VTL TL-7.5 Reference
Review By Wayne Donnelly
here to e-mail reviewer.
On first seeing the
production VTL TL-7.5, I remember thinking that this impressively weighty,
extremely full-featured, handsome two-chassis preamplifier would be a
good choice to illustrate the phrase “statement product” in that big
high-end audio glossary in the sky. Although far from the costliest preamplifier
available, the $12,500 7.5 is clearly an ambitiously
conceived big-ticket component, and it looks every inch the part.
I had encountered various iterations of the 7.5 over the
five years it was in development. Luke Manley and Beatrice Lam (Mr. &
Mrs. VTL) commute most weekends from the Southern California VTL factory
to their Bay Area home, a 15-minute drive from me. Luke stops by
occasionally when my VTL amplifiers need some TLC. At the beginning of the
7.5 project Luke told me that one of his goals was to beat my longtime
reference Thor TA-1000 line stage, which he found quite impressive.
Thereafter, he would occasionally bring over his working prototype 7.5 to
compare to the Thor. Early on, the 7.5 didn’t quite measure up, although
the prototype sounded better each time. But at the last such visit,
shortly before the 7.5 was formally unveiled at the 2002 CES show, the
tide was turning in favor of the VTL. I’ll comment below on the recent
comparison between the two.
My first impression of the 7.5 was formed while watching the UPS
driver start to hoist the two shipping cartons at once, then quickly set
them down and bring out his two-wheeler. After unpacking the two
cartons I was even more impressed. These things are heavy —
about 70 lbs altogether. I have wrangled 200+ watt amplifiers that
were less substantial than either the power supply/control or audio
circuit chassis of the 7.5!
But weight is only the beginning. The industrial design of this preamplifier
is elegant. The subtly sculpted fascia of the audio
unit displays only the VTL logo and a small power LED.
The control unit is a fine example of aesthetic simplicity concealing
functional complexity: a single row of discreetly labeled input
pushbuttons, each with an LED indicator; on the far right a black display
window containing the numeric volume level/channel balance indicator, a
flush-mounted manual volume control with a finger indent (way cool!), and three
red LEDs to indicate activation of the phase reversal, channel balance and
The rear panel of the control unit has only three connections: one for the
large center umbilical that carries pure DC current, and SCSI connectors
for each channel, which transfer control commands that activate the
switching relays in the audio chassis.
The rear panel of the audio chassis is initially daunting — in addition
to the power and control interface connectors, there are (starting from
the bottom) a row of XLR connectors and then a row of RCA jacks for six
inputs and two main outputs. Above them is another row of RCA jacks
for the tape monitor and processor circuits. So logical and well
marked is the mirror-image layout that one quickly grasps it, and after a
short time I found that I could easily connect and disconnect other
components simply by counting over to the proper jack — a real benefit
as there is no room to go behind my equipment rack, and the massive audio
chassis is not easy to move around on the shelf.
It is worth noting that the XLR and RCA inputs may be simultaneously
connected to different sources. To switch from one to the other one
need only press and hold briefly the corresponding front-panel button; the
LED will switch from green (RCA) to blue (XLR) or vice versa. These
inputs are so well buffered that I was never able to hear any leak-through
when so configuring them.
Technical Design Highlights
As its name suggests, VTL (Vacuum Tube Logic) has heretofore been
devoted exclusively to glowing glass. VTL products have proudly carried
the “Pure Tube” badge. But this, VTL’s flagship preamplifier,
is a hybrid design with tube input and solid-state output. When I
asked Luke Manley about this, his answer was that performance was more
important than ideology, and that the hybrid design was necessary in order
to achieve all of the design goals of the TL-7.5. It works for me
— the proof is in the listening.
The TL 7.5 is as thoroughly conceived and meticulously engineered and
built as any audio component I have seen and heard. The following
highlights taken from the VTL Web site are far from comprehensive, but
will give the reader some idea of the depth of Luke Manley’s vision for
his ultimate line preamplifier. I have added comments on the relevance to
audiophiles of these features.
Tube complement: two 12AX7 tubes. The 7.5 is purposely
voiced with moderately priced and widely available input tubes—in this
case Svetlanas. I suspect that tube rolling is likely to prove
superfluous, and might well throw off the preamplifier’s flawless tonal
Fully differential circuit, balanced inputs and outputs;
mirror-image layout. This brilliantly executed differential
architecture does sound better in balanced mode than in
single-ended—especially after I upgraded my VTL MB-750 Reference
monoblocks with the “Super Balanced” input stage VTL developed for the
new $40,000/pair, 800-watt Siegfried Reference amplifiers. For this
writer, the mirror-imaged rear panel layout facilitates connection and
disconnection by feel, compensating somewhat for my impaired vision.
Isolated Control Unit chassis with 12 separate fully regulated
power supplies. This and numerous other no-compromise design decisions
account in large part for the hefty price of the TL-7.5.
Separate Audio Unit chassis with zero internal digital activity.
This rigorous “clean box/dirty box” architecture strikes this writer
as so intuitively desirable that I wonder why it is not widely used in
flagship reference-level components.
Low-noise processor control design for all functions. See
Simple circuit topology with low negative feedback for musical
purity. Also characteristic of VTL amplifier designs. In my view, a
significant factor in the company’s characteristically open, airy upper
Logical sequenced soft-start power-up for extended tube life.
The 7.5’s 90-second stabilization interval also allows ample time for
most any tube amplifier to stabilize, avoiding nasty power-up noises. I
also appreciate that the preamplifier volume level is always at zero when
the 7.5 becomes operational. No rude surprises from last night’s party!
Ultra-low-impedance output stage to drive any length of cable
and any power amplifier. This highly desirable robust output
capability is also characteristic of the lower-priced VTL preamplifiers.
Shock-mounted gain stage. This and the next point exemplify
the premium placed on optimum audio performance, and of Luke Manley’s
refusal to cut corners with his Reference preamplifier.
Modular volume control and output stages.
notably better comes along, the architecture can accommodate it.
95-step 70dB discrete relay attenuator for all attenuation
functions. This control allows for very precise incremental
adjustments. One idiosyncrasy is the faint ttcking heard as the relays
operate during volume changes. Since I can’t read the numeric volume
display from my listening seat, the ticks give me a sense of how far up or
down I have gone.
Processor loop – any of 8 inputs can be assigned as fixed
unity gain pass-through. The 7.5 provides for exceptional
configuration flexibility, especially useful for complex home theater or
Four separately programmable trigger outputs. I have not
used this feature, but again it could be very convenient in a
multi-component home theater system.
Programmable input offsets.
In a system with multiple
sources, this feature allows the user to match precisely the playback
levels of all the components, so that the volume level remains consistent
when switching from one source to another. This capability offers a nice
civilizing touch, and it is a godsend to a reviewer comparing, for
example, CD players or DACs, SACD vs. Red Book CD, or vinyl vs. digital
software of a specific recording.
Rear IR receiver for all functions.
In my setup, remote
functionality is consistently easy, with the IR receiver having an
effectively broad angle of acceptance.
Rigid combination steel and non-magnetic chassis and machined
aluminum remote wand. I have not seen better fit ‘n finish than that
of the 7.5 and its ergonomically superb remote wand.
Review Setup, Ergonomics
This review is based primarily on putting the 7.5 into the reference
system described elsewhere on Enjoy the Music.com™ in place of my long-term
reference Thor TA-1000. A number of source components and other
amplifiers, either already reviewed or scheduled for future review, were
also auditioned with the 7.5. A variety of music from medieval to
the blues, on CD, SACD and vinyl, were brought to life by this marvelous preamplifier.
Although programming some of the configuration options may be slightly
complicated--judging from the lengthy but well organized and clearly
written 7.5 owner’s manual — the user interface for the music listener
is delightfully simple. After starting a CD or LP, everything a listener
needs is right there on the remote control: volume, balance, phase (or
polarity, if you will), mute and even a fade control that lets you drop
playback volume to, for instance, answer the phone, and then restore it
precisely to the original level. The layout of the remote wand is
simple, and easy to use even in the dark. The wand’s rounded
bottom edge fits pleasingly in the hand, and it feels sufficiently solid
and weighty to do double duty as a bludgeon should hand-to-hand combat
If you are sensitive to correct electrical phase, you know that there is
very little phase consistency among recorded sources. That being the case,
the ability to switch between 0 and 180 degrees from the listening
position is especially valuable. When playing CDs, phase differences are
more apparent in the digital domain, so I leave the manual phase flip
button on the Dodson DA-218 DAC set on reverse. That way I can
switch back and forth remotely and easily hear which setting sounds
better. And since I listen to lots of vinyl, having the phase flip on the preamplifier
remote allows me to also find correct phase for the LPs. I
continue to be puzzled by the omission of this control by countless
high-end audio manufacturers. Bravo VTL!
Listening to the TL-7.5
I’m not going to start gushing about stunning sonic
revelations--scads of previously unheard inner detail, vastly improved
extension, dynamics, air, etc. etc. After all, it’s not as if I’ve
been listening to audio “ chopped liver” until now! The Thor TA-1000
has stood up against quite a few superb preamplifiers for seven years —
virtually an epoch in the fickle world of high-end audio
reviewers. Having been upgraded a few months ago to Mk. II status,
it sounds better than ever, and now features remote volume control. None
of the excellent (but admittedly less expensive) preamplifiers
scheduled for future review can match it.
But on the whole, a point here, a point there, the 7.5 emerged as the
winner. Where were the main differences?
Differentiation: the Thor is very slightly more forgiving of
lesser-quality recordings, which from the standpoint of pure
listening pleasure can be a good thing. The 7.5 more clearly delineates
shortcomings in all genres of software, although it never comes across as
“ruthlessly revealing”… just honest.
Quietness: the 7.5 is simply the quietest preamplifier I
have ever used. Especially when playing a great CD through the Dodson DAC
and the 7.5, the sonic background is a deeper and more profoundly black
than with any other combination I have heard, and that degree of quietness
does allow some previously unperceived spatial and musical detail to be
heard. Moreover, the 7.5 is, in my environment at least, impervious
to external annoyances such as EMF/RFI noise corruption.
The usual suspects:
after listening week after week through
the 7.5, it is clear that frequency extension at both ends of the
spectrum, macro and micro dynamics, openness and air, spatial resolution
and imaging precision are, easily and without exaggeration, simply right.
Every audiophile knows the old saw that the perfect preamplifier would be
“a straight wire with gain.“ But the more I listen to every kind of
music through the 7.5, the more it seems to me like “no wire with
gain.“ This extraordinary component imposes less sound of its own on
music than anything else I have heard.
A few years back I had the privilege of reviewing the CTC Blowtorch preamplifier, with circuit design by John Curl, superb board layouts by
Carl Thomas and meticulous parts selection and voicing by Bob Crump. (This
same team created the Parasound Halo JC 1 monoblock amplifier I named as
an award winner in the January
Enjoy the Music.com Review Magazine.)
The qualities that for me had set the Blowtorch apart from all other preamplifiers were very much like those I ascribe here to the 7.5.
Returning it--most reluctantly--to John Curl after the review was complete
was the only time I was (slightly) unhappy to reconnect my esteemed Thor.
Had I had the funds, I would have ordered a Blowtorch right then.
There is no Blowtorch/7.5 shootout in the offing. The Blowtorch is built
to order, so there aren’t many lying around, and their owners are
understandably not inclined to loan them to reviewers. So, given the
interval between listening to the two, I don’t know which is
“better.” But I do believe the 7.5 is at least on a similarly exalted
level, and I’ve never felt that way about any other preamplifier.
If this all comes across as an immoderate rave, I suppose I must plead
guilty. Try as I might, I just haven’t found anything to complain
about to counterbalance the 7.5’s cornucopia of sonic and ergonomic
virtues. Would I like a simpler version, with fewer inputs and features,
at a lower cost? Absolutely. Perhaps if we close our eyes and wish
very hard, that dream will come true someday. The 7.5 has far more
connectivity than I will ever use — but I am unable to perceive any
trade-off in musical quality that can be related to this unusually
flexible architecture or to the well-thought-out user interface
features that make it such a pleasure to use. My advice? Don’t buy any
high-priced preamplifier without carefully listening to the VTL TL-7.5.
it is now my new reference preamplifier.
Vacuum Tube Complement: a pair of 12AX7
Inputs: Four pairs balanced/XLR or RCA single-ended
Four pairs single-ended/RCA
Outputs: two pairs balanced out
two pairs single-ended RCA out
two pairs single-ended RCA buffered Tape Out
Remote Control Functions: Power, Source Select, Volume up/down,
Mute, Fade, Balance Control, Phase Reverse
Output Impedance: 25 Ohms (Max 150 ohms at 10Hz)
Input Impedance : 50K Ohms (20k ohms min)
Frequency Response: 20Hz to 100kHz
Maximum Output Voltage: 45 Volts
Channel Separation: > 100 dB @ 1KHz
Channel To Channel Cross-Talk: >100dB
Power Consumption: 150 Watts
Dimensions (W x D H): Control chassis
17.5 x 17.5 x 4 inches
17.5 x 17.5 x 6 inches
Weight: 75 lbs.
Warranty: 5 years parts and labor with return of owner registration card; tubes 6 months
Vacuum Tube Logic, Inc.
4774 Murietta Street, Suite 10
Chino, CA 91710
Tel: (909) 627-5944
Fax: (909) 627-6988