Cherry MEGA technology and MK2

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AmpDesigner333

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Cherry MEGA technology and MK2
« on: 29 Mar 2019, 05:45 am »
The Cherry Amplifier® brand (manufactured by Digital Amp Co) was first known for its “big Cherry” amplifiers, which are now called Classic Cherry.  These are still built today, more than a decade later!  They are based on proprietary Class-D amplification circuits that are optimized for world class sound quality.

Classic Cherry amps drive speakers with authority!  They are high power (600-900Wpc into 4Ω), low noise (116dB SNR and up), low distortion (<0.009%), high bandwidth (>50kHz) amplifiers that have been called “the most tube sounding solid state”.  However, with Cherry Amplifiers, you don’t suffer from tube amp issues like rolled off frequency response, high noise, high distortion, low damping factor, anemic power output, wasteful inefficiency, and never-ending tube replacement.  So you’re left with authoritative power and silky smoothness, problem free.

The Classic Cherry utilizes an internal linear power supply based on a large toroidal transformer (750W to 1800W) and comes in Stereo and MONO versions.  The outputs are single ended and run from bi-polar power supply rails.  Weight ranges from 30 to 40 pounds.  Inputs are true balanced and single ended removable ground lift RCA input adapters are included.

Maraschino series of amplifiers was released in 2013 and received much acclaim.  The Maraschino uses a newer circuit design able to reach 100kHz bandwidth with end-to-end DC coupling for response down to 0Hz and no bass phase shift.  As with the Classic Cherry, measurable audio performance is spectacular. Distortion is even lower than the Classic Cherry at 0.002%. Output impedance is extremely low (<0.04Ω) for the entire audio band with a damping factor of 500 at 1kHz.  The Maraschino amps also offers auto-sleep, so they can be powered 24/7 and wake up as soon as the source becomes active.

We use a more refined approach to the control loop of the amplifier by allowing it to remain controlled way past the audio band, yielding minimal phase shift into the ultrasonic range.  The ground of the amplifier is locked to the audio source (preamp or DAC) ground to eliminate hum and ground noise.  The result?  Customers and professional reviewers have praised the Maraschino for sonics that go way beyond today's cookie-cutter "me-too" module based amplifiers.  You’d be surprised how many amplifier manufacturers don’t even design circuits these days.

Many customers have chosen to keep their existing speakers after hearing what Maraschino amplifiers can do for their system’s sound quality.  They enjoy the quieter noise floor, better bass, lower distortion, higher bandwidth, and the amazing control regardless of the music playing over a huge volume range.  The sound Maraschino amplifiers produce is often referred to as liquid and juicy.

The Maraschino Amplifier product line grew to include Desktop Maraschino, a new novel shape for monoblock amplifiers, In-Line Maraschino, amplifiers so light, you can hang them from your speakers, yet so powerful, they can deliver up to 1000W into 1.8Ω, and Stereo Maraschino, an integrated amp with single-ended front and true balanced back inputs, plus volume control.  All of these are powered by external, upgradable power supplies.  Max voltage is 60V (KING versions), and power output into 4Ω is 400Wpc.  Lower cost 48V versions supply up to 250Wpc.

So what if you want that juicy Maraschino sound with more power?  Through years of R&D, we were able to build a new, high-voltage version of the Maraschino, the MEGAschino.  This was no easy feat.  With this new “MEGA” amp design, released in 2017, we are able to provide all the benefits of the Maraschino design with the voltage and current carrying capability of the Classic Cherry, and MORE!  With even lower output impedance and wider pulse differentials, you can get approximately 10% more power into your speakers from the same power supply compared to Classic Cherry.

The Cherry MEGAschino (referred to as simply “MEGA”) is not just a higher power version of a Maraschino amplifier.  It is based on Maraschino technology, and does run at significantly higher voltage, but other advances have been made in order to facilitate this next level of refinement.

The MEGA uses 12 output devices per channel, and the Maraschino uses 4.  In a way, this is like comparing a V4 engine to a V12 engine.  We developed a superior method for removing spurs in the passband at low levels (as seen on an FFT), thus allowing an even lower "spike free" noise floor while allowing power output to exceed 1000Wpc.  The overall topology is similar to Classic Cherry in that both use the same 16 gauge cold rolled steel enclosures and large toroidal transformers.

Here’s how the MEGA was optimized for sound quality.... We start with amazing bench specs, like 128+dB SNR and 0.0008% THD+N, then we tweak for sound AFTER that, and we wind up with 120dB SNR and 0.001% THD+N, still pretty amazing on the bench, but even better into your ears.

The huge headroom and DC coupling deliver stunning bass with "hit you in the chest" transients.  This amp can deliver current!  With a strong toroidal transformer based power supply and ultra low output impedance into the upper registers, instruments and voices are rendered with unrivaled clarity on even power hungry speakers.  It's like a bottomless pit of super clean power!  Plus, the highs have a silkiness that allows the proper fade to cymbals, and super fast transients are no longer inhibited.  The most surprising thing of all is the performance at low volumes.  You don't need to crank it up to get refined focus and locked-in imaging.  The MEGA is meant to produce better sound on your existing speakers.

What could be better?  Enter the MEGA MK2!  We took things another step early 2019 by optimizing our modulator for slightly higher efficiency and significantly lower mid-power THD+N, which was 0.005% with the original MEGA, and is now 0.001% with the MEGA MK2!  The higher efficiency allows the MEGA to drive even the toughest speakers.

If you haven't tried Cherry Amps in your system, you might not believe changing the amps could make such a difference.  It can with Cherry Amps.  We get compliments on the improvements Cherry Amps make almost daily.  If you have pre-MEGA Cherry Amps, imagine the next step up capable of a feather touch as well as the brute force of previous "super amps".

So far, reviewers have said things like it's the best amp they've ever heard, regardless of price.  Some say they never thought a Class-D Amp could sound better than Class-A, but MEGAschino shatters that barrier.  Steven Stone of Home Theater Review said “....MEGAschino is the embodiment of the longstanding audiophile ideal of a straight wire with gain”.

As with all Cherry Amplifiers, power conditioners and fancy power cords are not required to reach specified performance.  AC power is filtered inside the amp.  Interconnects can be generic also with excellent results because we design our circuits to handle cable parasitics with ease.

The MEGA MK2 is highly recommended for premium no-compromise audio systems.

Samoyed

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Re: Cherry MEGA technology and MK2
« Reply #1 on: 29 Mar 2019, 11:47 am »
This is a great, long overdue summary of your products. I hope this is on your website, too.  :thumb:

kingdeezie

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Re: Cherry MEGA technology and MK2
« Reply #2 on: 29 Mar 2019, 01:29 pm »
Has anyone used a Mega on electrostatics?

I am running a pair of new Sound Labs M645s. With the wild impedance swings, and the ultra low impedance in the high frequencies, can the Mega MK2 potentially work?

Mike in NC

Re: Cherry MEGA technology and MK2
« Reply #3 on: 29 Mar 2019, 06:13 pm »
Thanks for the summary. Your products will be on my short list next time I'm shopping for an amplifier.

AmpDesigner333

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Re: Cherry MEGA technology and MK2
« Reply #4 on: 29 Mar 2019, 06:53 pm »
Has anyone used a Mega on electrostatics?

I am running a pair of new Sound Labs M645s. With the wild impedance swings, and the ultra low impedance in the high frequencies, can the Mega MK2 potentially work?

Yes, Acoustat and Martin Logan!  Excellent results 😎

AmpDesigner333

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Re: Cherry MEGA technology and MK2
« Reply #5 on: 29 Mar 2019, 06:57 pm »





AmpDesigner333

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Ric Schultz

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Re: Cherry MEGA technology and MK2
« Reply #7 on: 25 Jul 2019, 07:48 pm »
Just curious......what is the switching frequency of the Maraschino and Megaschino amps and what is the -3db point in high frequency response of these two amps?  Thanks.  You mention 100K and 150K but not any -db thang.

AmpDesigner333

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Re: Cherry MEGA technology and MK2
« Reply #8 on: 25 Jul 2019, 08:00 pm »
Just curious......what is the switching frequency of the Maraschino and Megaschino amps and what is the -3db point in high frequency response of these two amps?  Thanks.  You mention 100K and 150K but not any -db thang.
Switching frequency is variable, but mostly 1-2MHz.  -3dB points are about half of rated bandwidth.  The difference between our amps and other Class-D amps is the way we control the power stage.  We don't use gobs of feedback and complex filter networks to get good bench measurements into a resistive load.  We design for tight control of arbitrary waveforms into a reactive speaker load.  Unfortunately, there's no "bench spec" for that!

Ric Schultz

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Re: Cherry MEGA technology and MK2
« Reply #9 on: 25 Jul 2019, 09:29 pm »
Wow! So your power stage switching frequency is over 1 Meg?  Most have trouble even making 700K, 500K being the norm.  If you are switching that high then why not roll off the amp at a higher frequency.....say, make it flat to 150K......this would eliminate any phase shift in the audio band and you could use a smaller coil on the output and lower its resistance.

AmpDesigner333

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Re: Cherry MEGA technology and MK2
« Reply #10 on: 26 Jul 2019, 05:02 pm »
Wow! So your power stage switching frequency is over 1 Meg?  Most have trouble even making 700K, 500K being the norm.  If you are switching that high then why not roll off the amp at a higher frequency.....say, make it flat to 150K......this would eliminate any phase shift in the audio band and you could use a smaller coil on the output and lower its resistance.
Sound quality wise, which is our primary concern, we engineer our amps to handle reactance in a very stable fashion while assuring control at higher frequencies.  Other Class-D amps, with their crazy phase compensation networks, have issues like marginal stability and altered switching frequency based on the speaker’s “pushback”.  They may do very well into a purely resistive test load, but listeners report a strange “lifeless” sound.  After decades of tweaking, measuring, and listening, I’ve noticed some counter-intuitive aspects to bench measurement vs sound quality.

AmpDesigner333

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Re: Cherry MEGA technology and MK2
« Reply #11 on: 17 Sep 2019, 10:22 pm »
Some of the MEGA MK2 modifications have made it to our lowest priced stereo amp: The Stereo Maraschino MK2!  Early information here:
https://www.audiocircle.com/index.php?topic=165498.0

Shear Bliss VMPS

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Re: Cherry MEGA technology and MK2
« Reply #12 on: 25 Sep 2019, 03:25 pm »
Has anyone used a Mega on electrostatics?

I am running a pair of new Sound Labs M645s. With the wild impedance swings, and the ultra low impedance in the high frequencies, can the Mega MK2 potentially work?

Surprised Tommy hasn't chimed in on this as he has 1.7i Magnepans. I too have stats, Acoustat 1100s that kick butt in my 20 x 13 room. Would rather let Tommy answer your question as the MKII is different than the original MEGA that didn't like my Acoustats 2ohm top end, nor his 1.7i ….. betting your M645s will sing also!

AmpDesigner333

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Re: Cherry MEGA technology and MK2
« Reply #13 on: 29 Sep 2019, 04:58 pm »
Surprised Tommy hasn't chimed in on this as he has 1.7i Magnepans. I too have stats, Acoustat 1100s that kick butt in my 20 x 13 room. Would rather let Tommy answer your question as the MKII is different than the original MEGA that didn't like my Acoustats 2ohm top end, nor his 1.7i ….. betting your M645s will sing also!

Magnepans are electrodynamic, not electrostatic, but I’ll save that discussion for another time. These two types of panel speakers have a similar problem in that the impedance dips low.  Google “impedance curve” and the name of the speaker model, and usually you can get a graph.  The MEGA MK2 is more efficient, lower THD at mid power, and has modified thermals, allowing continuous high power playback with the toughest of speakers.

Don’t know of any speaker the MEGA MK2 won’t drive to full potential.  Sign up for our newsletter (we only send out a few per year), and you’ll be informed of the upcoming specials we have planned, including a few demo Cherry MEGAs.  Here’s the link:
bit.ly/1G8bsxZ