I have an Ads L1290 and the rare PA-1. anyone know where I can fix one?
Powering the ADS L1590s and L1290s:
I have found that any number of power amplifiers can do a decent job driving these speakers, but the ADS speaker efficiency is relatively low and their power-handling capability is high, so I have been using QSC professional amplifiers of late to drive them. For the L1590 I use a QSC PLX-3602 Two-Tier Class-H amp (switching power supply), and the sound is effortless. This amplifier is capable of nearly 1000 watts/channel into the 1590s, so fusing is a must. For the L1290 I have been using a slightly different QSC design, a class AB GX3 design, about 300 watts/channel. The 3602 is a highly advanced, high-power design with very low noise and low distortion, but frankly it is very difficult to discern any differences between any quality amplifiers operating in their safe range driving into an impedance that does not cause problems.
The reasons for using pro amps are simple: these amplifiers are far more rugged and conservatively designed than their consumer equivalents, and they are reasonably priced due to the competitive nature of the pro-sound market. These amplifiers can operate into very low impedances and capacitive-reactive loads without any stress, and the distortion levels are usually in the 0.05% range across the band. Also, the consumer-audio business is dying with the lack of interest in quality "stereo" high-fidelity sound (iPods and Bose Docking Stations rule now), but the professional-audio market is still very strong. In fact, the QSC RMX 2450 is the best-selling amplifier in the world, and it is among the most reliable devices of its sort available with a failure rate of less than 1/2 of 1%. Crown, Crest and other professional manufacturers offer similar devices.
The end result is effortless sound quality from these speakers, and the knowledge that very little can cause problems for these amps. There is fan noise, but the newer pro amps have a low fan noise unless the amps are driven excessively hard.
Image: rack-mounted Crown and QSC amplifiers
an yes, the ADS speakers are inefficient. I was driving the pair with an old Rotel 1412 that actually could cut it for awhile, until overload conditions. But I'd love to get the bi-amplifiers working...