New to Parasound’s “Z” half rack space lineup is the Zamp Quattro, a compact four channel amplifier which claims to deliver 50W RMS x 4 into an 8 ohm load and 90W RMS x2 into a 4 ohm load. With a suggested retail price of $650, Parasound appears to cram a lot of amp into a chassis that is 9.5" wide (with the rack mount faceplate), 10" deep, and 1.75" tall (sans feet). Inquiring Audioholics want to know: what secrets lay beneath the surface? Can this pint sized amplifier really deliver on its claims? Read on to see my thoughts.
Executive Summary
Overall the Parasound Z-line is pretty neat; the standard Zamp, now on version three, manages to pack two channels of amplification, each capable of delivering 45W RMS (8 ohms, both channels driven), in a chassis whose footprint is comparable to a letter size piece of paper. Now Parasound is upping the ante by offering 4 channels of amplification rated at 50W RMS (8 ohms, all channels driven) in the same sized box. So how does Parasound manage to pull off this feat? For starters, unlike the original Zamp which was at its heart still a conventional Class AB amplifier, the new Zamp Quattro is a class D design boasting a switching power supply. There are of course some exterior changes necessitated by the jump to four channels as well, most notably a switch from standard 5 way binding posts to little green terminal blocks which can accommodate up to 12AWG wire.
So what do the numbers tell us about the performance of the Zamp Quattro? Has Parasound pulled off a minor miracle? Not exactly... The rated output of 50W per channel x4 into an 8 ohm load and 90W per channel x2 into a 4 ohm load (20Hz-20kHz) is quite impressive given the size of the chassis it's shoehorned into; however, it must be noted that Parasound is a considerably more lax regarding allowable THD at full rated power on the Zamp Quattro (<1%) than the Zamp v3 (<0.07%). If rated to the same <0.07% THD standard, it wouldn't be totally surprising to see those output numbers get cut in half.
Above and beyond raw performance and size, the Zamp Quattro does have a few features worth discussing. As previously mentioned, the Quattro skips binding posts in favor of green terminal blocks that can accommodate up to 12AWG wire; given the tight quarters, users would be well advised to be extra careful in connecting wire to prevent any shorts. In terms of voltage gain, the Parasound is an adjustable gain device with a maximum gain of 29dB (the THX standard). Gain is adjustable on a per channel basis, which may come in handy in multi-zone installations, which is likely to be the Zamp Quattro’s bread and butter. Finally, the Zamp Quattro also offers speaker level inputs in addition to the more typical unbalanced line level inputs to allow compatibility with receivers lacking preamp outputs.
Summary
Parasound appears to pack quite a lot into a miniscule package with the Zamp Quattro; you get four channels of class D amplification, adjustable gain on a per channel basis, and even speaker level inputs in an amplifier with a footprint under 10”x10”. Output is rated a bit more liberally than is usual for Parasound, and one shouldn't expect this half pint to fill in where full sized amplification is needed. Still, if you need to power a quartet of speakers to moderate levels, and you don't have the space for full sized amplification, the Zamp Quattro is worth a look (and maybe even two or three).
So what do you guys think? Anybody own or want to own one?
Any interest in a full review?
Quick Specs
Power Output: 50 watts RMS x 4, (20 Hz - 20 kHz, 8O), 90 watts RMS x 4, (20 Hz - 20 kHz, 4O)
Frequency Response: 10 Hz - 60 kHz, +0/-3 dB
Total Harmonic Distortion: < .05 % at typical listening levels; < 1 % at full power
Interchannel Crosstalk: 70 dB at 20 kHz
Input Sensitivity: 700mv = Full output (50 Watts @ 8 O)
Total Gain = 29 dB (Level controls set to Maximum)
S/N Ratio: > 112 dB, input shorted, IHF A-weighted
Dimensions: W (Black): 9.5" (241 mm) - Rack Mount Face Plate; W (Silver): 8.5" (220 mm) - Non-Rack mount Face Plate; Depth: 10" (254 mm); Height, with feet: 2" (51 mm); Height, without feet: 1.75" (45 mm)
Weight: Net: 4.5 lbs. (2.0kg); Shipping: 7.5 lbs. (3.4kg)
