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 32 ohms up to 600 ohms. 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.

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Nothing that exotic at the moment...... I have directly compared it to my WNA MKll / WNA MKlll / Graham Slee SOLO / MF X-CANS / MF X-CANS V2 / MF X-CANS V3 (all modded) and Corda HA-2 MKll. The three dimensionality of the HEED trounces all of them by quite some margin, it's close to the MF V3 in places and close to the SOLO in the excitement department.. in fact, I know this may sound a bit stupid and maybe Miguel will slap me and bring me back down to earth but..... take the best of the V3, the best of the SOLO, the best of the WNA MKlll and you've got the HEED. Jack of all trades and "master" of all trades in this case.

I'm not yet sure what kind of job it's doing with the Grado SR225s as I'm not a Grado maestro but it sure drives them better than either the Slee SOLO or MF X-CAN V3 IMO. The WNA MKlll makes them sound smoooooth but I think it's adding some colouration and presenting the music through rose tinted specs... the HEED / SR225 combo is a warts and all "natural" insight into the recording, maybe Miguel is in a better position to comment on its abilities with Grado 'phones as I'm not yet fully acquainted with their house sound. Alpar of HEED comments (with regard to the amps ability to drive loads from 8 to 600 omega)

"However this specification comes from us, let me qualify it a bit. The CanAmp can drive headphones with lowish impedance but for optimal performance one should actually consider headphones from 64 ohms upwards, the higher the better. In the process of its development, a pair of Sennheiser HD600 (600 ohms) served for reference which are highly regarded everywhere, especially in Germany, the CanAmp's only target country for quite some time."

To me it does a superb job of driving the Grados but, as I say, I'm no Grado expert and you'd need to ask a Grado head what he / she thinks. As for the Senn HD600, HD414, HD25 / 1, AKG K501 it does an absolutely incredible job taking control of the drivers and pummeling your ears with the most glorious sound and absolutely gargantuan presentation. You want to hear your HD600 in 3D? Look no further than the HEED. You want to be able to pick out every layer in your recording? The HEED. You want to tap your toes so much and have a big smile on your face? The HEED.