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August 2013
Enjoy the Music.com Review Magazine
Audio Electronics Hercules EL34 Vacuum Tube Stereo Amplifier
Cary's new leader in the crowded EL34 field.
Review By A. Colin Flood


Audio Electronics Hercules EL34 Vacuum Tube Stereo Amplifier  Cary's new Audio Electronics is a direct-to-consumer Internet line. It includes a beefy and competent Constellation preamplifier, plus a power and headphone amplifier. The Hercules matches the Constellation like a pair of bookends. They are professionally designed and executed versions of the same reliably solid, components for which the Cary line is deservedly famous. In ancient Roman mythology, the semi-god Hercules was a legend of strength. This amplifier of the same name is 30-watts with two classic 12AX7s input tubes driving four classic EL34 output ones. In solid-state terms, this equals about 150-watts, plenty enough for many above-average efficiency loudspeakers with average impedance.

The massively popular Dynaco Stereo 70 amplifier of the seventies also used four EL34s, but with two 7199s as driver tubes. The ST 70 sold an amazing 350,000 units over two decades, making the EL34 the Volkswagen Beetle of audio tubes. The EL34 was then, and remains now, the industry standard for the sonic signature of tubes. The EL34 defines Hercules sound quality more than any other feature of the amplifier. The venerable EL34 is a power pentode tube. The pentode consists of five electrodes: a cathode heated by a filament, a control grid, a screen grid, a suppressor grid and a plate. The EL34 is manufactured by J/J Electronic, Shuguang, Svetlana and Reflector (Sovtek, Electro-Harmonix, Tung-Sol and others). The EL34 is also very popular in guitar amplifiers.

Jam Somasundram Of Cary AudioJam Somasundram, Director of Engineering and Product Development, designed the old-world look of the brother and sister amplifiers. Both amplifiers appear and feel heavy. The power amplifier is a hefty 45-pounds! Unlike some glamorous amplifiers, I reviewed lately, the new Cary line looks, sounds and feels like a substantial value for the money. These are well-built and designed units. Somasundram suggests loudspeakers of medium to high sensitivity. Speakers with nominal 4- or 6- Ohm nominal impedance are not recommended. Cary rates the amplifier for drive nominal 8-Ohm loads.

Sadly, neither the power nor the pre-amplifier has a balance control, a necessary feature for audio systems in asymmetrical set-ups. Cary may have additional options in upcoming products. They manufacture their products in their facility in Apex N.C. See the Constellation review for important product information on both amplifiers and company background. Have auditioned over a dozen amplifiers and receivers on my big ole horn* (see Bio) and other loudspeakers for Enjoy the Music.com. The Hercules impressed me with its over-all professional design, quality sound and packaging. The sound of the Hercules are perhaps the best sonics possible from the EL34.


Up Against It
Yet the Hercules has some stiff competition in several tube amplifiers I reviewed. My review of the Antique Sound Lab (ASL) AQ1003DT integrated amplifier, for example, found the amplifier equally impressive in heft, features and sound. The MARK II version is now about 50% more expensive than the previous version 10 years ago, $1600. Less efficient than the Hercules, the ASL also puts out 30-watts with a similar tube complement.

The Chinese-made ASL doesn't have the American-made Cary cachet. It probably does not have the higher re-sale value either. Like a sporty Mini Cooper, these two attributes may make the pride and total cost of ownership for Cary's new line very competitive. Plus, the Cary amplifier has a ready-made list of possible upgrades. You can swap out capacitors, rectifiers and speaker binding posts.

The ASL though does have features the Hercules lacks, and for a few hundred dollars less (15%). It includes built-in bias meter, triode/pentode mode switch, remote volume control, 16-Ohm output impedance, outputs for subwoofers and a wire tube cage. Reputable brand name aside, the ASL is a tough act to beat. The Cary units do make the rounds at the audio shows*. Where you have to audition the ASL on faith and reviews, you might actually get to hear the Cary before purchasing it.

Also in the same EL34 league as the Hercules is the similar $1295 Cayin A-50T. Not quite as heavy as the Hercules at only 28-pounds, the Cayin does not have outputs for subwoofers or balance control either. The Cayin however switches "on the fly from its ultra linear to triode mode with the gray remote control." Like the other two amplifiers, the Cayin has "robust and practical construction, design and price."

The sound of the Hercules resembles my memory of the Cayin more than the ASL and I scored the Enjoy the Music.com Blue Note scale accordingly. For a EL34 tube amplifier, the Hercules is a solid, name-brand good value for most audiophiles with above-average efficiency speakers. The sound is relatively solid and powerful, with sufficient mid-bass, bookshelf speakers. No, it doesn't have the big bass boom of the beasty Delta Studio 6s33. Or the wide soundstage and mid-range nuances of the far heavier and more expensive amplifier. Yet, with either incarnation of the EL34, the tubed music resembles the live event.


In the house for review is Glow Audio's charming new white model Two. Although its thumb-size EL84 tubes provide only half the power of the classic EL34s, and it does not have the feature list of the ASL, this $1508 integrated amplifier (introduced with a DAC) has a sweet sound. Tube watts aren't solid-state watts. All three-tube amplifiers provided plenty of moderate to loud volume on horns and small cone speakers in average size rooms. Steve Deckert of Decware argues that it is primarily the first watt that matters in the critical range (100 Hz to 10 kHz). "The magic," he says, "predominately lies in the first watt... there is over 10 times the dynamic range in the first watt as there is in the second." So also competing with the Hercules in this price range, for tweaking audiophiles with über-efficient loudspeakers like mine, is "Don Garber's Magical Fi X4 Stereo Amplifier."* This is a stunning, 1.5-watt, Tung-Sol 46 amplifier with unique X shape construction and looks for only $1095!" Money no object? This is the amplifier I would pair with Nelson Pass' massive X250s* driving my bass bins.

Yet the 30-watt output of the EL34 is a better choice for most tweaking audiophiles. I listened to the Hercules with its new Constellation companion and other pre-amplifiers on a variety of systems and rooms. On leaning Carnegie Acoustics CST towers and Klipsch Quartet loudspeakers, the Constellation was effortless, natural and all-around good performer. Twenty-three feet apart in a large room on classic Klipsch Khorns, they easily had enough power for the huge Globus symphony orchestra to sound incredibly wide. Violins were thin, light and airy. The bottom was smooth and gentle. Edges to the soundstage were not obvious. "Maxo Man" by Fourplay was effortless, natural, peppy, full of pop, fresh, without any warm-up. The bass, sounding more string than electric, was suitable. Tubes love horns!

The Welborne 2A3s are eminently respected amplifiers on Khorns. However, in another set-up, the Hercules was warmer, deeper, fuller, more conventional, not as sweet or as bright either. On Hayley Westenra's "Prayer," the Hercules had more punch, made songs sound different, with more attention to supporting instruments. The sonic differences between the two amplifiers are due perhaps more to the electrical differences between triode and pentode tubes than anything else. Yet on Allison Krause's beguiling sonnet "Down to the River," the Hercules exhibited more depth, less 3D imagining to the vocals, but sharper and brighter treble. Here the pentode had more energy for details, with more bite and kick to the drums.

With the palm-size Trends PA-10 instead of my Dynaco pre-amplifier (see Reviewer's Bio), the Hercules was sharper, more edgy and brighter. In this set-up, the Hercules easily bested a solid-state Adcom GFA-535 (60W into 8 Ohms (17.8dBW). The soft clipping of tubes makes a difference with challenging musical passages. The Hercules was warmer, fuller, though bass was not as hard or as sharp, but deep enough to question the need for a sub-woofer.

With über-sensitive big ole horn loudspeakers (104dB/W/m), almost any amplifier has some background hum. Even with a Signal-to-Noise ratio of -91dB, the Cary combo did too. It was present, but not attention grabbing. On bare cables, the plastic shields on the speaker cable binding posts were almost as easy banana pinholes. Like other tube amplifiers, the Hercules is butt-heavy towards the back. The off-balance center makes lifting the beast heavier than it looks. Sadly, neither unit has iPod or USB connections. Cary will have these options in upcoming products. Both products are manufactured is their facility in Apex N.C. Cary wires the units point-to-point with the exception of the remote control board. Both models were broken in, and while they blink while warming-up, you should be able to listen to the units almost immediately after turn on.

Neither of Cary's new amplifiers have a protective tube cage or bias meter. The amplifier is cathode biased and does not require biasing. Cary uses a method of bias called cathode bias. They set the bias by using a predetermined set of bias components. The owner will replace the tubes when the sound starts to degrade or the amplifier makes more noise, though a tube tester is the most accurate way. Cary does include soft white gloves, so you don't get oils from your hands on the tubes. There are fuses for protection. Cary does test and label the tubes before packaging.


Can It Stand Out?
This is certainly a good, all-around capable performer, with a justifiably proud name for quality. In my own personal category, Enjoyment, the beefy Hercules scores four Blue Notes on big ole horn loudspeakers. It is good, solid EL34 sound. I would love to hear one of the hot-rodded (heavily modified) Dynaco ST 70s up against this well-built modern reincarnation. Like Volkswagen did, Cary has reintroduced the Dynaco ST 70 sound in a heavier, capably packaged and designed version. Like the new Beetle, it stands out in a crowded field of sedans. Hope they sell 350,000 copies.



Sub-bass (10Hz - 60Hz)

Mid-bass (80Hz - 200Hz)

Midrange (200Hz - 3,000Hz)

High Frequencies (3,000Hz On Up)



Inner Resolution

Soundscape Width Front

Soundscape Width Rear  
Soundscape Depth Behind Speakers

Soundscape Extension Into Room


Fit And Finish

Self Noise

Value For The Money


Type: Vacuum tube stereo amplifier
Frequency Response: 15 Hz to 20 kHz 
Power Output: 30 watts ultra-linear 
Tube Complement: Two 12AX7 input and driver plus four EL34 for output 
Signal To Noise Ratio: -91dB 
Input Impedance: 150 kOhms 
Gain: 26dB 
Feedback: Zero
Sensitivity: 0.8V 
Output Impedances 4 or 8 Ohm 
Dimensions: 13" x 14.25" x 7.5" (LxWxH) 
Weight: 45 lbs.
Price: $1895 standard. Various optional upgrades available.


Company Information
Cary's Audio Electronics Division
1020 Goodworth Drive 
Apex, NC 27539

Voice: (919) 355-0010
Website: www.aebycary.com






























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