How much power is too much for a Quad 988?
The 988 does not seem to need a lot of power and the best amps to drive them seem to be tube amps, but the impedance of the speaker is rather low. Quad seems to be pursuing the same course that Martin-Logan has, that of trying to make the speaker work better with transistors. The problem is that the impedance curve of an ESL is not related to a box (so no box resonance) so the usual 'voltage source' rules that govern the behavior of most transistor amps do not apply. Because Quad reduced the impedance down of the speaker, the use of tubes with the speaker is an issue! You solve this by getting a set of ZEROs http://www.zeroimpedance.com and then you can use a 60-150 watt tube amp quite easily. Many ESL owners that use transistors tend to put the speaker too close to the rear wall, to deal with the fact that the transistor amp does not want to play bass on the speaker. By being close to the wall, you do get some bass reinforcement, but usually its a one-note bass. The speaker needs to be at least 5 feet from the rear wall to work right, and that is where an amplifier's difficulties in playing bass on the speaker is revealed. |
