In addition, the TL-7.5 offers control over mute, fade, balance and absolute phase, with all functionality being duplicated on a handy and (thankfully) none too heavy IR remote control. The svelte casework is available in black or silver finish. The front panel power button (and its twin on the remote handset) switch the unit to stand-by mode, with the display showing a pair of flat bars. Hit the power and that switches to a 90-second start-up countdown, after which the 7.5 is ready to play.
Inside the chassis, you are going to be in for another surprise. The Power supply is entirely solid-state, while the audio chassis contains only a single pair of audio-specific 12AU7 tubes, nestled in a circuit that’s free of global feedback. Only two tubes? What’s doing the rest of the work? In fact, the output stage is built around FETs, which really makes this a hybrid rather than a pure-tube design. However, while the use of a solid-state output stage might cause tube die-hards to throw up their hands in horror, it does afford superior stability and a lower output impedance, making the TL-7.5 notably insensitive to the type or length of cables connected to it – not something too many tube pre-amps can claim. Meanwhile, the all important voltage gain that gives tube pre-amps their solid, dimensional quality and emphatic dynamics is all down to those audio specific 12AU7s. The highly regulated, solid-state power supply is both quiet and stable, underpinning one of the 7.5’s great sonic strengths – the sheer solidity and stability of its musical presentation. The very latest 7.5 PSU offers upgraded UI transformers (in place of the previous toroidals) and more precise adjustment of the output FETs, changes that VTL claims further reduces the noise floor and increases the soundstage width and depth. I haven’t done a straight comparison, but listening suggests they may well be right.
The S-400 II Reference Stereo Power Amp
Prior to the arrival of CH Precision, Mark Levinson amplifiers were arguably the most instantly recognisable electronics on the market. The iconic brand was much more than just a pretty face, setting the pace when it came to innovation and ergonomics as well as industrial design. Having conjured the ghost of audio-past once already, I’m about to do it again: the narrow footprint and vertical tower structure of the S-400 (and the Siegfrieds before it) channel the form first established by Levinson’s 33 and 33H. And that’s no bad thing. Just as the topology, versatility and usability of the TL-7.5 are reminiscent of the Levinson No. 32 pre-amp (at least to my mind), the S-400 shares the virtues of its stylistic precursors, with a narrow and easily accommodated footprint, an elegant profile and plenty of internal volume to fill with power supply. In the case of the VTLs, the enclosed top-deck also offers the perfect, protected space for the four driver and dozen output tubes, whilst maintaining the sleek (and electrical standards compliant) appearance. Those who want to see their tubes glow might be disappointed, but personally I’d rather listen to than look at them.
