said he would service it and fix the problem. Today (20-Jun-2016) the correct part arrived, I installed it, and now the right voltage adjustment is as predictable as the left one, and easy to dial in an exact voltage.3. Minor: There is no separate switch to turn on the output after the desired adjustments have been made. Voltage arrives at the output terminals as soon as the power switch is turned on, and it changes immediately as you make adjustments. To be super-safe, you can disconnect your equipment between sessions, and perhaps even return the voltage adjustment to 0 after each session, though this really isn't necessary that I have found: upon powering up, voltage returns to where it was set when it was shut down.4. Minor: to adjust the current limit, you have to raise the voltage a tiny bit above zero, then short the (+) and (-) terminals of the output being adjusted. Then you can adjust the "Current" knob to match what you want to be the limit. Then remove the shorting connection and continue as usual. (Some higher-end power supplies allow you to see and set the current limit without having to short the terminals.) I do consider this minor since this procedure also serves to test and prove that the current limit function is operating properly.Pro or Con, depending on your needs:-------------------------------------------------------1. The current-limiting function limits current by reducing voltage. While this function is very fast, if you need the power supply to immediately cease trying to power the circuit on an over-current situation, this may not be the perfect power supply for you. (This appears to be considered an additional "feature" of higher-end power supplies.) This may or may not be bad, however, depending on your application. I watched a gentleman on YouTube repeatedly demonstrate the safety of this feature with a power supply of a similar design (I'm convinced it is the same OEM). He did this by turning the voltage to the maximum with the current limit set to 0.5A, and then repeatedly connecting an LED across the output terminals, and in each case, voltage was very quickly clamped and the LED remained unharmed. (In fact, this very fast safety voltage clamping was the final point I needed to make my purchase decision in favor of this power supply, because the circuit boards I power are very expensive to replace!)Conclusion:-----------------I'm a bit of a perfectionist (no apologies), and after using this power supply for about 5 weeks now, I like it, and I would not hesitate to purchase another.Also, Kudos to the supplier Electronnix for providing me with outstanding customer service.

Short Summary for the TP3005D-3:This is a completely different product from the similar-looking Mastech / Dr. Meter HY3005F with much better internal construction, a nice big toroid transformer, and measured 6 - 8mVpp CV regulation (well within the 20mVpp specification) at 20Mhz bandwidth. Output goes up to 32V per channel, uses a generous amount of TO247 TIP3055 transistors with a well-designed active cooling system. The supply even puts out 29.6V, 5.2A with no problems! Negligible overshoot (if any) which basically disappears with any load. The things I want to be improved the most would be a selectable switch for 240V operation, and multi-turn potentiometers for voltage / current control. Overall, much better than I had expected and an excellent value compared to any other product for sub $200.Longer Review:In my previous lab, I had used a 3-channel power supply (0-30V 3A) and liked it very much. After moving to a different place, I was in the market for a new power supply. While I would really want a good quality Rigol or Agilent power supply, these supplies are very expensive and begin around $400, placing them firmly out of my budget.I looked at many other reasonable brands such as BK Precision and and Instek, but they were still too expensive. Then I came across the Mastech HY3005F-3, a 3-channel 5A power supply and it looked like exactly the product I was looking for. However, I realized from looking at the photographs and reading the reviews that the 'Mastech' product on Amazon was in fact replaced with a 'Dr. Meter' brand, and I really didn't like how cheap-looking the front panel of the Dr. Meter was. I also did some searching on the Mastech HY3005F on Youtube and found a teardown of the product, which really left me quite disappointed with the haphazard through-hole component placing and overall poor-quality looking construction.What really got my attention though was how much better and professional looking the front panel looked, and how the heat-sinks were inside the case with active cooling. This made me think that more thought had gone into the construction of the power supply, and that it would also be easier to transport since there were no sharp heat-sink fins protruding from the back unlike the Mastech or Dr. Meter ones. So I ordered one.It arrived well packaged and looked much nicer than the photos. The LCD backlight was even and very nice, and looks like the high quality electro-luminescent backlight and not a cheap LED. I was a bit disappointed that it did not have a switch for 220V/240V operation, but this is probably due to the transformer they use inside. The voltage and current knobs are also unfortunately one turn knobs, but this is on-par with the price point.I tested the supply for its load capabilities. The supply goes up all the way to 32V per channel with a 120V line. Based on the load resistors I have, I found that the supply was able to supply 29.6V at 5.2A with no problems - this is far more power than most people would realistically need! I was also surprised that it was able to do that but I haven't been able to test full load on both channels yet. Voltage and current readouts were basically spot on to the least significant digit, and the 5V rail was within 1% depending on load - all within specifications.Next, shoot-through and regulation. I tested a variety of resistive loads from 0 up to about 2A. Voltage regulation at CV was around 6 to 8mVpp at 20Mhz bandwidth, which is well within the 20mVpp specification. Switching spikes during turn-on with no load varies around 2 to 8V, but this significantly drops with any sort of load. I found shoot-through to be basically non-existent, with at most a 1V shoot-through with no load. This drops to nothing with a load. Voltage rises usually linearly with a single step. Overall, exactly as expected with generally good performance.Construction wise, it is a very nice powder-coated steel which extends all the way in the inside! The main transformer looks like a single 300W toroid transformer (excellent) made in 2014. Internal construction is significantly nicer than what I had expected after looking at the Mastech teardown, so thumbs up to Tekpower (I was expecting poorly soldered single-sided paper-board through-hole components)! Power connections are nicely crimped and insulated with proper boots and ring connections all come with locking washers. There are 3 main boards - the logic and control panel board (this is a very nice PCB with all SMD components and a smattering of TI op-amps including the nice OP07C and LM324 and significantly nicer construction than the Mastech / Dr. Meter).What impressed me was the construction and design of the linear power stage with a nice integrated heat-sink/fan assembly, but very compact. It looks like a total of 9 TO-247 TIP3055 transistors are used, 4 for each channel and one for the 5V rail. I didn't take apart the double sided logic/control board, but a daughter board mounted beside the transformer looks like the power circuit (with a LM723CM voltage regulator) for the 5V rail. Overall, great internal construction and exceeded my expectations for such a power supply at this price point. Is this a true lab-grade precision bench supply? Definitely not! And if you want one, you'd be better of getting a good quality Rigol or Agilent. But is it a good value power supply for the everyday hobbyist? Yes!To conclude, the power supply looks and performs the part for now and I am happy to have taken the bet to specifically get a Tekpower instead of a Mastech or Dr. Meter (the Amazon page for the Mastech has a wrong picture!). Thumbs up for the TP3005D-3, and make sure that the one you are getting is the Tekpower, not another brand. I will continually update this as I go along testing the supply.>> See my website [...] for a more detailed review.