This is a review and detailed measurements of the WA11 Topaz Portable (battery operated) headphone amplifier and USB-C DAC. It is on kind loan from a member. The WA11 costs US $1,400. No, that is not a typo. It really costs well over a thousand dollars.The WA11 comes in a refreshing new form factor with nice Alcantera fabric covering on one side:There are separate USB-C connectors, one for charging and one for operating as a DAC/Amp.There is a 1/4 inch unbalanced connector and a pentaconn 4.4mm balanced connector.Despite its very large size and weight, the WA11 eats through its power charge quickly. I have never had to watch the battery on a unit while testing it but I had to here. It is rated to play for just 6 hours by the company. Inefficient class A amplification to blame for high power consumption that actually warms up the case.The volume control has a very nice feel but as you rotate it, your skin gets caught on the sharp corners of the semicircle around it.There is a loud pop on power up and short buzz before output is muted.I must say while I like the packaging, I am not sure what the target application is. This thing is way heavier and larger than a phone to lug around. And with short battery life, it is not much good on the go anyway.Let's start with the DAC portion by setting the output to 2 volts using unbalanced out:Sorry, forgot to zero out the FFT spectrum on top right. Overall, this is decent performance with a SINAD of 100 dB:Signal to noise ratio is OK at 2 volts but disappointing at 50 millivolts to simulate the noise you may get with a sensitive IEM/headphone:IMD versus level shows high level of noise but at max output, distortion is well controlled:Jitter test showed the same high noise floor and some unwanted spikes:Linearity test shows decent fidelity but not as good as a desktop amp/dac at 1/8 the price of WA11:Multitone test comprising of 32 tones to resemble "music" shows problematic distortion spikes at low frequencies:The normal trend is higher distortion at higher frequencies. Noise floor was also high again.The worse showing was in distortion+noise versus frequency with a wide bandwidth of 90 kHz:To figure out what is going on, I ran a spectrum analysis of a 30 Hz and 1 kHz tones:We can see that the harmonics of the 30 Hz tone (in blue) are clearly much higher than our 1 kHz tone harmonics (in red). So we do have a problem with low frequency reproduction (below 50 Hz).We also have a noise shaping rise in noise that is usually caused by low cost DACs. This is why the flat portion of THD+N versus frequency is also high.An ES9018 DAC IC is used here and implementation doesn't seem that great.While still feeding the unit digital data, here is the performance with 1/4 inch unbalance output:Both low and high gain have excessive noise as we have seen in other measurements. High gain though as a strange sudden peak in distortion which then settles down. Output power is short of desktop products at much lower cost so not a good showing overall.Measuring the balanced headphone out does produce good bit more power though:But sadly also magnifies the heck out of the distortion problems below 1 milliwatt. Combined with high noise floor, the WA11 is not something I would use with sensitive IEMs.Switching to 33 ohm load in unbalanced mode we get:Strange to see the rise in distortion in low gain mode (red). Why is that different than high gain mode in that regard? Max power in high gain mode is again not competitive with desktop products at much lower cost.Output impedance was comfortably low:Channel balance was poor:You get most of your gain and channel imbalance at the start of the range.I used my Sennheiser HD-650 in unbalanced mode with WA11. Sound was fine and fairly loud but short of skull shaking I like to see.I then tested the balanced mode using my inefficient and low impedance Ether CX headphones. There was plenty of power here to generate a nice experience yet again.So subjectively the WA11 is "fine."I am unclear as to the target market for this device. With rather short battery life, it is going to find life mostly on your desk. If so, there are much cheaper and better options there.At this price point, I get super grumpy if I see design issues and there are plenty of them. If $1,400 doesn't get you perfection as far as noise level, and distortion, I am not sure where the money has gone. The design needed to have been verified using the instrumentation I have and problems ironed out.The subjective experience was good so I am not going to give it the bottom score. But I can't recommend it either.------------As always, questions, comments, recommendations, etc. are welcome.The headless panther is asking me to take its head and get a haircut. I don't have the heart to tell him that his hair never grows so I am going to do that. Need some money for that so pleasewhat you can using