Koolertron Upgraded 15MHz DDS Signal Generator Counter,High Precision Dual-Channel Arbitrary Waveform Function Generator Frequency Meter 200MSa/s (15MHz)

This is a great audio generator for the money. It's stable, has a clean output, tons of features and it's really easy to use. The screen is well lit, and it only takes a short time to learn the UI. I work on audio gear, and it's got everything that I need. The stability is good enough for my wow/flutter test, and the multifrequency waveform is perfect to troubleshoot filters. Everything works like it should. The only negative would be the thing is so light, you have to have a hand on top when you push a button or you'll push it off the shelf. Tie it down some way, or just learn to hold it while you use the buttons. I'm very happy with mine.

Good value for the money, not for every day use

I have only used this for about 2 hours so don't consider this a complete review. First the bad: The BNC jacks or cables are defective but mostly usable. Just breathing on where the cables connect to the machine creates horrible noise visible on an oscilloscope even when the channel is turned off. Some weights on the cables to keep them still is a kludgy fix. The cable is also very stiff compared to oscilloscope cables. Finding the sweet spot where the signal is clear and uninterrupted reminds me of the old days of doing reception ballet with old TV sets. I'm not yet 100% certain, but the voltage might randomly jump up and down slightly ( a few mV @ 1V) when going from one frequency to another. The 2nd channel has the same noise problem. The display for it is small and hard to see. But may be a good tradeoff so that the 1st channel is easier to see on the smallish screen. The good: The user interface is very intuitive. I didn't need the manual to figure out how to change frequency, amplitude, waveform, or do sweeps. It is actually the best I've seen on electronics test equipment. It boots up quickly. Just eyeballing it, but it seems reasonably accurate. They went to great pains to keep the price down. Other: It is very lightweight because the plastic case is mostly full of air. It is powered by low voltage from a wallwart(ugh), but that means it could easily be made battery powered and portable. There is plenty of room in the case to add a battery pack. Its brain appears to be made by Lattice Semiconductor, I can't see exactly which chip but I assume it is an FPGA. There is a place for a 6(?) pin header on the mainboard, and a 5(?) pin header on the front panel interior which may be handy for hacking it. There are also 4 very small, cellphone antenna like sockets on the mainboard, likely for testing, but which could possibly find other uses. Except for screwing up the cables (or sockets) manufacturing, I'd say this is a good value for price. It is probably good enough for hobbyists getting their electronics feet wet, high school students, and curious characters. Obviously it isn't intended for advanced hobbyists, scientists or electronics engineers, or those who just like the feel of high quality. Although I fall into one of the former categories, I wish I had spent 3x more for a something like a Rigol. I think I would feel differently if they had just gone the extra meter and spent a few more cents on the connectors and added rubber feet for grip so that I wouldn't feel like the magic smoke will puff out of it soon and to help me trust it a bit more as far as accuracy and that that horrendous noise won't damage delicate components.

I'm writing this fairly soon after receiving my generator since I feel others might benefit from a quick review. As most of us know there a long term review is also necessary, how does this device hold up under use and does the support continue. Pros I'm happy with the waveform out of it. Especially the flatness vs. frequency. The controls looked daunting online but they are actually very intuitive and I'm quite pleased with them. The controls have a good feel to them. It appears to have a nice 50 ohm output. Cons It's very light. I don't knock this as a quality issue but you need to know it's very light. In most setups you are going to need to lock it down in some fashion since even a moderately long bnc cable will drag it off the work bench. As has been mentioned elsewhere, the bnc connectors on the front are not a tight fit. To be honest I'm not a fan of bnc connectors you almost need a ratchet to get on but you do wonder how these connectors might hold up. The last thing I've noticed is that it doesn't appear to have much oomph on the output. So if you are looking to drive long cables you may need to build a line driver. In many applications this is needed anyway, either due to cable capacitance or other capacitive loads and this unit is not an exception to this. I don't count this as a fatal flaw but I mention it in case this is your need. But at this price point there are going to be trade offs and this is one I can live with. For me this is a nice frequency source to test simple breadboard circuits and it's light enough I could pop it in the backpack and take with me. I feel like the value outweighs the concerns at this point and would look at other products from this company.

Edited review: regarding the duty, I realized that there was specifically a pulse wave which is affected, and that the square wave is not. This was confusing since duty is selectable for all waves, but it does work. I also took this into the lab today and compared it to lab quality generators. I’m creating very low voltage, low frequency signals on this thing (10 Hz at 0.1V) and attenuating it down to about 200uV. This thing is a beast and does that no problem, even slightly better than some of the lab grade equipment we have. Do your own tests, but for my purposes this exceeds my expectations. I still have not tried creating software defined arbitrary waves, but if that works reliably I’d give this 6 stars if it was possible. Original Review: I’m using this for very low frequency, low voltage stuff (10Hz @ 0.1V) and it does a pretty good and reliable job. So far the only thing that doesn’t work is the duty. Adjusting it still results in a fully symmetrical wave. I also haven’t tried uploading arbitrary waveforms yet, but watched a YouTube video that tracked down the required software and it seemed a bit annoying to set up. So far it’s been a productive instrument, but unfortunate that I didn’t get a feature I paid for.