When viewing specifications, one has to differentiate between products that are designed to provide accuracy versus those designed to color and enthral. The Firefly falls into the second category. Therefore the specifications that are normally used to qualify ‘accuracy’ have been omitted leaving those that are still relevant such as noise. One must also consider that tubes are inherently noisy compared with solid state devices, so even here, the specs may seem less than ideal. But tubes bring a sonic character that excites. With the Firefly… one must really listen to appreciate.