From the Vault

For the past four years, I've been waiting impatiently for a stab at the electronics from Air Tight. I admit that the charm of the name, the absolute perfection of that moniker for a brand of valve amplifiers, caught my attention as much as did the obviously exquisite manufacture. The price, too, appealed, considering that these amplifiers promised peerless construction and attention to detail you just don't find this side west of a Jadis. At last there's a UK importer, so my wait is over.

By 1985 standards, preamps selling for between £500 and £1000 are thought of as 'upper mid-fi' and not really expected to match the standards of the Krell PAM-3/Audio Research SP-10 variety. But they should bring you close enough to the state-of-the-art that you have to think long and hard about justifying an expenditure of double their prices – or even more. Aah, diminishing returns...

Following last month's batch of integrated amplifiers costing under the £200 mark, more advanced models have been chosen for this project. The new Mission 778 (Mission Cambridge) represents the UK contribution (£240). The Harman Kardon PM650 combines Japanese and American design (£250), while the European contender is the Revox B251 (£900 plus £45 for the remote controller). All three models are integrated amps with MC and MM input facilities. I also look at another new UK model, the powerhouse P128 from Sugden, which is a dual 'monoblock' power amp (£395).

It is no exaggeration to state that the SL6 is one of the most interesting moving-coil speakers to come my way for a long time, and that it embodies significant advances in driver design. Many readers may find this surprising. After all, Celestion has traditionally been associated with the mass end of the market, its reputation justifiably built on product consistency and value-for-money rather than on innovation.

Carbon is one of the most common and versatile elements found on Earth. In its purest form it has the odd characteristic of being what chemists call allotropic. That is to say, it can appear in more than one distinct form of the same state.