Heed CanAmp

Open up the case (2mm Allen key required) and you will find very little to speak of.  A basic non torroidal double wound transformer providing 2 x 8.8 volts AC to drive each chanel. two pairs of wave rectifying diodes with smoothing capacitors.  An NE5532 OP-amp to boost the audio input voltage and a single output transistor per chanel operating in class-A mode (the case does get warm to the touch but never hot).  A couple of heat sinks and a few film and electrolytic capacitors plus resistors.  The circuit looks too simple with too few components to possibly be any good especially as the electrolytic capacitors are from cheap branded manufacturers and not of usually expected audiophile quality.  So with the case bolted back on how does it sound?  To be honest at first I was quite underwhelmed by the thing and began to experience regret at my purchase.  I decided that despite it being solid state it might need a period of break in at full running temperature.  I was not really expecting much improvement unlike the change you get with vaccum tubes over time but 2-full days later having left my CD player on repeat I gave it another try.  I should have perhaps mentioned that I am using Sennheiser HD650 headphones. What a difference.  The soundtage seems to stretch way beyond the headphones with an airy feel each instrument separated in its own space.  Imaging is well defined and the midrange and treble are at a level that makes listening for long periods very non-fatiguing.  A criticism I can make is that the bass is not the tightest I've heard and with very heavy overblown bass of the type Columbia entertainment enjoy under the SONY brand name it can even get out of control on occasion however it remains musical and rhythmical and is easily followed in the mix. the depth of the sound stage is as good as I've heard. The Op-amp can be swapped for other types to give a different sound balance if preferred such as the AD823AN (more pronounced high end) or LM4562NA (more forward sound with better bass control). Having said that the supplied chip sounded the best overall to my ears.  I am very happy with the Canamp having firstly tried the Graham Slee Solo (analytical), the Musical Fidelity X-CAN V3 (coloured) and the somewhat cheaper Creek OBH 21se (harsh).  The Canamp allows you to enjoy the music rather than listening to the headphones.  It would appear that we have a case of less is more where the circuit simplicity is concerned.  Less electronics to get in the way of the signal maybe. The alternative Op-amps may be worth a try as they cost very little on eBay and may suit your musical taste and headphone brand plus it can be fun to experiment.  Warning! earlier examples do not facilitate you to swap out the chips unless you are able to use a soldering iron and fit a dip 8 socket.   Enjoy.