Marantz AMP 10 200 Watt x 16CH Amplifier Bench Test Results

The Marantz AMP 10 is a 200 watt/ch 16CH audio amplifier designed to be a companion to their new flagship AV 10 15.4CH 8K AV processor. Unlike the linear Class AB designs of their other models, namely their MM8077 150 watt/ch 7CH ($2,500) or their 140 watt/ch 5CH MM7055 ($1,500), the Amp 10 utilizes a ICE Edge Class D topology. The Amp 10 utilizes a regulated SMPS power supply located on the front panel side of the product that feeds power to all power amplifier modules through brass bus bars attached to the center chassis of the product. Brass helps to add rigidity, and is efficient in managing high current which is why it's also used by the AMP 10 speaker terminals and speaker relay.

The toroidal transformer feeds power not only to analog HDAM circuits but also the power amplifier input buffer circuitries and signal selector IC. According to Marantz engineering, this hybrid approach helps isolate those critical circuits from noise influences by power supply and helps preserve audio quality and performance of the product.

Unlike the other Marantz models previously mentioned, each Amp 10 module is bridgeable to output 400 watts/ch (8 ohms). The advantage to Class D is a much higher efficiency (> 90% vs 60-70% of a typical linear amp under full load). This means you can pack more channels into a single chassis while generating less heat, which is bad for your AV rack and power bill. It also means you will have more available power for multi-channel loading conditions than a typical traditional Class AB amplifier. Prior to the Amp 10, in order to power 16 channels using Marantz amplification, you’d have to purchase two 7CH MM8077 and one 2CH MM7025, which would cost about $1k less than the AV 10 but also require 3 black boxes in your rack instead of one, all while generating more heat and delivering less available output power. If the Amp 10 checks out in our bench tests, it seems like a veritable bargain to any audiophile wishing to build a home theater with a high channel count.

 

Editorial Note About the Marantz Amp 10 Testing:

Because the Amp 10 is a very low noise and distortion Class D design, some of my distortion and noise measurements may NOT exactly match those of the manufacturer due to different measurement techniques. I did my best to bandwidth limit the test signals and have also redesigned my entire test fixture with the help of Bluejeanscable.com by replacing all of my test leads with low resistance speaker cables and copper alligator clips at the test loads and short balanced shielded XLR leads to the input. The measurements are conducted at the amplifier end to reduce noise pickup the power resistors are all very low inductance 8-ohm loads.

For more information about how we measure power amplifiers, please see: Basic Amplifier Measurement Techniques

Marantz Amp 10 16CH Amplifier Top View

The Marantz Amp 10 is a beautiful beast with the top cover removed. The amplifier blades are all neatly aligned at the back of the unit and high-quality brass bus bars are utilized to connect the amp modules to power. The toroidal transformer at the front right of the unit powers the analog HDAM and control circuits while each channel pair is powered by a high efficiency regulated SMPS power supply.

Marantz Amp 10 Gain Structure

The Marantz Amp 10 has 23dB of gain when using the XLR inputs and +6dB or 29dB for the RCA inputs or when you bridge the amplifier.  This is a standard practice in most consumer and pro audio. The preamp therefore usually has a +6dB boost via the balanced outputs to compensate. The AV 10 is capable of 12Vrms output which is almost 6X more output then needed to drive the Amp 10 into clipping.

Note: If an end user is implementing RCA to RCA and XLR to XLR connections between their AV 10 and AMP 10 products, the net gain will be identical and thus the levels will be matched accordingly.

Frequency Response & FFT Distortion Tests

 

Marantz Amp 10 Frequency Response under Various Load Conditions

I measured the Marantz Amp 10 Frequency Response when driving 8- and 4-ohm load conditions. The frequency response was identical under 20kHz and only slightly altered above. This is a true load invariant amplifier like we’ve seen from some of the newest well-engineered Class D amp designs. This means the amp will sound consistent regardless of the loudspeaker impedance that is presented. There’s a slight rolloff of high frequencies of -0.46dB at 20kHz that is likely a result of the output filter but this should prove to be imperceptible.  Channel-Channel frequency response variation across seven of the channels that were tested was +-0.2dB to 80kHz, which is excellent.

 

Marantz Amp 10 1 kHz FFT @ 2.83Vrms (1 watt, 8 ohms)

The Marantz Amp 10 produced exceedingly good FFT distortion results. At 1 watt, the 3^rd harmonic was 113dB below the fundamental. The higher order harmonics were still very low and clean at > 100dB below the fundamental. The annoying 60Hz hum that plagues some amplifiers is completely absent here.

 

Marantz Amp 10 1 kHz FFT @ (200 watts, 8 ohms)

At rated power (200 watts/ch, both channels driven, 8 ohms), the harmonics get pretty high compared to what I’ve measured from a PuriFi Class D module in the NAD M23. Backing the power off significantly reduced these nasties but even in this case the 3^rd order harmonic is still 75dB below the fundamental which is about as good as I see in many linear amps driven to rated power.

Power Tests

 

Marantz Amp 10 Frequency Response @ Full Rated Power (400 watts, 4 ohms)

I wanted to see how the Amp 10 handled continuous full bandwidth sweeps at high power. With just 2CH driven, I was able to get their rated 200wpc x 2, 8 ohms and 395wpc x 2, 4 ohms at 0.1% THD+N across the entire 20Hz to 20kHz bandwidth. This power dropped to 172wpc x 5 and 145wpc x 7 driving 8 ohm loads at the same distortion levels. When I attempted to sweep at higher power levels, the Amp 10 seemed to go into some sort of limiting (perhaps in the SMPS power supply) at low frequencies as can be seen in the graph below.

Note: Marantz wasn’t able to recreate the 70Hz dip I measured at full rated power with all channels drive, but their graphs did show some power drop below 200Hz in this test condition so I can only imagine it really depends on the sweep duration that can affect this result. This is not a likely scenario for real world usage since we don't listen to continuous tones with music or movie program material. This power sag didin't show up in ANY of my 1kHz power sweeps with seven channels driven as you will see later in this report.

These are impressive continuous power results, comfortably exceeding the Marantz 70% 2CH power rating rule with even 7CH driven!

 

Marantz Amp 10 Frequency Response Overdriven (7CH, 8 Ohm)

 

Marantz Amp 10  1kHz PSweep (2CH) - 8 ohms

 

Marantz Amp 10  1kHz PSweep (7CH) - 8 ohms

The Marantz Amp 10 is the first amplifier I’ve ever reviewed that delivers roughly the same power with 1CH driven or 7CH driven. With traditional linear amps with a large centralized power supply, you would see significantly more power in these tests with 1CH vs. 7CH driven, especially with dynamic power testing. That’s not the case here and likely due to the very tight regulation of the SMPS power supplies in the Amp 10. Which approach is better? This is a topic I plan to cover in a separate editorial and YouTube video so stay tuned…

Whether the Amp 10 was driving 1CH or 7CH, it produced 215wpc at 0.1% THD+N and 226wpc at 1% THD+N at 8 ohms. This exceeds the 200-watt power rating by Marantz. The measured 96dB SINAD or .0015% THD+N all the way up to 100 watts/ch. That’s a very good distortion figure. There was a distortion blip in one of the channels at 50 watts which rose to .005% THD+N. I initially thought there was a bad channel or my test fixture was whack, but I figured out this was caused by driving just 1CH of the 2CH blade. This happened with any channel driven by itself, which I suspect is causing a slight load imbalance. This is completely inaudible and only mentioned for academic purposes. Incidentally, Marantz was unable to replicate this in their measurements as they observed the same distortion whether one or both channels were driven on any power blade.

 

Marantz Amp 10  1kHz PSweep (2CH) - 4 ohms

When driving 4-ohm loads, the Amp 10 produced 428wpc at 0.1% THD+N and 457wpc at 1% THD+N with 2CH driven. I always love seeing amps double down with halving load impedance while also exceeding their published power specs like we see here. The 96dB SINAD or .0015% THD+N was maintained all the way up to 200 watts/ch.

 

Marantz Amp 10  1kHz PSweep (2CH) - 8 ohms - Bridged

When driving 8 ohm loads in bridged configuration, the Amp 10 produced 519wpc at 0.1% THD+N and 550wpc at 1% THD+N with 2CH driven. This is impressive as the Amp 10 was delivering nearly all of the power available from the supply bank for the blade.

I always love seeing amps double down with halving load impedance while also exceeding their published power specs like we see here. The 96dB SINAD or .0015% THD+N was maintained all the way up to 350 watts/ch. I definitely recommend bridging unused channels if you’re running speakers with a minimum impedance of 6 ohms.

 

Marantz Amp 10  1kHz PSweep (2CH) - 4 ohms - Bridged

Caution: Marantz clearly states the Amp 10 should be used with 8-ohm nominal speakers when bridging, but I still couldn’t resist testing it into a 4-ohm load to see what it could produce. Be warned that when bridging an amp in a Bridge Tied Load configuration like this, each amplifier sees ½ the load impedance. Thus, each of the two amplifiers in the Amp 10 are really driving a 2-ohm load, which is a risk of over current at full power if the amplifier cannot handle it.  When driving 4-ohm loads in bridged configuration, the Amp 10 produced 597wpc at 0.1% THD+N and 612wpc at 1% THD+N with 2CH driven. SINAD dropped a bit to 94dB or .002% THD+N. The Amp 10 didn’t like this and shut down with a red flashing illumination from the porthole. To anyone bridging the Amp 10, I caution doing so if your speakers are 4-ohm rated. I am currently running my 4-ohm Perlisten S7t towers in bridged mode without incident but I’m not running out to tell you to do similar.

 

Marantz Amp 10 CEA 2006 Dynamic Power – 4 ohms

As indicated earlier, the CEA 2006 Dynamic Power burst tests produced virtually identical power results to our 1kHz power sweep tests. This is the type of behavior you will see from regulated power supplies. The give you more stable continuous power but less dynamic power for transients compared to a non-regulated centralized power supply.

There are two ways of looking at the dynamic headroom situation:

• The Amp 10 has no dynamic headroom IF you consider it a 200 wpc amplifier.
• The Amp 10 has +2.5 dB of dynamic headroom IF you consider it a 125 wpc amplifier (based on the horizontal line on the power curve before the knee and clipping sets in).

Power Table Summary of Results

Marantz Amp 10 Power Measurement Table

* Marantz does not recommend bridging the Amp 10 when driving 4-ohm speakers. The amp could current limit and potentially shut down at max power, which is what happened in my max power sweep test. In practice, the Amp 10 has been driving my 4-ohm Perlisten S7ts in bridged mode without incident when testing a sustained loud (> 85dB) output in my large family room.

SNR & Crosstalk

Marantz Amp 10 SNR @ 1 Watt (a-wt)

Marantz Amp 10 CH-CH Crosstalk (1CH, Undriven) @ 100 watts

Summary

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.