Infinity Kappa Four Channel Amplifier
Product Details
Manufacturer: Infinity
Distributor: Car Audio & Security
Website: link
Typical Selling price: £349.99 (CAS Price £269.00)
A four channel amplifier with 4×125 watts of RMS power, verified by the USA CEA amplifier ratings system. This was brought in back in 2006 so that reputable manufacturers’ power claims could be believed. Some makers of cheap and nasty stuff, like the much-derided Koac, (link) put silly claims on their products. In the KOAC’s case, that it was an amplifier at all But this simply-named item is the latest Kappa series amplifier from Infinity.
It is tremendously compact due to its use of the better quality Class D amplification around nowadays (Infinity’s own tech is involved here and is to do with even more efficient FETs) and is only one and three quarter inches thick. (with no apology to metrication) Although, it has to be said, Infinity were one of the very first to offer Class D full-range car amplifiers, even if they did hiss like a bag of snakes if badly set up! So they have the experience
However, this is a much more sophisticated device than that first generation and brags of differential noise rejecting circuitry for both the signal and speaker level inputs. It has crossovers and a bass boost but does not feature the Infinity DBO or Dynamic Bass Optimisation circuit found on its bigger and littler brothers, which is a shame as that is damn clever. Let’s go see how well it did
– Class D with proprietary DirectFET® transistors
– 4 x 125w RMS @ 4 Ohms
– 4 x 150w RMS @ 2 Ohms
– 2 x 3000w RMS @ 4 Ohms bridged
– CEA 2006A Compliant
– Finned Aluminium heatsink with dark finished top and shiny trim panel bearing crossover controls
– 8Ga. Power Terminals with cross headed grub screw bare wire socket connection
– Also includes a larger 4 Gauge wire adaptor piece for use with longer cable runs
– 12dB per Octave high/low pass crossovers
– 0 to +12dB Bass Boost @ 50Hz
– Adjustable input sensitivity 200mV to 6V
– Illuminated with blue LEDs
– Four, three and two channel operation
– Frequency response 10Hz to 75kHz
– Signal to Noise Ratio 106dBA
– High/Low Pass Filters 32Hz to 320Hz
– Fuse Rating 40A x2
– HxWxD(mm) 45 x 330 x 180mm
Editor Review : Infinity Kappa Four 4ch Power Amplifier
Regular readers will know I have been using this beastie for a few reviews of speakers from Alpine and from Pioneer and the no bull-poo right now honesty is that this is because it is a damn fine clean slice of watts.
There was none of the Class D harshness and the efficiency was huge with great output for the current suck, as I use an Odyssey battery and run a volt meter across the wires when running the systems on the rig. The sound is sweet and can really drive pretty damn hard, especially for the small size of the heatsink. Like the Alpine Power Density series here: link and the Massive Audio Nanoblock here: link they are incredible for the space taken up and also really dynamic, snappy and revealing of detail and nuance in the music if the speakers can muster the performance.
I liked the crossovers, although the switchgear is no better than it used to be ten years ago in terms of feel and solidity as the effectiveness is excellent. (I really wish those three-position switches felt more positive and had a bigger travel) You can still do fine-tuned arrangements of channels and I was able to balance a lovely overall system with the Clarion APX1301E bass amp (here: link) and some Alpine speakers (or was it Pioneer’s as both sets of comps-and-ovals were bloody good at each price point?) and ended up simply listening to the system for pleasure instead of getting on with my work, which says all you need to know.
It’s a handsome thing and has a clean cover you take off after installation and then you’ll be dusting it with a nice lint free cloth for ever after as it is so pretty. Prettier than the Alps or the Nano, it has to be said and definitely in that Modern Class D scene where the pejorative of Class AB versus D is now meaningless.
It really won’t be many years when amps are made like this for all applications, home and car. Mind you, I also saw two class D monoblocks running the Pioneer-TAD £50,000 a pair stereo speakers being used for mastering at Air studios that time as well.. so pro too!
Good looking, great sound quality and powerful with it. In fact, just like the Top Gear TV programme guys recognising that a modern hot hatch will outperform a rally Escort from the Eighties, this amp can do 2x300w RMS bridged and that 2x300w rating, although at 4 Ohms was what the Hifonics Colossus was rated at.
And that was ‘˜Pure Sex on a 12V battery!’ all of which means that even in these tougher and more technically clever times, this lovely amplifier is able to score sufficient points to earn itself the Talk Audio Magazine Recommended status.
Overall 8.8
Sound Quality 9
Power Output 10
Features 8
Build Quality 9
Value For Money 8