Reviewing Manley Neo-Classic SE / PP 300B
Reprinted with kind permission from the Inner Ear Report magazine
Vol. 14#2, 2002
Manley Neo-Classic SE/PP 300B Monoblocks
Source: Manley Laboratories Inc.
Price: $10,800.00 Cdn, $7,200.00 US,
Rating: 3 1/2 musical notes
We introduced our readers to this US company last year, when we reviewed the older version of the 'Retros' in Vol. 12, #3. The Neo-Classics under review here are brand new models and, according to the company, an improved, redesigned version of their older classic 300B design. What we have here is "overhauled Retros to create the Neos".
As were the earlier units, these are handsome monoblocks which, when switched on, are impossible to ignore, as they radiate the vacuum tubes' gentle glow into the listening environment. The highly polished steel chassis accommodates the vacuum tubes and sockets on the units' front sections where we also find the transformers and caps. A variable feedback control and the bias adjustments are located close to the input tubes. Load impedances are switchable at the top rear of each amplifier and allow connection to 4 to 12 Ohm loudspeakers (appropriate for 4 and 8 Ohm speakers) and 12 to 20 Ohm (appropriate for 16 Ohm speakers). Speaker terminals and inputs are on the rear of the chassis. The left front accommodates the toggle switch to select single ended or push-pull operation; and the right holds another toggle that mutes the inputs. Front centre features a large display window which, when switched on, displays the Manley logo and highlights the elegant appearance of these monoblocks.
The amplifiers measure 8.5 inches wide, 11 inches deep and 9 inches high, including projecting controls and parts. These little devils aren't lightweights at 41lbs. each.
These monoblocks allow the user to choose between two circuit topologies and tailor the sound to one's liking. They can be operated in single ended or push-pull mode and can be switched while in use. In the single ended mode, the amplifiers employ both 300Bs in parallel. In this mode, the amp employs minimal circuitry, requiring no phase splitter and maintains purity of sound, but at a price: less power
The 300B circuit has variable feedback, featuring adjustments in 1 dB steps from zero to 10 dB of negative feedback above minimum. We'll get back to the practical application of feedback later, but it is important to know that more feedback will cause less gain, flatter frequency response and lower distortion. Sonic properties change as well and include differences in smoothness, imaging, brightness and control over the loudspeakers
Each amplifier delivers 11 watts in the single ended mode with total harmonic distortion of 3% and 24 watts in the push-pull mode with THD of 1.5%. Frequency response measured at 5 watts is 15Hz to 15kHz, in single ended mode, and from 10Hz to 20kHz in push-pull mode. Input sensitivity is
For our auditioning sessions, we used the JMlab Micro Utopias and Fab Audio speakers (both reviewed in Vol. 13 #3) and the B&W 801s reviewed in this issue. The Wyetech Labs Opal preamplifier and the Audio Aero CD player, reviewed in this issue, made up our front end. Speaker wire and interconnects were the Valhalla models, supplied by Nordost.
We connected the Fab Audio speakers for our first listening session which took place after we had operated the amplifiers continually for about one week (burning in was accomplished with a Magnum MD 108 tuner). Operated in the single ended mode, the Neo-Classics' most distinct sonic attribute was immediately audible: a suave, blossoming, yet sophisticated, almost alluring midrange. These units manage to tame digital glare better than any other recently auditioned amplifiers. This trait makes listening to vocals an experience to savour
Everyone considered that the best match was achieved with the JMlab Micro Utopias. Single ended at 3dB feedback, top and midrange frequencies remained smooth as butter, but allowed our listening panel to realize "definition and texture beyond expectation". In the push-pull mode, the Manleys' robust bass energy complemented the Micros somewhat lean bass, thereby enriching the overall sound and defining and establishing a unique musical character. To accomplish this bass resolution, we experimented with feedback adjustments until we managed to please most panelists.
The B&W/Manley combination was a surprisingly fine system, especially in the push-pull mode with feedback at 7dB. The slightly leaner sounding single ended mode with feedback at 3dB was a touch more "refined" in the midrange areas. After listening for a few hours, we decided that the push-pull mode was more pleasing when listening at low volume levels and, surprisingly, at very high gain. At about 85dB sound pressure levels, we preferred the single ended mode which seemed to add that "cerebral" touch to all program material.
The Neo-Classics are, without a doubt, very special designs, not as powerful as the Retro model, but more ambidextrous at executing complex musical material. All loudspeakers used for this evaluation exhibited the Manleys' unparalleled midrange bloom, which is seductive. These monoblocks also recreate an outstanding image; so convincingly real that, in order to locate the loudspeakers in a set-up, one has to actually look at them. While the older model Retros did this very well indeed, the new models surpass them.
Some of our panelists liked the overall sound of the older models, stating that they offered better resolution across the audible range. While this may be so, the improved musical finesse of the Neo-Classics more than compensates.
Synopsis & Commentary:
These amplifiers are made for those who wish to achieve a very personalized sound. Many types of loudspeakers can be used, as long as they are reasonably efficient< 88dB or more. "Tweaking" or calibrating the system is not just allowed, it's obligatory, because much depends on the loudspeakers' personality and reaction to the amplifiers. The end-user can decide whether the Manleys should be used in single ended or push-pull operation, as both modes offer first-class sound. Some of our panelists preferred the single ended mode, maintaining that inner detail, imaging and upper midrange clarity is superior. Others stated that the push-pull mode better represents tonal textures, offers more body and weight to the sound and deals more proficiently with speakers' impedance loads. However, the ultimate sound is determined when modes and feedback are chosen to complement the loudspeakers. Generally, with less feedback, the sound will be more aggressive, but focus, inner detail and imaging is exceptionally good. Increased feedback results in smoother sound over the bass and midband frequencies, but also introduces a slightly vivid character to the highs. At maximum feedback, the amplifiers take on a slightly harder sound quality which adds resolution, especially in the bass (that's why most solid state amps use feedback which also improves the damping factor). Nevertheless, the best position for feedback will not only depend on the loudspeakers and personal taste, but also on the acoustic properties of the listening environment. Our Editor listened to the B&W 801/Manley system in the push-pull mode and stated that he enjoyed the Neo-Classics' ability to communicate timbre, texture and body, especially at medium or low volume levels, adding that this new design performs better than the Retro 300Bs. We feel that it is unfair to write off one mode or operating system in favour of another, for both have musical merit. One thing is certain: the Manleys aren't run-of-the-mill; they are great sounding amplifiers and belong in a category where few designs can compete.