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ZOTL Ultralinear

Can I monoblock the ZOTL Ultralinear amplifier?

Yes. All our power amplifiers can be used as either stereo or monoblock amps. You can switch back and forth between the two modes via a switch on the back of the unit (in older amps) or inside the unit (in newer models).

When used in parallel mode (our more specific term for how the amp is operating when used as monoblocks), the power is increased to varying degrees based on the impedance of the speaker. Changes will be more significant at lower speaker impedances. Since all speakers have impedance dips, it should be significant for all speakers.

Running our amps in parallel offers other important performance gains, such as lowering the output impedance and increasing the current output capacity. Lowering the output impedance (by half) doubles the damping factor. This also means that the amps are more linear to lower impedances.

Here is a testimonial from a customer who upgraded from running one stereo Ultralinear+ to monoblocks:

“In my system...[the monoblocks] brought a more unrestrained quality when listening at higher volumes. Sound is projected more clearly and the speakers disappear to an even greater extent as sound sources. Any distortion that may have been present at high listening levels certainly was vanquished by the addition of the second amp. I expected more image specificity but this was not the case, nor did the stage get wider or deeper. Bass response got slightly tighter, which had the effect of making the system sound ever so slightly leaner on the bottom end. The richness of the lower midrange remained, however, affirming the most striking improvement of the PLUS enhancements--more meat on the bones as such, particularly for piano and strings.”


Related FAQs

What does the ZOTL Ultralinear amplifier sound like?

Here is how a selection of customers and reviewers have described the ZOTL Ultralinear amp:

Terry London’s 6moons.com review:

Think of the ZOTL Ultralinear amplifier as a world-class SET for its inner glow of gorgeous color/timbres plus the sense of aliveness and dynamics of a more powerful push/pull. This amplifier would be welcome in any system with standard speakers and listeners who prioritize beautiful tonality and timbres, first-rate imaging and the aliveness and 'speed' of live music.

~Audiogon User dodgealum

In my system the Ultralinear conveys the natural warmth of acoustic instruments and voices without editorializing. It is exceptionally clean, quick and dynamic yet completely uncolored and free of sonic artifacts. When you listen through this amp your focus will be squarely upon the music, not the means (transistors or tubes) by which it is being reproduced.

~ The Audio Beatnik Review

I’ll start by saying this is the best Class AB amplifier I have ever heard. The first thing I noticed was that the LTA Ultralinear was the quietest amp I have ever heard; not the quietest tube amp, but the quietest amp. I think this enabled me to hear some of its most captivating qualities; its incredible sense of pace and rhythm, explosive dynamics, and micro-dynamics. I found myself tapping my foot almost as often as I do when listening to live music. The amp is so unbelievably natural that it was hard to think about anything but the music, the glorious music.

Will the ZOTL Ultralinear amplifier pair well with my speakers?

The ZOTL Ultralinear amplifier outputs 20 watts per channel into 8 ohms, 22 watts per channel into 4 ohms.

To help guide you in speaker / amp selection, we have developed speaker recommendations for each of our amps. It is important to note that LTA amplifier owners have found great enjoyment using their amps with a variety of speakers outside of the below ranges. The below are guidelines, not rules.

  • Critical listening environments: 88db sensitivity and above

  • Smaller rooms / lower volume levels / non-critical listening: 85db sensitivity and above

If you have questions about your specific speakers, chances are someone we know has tried them. Don’t hesitate to reach out with questions about your specific setup.

Some of the wide variety of speakers that have been heard to work well with ZOTL amplification: Quad 57s, Maggie Minis, Tekton Design, Fern & Roby, Voxativ, Janszen, Decware, Klipsch, Silverline, Spatial, DeVore, Daedalus, Zu, Ryan, Living Voice, Omega, and many others.

Also, don’t forget we have a 14-day no-questions-asked return policy.

Need more power? The ZOTL Ultralinear amplifier can be used as a monoblocked pair configuration to double the power output of each amp to 40+ watts. This is easily done at the flip of a switch on the back of the amp.

Note for high-sensitivity speaker owners:

You may have heard that the ZOTL Ultralinear was designed specifically for highly sensitive speakers. This doesn’t mean it won’t work with low sensitivity speakers, just that the unique benefits of the ultralinear topology - namely the high levels of detail and slightly more refined, less forward presentation - will be more noticeable in high sensitivity speakers.


Related Products

ZOTL Ultralinear+ Amplifier

The ZOTL Ultralinear+ is the latest amplifier design by David Berning: the first ultralinear amplifier not limited by traditional output transformers.

What’s the difference between the ZOTL40 Reference and ZOTL Ultralinear amplifiers?

The ZOTL Ultralinear+ and ZOTL40 Reference+ are our flagship amplifiers, and generate 20 watts and 45+ watts per channel, respectively.

Like all of our amps, the ZOTL40 Reference+ and the Ultralinear+ both have the clarity, realism, precise imaging, and 3D soundstage inherent in our patented ZOTL technology.

Both amps are fast, fluid and do an excellent job of reproducing the pace and punch of the music. Likewise, both amps have the black background, high clarity, accuracy, realism, and dynamics that fool your brain into thinking the performers are in the room with you.

The ZOTL40 has a solid midrange and projects a large and deep soundstage. While offering more detail and clarity than most traditional tube amps, it is slightly less so than the Ultralinear.

The Ultralinear is a little more relaxed, more refined, and is our most tonally accurate amp. Despite having “only” 20 wpc, it has very strong bass. The Ultralinear+ has a little more detail and accuracy than the ZOTL40.

Both amps can be used in stereo mode or monoblocked pairs at the flip of a switch, should you require more power.


Related Products

ZOTL40 Reference+ Amplifier

The latest iteration of LTA's EL34-based amplifier, the ZOTL40 Reference+ amplifier is an end-game component for guaranteed excellence in any environment.

ZOTL Ultralinear+ Amplifier

The ZOTL Ultralinear+ is the latest amplifier design by David Berning: the first ultralinear amplifier not limited by traditional output transformers.


Related FAQs

Do LTA amps have subwoofer outputs?

The following Linear Tube Audio amplifiers have dedicated stereo subwoofer outputs, which allow you to use a subwoofer with “low-level” or RCA inputs.

If your amp doesn’t have a subwoofer output, you can still use the speaker outputs on any of our amps to connect to your subwoofer, and this is a common and often recommended solution.

You will need a subwoofer with a "high-level" input, often called a "speaker-level" input, which again is pretty common. (If your amp doesn’t have this sort of input, the preamp outputs from the MZ2 and MZ3 will work for line-level subwoofer connections.)

This method of connecting a subwoofer is recommended over a dedicated subwoofer/preamp output because it ensures that your subwoofer and speakers are using the exact same signal.

Don’t take our word for it. REL, maker of some of the finest subwoofers in the world, recommends using this method for connecting their subwoofers to amps of all kinds:

Using the High Level input is always the best option. Using the High Level Input, instead of the Low Level Input, and connecting to the speaker output terminals of your amplifier is one of the unique secrets of REL’s success. When using the High Level input, your REL is fed the same signal that your main speakers are receiving. When connecting to the High Level input on the REL from the amplifier, you capture the sonic signature of your main system, including the tonal balance and timing cues of the entire electronics chain.