Manley Neo-Classic 300B Preamplifier Review 
Home Theater Preamplifiers Stereo Preamps
Written by Andre Marc   
Monday, 28 September 2009

In the high end audio world, tubed Hi-Fi components almost became extinct in the late 70’s, with issues of reliability, neutrality, and the very future of tube production being of major concern. There were a few manufacturers still plugging away, such as Audio Research and Quad, but at the same time some of the iconic producers of tube equipment started bringing solid state products to market.  But early solid state products had many detractors. Harsh sounding transistors in early designs were tough for tube proponents to take.  But low maintenance, well built, excellent sounding transistor designs eventually gained major acceptance.  

Yet the “TuboPhile’ kept fighting the good fight. Companies like Conrad Johnson, Audio Research, Cary, and a host of others continued to design tube amplifiers, preamplifiers, and even cd players despite being out of favor. Thankfully, what is old is new again.  In the last 10 years or so, tube equipment is back in vogue due to the old cliché that tubes are generally “warmer”, mellower, and more musical sounding than transistors. What complicates this is that we have all heard harsh, not so great sounding tube equipment, and warm, full-bodied solid state equipment.  

One thing is true for sure, tube designs are more reliable than ever before, require less maintenance than in the past, and are far more neutral than in previous days. Some are insanely expensive. Some use hybrid designs, with either solid state output or input stages working in conjunction with tubes.

Manley 300B front

Manley Labs, of Chino, California has been making high end, tube based mono, stereo, and integrated amplifiers, preamplifiers, and pro audio studio gear since the 1980’s. The subject of this review is their Neo-Classic 300B Preamplifier (MSRP: $5500). Manley was the first Hi-Fi company to offer a preamplifier using the classic 300B tube. What makes that so interesting? The 300B tube is a heated power triode using a four pin base, first introduced by Western Electric in 1937. Believe it or not, it was in early telephone systems. For home audio equipment, the 300B is known for high fidelity, low noise, and reliability.  It is generally used in very low powered SET (Single Ended Triode) amplifiers. It is revered for its purity of tone and its sense of immediacy.

NOS (New Old Stock) 300B tubes can command what may seem like outlandish prices. But thankfully, there are more than a few modern manufacturers who offer the 300B, including Electro-Harmonix (made in Russia), which is the tube Manley chose. Their philosophy is to rely on a supplier who is reliable, and where supply will be available for many years to come. Incidentally, Manley has been producing the Neo Classic 300B Preamp for a number of years.  All Manley components are 100% made in the United States in their Chino factory.

The Neo-Classic is single ended only. Manley believes in keeping circuit paths short and simple, and they do not offer balanced connections except on their mono block power amplifiers Along with two Russian made 300B’s, there are SIX other tubes. There is a pair of 6SL7GT’s, for the input stage, a pair of 0D3’s, and a pair of 5U4GBEH rectifiers. There are two headphone jacks on the front panel.  This is a very headphone friendly preamp. On the top of the unit, there are three silver toggle switches for Output: “Transformer/Direct”, Line Output: “To Amplifier/Headphones, and a toggle for matching headphone impedance. Very cool!

Along with this, the preamp is finished with high quality, gold plated RCA connectors, high grade silver internal wiring, and a substantial chassis finished in the typical “Manley Blue”. The overall look is very retro, which I adore. There are 3 black knobs on the front panel, one to select Input (Aux, Tape, CD, Tuner, and Video), Volume, and Power On/Off knob. On the back panel, there is a Main Out set of jacks, a Subwoofer output, and a Tape Out.  There is a supplied remote control, and in keeping with the retro mode, it looks like an old fashioned garage opener, and features only Volume Up or Volume Down.

Set Up

The Neo Classic 300B will take some consideration when setting up as the 8 tubes extrude from the top of the chassis. Because of the tube extrusion, I had to switch my CD player from the top of the rack to middle shelf, and place the Manley on the top shelf.  The 300B will need adequate ventilation, as the unit will produce some significant heat. If you have a tube amplifier it is driving, as I do, their combined heat is considerable. Suffice it to say, I had the air conditioning running for extended listening sessions.

300b back

Other than that, the Neo Classic 300B was a snap to set up After carefully installing all eight tubes,  I ran my interconnects from my CD player into the preamp input jacks, and from the Main Out connections on the back panel to my Audio Research VS55  tubed power amp. I powered everything on and was up and running. It should be noted that Manley’s National Sales Manager recommended 200 hours of burn in/break in. He was right. The Manley sounded very good to me out of the box, but really improved at around 150 hours.


From the get go, let it be known that the Neo Classic 300B was something special. The first thing that I noticed was how wide the soundstage became. Compared to my reference Audio Research SP16, ($2995, when available), musical images were more lifelike and seemed to extend several feet around the speakers.  Secondly, there was neutrality and purity in the midrange that one would expect from preamplifiers costing several times as much.  To lay it on the line, after a bit of extended listening, I actually asked myself “Where is the preamp?”. The sound seemed so open, transparent, and wide. The Neo Classic did a disappearing act, the good kind.  The type that allows the source to get your amplifier and speakers with everything intact, but without any hint of edge. I have heard CD players with volume controls going directly to power amps, bypassing the need for a preamp. Suffice to say, I would never allow for that kind of set up in my system.

As my listening sessions progressed, one of the only hints that put the Manley in the signal path was the wonderful, round, warm (but not overly warm!) and authoritative bass.  The Manley’s bass presentation was human; exactly the way I like it. Bass notes are not just notes as they are played by musicians on a variety of instruments.  Can bass have soul? I don’t know, but the 300B sure came the closest to making me think so. For all practical purposes, I have never heard such clean, extended, and articulate bass from my Harbeth Compact 7’s; in the most organic sense.

I listened to a variety of music during this review period.  First up was the Deluxe Edition remaster of REM’s “Murmer” (CD, Universal, 2009). This release, in various formats, has been in my collection since the early 80’s.  I can honestly say I had never quite heard it like this. All was laid out as it appears on the master tape: the studio reverbs, the dated snare drum sound, the thick, melodic bass lines, and lead vocals; upfront, throaty, and lyrics still obscured!

The 300B is certainly a marriage made in heaven for older analog rock recordings. Disc after disc that I spun from this genre simply allowed me to melt away in my chair. Another particular title that had me reliving my past was the brand new reissue of the Stone Roses classic, first album.  The lush, percussion heavy, psychedelic mix sounded stunning through the 300B.  The Deluxe Edition of Jeff Buckley’s classic “Grace” (CD, Columbia, 2004) is a tough recording for even good systems to unravel, due to the sheer force of Buckley’s five octave voice, the unique way in which he plays his Fender Telecaster, alternating between a delicacy that few can muster and a punk like attack, and the thunder of the band in full flight in conjunction with Andy Wallace’s brilliant production.  On other systems, I have heard this album sound like a “recording of a genius at work”. Through the Manley, it was a performance.  What a HUGE distinction that is!

The mother of ALL classic analog recordings is the 2009 re-mastered box set of every single Beatles original studio album, plus the non album singles collected on “Past Masters”.  Suffice it to say, much is expected of this project that was four years in the making. I’m happy to report it does not disappoint.  The Manley allowed me to hear this music that I am intimately familiar with as if for the first time. I have had each of the titles available in the box set on LPs, discs, and reel to reel tapes.  For me to hear a sound stage as precise as this is stunning. It revealed aspects of the Beatles recordings that were impossible to detect in prior releases.  The Beatles and tubes in the Manley are beyond a heavenly match. Through the 300B, there were percussion, harmony, tape effect, guitar, keyboard, and bass parts that seemed to appear out of nowhere.  The timing of the review period and the arrival of my box set from Amazon could not have been better!

Manely 300b top

The modern rock recordings I listened were never, ever edgy, bright, or over-cooked. Titles from the Raconteurs, MuteMath, U2, Duffy, The Dead Weather, John Legend, and scores more sounded as organic as they are going to in a Pro Tools world, I suspect. As a matter of fact, many newer recordings were just as engaging and musically satisfying as older “classic” tracks, despite the unbridled use of compression, limiting, and digital recording that is the vogue.

Moving on to classical recordings, I was absolutely knocked out by what the Manley did with large scale orchestral works from Lalo, Saint-Saens, and Mahler. I have several versions of Mahler’s No.2, including the classic RCA Living Stereo SACD hybrid.  Talk about hearing the recording space! That is generally an area I don’t focus on too much, but soundstage width and depth that the Manley brings to the table makes it impossible to ignore.( Just going back to classic rock for a moment, I really did hear the “sound of the room” on the 2009 Neil Young re-masters, something I had just filed under “audiophile” craziness). I also put on one of my favorite show stopping discs, the now, very unfortunately defunct Telarc two disc 25th Anniversary Collection, (CD, Telarc, 2002). With forty excerpts from classic Telarc recordings, it’s a stunner with the Manley in the chain. It was breathing life into every recording I listened too.  It was providing the flesh and blood.

Acoustic music convinced me that the Neo Classic produces sweet, crystalline, and seductive highs.   The natural tone of instruments and voices shone through. To me, this is paramount. It does not matter what component, speaker, or cable I’m auditioning. If the natural timbres and woodiness of un-amplified instruments are not recognizable, all bets are off. Spinning offerings of acoustic music from Bert Jansch, Joan Baez, Cat Stevens, and more exotic fare from Anour Brahim illustrated how right the Manley was getting the performances in spades.  From attending live performances and being a music lover, the average audiophile knows when a component is not fatally flawed, and presenting a recording in a natural, and musical way.  I’ve heard some mega buck systems and thought to my self, “They have got to be kidding”. But that is just proof that this is a very subjective hobby.


I did try the Neo Classic 300B with a few aftermarket accessories, and with a few different cables. I replaced the stock power cord towards the end of the review process with my Acoustic Zen Tsunami II. There was a subtle improvement in dynamics, not earth shattering but certainly detectable. That only tells me the 300B’s power supply is primo. The 300B was able to distinguish immediately between different brands of interconnects and speaker cables. As far as isolation devices are concerned, that was bit trickier, as the Manley comes with four spiked columns attached to the chassis that act as feet, and I assume, resonance control. My usual Symposium Rollerblocks and Cardas Myrtle Wood blocks were too short to reach the underside of the chassis due to the spiked columns. But, I did not mind a bit, as those columns seemed to be doing a fine job of stabilizing the preamp.


I can safely say that any audiophile shopping for a tubed preamplifier in the $5000 to $6000 range should put the Manley Neo Classic 300B preamplifier near the top, or even AT the top of a short list.  Build quality, reliability, ease of use, and sound quality are all outstanding and beyond reproach. Speaking for myself, the next component I plan on upgrading is my preamp, I can tell you the Manley will be the two or three I would consider.  The only other ones that I would audition at this price point are offerings from Audio Research, (maybe the LS17), Conrad Johnson, or a Cary. That is exalted company.  Sending back this unit to Manley is going to be a sad day indeed, as music was a living, breathing thing with the 300B preamplifier being a conduit for long, enjoyable listening sessions.  This preamp is world class, and music came out of the loudspeakers like butter, the organic kind.  It’s a universe away from margarine, trust me on that!  Not a hint of trouble in operation was to be found in the time I had the unit in my system.  I highly recommend an audition. If it makes things any more attractive, Manley is a very consumer friendly company that makes their components by hand, to order.


Manely 300B Specs

  • Inputs: 5 stereo pair unbalanced RCA jacks
  • Outputs: 2 stereo pairs MAIN out same as SUB out unbalanced RCA jacks
  • RECORD output: 1 stereo pair pre-volume control unbalanced RCA jacks
  • HEADPHONE Outs: 2 front panel 1/4" headphone jacks
  • Optimized headphone impedance switching: 30-400 ohms to 300-4000 ohms
  • Output Vacuum Tubes: 2 x 300B Electro-Harmonix
  • Input Tubes: 2 x 6SL7GT Electro-Harmonix
  • Rectifier Tubes: 2 x 5U4GBEH Electro-Harmonix
  • Regulator Tubes:  2 x OD3 NOS JAN USA
  • Gain: factory set at 12 dB at max Volume
  • S/N Ratio: typically 105 dB (A WGT, 20 Hz - 20 KHz)
  • Frequency Response: 5 Hz to 50 KHz ±1dB
  • Input Sensitivity: 250mV (-9.8dBu) yields 1V out
  • Input Impedance: 100 Kohm Noble volume control
  • Output Impedance (LINE STAGE): 100 ohms
  • Maximum Output Level: 17.2dBu or 5.636 Vrms @ 1KHz, volume control at maximum
  • Output Power (100 ohm Headphones): 1W (10 V RMS) (28 V P-P)
  • Output Power (600 ohm Headphones): 1W( 25 V RMS) (70 V P-P)
  • Power Consumption: 170 Watts (1.4 A @ 120VAC)  
  • Mains Voltage Frequency: 50~ 60Hz
  • Dimensions: W=19". L=13". H=3 1/2"
  • Shipping Weight: 28 Ibs.

Reviewer's Gear

  • CD Player: Naim CD5x with Flatcap 2X
  • Preamp: Audio Research SP16
  • Amplifier: Audio Research VS55
  • Speaker: Harbeth Compact 7ES
  • Cables:NuForce/ Kimber/QED/Acoustic Zen (AC)/Transparent (AC)

Company Info

Manley Laboratories, Inc.
13880 Magnolia Ave.
Chino, CA 91710 USA

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