So why try a Fosi V3 when my studio has a full active Paradigm Reference 5.1 system and I also have a Denon receiver for project power? Well there were two reasons, the first being all the positive reviews from diverse users regarding a small factor class D amp and secondly, I am designing a 3d printed turntable and want a very compact system for demo days.
The amp has been put into service powering a dsp controlled open baffle speaker I created from drivers I had lying around the studio. The portable requirement and open baffle was a perfect fit and enter the Fosi! The speaker is an unholy match up of a Celestion 12" Seventy 80 16 ohm guitar speaker and a 1990s Radio Shack 4" 4 ohm coaxial car speaker mounted to a piece of 3/4" plywood. On first power up the whole thing almost ended up in the bin, but..once the dsp crossover and eq was applied, it came to life. Driving an open baffle with a 12" driver is no small task to keep the excursion controlled and tight but the wee amp is doing the job extremely well! It is also using the stock power supply and at normal listening levels, transients and details are excellent.
The combo of the open baffle and the Fosi produce sound, especially for acoustic pop and jazz, that is surreal! It is almost like the artist is in the room with you. This effect of open baffle dipole speakers is well documented but being able to do it with a cost effective amp the size of a paperback and some leftover speakers is in fact a game changer.
I normally work with large systems from Meyer and L Acoustics and such and using DSP is a given, but bringing this tech down to numbers individuals can afford is what we have here. The system will be tuned and a second speaker will be built (this test was in mono) as well as another Fosi V3 will be added to create my demo rig to show of the turntable.
I have to thank Jerry from Fosi for sending me this lovely little beast to test and I am truly happy to have seen something very different and useful!
BTW, the Fosi sounds much better than the old Denom AV receiver.
Pros
•Compact size
•Very smooth sound for a class D amp
•Adequate power from supplied power supply for conservative listening levels
•Handles large drivers in an open baffle speaker very nicely
•Price!
Cons
•binding posts very close together
•small power supply as standard
