Heed CanAmp MKII - Headphone Amplifier
Many audiophiles use headphones to enjoy their system. While some people are compelled to do so by their living circumstances, others simply prefer cans to loudspeakers. However, some amplifiers either have no headphone output, just as they don't have phone stages, or if they do have one, it is often just a simple IC-based stage. Regrettably, even many outboard amplifiers resort to this simple - and cheap - solution, making it impossible for headphones to perform at their best. Let us introduce the CanAmp, offering a no-compromise solution at a realistic price - in fact, given its technology and manufacturing quality we might even say at a "discount" price.
Headphones can be considered as high quality loudspeakers, but with a much lower power requirement. For this reason, they have distortion levels an order of magnitude lower than conventional speakers, and therefore are capable of showing up amplifier deficiencies more clearly. What's more, headphones are one-way systems, with very few exceptions, and for this reason crossovers do not interfere with sound quality. Consequently, a headphone amplifier must offer the best possible sound quality, even at very low volume levels, whilst working not unlike a real power amplifier.
The CanAmp is a two-stage amplifier. While the first - voltage gain - stage is based on an integrated circuit of the highest audio pedigree, the second - power gain - stage is a single-ended, pure Class-A amplifier. It enables the CanAmp to drive virtually any headphones from 8 ohms up to 600 ohms. As its output power (at 8 ohm) is nearly 1W, the CanAmp could drive even a high-sensitivity loudspeaker!
The unit has no internal wiring, and the signal path is kept to a minimum on its PCB.
Its high-quality, 1 dB-tolerance Blue Alps volume pot goes through a further selection process during manufacturing to achieve an even tighter, 0.5 dB tolerance.
The CanAmp not only has a line-level input but offers a line-level output to boot; it can therefore be connected to the TAPE MONITOR output of an amplifier, leaving the TAPE output free for additional components (MP3, MiniDisc, CDR, etc.). Gold-plated RCA terminals are used, and soldered directly onto the fibreglass PCB.
Measured performance is excellent, the bandwidth going far beyond the audio range in both bass and treble, with low distortion into any normal headphone impedance and plentiful output.
Output level isn’t everything and the Heed will in any case drive even harder, but this amp impressed not least on account of its large audio scale. Indeed, even with quite modest volume-control settings the soun just seemed big and generous, tonally, dynamically and even spatially. Once again, there’s a lot of detail, but the dominant impression is of size.
Funnily enough, this was perhaps more pronounced with some unaccompanied solo vocals than with orchestra or mega-rock, but that just serves to remind one that the human voice can indeed be a very big instrument. Perhaps if you like your music a bit on the polite side this may seem a touch excessive, but we freely confess that we just loved it. Tonality is great too.
Input Sensitivity/Impedance: 200 mV/10 kOhm
Power Output: 900 mW @ 8 Ohm
Signal-to-Noise Ratio: 95dB
Distortion: <0,5% (900 mW/1 kHz)
Frequency Range: 10 Hz - 50 kHz (+/- 0,5dB)