Audible Illusions L3B Tube Line Stage Preamplifier

Description

MY TAKE: A truly marvelous line stage preamp and a classic in the making, the Audible Illusions L3B tube line-stage preamplifier will embarrass far more expensive competitors. Compare this preamp to anything under $10K. Absolutely, wholeheartedly recommended - Galen Carol

Art at Audible Illusions has agreed to make a Special Edition version for us using the renowned and coveted (no longer being made) Black Gate capacitors!
These highly prized and expensive capacitors are available as an extra-cost upgrade ($250). Please call for details.

Audiophiles remember how the introduction of the original Modulus Preamplifier excited the audio industry. For the first time, a full-function, reliable, vacuum tube preamplifier with true high-end sound was made available at an honest-affordable price. It's rare for a company to capture people's imagination and loyalty even once in such a manner.

As many audiophiles turned to CD and digital playback as their main source, Audible Illusions felt it was appropriate to introduce a product specifically designed to optimize digital playback. Thus the L-1 and subsequently the L-2 was born. With the debut of the new L3A Line Stage with Remote Control, the legend continues.

The L3B follows the Company's design philosophy that "Simpler is Better". The preamp clearly demonstrates the proven superiority of single-ended, pure class A, no-feedback tube designs that have garnered critical acclaim from audio authorities around the world.

Not a simple rehashing of old ideas, the L3B is very much on the leading edge of audio technology. It employs elegant engineering approaches from circuit board layout and construction to mechanical control implementation. It is still manufactured the old-fashioned way; completely hand-crafted using the finest parts available.

The L3B is an Audio Control Center that is second to none. As many audiophiles have migrated primarily digital sources, the L3B has inputs and switching optimized for CD, DVD, Tuner, External Phono, Video, AUX, and conventional Tape. To keep signal paths as short as possible, selector switches use special cross-chassis axles to bring switching functions closer to the delicate audio circuitry thus minimizing distortion and crosstalk.

The L3B features a Dedicated Outboard Power Supply to keep unwanted AC fields from the main chassis. Volume and muting functions are operated from the front panel or by Remote Control. The L-R Balance Controls are Precision Stepped Attenuators.

This preamplifier retains all the fine features of its predecessor but with improved active, unity-gain circuitry to accommodate surround-sound processors used in home theater applications. The new L3A also incorporates the improved signal input switching circuitry of the M3B by which each input jack has a dedicated relay that permits a more direct signal path. Further improvements to the preamp lower the drive impedance of the separate power supplies and improve the stepped attenuator volume controls. The automatic muting circuitry has been refined and the design of our proprietary film capacitors. Redesigning the motherboard has also resulted in improved signal to noise ratio and channel separation.

For many years it has been understood that tube preamplifiers are susceptible to common-mode noise. In an effort to further reduce these common-mode noises the external power supply was redesigned. The new design utilizes choke input filtering and is fully regulated. The net result of these changes is lower open-loop impedances and a virtual elimination of common modes noises. This increases the L-3B’s ability to pass complex waveforms resulting in an even more accurate reproduction of music. Additional enhancements have been made to internally dampen the L3B and eliminate resonances at the source. The resulting sonics and dynamic contrasts are breathtaking.

For Home Theater use the L3B includes complete input and output switching facilities for external surround-sound processors. Another feature incorporates special active circuitry for optimum matching of components and prevents signal degradation and impedance mismatches.

Special provision has also been made to incorporate Audibles' Optional Plug-in Phono Stage. This discrete circuit, designed with advanced JFET technology, gives new meaning to vinyl playback.

As the Modulus Preamplifier was for the previous decade, the L3B Line Stage is the next step in the evolution of audio technology. The heart of fine audio and video systems for years to come.

The L3A vs the L3B - A host of significant performance and cosmetics upgrades have been added to make the L3B a significant step up from the L3A.

L3B Upgrades:

• Upgraded metalwork - faceplate, turned billet knobs and switches
• Relay Switching – the signal does not pass through switches resulting in better clarity and definition
• Upgraded interstage coupling capacitors – All capacitors in the signal path are film and foil for better resolution and lower noise
• Larger, low-noise transformer in the outboard power supply for improved performance in all areas
• Cleaner, more direct signal path resulting in improved performance in all areas
• Revised taper on attenuator for better matching with a wider range of source components
• Fully regulated filament supply
• Significantly more filter capacitance for increased dynamic contrasts

REVIEWS:
 

Positive Feedback:  $42,790 worth of preamp sound for $4695?

Preamps are the heart of an audio system because they deliver music like blood into the system's vital organs and up into our brain. An upgrade in one's preamp is an upgrade to everything it is linked to.
 

"In 2014, Stereophile's Robert Reina published a review of Lamm's four-chassis (two mono preamps with their respective power supplies) then-flagship linestage, the LL1 Signature*. At the time, the LL1 cost a whopping $42,790, a price RR determined, by review's end, to be in line with the preamp's build quality and audio performance.
 

"So what? So this: As per Reina’s review, the Lamm was a single-ended, class A, no feedback design. Ditto the L3A. The Lamm used four Russian dual-triode (two triode tubes in one) tubes per chassis, connected in parallel to provide high bias current without the need to use a cathode follower in the signal path. Similarly, the L3A uses 2 dual-triode tubes connected in parallel. Each of the Lamm's external power supplies used a choke input to reject EMI-induced noise. Ditto the L3A's main power supply, although this one attaches to the main chassis via a captive umbilical cord, unlike the Lamm's two detachable ones.
 

"The similarities don't end there. As with the Lamm, the L3A comes equipped with outputs that invert polarity; a volume pot for each channel and a tape loop one can engage to bypass the main input selector to achieve greater signal purity, which is how, for the purposes of this review, my phonostage was hitched to the L3A. (I played only vinyl.)
 

"Obviously, the Lamm came in more boxes than the L3A. But the L3A is simpler by design, on purpose:  Ferris is unwavering in his belief that, in his words, "in high-resolution audio systems, the ear quickly discerns a loss of clarity and immediacy created by every unnecessary active device, resistor, capacitor, etc. in the circuit path."
 

"I am not, by the way, alleging that the AI sounded as perfect as the Lamm, or was as sophisticatedly engineered, or contained as many quality parts. What I'm saying is that both AI's and Lamm's philosophical preamp-design underpinnings hail from the same neighborhood.
 

The Bottom Line
 

"We have a thing for audio gear or we wouldn't be audiophiles; we'd be music lovers like everyone else.
 

"But I believe there's a part of our audio psyche that wants us to find that special something, a soulmate piece of gear, one for every component category in our life. Once we've taken stock of the equipment we've bought over the years, and tallied those pieces that have made us happy and those not nearly so; once we become more attuned to the kind of hobbyist we are, we gain a deeper appreciation for the real deal:  that component that has stood the test of time in our lives that it became like "family" to us.
 

"Only time will tell, but I believe the L3A might be, for me, such a real-deal component. It made me happy to turn on every time. It encouraged me to do something I never do: close my eyes while the music played. The L3A sounded expensive.
 

"As expensive as the many times the price Lamm LL1 Signature? Don't know. But here's a thought: While I listened to it, I never concerned myself with doubts about how less perfect the L3A might sound compared to other preamps, the Lamm included. The L3A was the anti-audiophilia nervosa.
 

"Here's what I do know: many of the same fundamental design principles used in building the $42,790 Lamm are used in building the $4695 L3A.
 

"Chalk up that last bit as one those things that, as C+C Music Factory might've put it, makes me go hmmmm." - Robert Schryer

Read the Full Positive Feedback review

The Absolute Sound: "The L3A line preamp distills the best attributes of modern tube sound: swift transients, a detailed presentation, and natural yet non-euphonic textures. It is its insistence on the sonic truth that defines it as a true reference line preamp. The L3A’s ability to retrieve the music’s rhythmic drive and drama make it one of the most sonically persuasive line preamps on the market and one of the best I’ve auditioned over the years at any price. If your goal is to conjure up audible illusions on a grand scale, this is your preamp!" - Dick Olsher

Read the full TAS review

CUSTOMER COMMENTS:
 

"The L-3 is the best sounding preamp AI has come up with yet and I have owned them all. I have always been an AI fan for what they do and the price they sell it for. It is not exactly the same linestage as the M3b but has been refined somewhat. The power supply has been modified. I have owned mine for about 6 months and can say without reservation, it is one of the best sounding line stages I have heard. I replaced an Aesthetix Calypso because L-3 was more open, quieter and threw up a bigger soundstage. It was flat out more transparent and quicker. For a tube preamp, it is unbelievably quiet.
A phono board is optional." - Bigtee

"I have been using the L-3 for about a year now and my opinion has not changed. I compared it to a couple of "Class A Stereophile" solid-state preamps (Ayre K5xemp and Parasound JC2) and it came away as the hands-down winner. It is just so open and presents so naturally.
I do believe the L-3 is AI's top of the line currently. It is within a couple of hundred dollars of the M3b and has been tweaked somewhat. No phono is included. It is optional. It does come with a remote that allows very fine adjustment of volume and the input level controls are stepped, precision attenuators. So much better than in the past. Just a superb, well-built preamp that sounds as good as anything I have heard. It has performed flawlessly in the time I have had it and is dead quiet. Tubes seem to really last with this one." - AG Member

"I received my L3 yesterday afternoon, and after the initial first hour of reviewing the manual and removing the top cover to confirm that all was well with the tubes, I set it up and let the listening begin.  First off, everything arrived in perfect condition.  No damage anywhere - perfect.  Now, how this baby sounds is beyond description in one word - beyond amazing.  I'm incredibly happy.  I never imagined the change to be this substantial.  I tried to hold off on making any immediate judgements for as long as I could - to let things gel and break in a bit first - but in the end, it took all of about 10 minutes to identify that the changes the L3 was making to the sound were huge, and that was while listening initially only to CD, my much weaker playback end.  LP playback literally took me to another dimension, and I was up until 3 AM listening -  completely unable to pull myself away from the music.  The L3 does a few things.  It seems to anticipate the music.  Gone is any sense of centered forwardness with increased dynamics - music  is being presented more musically somehow .  The soundstage has definitely deepened, which I never thought might be possible in this smaller listening environment.  But mostly, this unit is truly unbelievably musical - the notes somehow seem to have a rounder fuller sustain, while at the same time not having lost any of their attack or leading edge.  The bass is certainly all that one can use to define great sounding a bass - full, focused, great tone and sustain, but I'm hearing more body.    Listening has become even that much easier.  I'm very happy John, and I hope we can do business again someday.  I've crunched my numbers, and according to my math I hope to invest in the AVID black Acutus in about 3 years.  The Sequel absolutely continues to blow me away, and despite the small power supply hiccups I've had, if worse were to come to worse, I'd buy the entire upgrade Sequel power supply over again in a heart beat, that's how much I love this thing.  I'm happy to say the L3 has equally warmed my heart." - D.A.


CONTROL FUNCTIONS:

• Master Stereo Volume
• L&R Stepped Attenuator Balance Controls
• Source-Tape
• External S/S Processor
• Mute
• Remote selects Stereo
• Volume Up/Down, Muting.

INPUT SELECTION:

• CD
• DVD
• Tuner
• External Phono
• Video
• Aux
• Tape
• External S/S Processor
• Output Selection: Main, Tape, External S/S Processor.
• Optional: Brushed Aluminum, Mirror-Finish, and Nickel-Silver.

TECHNICAL FEATURES:

• Circuit Design is Pure Class-A, Single-Ended Triode, Zero Feedback, Dual-Mono.
• Audio Circuit has no Cathode Followers or Buffers.
• To prevent unwanted AC-induced distortions, the L3 features an External Power Supply housing three separate supplies and a large-shielded, custom-wound transformer.
• In the main chassis, four-separate, fully-regulated FET power supplies drive the audio circuitry in addition to separate filament supplies.
• Automatic-timed muting with Tri-Color LED indicator.
• Low-light Illumination for Selector Switch and Master Volume Control Knobs.
• Standby Mode avoids cold starts and prolongs tube life and circuit components.
• Active Tape Output and External S/S Output Buffers are FET regulated, set for unity-gain.
• All circuit boards are hand-soldered using the finest silver solder available. All polypropylene and polystyrene film capacitors used are proprietary designs of Audible Illusions. Resistors are precision 1% Holco and Roederstein.
• Proprietary gold-plated RCA Jacks with Teflon insulators.
• Master stereo volume control is a top-quality laser-trimmed Alps potentiometer.
• Balance Controls are Precision Stepped Attenuators.
• Handcrafted in the USA.

TECHNICAL SPECIFICATIONS:

• Gain: 30dB, Tape & S/S Processor 0dB
• Distortion: .10% at 1.5V RMS, 20-20kHz, into 50k Ohm. Less than .12% at 1V out 20-20kHz into IHF load
• Frequency Response: Within +/-1dB 2Hz to 100kHz measured w 1-1 probe/50k Ohms,100pf
• Signal to Noise: 90dB below 1.5V RMS output wideband
• Max Input: 9V RMS
• Signal Phase: Main Out-Inverting, Tape and S/S Processor-Non Inverting
• Input Impedance: 50kOhm – all
• Output Impedance: Main-1.2 k Ohms Tape, S/S Processor-150 Ohms
• Muting: 45-second warm-up and automatic brown-out protection
• Tube Compliment: 2-6922, 6H23EB twin-triodes, graded & matched
• Power Requirements: 115-125VAC, 60Hz 45 watt maximum. 6 foot IEC Line Cord-Supplied.
• Optional 100, 220, 230, 240 50-60Hz transformers.
• Dimensions: 19″W x 3.5″H standard rack mount
• Chassis is 17″W x 11″D x 3″H
• Power Supply, 6″W x 10″D x 5″H
• Weight: 19.5 lbs, 24 lbs (shipping wt.)

NOTES:

• Use Aux or Tape inputs for the highest quality reproduction.
• Use CD input for modest-quality CD players (the L- Pad network may help to soften their sound)

Audible Illusions Trade-In Program

Did you know you can trade-in your vintage Audible Illusions preamp toward the latest version? You can, and your old preamp is worth a lot more than you might think (and possibly more than you paid for it!).

The fine print: Your preamp must be in excellent cosmetic condition and in good working order.