Associated Equipment:
Front End
Digital Front End
Monarchy Audio SE-160

Single-Ended Class A Monoblock Amplifiers

Frank Alles

26 April 2001


Frequency Response:
20Hz to 20kHz +/- 0.5 dB
THD: under 0.05%
S/N Ratio: better than 90 dB Single-ended or Balanced Mode
Power Output:
8 Ohm Load: 160 Watts rms/channel, 4 Ohm Load: 320 Watts rms/channel
Input Impedance: 100k-Ohm
Input Sensitivity: 2.5V
Dimensions: 5.5" × 12.5" × 16.5" (H × W × D)
Weight: 35 lb. each
Price: $2000. USD each

Monarchy Audio
380 Swift Ave., #21
S. San Francisco, CA 94080
Phone: 650-873-3055
Fax: 650-588-0335

High-Power Hybrid Monos Make Music!

Do you ever wish you could find a simple high power amplifier that sounds as sweet as your favorite little tube amp and yet can provide the same kind of musically involving presentation when pushing your not-so-sensitive reference speakers to relatively loud volume levels? Do you also yearn for an amp that can keep its composure while reproducing complex instrumental passages along with a wide range of dynamic gradations and inner detail? If your answer was yes, then you may want to take a close look at the Monarchy Audio SE-160 single-ended class-A monoblock amplifiers.

The SE-160 is a relatively compact monophonic hybrid design that couples a 6DJ8/6922-based tube input stage to a high-power MOSFET output stage. High-quality parts are used throughout, including a heavy-duty, 650-Watt toroidal transformer per amplifier (1300 Watts per pair). Balanced XLR connectors, as well as high-quality, single-ended RCA jacks are provided, as is a female IEC connector for use with detachable AC power cords.

The amps are physically a bit smaller than one might expect for units of this power rating, but they are attractive, meaty packages, boasting thick black aluminum faceplates with heavy-duty gold-plated rack handles. While one wouldn’t rank them at the pinnacle of modern art, their appearance is quite respectable.

Each SE-160 monoblock uses a single dual-triode driver tube and Monarchy’s designer and CEO, Mr. C.C. Poon tells me that any 6.3 volt dual triode having the same pin configuration as the 6DJ8, such as the 6922, 7308, 6CG7/6FQ7, E88CC, 6N1P, etc. can be substituted. No matching of the triodes is necessary as only one triode section is used for the voltage amplification, while the other triode section is used as a current source.

Roll Your Own Amp, Dude!

SE-160s are made to order, with a lead-time of 2 to 3 weeks. Mr. Poon states that the final sonic character of the amplifier is influenced mainly by the owner’s choice of tube and encourages experimentation. That way the sound can be tailored to the user’s personal taste (within certain limits). Since there is only one tube per chassis, trying a couple of different tube types ("tube rolling") is both affordable and fun.

The 6DJ8 tubes that came with my review amplifiers may not be the best sounding choice. I tried a few different types of tubes in the SE-160s, including some 7308s and 6FQ7s. I will caution those of you who prefer the 6FQ7/6CG7 tubes that these are taller that the 6DJ8 genre and the glass tips on some will not allow the amp’s top covers to be reinstalled. Those who prefer the taller tubes could always have the covers drilled to allow the tip of the tube to protrude. At any rate, I got extremely gratifying results using the shorter tube types, so this is not a valid cause for concern. I left the covers off when making quick tube comparisons to save time between listening samples. Taking the additional time to unscrew and then refasten the covers (16 screws in all) would have wreaked havoc with my short-term memory. The safety conscious can get away with merely laying the covers back atop the amps and putting a couple of screws in each cover.

Toward the end of my review process, Mr. Poon sent me a pair of Siemens ECC88 premium quality gold-pin tubes to try and I must admit that they changed my impression of the amp’s performance potential for the better. I had thought that the Amperex 7308s and the General Electric 6FQ7s that I used were in very good condition and sounded fine, yet the Siemens ECC88s achieved a level of focus and high frequency extension that I did not hear through these other tubes. I also tried the Russian Sovtek 6N1P tubes, and though they were possibly not quite as detailed as the E88CC tubes, they achieved an ideal tonal balance in my system and sounded more at ease. The E88CCs tended to be a little harder sounding on dynamic peaks, and their timbre was slightly skewed.

Of all the tubes I tried, the 6N1Ps were my favorites, followed by the 7308s and the E88CCs. My preference is for musicality over detail and the 6N1Ps offered the better blend of both attributes. Although the E88CCs had more detail and ultimate frequency extension than the 7308s that I had on hand, I preferred the more musical and natural tonal balance of the 7308s (which grates less on the ears over time).

The Sound: Welcome to the Grand Illusion

I first installed the Monarchy SE-160s in my alternative reference system using Magnepan MG 1.4 speakers (with custom outboard Walsh-type tweeters) and a Sonogy Black Knight high-power solid-state amplifier. My preamp was a B&K Pro 10, and my source was an older JVC direct-drive turntable, with a Grace uni-pivot arm and a vintage Micro Acoustics 3002 moving-magnet cartridge. I did this for two reasons: first, to gauge the full-range sound of the amp, and second, to hear the amp with different speakers before inserting it into my primary reference system to power the electrostatic panels of the InnerSound Eros hybrid speakers.

My initial impressions were quite favorable. Compared to the presentation of the Sonogy Black Knight, the SE-160s appeared to have slightly more lower-treble emphasis, but slightly less extension into the uppermost high frequencies. If anything, the midrange was a bit smoother and the bass was quite punchy and full-bodied – not very different from the Black Knight’s bass performance, which is an area where the Sonogy amp excels.

Through the Maggie 1.4s, I had the impression that the SE-160s were a bit smoother and sweeter sounding in the midrange to upper midrange area. This worked very well on vocal works, brass, piano, and other midrange-rife recordings.

The bass performance suited me (and the Maggies) just fine. It was agile, rhythmic and weighty; not Krell, vise-grip tight, but certainly convincing in the context of how real low-frequency instruments actually sound. Speakers that are slightly lean in the mid-bass area would welcome the SE-160s’ robust and punchy persona.

Because of the slight highlighting I observed in the lower treble, I was concerned about whether or not this might become problematic when the amps were used to power the very extended and revealing electrostatic panels of my InnerSound Eros speakers. So it was with some hesitation that I transplanted the Monarchy amps into my reference system, usurping the critically acclaimed InnerSound ESL amp that I knew and loved. As it turned out, my fears were not justified. Upon running through various tracks on different CDs and LPs, it became apparent that the high-frequency character of the SE-160s was more synergistic with the Eros electrostats than I had assumed.

Although with some tubes the SE-160’s recreation of air and uppermost treble seemed very slightly truncated, when I swapped the Siemens ECC88s for the Amperex 7308s (and later with the Sovteks), the highest audible frequencies were suddenly apparent to the same approximate degree as with the ESL amp. Additionally, the broadband focus seemed to improve and the width of the soundstage appeared to widen. However, along with these improvements came a slight hardness, which was noticeable only in contrast to the amp’s presentation with the 7308s.

Getting back to that lower treble region, through the Eros, on Gershwin’s An American in Paris from the CD Dayful of Song (Delos DE3216) it served the triangle well. Chiming in from stage left, the initial strikes and the trailing overtones were rendered in just the right proportion and sounded utterly natural. "Absolutely authentic," read my listening notes. Next, on the remastered version of Led Zeppelin II (Atlantic 82633-2), the brush on the snare on the song "Moby Dick" sounded extremely convincing. Other recordings left me with the impression that there was a slight lower-treble aggressiveness, but since it was more noticeable with my digital gear than it was with my analogue turntable system, I thought it could have been an artifact of the digital recording process.

At about that time, I was hearing good things about a modification for my Perpetual Technologies P-3A DAC, offered by ModWright LLC. To make a long story short, I had the modification done and I’m happy to report that it did indeed improve the treble presentation to the point where I could no longer point a critical finger. At that juncture, with the Monarchy amps, the sound of my digital gear (the complete system, really) became very natural and analogue-like. Cymbals shimmered with plenty of natural air and focus in a way that was very realistic and pleasing to the senses. And the upper harmonics of acoustic guitar seemed right and raised goose bumps with certain recordings.

I thought the SE-160s held a slight edge over the ESL amp was in the area of stereo separation. Instruments seemed more distinct as they emanated from their respective locations within the huge multi-layered soundstage. It appears that you can only get that kind of separation from monoblocks, where the two channels are completely isolated from each other, both physically and electrically.

The SE-160s are very dimensional sounding amplifiers and throw a very wide soundstage with a good sense of depth and excellent placement of individual instruments and voices. Surprisingly, with both the 6N1Ps and the ECC88 tubes, the Monarchy amps appeared to equal or perhaps exceed the expansive soundstage dimensions achieved by the InnerSound ESL amp. With certain recordings I thought the SE-160s exhibited a bit more width, whereas the recreation of soundstage depth varied with the individual recordings and was a virtual toss-up, with both contenders reproducing this aspect equally well on average. This is impressive considering that the ESL amp has bested all previous amplifiers that I’ve tried in its ability to recreate a credible and expansive soundstage.

Importantly, the Monarchy amps sound fast, palpable, and very involving and life-like when reproducing acoustic instruments. From ferocious fortissimi on the Grand Piano to triumphant blasts of the brass, to the agility and sweetness of a solo violin, the SE-160s painted a portrait of sonic splendor with such liquidity and finesse that on more than one occasion it raised goose bumps and coaxed sympathetic tears. They are that good!

"Soldier at the Brook" from Stravinsky’s L’ Histoire du Soldat (Everest EVC 9049) is an excellent example of an emotionally involving movement. Listening through the SE-160s, the sprightly violin on the left and the cello on the right certainly sounded sweet, but there is more to it than that. One has a clear picture of the bow as it’s pushed and pulled across the strings, with the short snappy strokes of the violin contrasting nicely with the slower and more deliberate bowing of the cello. Here, the rosin on the bow sounds authentic and convincing – as opposed to the coarseness often mistaken for fidelity – routinely emitted by wanna-be amplifiers. (If the preceding statement seems bold, you have interpreted it correctly.)

Another passage that really blew me away was the finale of Rhapsody in Blue (Delos DE3216). Combining Litton’s passionate pounding of the ivories with the formidable horn section, the big bass drum, and the rest of the orchestra, this recording was reproduced magnificently through the Monarchy pair. The best part was the degree of octave-to-octave harmonic integrity exhibited in the reproduction of piano notes as Litton’s playing spanned the instrument’s considerable range. I was humbled, mesmerized, and satisfied by the scope and plausibility that the Monarchy amps presented.

What with the dynamic and heartfelt lyrics punctuated by his poignant acoustic guitar, Johnny Cash’s "Down by the Train" from American Recordings (American 9-45520-1) on vinyl raised goose bumps. The SE-160s kept the soul of this great artist intact. It provided a seamless transition between the upper and lower vocal registers, with the requisite proportion of upper-bass chestiness to evoke a palpable visual image of the man in black. Truth be told, the upper bass to lower midrange transition was more realistic and satisfying through the Monarchy amps than it was through my reference amplifier. Reproduction of consonants is simply first rate, which heightened my comprehension of the lyrics on this and many other recordings.


By now it must be apparent that I am smitten by the considerable sonic virtues of the Monarchy Audio SE-160 amplifiers. They proved a synergistic match in my reference system, and I believe these amps will be happy in most installations, especially those that require stable, high-power amplification. If it were only a question of power and stability, there are surely less expensive amplifiers that could fill those requirements. However, for most audiophiles, who are rightly concerned with an amplifier’s ability to render a convincing facsimile of real acoustic instruments in a live venue, the choices are few and usually quite expensive.

Though I have used more extravagant, highly praised amplifiers in my system, the SE-160s paint a more convincing musical portrait those that I’ve tried. The fact that the audiophile can tailor the amp’s sound (by tube swapping) to match his taste and system characteristics is another very real benefit. The Monarchy SE-160 amplifiers are among a rare breed of products that can fool the listener into imagining he is witnessing a live musical event. I can offer no higher praise than that. Put them on your short list.























































Luminous Audio

Monarchy Audio SE-160