I am very happy with this purchase - other than I had to hot wire the plug to make it work since I did not receive a US power cable. Now I have to find a US power cable that will work with it. 4 stars, since I am very disappointed that I did not receive a US power cable, or an adaptor that will work for US.
The display is bright and great fun to watch. Brightness knob is a great option since the green LEDs are very bright. I ran a frequency sweep into the unit and the LEDs respond as they should for each frequency. A couple comments: I would change is to add a couple yellow LEDs below the top red LED, in each frequency set, this would improve the appearance greatly and would let you know the signal is close to the top LED value. Also, I would include a way to adjust the display decay speed. Oh yes, and an option to add a peak hold that displays for a short time.