VTL 225W Deluxe monoblock power amplifier
By Robert Harley • Posted: May 31, 2011
The VTL 225W DeLuxe monoblocks are very similar to the 300W monoblocks that received such an enthusiastic reception from J. Gordon Holt a year or so ago (in Vol.11 No.10) and, ultimately, most of the audiophile community. Technically, they differ only in output tubes and transformer: the 225W uses EL34s, the 300W uses 6550s. The 225Ws, at $4200/pair, cost $700 less than their more powerful brothers. The question may be raised: Why have two models so close in price and performance? According to David Manley, the 225Ws were built on special order for audiophiles who preferred the sound of EL34s to the 300Ws' 6550s. Demand was so great for the EL34 version that he decided to add it to the line. They look almost identical, the only difference being the smaller output transformer on the 225W and an additional filter capacitor on the 300W's top chassis.
Appearance and construction are typical VTL: the "industrial" look of exposed transformers, reservoir capacitors, and tubes. Two strips of metal over the amplifier protect the tubes from physical hazards. One is tempted to use these as handles, but David Manley insists they are not designed to support the weight of the amplifier. I must differ with Sam Tellig's statement in Vol.12 No.11 (p.89) that, because of their appearance, he could not own VTLs no matter how good they sound. I find them elegant. They exude a pride in their tradition and history that gives them a certain appeal.
The 225W monoblock's circuitry is extremely simple, with very few active components in the signal path. The input and driver stage consist of a 12AT7 and 12BH7, both dual triodes. The output section is comprised of two quartets of EL34s driven in a push-pull configuration. Both the power-supply transformer and output-signal transformer are very large, comprising the majority of the 225W's substantial weight. These transformers were designed by VTL and built to their specifications. The output circuitry is optimized to drive a 5 ohm load. One word of caution: all tube amplifiers, VTLs in particular, must never be driven without a load attached. In fact, the power should be left off if they are not connected to the loudspeakers. In addition, when changing speakers or cables, they should be first turned off.
The most immediate and striking characteristic of these amplifiers is their total lack of veiling, especially in the midrange. I listened to the 225Ws last in this series of three monoblock pairs and was astounded by the palpability of instruments they presented. The midrange, especially, had a present quality so real it was eerie. It was as though the instruments were in the room. The tonal and harmonic "rightness" of these amplifiers added a new dimension to my listening experience. Music sounded so smooth and natural, with instrumental timbres portrayed without annoying coloration or edginess. Textures were liquid and velvety, but not overly romantic. This ability to render natural timbres was exemplified by Handel's Water Music (Harmonia Mundi 907010). The string sound was rich and gorgeous.
The VTLs' rendering of space and depth was remarkable. Vocals moved out in front of the speakers and seemed to exist independently of them. The VTL 225Ws had the ability to recreate a spatial perspective I have heard from no other amplifier. The soundstage was deep, with extraordinary focus of instrumental outlines. The impression of depth rendered by the 225Ws was greatly heightened by the fact that some instruments moved forward in the soundstage, leaving plenty of space behind. The excellent depth portrayed by the Muse 150s also reviewed this month was presented behind the speakers.
The VTL 225Ws, however, took depth of soundstage further by presenting some instruments right in front of the listening chair. One record, Cascades, by the Brazilian trio Azymuth (Milestone M 9109), has an amazing feeling of three-dimensionality. This superb recording features extensive and intricate percussion at varying distances from the listener. Through the 225Ws, all the spatial cues present in the recording were fleshed out with extraordinary precision. I had heard this record countless times, but never with the feeling of envelopment provided by the VTLs. Some percussion instruments jumped out of the soundstage toward the listener, an effect that made listening in the dark (well, by the glow of eight EL34s) almost spooky.
The soundstage was so open and transparent that the amplifiers seemed to disappear, leaving only the music. The presentation was more forward and immediate than I am accustomed to. I attribute this to the VTLs' tonal purity, which removes the veil between music and listener, and to the astonishing front-to-rear spatial perspective they portray.
At first impression, the VTL 225Ws appeared to lack the upper-octave detail I had become accustomed to through the Muse monoblocks. Upon further listening, however, I discovered that the VTLs presented as much detail as the Muses, but far more subtly. Instead of having detail thrust at the listener, I had to "lean into" the music to hear it. The latter was a more rewarding experience: I felt drawn into, and intimate with, the performance instead of listening from a distance. In addition, detail was rendered with a greater variance of spatial perspective, further enhancing the feeling of envelopment.
Bass reproduction was impressive. The 225Ws provided a solid, tight musical foundation that was very satisfying. I had never heard this tight and punchy bass from tubes before. The bottom end was rock-solid, with depth, impact and tautness. LF textures were round and liquid. Midbass, however, was a little thin in comparison to the Muse monoblocks, but this did not detract significantly from the musical experience.
One thinks of tube amplifiers having soft, romantic trebles, loose bass, and velvety textures, as exemplified by the Quicksilver monoblock, Music Reference RM-9, or the Prodigy OTL. Ironically, the real tube amplifier I reviewed this month sounded very little like tubes. That is meant as a compliment. The VTLs had tight, punchy bass and a crisp, detailed top end, characteristics one associates with solid-state. However, the VTL 225Ws' musicality, midrange transparency, tonal purity, and soundstaging would never mistaken be for transistors.
The VTL 225W monoblocks are easily the most musical and enjoyable amplifiers I have heard. They have an exquisitely liquid and tonally pure presentation that puts the listener closer to the musical experience. The midrange in particular was free from the veiling common to so many amplifiers. Listening to the 225W monoblocks was like washing months of winter off a picture window. Timbres were smooth and natural, but not at the expense of detail or sounding rolled-off.
Soundstaging was equally impressive, with a transparent, see-through quality. Combining fairly good width with impressive depth, the soundstage made the speakers disappear into the music. In fact, it was very easy to concentrate on the music and forget about the amplifiers. This is perhaps the highest praise one can give an audio component. Bass reproduction was excellent by any standards, tube or solid-state. The 225Ws have a bottom-end punch and tautness one does not normally associate with tube amplifiers. The only criticism is a slight leanness in the midbass.
The 225W monoblocks aren't cheap at $4200/pair, but they're a bargain in relation to other amplifiers approaching four figures. If you can afford them, they're highly recommended: I cannot imagine them
The VTL 225W monoblock clipped at 178W into 8 ohms (22.5dBW), and 208W into 4 ohms (20.2dBW), which is good for a tube amplifier. When driving 2 ohms, they did not increase their power output at clipping, indicating that they are current-limited. Frequency response featured a slightly rising HF response above 10kHz, reaching +0.2dB at 20kHz. When driving a capacitive load (2.2µF in parallel with the load resistor), this HF rise started at a lower frequency and reached a greater amplitude. At 20kHz, the response into this load was up nearly 2dB, which will be audible.
Output impedance was 0.86 ohm at 20Hz, dropping to 0.67 ohm at 20kHz. This is typical for a tube amplifier, and together with the peakiness into a capacitative load, suggests that the 225W's signature will to some extent be dependent on the loudspeaker with which it is