by: Danny Holdman
The Zapco Z100C2-SL is a physically small amplifier at 10"x 8"x 2.4". It is rated at 25 watts into each of two channels driven at 4 ohms. This translates to a 25x2 amp to all of you technically challenged folks out there. It also boasts power ratings of 50x2 @ 2 ohm stereo and 100x2 @ 1 ohm stereo. Mono ratings are 100x1 @ 4 ohms and 200x1 @ 2 ohms. THD + noise is <.015% @ 4 ohms and S/N ratio is >102 dB. For those interested, damping factor is >400, assuring good clean control of subwoofers at even 2 ohm mono. It uses Zapco's balanced Symbilink input and has a voltage input of up to 18V balanced/9V unbalanced. Items like crossover and bass boost controls are conspicuously absent, as this amp is designed for the true audiophile, who usually will use a high-quality outboard signal processor (of which Zapco offers several to choose from).
This amp installs much as any other with screw-type power and ground connectors, while speaker terminals are the same, all of them gold-plated and easily accessible on one side of the amp. Protection circuitry is built-in, as with any decent-quality amplifier. Mounting is handled by four screw holes, one on each corner. Its Class A/B design gives it a max current draw of 30 amps, which is the size of the standard blade fuse built into its chassis. External fusing is somewhat redundant, but nonetheless, I would recommend it. Overkill is my motto. As noted earlier, no RCA inputs exist, only the Zapco Symbilink plug. This problem is overcome by the 1-foot RCA-Symbilink adapter included with the amplifier.
This amplifier is rated at 25x2, but the actual test sheet (aka 'birth certificate') that arrived with it from the factory showed a flat even response up to 43 watts per channel, each channel driven into 4 ohms resistive. The sheet did not specify input voltage. No matter what, suffice it to say that this amp will perform adequately to drive decent set of efficient coaxials or components. I myself have used it to power both a set of 5.25" Pioneer components, and more recently a set of DEI 6.5" neodymium components (HF 3065s). The DEIs are rated at 100 watts RMS, and the little amp had a bit of trouble pushing them, but it did an admirable job trying. As I write, this amp is currently driving only the tweeters of the DEI set, as I moved to bi-amping when I purchased my Premier P1R headunit (see the review) which has 4V outputs. This amp will take all the power the P1R will dish out, and begs for more! hehehe. Seriously, this is one stout little amp for its mediocre power rating. It certainly justifies the price, but maybe not if you are wanting to run it @ 4 ohm stereo. It is more efficient @ 2 ohms, and possibly a little bit cleaner as well. The Competition Series amps are built to be driven into lower impedance loads, and if you do not plan on using them for that function, then perhaps you should consider Zapco's more affordable Studio or AG lines. However, for those wanting an all-out, SQ system, Zapco has been a very popular choice for many years for those with little or no budget constraints. Build quality is impeccable, and they tend to last forever, even under serious abuse. The spec sheet actually shows 130W RMS @ 4 ohm mono, so it is a good match for an efficient sub system, perhaps bandpass, or ported. It would also perform very well driving a set of rear-fill speakers or a set of tweeters as I use it for. Overall it is a VERY good performer, as long as you are not looking for kilowatt performance.
Manufacturer info:
http://www.zapco.com