Adding To An Already Good Thing
Fosi listened to their customers in a number of ways, including making the copper dial the default and keeping the Taper A pot behind it every bit as good as on previous models. The Fosi ZA3 will also remember the volume you last used before turning it off, so if someone happened to adjust the volume knob either inadvertently or purposefully, you won’t blow out your speakers the next time you power it up. Fosi did also move the power to that knob, you depress it for two seconds to power on or off instead of having a dedicated power toggle.
The technical specs are similar to the Fosi V3, up to and including dropping the treble and bass controls in favour of a more natural sound. The SINAD, SNR and THD remain essentially unchanged, which is to say they aren’t going the match an audiophile amp but for one costing just over $100 they remain very impressive.
The extra power contained in the ZA3 is dealt with by upgrading the cooling system first seen in the V3, adding vents to the side in addition to the heatspreader under the Texas Instruments TPA3255 amp chip. With a bit of work with a TR8 bit and some pliers, you can expose the chip as well as the Op-Amps. A bit of work with some tweezers and lining up the O1 on the board with the one on your new Op-Amp and you are ready for a new sound, or the old sound if you managed to kill one of your channels somehow.
