Cherry Audio MEGAschino Mk2 Standard Edition Amplifier Review

MEGAschino Mk2 Standard Edition Introduction

The Cherry Digital Amplifier Company is an American-based high-end amplifier company that was founded in 1996 which specializes in designing proprietary Class D amplifiers and DACs. Cherry is a small company and is owned and operated by Tommy O’Brien. Tommy has worked in a number of industries as an electrical engineer and designed Class D amps for major companies like Crest Audio.  Frustrated with an inability to design truly good amplifiers without respect for cost or nonsensical traditions, Tommy Founded Digital Amp Company.  With a desire to provide his own state of the art amplifiers, he then added Cherry Amplifiers as the Digital Amp Company direct sale arm. Cherry has licensed proprietary technology to numerous major chip manufacturers and amplifier OEMs over the years. In for review today is their top-of-the-line Cherry Audio MEGAschino Mk2 standard edition which retails for $6,100 with shipping included in the price. That is a hefty chunk of change for any piece of audio gear, but according to Cherry, this is a state-of-the-art amplifier with an extremely high signal-to-noise ratio and ultra low distortion. There are many more expensive audiophile amplifiers out there that do not have the power output specs of the MEGAschino, so what separates it from the others? In a word, class-D amplification.

Most pricey audiophile amps use class-AB amplification. That works well, but it isn’t very efficient, and those amps tend to need heavier-duty hardware to accomplish the same effect. Class-D is far more efficient, especially at lower levels, and doesn’t need 50 lbs of components with massive heatsinks and a large chassis. Audiophiles have traditionally eschewed class-D amps because of less refined examples in the pro-audio realm and also theoretical advantages of keeping fidelity intact in signal reconstruction. Cherry seeks to keep the major advantages of class-D amps but eliminate its traditional disadvantages for extreme high-fidelity sound reproduction. Let’s now take a close look at the MEGAschino amplifier to see how far they have come to attaining their goal...

Design Overview

Fresh out of the box, the MEGAschino has an interesting look, and certainly better than the online images would suggest. It feels high-quality with solidity and heft, but it looks very reminiscent of amplifier design from the 1990s. While I don’t think it looks bad, I am not a huge fan of its aesthetics and think there are other more attractive amplifiers in its price range. However, its looks also would have no impact on my purchase decision since it would get stuffed into a cabinet and so would be heard and not seen. For those who care about country of origin, the MEGAschino is fully manufactured in the USA. The only parts not from America would be the semiconductors and passive components themselves; even the PCB boards and board stuffing is done within the United States (New Jersey in fact!). This is in contrast to many “US” manufacturers of high-end audio gear that uses Chinese built modules which dramatically lowered costs.

It’s worth it to note again how much more it costs to make these amplifiers in the USA than it is to use Chinese manufactured components, and that does have a considerable effect on the end cost. Having built plenty of amplifiers myself, I have had to design and source components and have done so from both China and the Americas. The cost is not slightly different, but substantially so. A custom made steel and aluminum chassis like Cherry uses could be had from China for around $150-$200, maybe less in bulk. That same chassis, custom made in the United States, would more than double, and likely cost closer to $400 to $600. In one of my amplifiers, I went with a custom-designed cast Aluminum clamshell chassis, and the American made chassis would have cost me $2000, and the price could not drop lower than half that even in bulk. A similar design was had from a Chinese supplier for just $500 and could have been much lower in quantity. The same is true for toroidal transformers, capacitors, etc. These parts often cost much more when you go with the major American based brands. As such, while we can complain that Cherry isn’t providing much value compared to the competition, that for the price we want better, keep in mind, much of this amplifiers price is the physical parts alone. Cherry then needs to pay its employees, keep the lights on, and turn enough of a profit for the owner, Tommy O’Brien to raise his family.  I don’t think Tommy is lining his pockets, I think it is very expensive to build amplifiers this way. We’ve been spoiled by cheap labor.  Many want to see manufacturing return to the US.  This is how it starts and we have to accept higher prices if that is what we want.    

The MEGAschino is the top of the line series that uses a Proprietary Class D amplifier with a novel  feedback design. Among many of its highlights, it can output 1,000 watts into 4 ohms and 2,000 watts into 2 ohms and is 95% efficient at full power. It has a signal-to-Noise Ratio of 120dB relative to full power and distortion as low as .001%. It has a linear power supply with a large 750-watt toroidal transformer in the standard version and a 1500-watt power supply in the ‘King’ version. It is a full double differential amplifier, where the minus terminal is the negative phase not tied to the ground. It is DC coupled for perfectly flat and extended bass response down to 0 Hz. It uses WBT Output Connectors and Neutrik  XLR inputs. It also has a steel chassis with a ½” thick aluminum front panel in Cherry Red.

While that is an impressive list of features, I do have some critiques about the design. Firstly, in my  opinion, the linear power supply is a mistake. There are real advantages to be sure, such as being capable of a more gradual clipping of their own output which prevents the amplifier from hitting a hard limit, but they are heavy and noisy. A large high-output regulated and low-ripple SMPS supply would, in my opinion, improve performance. It also would reduce weight, which I like! The MEGAschino’s WBT connectors are very high quality, but I would have liked to see Speakon, which are cheaper and more reliable connectors. The RCA to XLR adapter means that the single-ended preamp will need to be able to cleanly produce at least 4 volts for the amplifier to reach maximum output, but most AV receiver preamp outputs struggle to cleanly produce more than 2 volts. A single-ended to balanced conversion board in the amplifier would be better for those using single-ended sources.

The MEGAschino is a true fully balanced differential amplifier from input to output. It is essentially two  amps for each channel, and one amp per phase. This means it really should be used in a fully balanced system.The manufacturer supplies an XLR to RCA adapter, but these should not be used. If a balanced connection cannot be used, note that the amp cannot be driven to full power from a 2-volt single-ended output, the limit of most receivers. You leave half the power on the table. Further, this particular method also has an increased chance of noise. It would have been better to use a single-ended to XLR cable that ties the ground and negative phase together at the RCA end.

How Does It Sound?

In my view, trying to explain what a well-functioning amplifier sounds like is problematic. I don’t find that well-designed amplifiers make a huge difference in sound quality other than at the limits. At very low levels, the amplifier’s self-noise can become an audible distraction, even in noisy rooms. Clipping distortion, even if just momentarily, can lead to significant degradation of sound and ends the fun by taking you out of the music. So, in my view, the best solution is to have more power than you need by a lot and very low noise. The question then becomes, could the MEGAschino amp deliver on these counts?

Before any listening began, I had serious ground loop problems with my single-ended devices, but no ground loop problems with balanced devices such as my Motu 828x or the Cherry Dac Dac. I’m not sure if this is an amplifier issue or my own, but I don’t have these problems with my other amps. I had to use a ground lift plug when converting to single-ended inputs.

With the ground loop problem solved, I first decided to look for an audible noise floor. I plugged the MEGAschino into my own Gedlee Abbeys (95dB at 2.83v 1m sensitivity) and the JTR Noesis 212RT’s (101 dB at 2v 1m); both of these being very sensitive speakers would be the most revealing of noise. With no signal at all, I heard no audible hiss when used with the Cherry Dac Dac, but did hear hiss with other sources, showing the sources to be the cause of noise. As a test, I used XLR shorting plugs for noise testing and similarly found no audible hiss or hum. I then sent a very low -100dB 1khz test signal to ensure everything was on correctly and placed my ear against the tweeter. In this scenario, there was a very faint hiss that was not audible even a few inches away. I concluded from these tests that the MEGAschino is as quiet as anything I’ve used.

I then listened to some typical music by using various tracks. Everything sounded good. Most listening at modest sound levels didn’t sound any better or worse than other amplifiers on hand, including a Yamaha R-N803 receiver and Acurus A200 amplifier. All of these amplifiers are competently designed and under these conditions, I couldn’t really hear a difference between amplifiers. The Acurus amplifier has a higher noise floor with a slight audible hum, but this wasn’t noticeable during music.

I then turned to much louder listening levels to see how the MEGAschino handled a wider dynamic range. The average level at my listening position hovered around 85dB to 95dB with peaks over 100dB. I let the speakers run full-range with a signal path of a laptop as the source. I used the Cherry Dac Dac as the pre-amp, and either the Gedlee or JTR speakers. As was mentioned before, these speakers are very efficient and don’t need a lot of power to hit these loud levels but can still draw a lot of power if run full range. Still, this test only likely drew up to 100 watts. This kind of dynamic test again showed no issues. In comparison with the other amps I had on hand, the Yamaha receiver struggled a bit, at times, but all of them mostly sounded fine. No differences could be heard, even with big bass, from the Acurus A200 and MEGAschino amplifier.

I then turned to movies as a source of content with a wide dynamic range. Movies can often have a greater difference between peak levels and nominal levels, more so than most music recordings. I moved on to using the MEGAschino in place of my Acurus to run my main speakers during movies, and the biggest improvement was the noticeably lower noise floor. The dynamics sounded at least as good as I am used to. One movie I watched for its dynamic range was ‘X-Men: Apocalypse.’ This movie has a lot of big action scenes such as when Erik plays with the magnetic poles of the earth thereby causing huge destruction. The effects in this movie are intense and a strain on most systems when played at reference levels that can cause many lesser amps to quickly clip and distort. But it wasn’t a problem with the Cherry MEGAschino which had plenty of power. The MEGAschino amplifier exhibited no faults, and here no news is good news. There is nothing special to report; the amp did its job and was great during movies.

Another listening test I conducted was to use the MEGAschino with less sensitive speakers. I had a review pair of Polk Legend L800 speakers, and they have a sensitivity that is more reflective of typical home audio loudspeakers at 87dB. Polk’s SDA tech is negatively impacted by the differential output of the amp but I could disengage that, and it worked fine for regular testing of the speaker. This turned out to be a much more revealing test. By pushing more bass-heavy and dynamic music, the Cherry Amp clearly showed the dynamic flaws in the Yamaha receiver I had used to power the other speakers for a bit. The Polks didn’t like being fed just 150 watts RMS, and they wanted more. The Cherry amplifier could provide them with upwards of 600 watts and the difference was audible. There was less hardness on the dynamic peaks, the bass sounded tighter and deeper at higher output levels, and music had a more effortless quality to the presentation. Compared to the Acurus, the differences were nill, but again, I did notice the lower noise floor. 

After evaluating the amp from simply listening to it, I can only conclude that the MEGAschino does exactly what it is supposed to do. I could bring in a lot of flowery language around sound quality, but that would be a lie. I don’t find that amplifiers have huge sound quality differences when operating within their linear range. For me, the decision comes down to more pragmatic issues. Does the amp produce enough extra power that I can get at least 3-6dB of headroom, to avoid inadvertently clipping the amplifier? Is the noise floor low enough that I cannot hear it at any point when listening to music or movies? If so, then it is good enough, and any better is just academic. Is the frequency response, with a reactive load, good enough to add no audible distortions? With Class-AB amps, this isn’t an issue, but with Class-D, it can be. The Cherry amplifier clearly didn’t color the sound in any way, and it didn’t change the response or add audible noise or distortion. From that perspective, the amp is great. Getting amplifiers capable of giving me 6dB of headroom over the upper end of the levels I listen requires about 400 watts with my own Gedlee speakers and 1500 watts with the Polks (reality is, the Polks can’t play that loud or handle that kind of power). Finding good low noise/distortion amplifiers with a flat frequency response and 300-400 watts RMS of output into 8 ohms is difficult. The best options tend to be Pro audio and often they are sonically inferior, with mediocre performance, high noise, and non-flat responses. Class-AB designs exist that can work from ATI and Monolith, but it is not a joke to say that my theater noticeably increased my electrical bill and, prior to moving to multiple dedicated lines, had occasionally tripped a breaker. I like the idea of cool running and efficient Class D amplifiers. The fact that the Cherry Amplifier equaled the performance of my Class-AB Acurus amplifier is actually high praise in this world. It’s hard to get amplifiers that are this powerful and perform this well that are also Class-D and made in America.

One more bit that deserves mentioning was that I appreciated that the amp goes to sleep to save energy when not in use. It is nice not to have to worry about remembering to turn it on and off.

Cherry Audio MEGAschino Mk2 Amplifier Measurements & Conclusion

Measuring the Cherry MEGAschino amplifier turned out to be a tough proposition. In theory, the amplifier is capable of close to 1000 watts per channel into 4 ohms RMS and sustained output well past 600 watts. Yet it also produces distortion levels, at more reasonable power levels, that test the limit of my equipment. The combined need for low noise and distortion with very high power handling made testing difficult, as the gear I have just isn’t good for that. Add that it is a Class D amp and without the Class D measurement filter, distortion and noise rise as a result of the effects of ultrasonics feeding back into the audio band and potentially slewing the input opamps.  I’ve included a factory measurement of the exact amplifier under review showing a sweep into both 4 and 8 ohms of THD+N.  Since the max power that this produced exceeded my measurement limits at the time of this review, the factory measurements were confirmed at lower levels and included here for reference.

The main test rig consists of a Quantum Asylum QA401 & QA451 with external resistive load build using ARCOS LPR100 resistors. The test rig is really designed to test no more than around 175 watts into 8 ohms and 300 watts into 4 ohms, but with additional attenuation, can measure any power level necessary, with the negative side effect of increasing noise floor with added attenuation. As such, a decision was made to focus on the frequency response and noise distortion at set power levels within the linear limits of the testing apparatus. In addition, the manufacturer supplied and repeated tests of the same amplifier using their own Audio Precision based test system, which both validated my own measurements and allowed for more accurate measurements beyond the limits of my measurements.

Cherry Audio MEGAschino Amplifier FFT @ 1 watt

First, looking at the 1 watt 1Khz FFT (64K with 10 averages), we see a few interesting properties. First, the basic noise floor is around -110 to -120dB with an overall noise plus distortion noise floor of -76 dBV. THD+N came in at .0056% (-86dBV) and THD came in at a much lower .0005% (-105.5 dBv). Why such a difference? Where is the noise coming from? Well, that became more obvious throughout all testing and shows that one of the upgrades for the Cherry amplifier is probably worth buying. Power supply noise was significant relative to the noise floor, with the highest being the harmonics between 120hz and 800hz, but actually extending well past 1khz. Still, at 1 watt the spurs all fell below -90dBV, so maybe I am being too critical. I didn’t hear any obvious hum in use, but I would have liked to see less power supply noise in the measurement. Moving onto the S/N at 1 watt into 8 ohms, we see it comes in at 85.9 dB. That is decent performance for such an amplifier, not the best in the business, but certainly better than you see with lots of lesser amplifiers. I believe this spec would improve substantially with the optional power supply upgrade which was not tested here.

 

Cherry Audio MEGAschino Frequency Response - red (8 ohms); blue (4 ohms)

The frequency response of a Class-D amplifier varies with load, especially on lesser quality amps. This is a problem many of us thought we had long left in the past as we moved beyond Tube amplifiers, but with the advent of Class-D, their reactive nature brought back the problem, and in some cases, it can degrade the linearity of the amp so significantly that the change in response is very audible. As such, one of the most important measurements to perform on a Class D amplifier is a 4 and 8-ohm frequency response test. I did this and found the response did vary with the load but only slightly. With a reference level of 5.5 dBV at 1khz, the response is down -.5dBV at 10Hz for either 4 or 8 ohms, and this is very likely the LF response of my measurement system. Cherry claims a frequency response down to 0hz with no phase shift. On the other end of the spectrum, the 8-ohm load is down .5dBV at 30khz and 20Khz at 4 ohms.  This was tested using an output filter, but the output filter has little effect on the response at these low frequencies. The measurement filter is 6^th order with a corner frequency of -3dB at 65khz. In future reviews, I will be building test cables that will allow measurement of the frequency response without the filter, but that was not possible during this review. Since the response change is so substantial between 4 and 8 ohms, it suggests the difference is the amp, not the filter. Now, having called it substantial, let’s be clear, the substantial difference is at or above the limits of hearing, there is no meaningful attenuation measured between 20hz and 20khz, and as such, I will consider this amp to be well behaved.

 

What about high power testing you ask? Well, as noted, I couldn’t test the amplifier at high power levels, so instead, I tested the amplifier at various power levels until I hit a point where I was certain I was overloading the input of the analyzer. Again, changes are being made to the test rig to allow higher margins, but for now, these are the best I can do. For high power testing, I switched to 4 ohms, as this gave greater margins. Distortion goes up into 4 ohms with this amp, as with most amplifiers, so consider that into 8 ohms, it will achieve at least half these power levels with measurably lower distortion (and Cherry’s own AP results confirm this). At 10 watts, THD+N is .0028% (-91dB) and THD is .0012% (-99dB). At 20 watts into 4 ohms, we see THD+N of .004% and THD of .002%. SNR at 10 watts was a good but not great 92.6 dB, again strongly impacted by power supply noise, with the 120hz power supply spur at -100dB. At 200 watts into 4 ohms, THD+N and THD both increased to around .007%. This means noise is no longer dominating the spec and THD starting to emerge as the dominant factor. At 270 watts distortion remains about the same, increasing to .008%. At the time of this test, the way the Q451 was setup also reflected the point at which the QA451’s own distortion rises to a similar level, and I lose confidence in any power results above this.

I did measure up to 350 watts where distortion remained below .05%, but this reflects more the rising non-linearity of the load than it does of the amplifier. Sadly, after putting together a high power test load with sufficient attenuation for full-power testing, I inadvertently unplugged and re-plugged a cable while live quickly destroying the amplifier. For those concerned that this is a sign that the Cherry protection is weak, keep in mind that what I did is something you should never do with any amplifier and would cause the failure of most amps. A very large 1khz test signal was going through the amplifier when the load was set up for a much lower power level than it would see. When replugging it, either the 1khz tone or, more likely, a huge 60hz signal suddenly burst through an amplifier capable of well over 1000 watts and instantly destroyed a sense resistor in the load. This led to a chain reaction that destroyed parts inside the QA451 which led to the destruction of the output transisters in the amplifier. All in a matter of milliseconds. I can’t fault the Cherry MEGAschino; this was all me. This is why I can’t have nice things.

 

I wasn’t able to take a lot more measurements but will note that rising power supply noise was noted as higher power measurements were taken. This increase is a clear sign of insufficient power supply capacitance, though at all times the power supply noise remained still modest. Many receivers would measure as bad or worse. My main concern is that this is not a receiver but a very expensive and high-end amplifier. I do wish this amplifier came standard with the capacitor upgrade.

Summary of Measurements

How do we sum up these measurements? Are they good? Great? State of the Art? Well, no I don’t think they are state-of-the-art with respect to the highest-performing amplifiers out there, but I do think they are very good. The amplifier frequency response changes far less than we see with most pro audio class D amplifiers, along with many past cheaper options. While I don’t have a graph to share here, I have measured ICEpower modules and found their highest power modules to have far greater changes in the response between 4 and 8 ohms. The noise floor of the amp was dominated by the power supply spurs and as such were not state of the art. I was concerned with this and asked Cherry to measure amplifiers they had to see if he could replicate the results. It became clear that better power supplies dramatically lowered the noise to the point that I think this could be a state of the art amplifier in terms of noise if the power supply were better. As an example, we saw the noise floor of the FFT to move from around -110dBV to -140dBV when moving from the basic power supply to a lab supply (Keep in mind, these lab supplies cost 10’s of thousands of dollars often). Distortion was very low out to very high power levels, and it seems clear this amplifier has more power than the new Purifi 1ET400A. So while its noise and distortion were not quite as good, it is also putting out a lot more power.

Further, can we really complain about distortion levels of .004% or less over most of the power range? Is this really audible? In fact, looking at the manufacturer’s own AP results at 1khz, we see that into 8 ohms the THD+N levels were mostly below .002% from 1 watt to over 100 watts with clipping becoming evident at 270 watts at .004% THD+N. Compared to the results of some of the best new amplifiers like the earlier mentioned Purifi module, I can’t call the Cherry amplifier state of the art. On the other hand, both power output and performance is still better than a lot of other amplifiers on the market. Further, the price of the MEGAschino is substantial enough that I can’t call it a bargain for such measured performance, but I think the price is justified for other reasons.

Cherry Audio Dac Dac FFT

One measurement I want to add is of the Dac Dac used in the review.  This DAC was so clean that I had a hard time measuring it, so the only measurement I am including here is a 1khz FFT taken with my gear and a QA480 notch filter.  This shows a device with a S/N ratio of in excess of 121dB (this is not A weighted, expect a few dB improvement if A weighted) and THD+N of -112dB.  It is about as good as one can expect.  I really found nothing to complain about with the Dac Dac from these measurements.    

Conclusion

The bottom line for the Cherry Audio MEGAschino Mk2 is it is a very good amp, but that is as one would expect from its $6k+ cost. It doesn’t quite match the technical performance of the very best amps such as the Class-D amps from Hypex or Purifi or the Class-H amps from Benchmark in terms of THD, but its shortcomings relative to those models are still well below audible thresholds. Furthermore, it can come much closer to those extremes of performance with the optional upgrades to the power transformer and capacitors, although those upgrades do carry a hefty premium on the cost. What the MEGAschino does deliver that those amps do not is a lot more power. It’s a tall order to have both monster quantities of Class-D power with fantastically low distortion and noise, but it can be had in the Cherry MEGAschino, and it is built almost entirely in the USA, unlike those other brands. I enjoyed my time with the MEGAschino and was heartbroken to have accidentally wrecked my review unit, but my understanding is that the damage I did can mostly be repaired. I can easily recommend the Cherry MEGAschino, and were I shopping for high-powered amps in its price point, it would be at the top of my list.

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Frequency Response Linearity
SNR
Measured Power (8-ohms)
Measured Power (4-ohms)
Two-channel Audio Performance
Build Quality
Fit and Finish
Ergonomics & Usability
Features
Performance
Value