Solid State Preamp Reviews

The Tape Output source selector on the remote has an ergonomic problem. Instead of having a button for each output source, you have to cycle through all of them to get to the one you want. For example, if you want Bal.1 and are set on Bal.2, you have to scroll through nine other source choices (one choice is "Tape Out Off") to get back to Bal.1. This is a major drag if you want to use one of your tape outputs as the signal feed to your surround-sound processor. Every time you change main input sources, you have to then cycle through the tape output choices to get that source into your surround processor. Also, cycling through all the choices almost guarantees you'll get a feedback howl from one of them—sort of a misanthropic sonic Russian Roulette game. If the Tape button on the remote had a toggle action—allowing the source selector buttons to become output selector buttons when the switch was in Tape Out mode—the process wouldn't be so lugubrious or potentially lethal.

The T2 has 18dB of maximum gain, so it should be able to drive all but the most insensitive amplifiers into clipping with all common sources. I found that most of the time, at moderately high listening levels (footnote 1), the front panel read no higher than –25dB. The T2's volume controls are designed such that the unit becomes an active preamp (amplifying the signal source) only when its front-panel display reads –18dB or less. In the four months I've used the T2, I've almost never needed to turn the volume up past –12dB with a music source—and then only with some of my own DAT tapes, never with a commercial source.

Sound
Despite the ergonomic quibbles I mentioned earlier, my time with the Threshold T2 was extremely pleasurable. It's the best-sounding full-featured remote-control preamplifier I've heard to date. The T2 is the kind of product that made me want to listen to music, often to the point that I found myself waylaid by my system when I was supposed to be attending to more pressing matters (like finishing writing reviews on time). The term "uncolored" frequently popped up in my listening notes. The T2 would be a great device for those who want to hear music without a particular sonic spin on it. While it would be impudent (and incorrect) for me to proclaim the T2 a "straight wire with gain" (footnote 2), when you compare the T2 directly in a controlled A/B test to a preamp such as the Audio Research LS5 Mk.II, even the most critical listener will be hard-pressed to fault its transparency.

The T2 is very quiet (S/N 118dB); only the Pass Aleph P is its peer in this regard. With my ear an inch from the Avalon Eclipse's tweeter, I heard only the slightest difference between the noise level with the mute engaged or disengaged. I needed to turn the volume level up to –18dB or higher before I was able to hear any appreciable white noise. At my listening position, I didn't hear any noise until I reached –13dB or less. For Silence Is Golden Types such as myself, the T2 is an answered prayer—a virtually silent preamp. While the Audio Research is almost as quiet at its 12dB gain setting, it's far noisier when set for 30dB of gain (footnote 3), where it may become intrusive in quiet listening environments. The T2 is perfect for anyone who has managed to achieve a quiet listening space and wants to keep it that way.

The T2 is "fast," by which I mean there's no apparent loss of transient speed or blurring of leading or trailing edges. The mixes on 3rd Matinee's Meanwhile (Reprise 45396-2) are spectacularly dense with electronic and acoustic percussion; through the Threshold, the music was never murky or time-smeared. Bass lines remained clean, with percussion instruments and bass guitars remaining distinct and well-differentiated. When I compared D/A processors, the transparency of the T2 allowed it to reveal which units smeared and homogenized complex musical passages.

The harmonic balance and timbral accuracy of the T2 were uncanny—especially on female voice. For example, on Shawn Colvin's and Mary Chapin Carpenter's "One Cool Remove," from Cover Girl (Columbia CK 57875), the T2 didn't bleach out Colvin's slightly reedy voice or darken Carpenter's rich country contralto. Emma Kirkby (my equivalent of DO's Lesley Test) sounded harmonically right through the T2, without losing any of her essential harmonic signature. Audiophiles seeking a preamp to use as a warming or cooling device for the overall harmonic balance of their system will be neither aided nor abetted by the T2. Its harmonic personality is decidedly neutral.

The T2's soundstage width, depending on the source, could be very wide indeed. Lateral focus was very precise and exceedingly stable. On a recent recording JGH and I made of a chamber-orchestra concert, I could easily discern that the audience and hall had far greater width than the orchestra. Identifying each instrument's location on this recording was child's play, due in part to the M/S microphone array we employed, and to the T2's fine ability to retrieve spatial information.

Depth rendition was also convincingly portrayed. The front of the soundstage began only very slightly behind the front plane of the speakers with the T2, but on good discs—such as Music and Memories (Erato 4509-91777-2), an anthology of Joel Cohen's work with the Boston Camerata—the back of the hall was well behind the speakers, with tons of space between the performers and the back wall. This recording is especially good for determining the abilities of a system to resolve low-level background information. On track 19, which was recorded in the Church of the Covenant in downtown Boston, you should be able to hear the traffic outside the church and actually follow the trucks across the very back of the soundstage (notice how they're wider than the hall itself). You should also notice that the sound of the traffic is distinctly set farther back than the hall reverberation. A good system shouldn't homogenize these two separate sonic fields. The T2 accomplished this with a natural ease that made listening to music involving and exciting.

Up against the LS5 Mk.II
The T2 handled frequency extremes well. Highs lacked any etched quality, while low-frequency information was clean and well-defined. Only when I compared the T2 directly to the Audio Research LS5 Mk.II could I hear a very slight amount of additional high-frequency grain through the former. Low frequencies were slightly tighter on the T2 compared to the LS5, but the LS5 did have slightly more bass authority and bloom. Compared to the LS5, the T2's midrange was ever so slightly leaner, with the LS5 having a hair more lower-midrange energy.

The question is, of course, whether the T2 is subtracting harmonic information or the LS5 is adding extra harmonics. After much listening and thought, I concluded that the T2 did subtract a smidgen of harmonic juice from the midrange and bass, and added a hair of grain to the upper frequencies. The LS5 also had a more three-dimensional soundstage presentation. Both instruments and soloists had a certain dimensional palpability with the LS5 that was missing through the T2. The front of the soundstage through the LS5 began several feet behind the front of the speakers instead of at the speaker grilles, as with the T2.

A final difference between the LS5 and the T2 was that I was better able to hear into dense musical passages with the Audio Research. This was surprising, since transparency is a strong suit of the T2. Remarkably, the LS5 consistently surpassed it in rendition of inner details. Bear in mind that the LS5 is a purist design, lacking even a channel-balance control or any sort of display. The LS5 does have a remote, but it sports only Volume Up, Volume Down, and Mute. In terms of ergonomic ease, comparing the T2 to the LS5 is like comparing a modern Lamborghini to a vintage Bugatti.

Up against the No.38
I had an opportunity to briefly use the Mark Levinson No.38 in my small-room system, but I didn't do any tightly controlled A/B tests against the Threshold T2. I don't think the No.38 is in the same sonic league as the T2—it was never able to move me emotionally. It sounded clean and quiet but dead, and lacked life, sparkle, and musical joie de vivre. The No.38 also seemed dynamically compressed, with little differentiation between ff and fff passages.

With the T2, musical contrasts were quite well-defined, with almost no sense of compression. Only the Audio Research LS5's dynamic presentation surpassed that of the T2. The Levinson No.38 was not a sonic contender, but its ergonomics were impeccable. A more interesting comparison would be to put the T2 up against the Mark Levinson No.38S, something JA does in his review of the Levinson elsewhere in this issue.

Conclusion
The Threshold T2 is an excellent preamplifier, combining ergonomic and visual elegance with surprisingly good performance. While it's not the best-sounding preamp I've ever heard, it's close enough to the best that, except in tightly controlled critical comparisons, I was hard-pressed to identify its sonic shortcomings.

The T2 allows the excitement and enchantment of music to pass through its circuits almost unscathed. The T2 joins a very short list of exceptional preamps that offer maximum convenience and flexibility with minimum sonic sacrifice.

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Footnote 1: I don't "blast" my music. Levels almost never exceed 98dB peaks, even with large orchestral recordings.

Footnote 2: Stewart Hegeman's description of the perfect preamplifier.

Footnote 3: According to Audio Research's Michael Harvey, the LS5 Mk.II's 30dB setting is sonically superior to its 12dB setting, since the former removes an 18dB pad from the circuit.