The main problem with this machine is that it uses a carousel-based laser engine. This means that the four toner units are held in a rotating carousel and moved into position to work with one imaging drum. A page image for each colour is overlaid on the drum before the four-colour image is transferred to the paper.
The problem comes in the time it takes to lay down four images, rather than one. The more modern inline design runs the paper past four drums in-line, so a full-colour page takes no longer than a black one.
Xerox claims a black print speed of 20ppm, but only claims 5ppm for a colour page. This ratio was confirmed by our tests, though the black print speeds we recorded were 11.1ppm for the 5-page document, rising to 16.9ppm for 20 pages, and 4.4ppm for colour. The same comparison runs true for copies, too. A 5-page black text copy took a very reasonable 42s, while a single colour page ran to 57s.
Despite the low print speeds, or perhaps because of them, the output quality from the machine is generally very good. Black text is sharp and clean, with no sign of toner spatter and colour graphics are intense with areas of solid fill dense and bright. Black text registration over colour is also good. Even our test photo print came out well, looking reasonably natural hand not suffering from quite the limited colour range of some budget laser engines.
Consumables for the Phaser 6121MFP/N don't come cheap and you need to replace the imaging drum after 20,000 pages – or 10,000 pages if you're printing exclusively colour – as well as the toner cartridges. The colour cartridges are available in 1,500-sheet yields as well as the 2,600 sheet yield, common to the black cartridge.
Page costs work out at 4.0p for a black page and 16.3p per colour, both of which are high. Compare it, for example, with the £300 Canon i-SENSYS MF8050Cn, which produced figures of 2.9p and 11.9p.
Xerox’s Phaser 6121MFP/N is a good laser multifunction printer, hampered by the fairly outmoded design of its laser engine. Even modestly priced printers and multifunctions are now using in-line, which print colour as quickly as black pages. Here, though, colour pages takes roughly four times as long as black ones.
The other problem is running costs. Unless you can find consumables considerably cheaper than we could, you're paying over the odds for both black and colour print. Which is a shame, as the print quality itself is above average and very suitable for the SOHO market at which it's aimed.