One caveat about the choice of amplifiers: Though it may be tempting to consider the use of a low-power amp to drive the mid/tweeter…
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Loudspeaker-level drive might be more convenient for some, or even necessary for those with integrated amplifiers and no line outputs. I used the line connection, however, for all of my listening. (The output of my Rowland Consummate preamplifier has both normal and reverse-phase unbalanced outputs; I used its reverse-phase outputs to drive the OM-6 subwoofers, placing the latter's phase switch at 180° to make the overall connection positive phase.)
Sidebar 1: Specifications
Description: Three-way, floorstanding, sealed-box loudspeaker system with an integral powered woofer. Drive-units: two 1" (25mm) pure titanium hybrid tweeters, two 5.5" (140mm) mica-filled, injection-molded polypropylene-cone midranges with butyl surrounds, two 8" (200mm) long-throw, polypropylene-cone woofers. Woofer amplifier: 150W continuous, 600W peak. Crossover frequencies: 80Hz and 1.9kHz. Frequency range: 18Hz–22kHz (tolerance not specified). Sensitivity (in-room): 91dB. Impedance: 6 ohms nominal, 4 ohms minimum. Recommended amplifier power: 30–200Wpc (at…
Sidebar 2: Associated Equipment
The Mirage OM-6s were auditioned in a system consisting of the Mark Levinson No.37 CD transport and No.36S D/A converter, Rowland Consummate preamplifier, and either the Carver Lightstar Reference 2.0 or Kinergetics KBA-280 power amplifiers. Interconnecting was via TARA Labs RSC Reference from D/A to preamp, and Cardas Hexlink from preamp to power amp. A long length of TARA Labs RSC Master Generation 2 interconnect was used to drive the OM-6 subwoofers from the preamp. The digital link between the transport and the D/A converter was Kimber AGDL.…
Sidebar 3: Measurements
John Atkinson measured the Mirage OM-6 and provided me with the results after my listening tests were completed.
The Mirage's sensitivity measured 87dB/2.83V/m (B-weighted). The impedance of the unpowered midrange/tweeter module is shown in fig.1. The mid/tweeter section is tuned to 112Hz. The rise in the impedance magnitude below 80Hz is typical of a system with a series capacitor. The latter is undoubtedly designed to prevent overdriving the mid-tweeter module with low bass, as there is no other high-pass filter in the circuit (unless the user adds one,…
What comes to mind when you think of VTL? If you're like most of us, enormously powerful tube power amplifiers are inseparable from the name. To contemplate VTL is to think of some of the finest-sounding, most potent amps ever built—from the late-1980s, 400Wpc Ichiban, the first massively powerful tube monoblock of the audiophile era, to the mighty Wotan and Siegfried amplifiers of today. All well and good, as far as it goes.
But VTL also has a long history of building fine, if somewhat under-appreciated, line stages and preamplifiers, the excellent TL-5.5, reviewed for…
Microprocessors also control a myriad of background functions, including turning the tubes on in stages and warming them up gradually (you can watch the 90-second warmup countdown on the front-panel display), applying the high plate voltage only after the filaments are properly warmed. VTL asserts that this will dramatically lengthen tube life, which they estimate at 4000-5000 hours.
The software allows for an outstanding degree of flexibility and ease of use. Inputs can be set for single-ended or balanced operation (all inputs and outputs on the TL-7.5 are duplicated on excellent-…
The TL-7.5's treble was incredibly fast, smooth, and open, without any of the apparent (but not actual) speed that comes from goosing up the lower treble. Dynamics were a textbook exemplar of distinction from the top to the bottom of the audible spectrum, and the VTL's ability to resolve the precise differences in such things as a pianist's varying touch stands alone at the front of the field.
Big rock'n'roll was enrapturing through the TL-7.5. "Sultans of Swing," from Dire Straits' live album, Alchemy (LP, Warner Bros. 25085-1), slashed and swept across the room like a controlled…
Sidebar 1: Specifications
Description: Tubed, two-chassis, remote-control line preamplifier with MOSFET output stage. Tube complement: two 12AX7. Inputs: 4 pairs balanced/XLR or RCA single-ended, 4 pairs single-ended/RCA. Outputs: 2 pairs balanced out, 2 pairs single-ended RCA out, 2 pairs single-ended RCA buffered Tape Out. Remote-control functions: Power, Source Select, Volume up/down, Mute, Fade, Balance, Phase Reverse. Voltage Gain: 20dB to RCA outputs, 26dB to XLR outputs. Output impedance: 25 ohms (150 ohms maximum at 10Hz). Input impedance: 50k ohms (20k ohms minimum). Frequency…
Sidebar 2: Associated Equipment
Analog source: SOTA Cosmos Series III turntable, Graham 2.2 tonearm, Dynavector XV-1S cartridge.
Digital sources: Esoteric DV-50 universal player, Classé Omega SACD/CD player.
Preamplification: Manley Labs Steelhead, Aesthetix Io Signature, Rhea phono stages.
Power amplifiers: Lamm M2.1 & ML1.1, VTL MB-450 Signature, Classé CAM-350, Manley 250 Neo-Classic monoblocks; Plinius SA-102, Hovland Radia.
Loudspeakers: Calix Phoenix Grand Signature, Legacy Focus 20/20, EgglestonWorks Andra II.
Cables: Phono: Hovland Music Groove 2. Interconnect…
Sidebar 3: Measurements
The two-chassis TL-7.5 was a delight to test, both ergonomically and because it proved oblivious of every grounding scheme I tried between it and my test equipment. Someone has done their homework with respect to arranging the preamp circuit's grounding arrangement. Maximum voltage gain with balanced input to balanced output measured 25.25dB; unbalanced to unbalanced was 18.4dB, both figures slightly but inconsequentially lower than specified. Unity gain on the stepped volume control was "60" balanced, "69" unbalanced.
Unless the Phase button was pushed,…