This is a review and detailed measurements of the Headroom Balanced Desktop Ultra Amplifier. It is on kind loan from a member. Better known as "BUDA," the unit came out in 2011 I think and cost US $1,189.The BUDA reminds me of getting my first headroom amplifier circa 1999 (bought a portable and then a desktop unit with the latter being a disappointment). It is a chunky unit with outboard power supply:You can use two headphones with 1/4 stereo jacks or one balanced headphone with dual male XLR connectors.The back panel is what you expect:The large, 40 watts external power supply gave me hope of lots of power into low impedance loads. Alas, measurements showed this hope was misplaced.I used the XLR Input for all of my testing.Here is our performance with 4 volts in using XLR, and 4 volts out using stereo 1/4 jack:A couple of years ago this would have been newsworthy level of distortion and noise. Alas, time has moved on and innovations have left the BUDA behind:Signal to noise ratio is very good at 4 volts output but disappointing at just 50 millivolts to simulate what you may experience with a sensitive headphone or IEM:Frequency response is flat enough in audible band but I expect to see flatness extend to 40 kHz for the sake of it but it did not:Power into 300 ohm load was very good, albeit with elevated noise and distortion relative to what you can buy today:The situation became quite sour when testing with 33 ohm load:This is embarrassingly bad. It is as if it is running out of current but as I explained, there is plenty available.I was hoping to measure the output using balanced connection but I could not find any cable that would work. It needs dual XLR mono streams which I did not have despite having 30 other variety of balanced connections.Output impedance is higher than I like in this class product:If used with high impedance headphones, the performance of Headroom BUDA is very good. With 50 ohm or loader, performance drops substantially so don't recommend it for that application. Unless you can find one really cheap, or need its functionality or looks, then I suggest looking at a bunch of high performance headphone amplifiers I have reviewed which outperform it from $99 to $400.So, if you have it, keep it. Otherwise don't go searching for it.------------As always, questions, comments, recommendations, etc. are welcome.To keep up with how much gear I have here to review, I thought of cloning myself. Looked into prices for sheep cloning and it is actually reasonable. But for a human, likely they charge 10X given the high cost of liability insurance. It would still be worth it to have one of me review speakers and another, the electronics. If you agree, pleaseusing