(Reprinted from the Almanac 2000 Audio Ideas Guide)

      Now that preamplifiers are coming mostly with line-level inputs only, outboard phono stages are proliferating. It’s not a new concept to me, having owned the Bryston version for many years: I bought their professional BP-1 to use in my home broadcast production studio. I still use it for more casual listening, finding it superior to that inside my 11B preamp in terms of resolution and spatiality.

     There are good reasons to put phono stages, especially those intended for use with moving coil cartridges, in their own shielding enclosures. The primary one is to isolate the very low level phono signal from hum fields until it can be amplified and fed into the full preamplifier at a more robust line level.

     The AcousTech PH-1 handles all but the lowest output MCs, its maximum gain specified at 61.5 dB, with an MM setting of 42 dB, and proper resistive and capacitive matching for each cartridge type. As with the Rowland internal phono preamp, only the two settings are offered in each case, so more precise resistive matching to flatten upper octave frequency response is not possible. But then, today’s MCs are smoother in response than they used to be, anyway.

     As noted earlier, I compared the PH-1 to that in the Concentra, the latter being a consistent winner in both soundstaging and resolution. But the AcousTech was pretty close behind, offering perhaps a little more width and slightly less depth in its presentation. It suffered from the same limitations in noise performance, its noise floor not quite low enough for our Ortofon MC-3000.

     In all other respects, however, it was a remarkable product for its price, and very revealing of good phono sources. I found its sound a little softer and less revealing than the Concentra’s when played through that amplifier’s line inputs, but equally dynamic and solid in deep bass power.

     There are quite a few less expensive phono stages out there, but few of these have the gain or the outright sonic quality of the PH-1. The Bryston? Well, I would say that the BP-1 as I have it (that is, without the MC transformers) has slightly higher resolution, but lower gain than the AcousTech.

Andrew Marshall