Marantz Model 10 Integrated Amplifier Measurements

Link: reviewed by Jason Thorpe on SoundStage! Ultra on September 1, 2025

General Information

All measurements taken using an Audio Precision APx555 B Series analyzer.

The Marantz Model 10 was conditioned for 1 hour at 1/8th full rated power (~30W into 8 ohms) before any measurements were taken. All measurements were taken with both channels driven, using a 120V/20A dedicated circuit, unless otherwise stated.

The Model 10 offers five analog line-level inputs (three RCA, two XLR), one set of phono inputs (RCA, configurable for MM or MC), line-level pre-outs (RCA and XLR), line-level power-amp inputs (RCA and XLR), and two pair of speaker level outputs. In addition, a ¼″ TRS headphone jack can be found on the front panel. For the purposes of these measurements, the following inputs were evaluated: analog line-level balanced (XLR) input, phono (MM and MC), and the headphone output. There were no appreciable differences between the RCA and XLR inputs in terms of THD and noise, but 1kHz FFTs for both are shown in this report. The balanced inputs offer 6dB less gain than the unbalanced inputs (i.e., the designers expect balanced incoming signals to have twice the voltage as unbalanced signals).

Most measurements were made with a 4Vrms line-level analog input, 5mVrms MM input and 0.5mVrms MC input. For the MC configuration, the Model 10 offers three settings with different input impedances (Low at 33 ohms, Mid at 100 ohms, and High at 390 ohms). For the purposes of these measurements, the Mid setting was used. The signal-to-noise ratio (SNR) measurements were made with the same input signal values but with the volume set to achieve the rated output power of 250W. For comparison, on the analog input, a SNR measurement was also made with the volume at maximum.

Based on the accuracy and randomness at various volume levels of the left/right channel matching (see table below), the Model 10 volume control is likely digitally controlled but operating in the analog domain. The volume control offers a total range from -62dB to +36.4dB (XLR line-level input to speaker level outputs). The range is -99.5dB to 0dB, in 0.5dB increments.

Our typical input bandwidth filter setting of 10Hz-22.4kHz was used for all measurements except FFTs, where a bandwidth of 10Hz-90kHz was used. Frequency response measurements utilize a DC to 1 MHz input bandwidth. Because the Model 10 is a digital amplifier technology that exhibits noise above 20kHz (see FFTs below), the 22.4kHz bandwidth setting was maintained for THD versus frequency sweeps as well. For these sweeps, the highest frequency was 6kHz, to adequately capture the second and third signal harmonics with the restricted bandwidth setting.

Volume-control accuracy (measured at speaker outputs): left-right channel tracking

Published specifications vs. our primary measurements

The table below summarizes the measurements published by Marantz for the Model 10 compared directly against our own. The published specifications are sourced from Marantz’s website, either directly or from the manual available for download, or a combination thereof. With the exception of frequency response, where the Audio Precision bandwidth was set at its maximum (DC to 1MHz), assume, unless otherwise stated, a measurement input bandwidth of 10Hz to 22.4kHz, and the worst-case measured result between the left and right channels.

Our primary measurements revealed the following using the analog input (unless specified, assume a 1kHz sinewave at 4Vrms, 10W output, 8-ohm loading, 10Hz to 22.4kHz bandwidth):

For the continuous dynamic power test, the Model 10 was able to sustain 750W (3% THD) into 4 ohms using an 80 Hz tone for 500ms, alternating with a signal at -10 dB of the peak (75W) for 5 seconds, for 5 continuous minutes without inducing a fault or the initiation of a protective circuit. This test is meant to simulate sporadic dynamic bass peaks in music and movies. During the test, the Model 10 was only slightly warm to the touch.

Our primary measurements revealed the following using the phono-level input, MM configuration (unless specified, assume a 1kHz 5mVrms sinewave input, 10W output, 8-ohm loading, 10Hz to 22.4kHz bandwidth):

Our primary measurements revealed the following using the phono-level input, MC configuration (unless specified, assume a 1kHz 0.5mVrms sinewave input, 10W output, 8-ohm loading, 10Hz to 22.4kHz bandwidth):

Our primary measurements revealed the following using the analog input at the headphone output (unless specified, assume a 1kHz sinewave, 2Vrms input/output, 300 ohms loading, 10Hz to 22.4kHz bandwidth):

Frequency response (8-ohm loading, line-level input)

In our measured frequency-response (relative to 1kHz) chart above, the Model 10 is essentially perfectly flat within the audioband (20Hz to 20kHz). At the extremes the Model 10 is 0dB at 5Hz, and -3dB at just past 60kHz. In the graph above and most of the graphs below, only a single trace may be visible. This is because the left channel (blue or purple trace) is performing identically to the right channel (red or green trace), and so they perfectly overlap, indicating that the two channels are ideally matched.

Frequency response (8-ohm loading, line-level input, bass and treble controls at maximum and minimum)

Above are two frequency-response plots (relative to 1kHz) for the analog input, measured at 10W (8-ohm) at the speaker outputs, with the treble/balance controls set at both minimum and maximum. They show that the Model 10 will provide a maximum gain/cut of approximately 11dB at 20Hz, and a maximum gain/cut of approximately 10dB at 20kHz.

Phase response (8-ohm loading, line-level input)

Above is the phase response plot from 20Hz to 20kHz for the analog input. The Model 10 does not invert polarity and exhibits just past -20 degrees of phase shift at 20kHz.

Frequency response (8-ohm loading, MM phono input)

The chart above shows the frequency response for the phono input (MM configuration) measured across the speaker outputs at 10W into 8 ohms. What is shown is the deviation from the RIAA curve, where the input signal sweep is EQ’d with an inverted RIAA curve supplied by Audio Precision (i.e., zero deviation would yield a flat line at 0dB). We see a maximum deviation of about +0.2/+0.25dB (150Hz and 10kHz-20kHz) from 20Hz to 20kHz for the left channel. The right channel performed better and was essentially perfectly flat within the audioband. Below 20Hz, there’s a significant rise in response, peaking at +2.5dB at 6-7Hz. The high frequency response (above 20kHz) is the same as the line-level response above.

Phase response (MM input)

Above is the phase response plot from 20Hz to 20kHz for the phono input (MM configuration) measured across the speaker outputs at 10W into 8 ohms. The Model 10 does not invert polarity. For the phono input, since the RIAA equalization curve must be implemented, which ranges from +19.9dB (20Hz) to -32.6dB (90kHz), phase shift at the output is inevitable. Here we find a worst case of about -60 degrees at 200Hz, and -120 degrees at 20kHz.

Frequency response (8-ohm loading, MC phono input)

The chart above shows the frequency response for the phono input (MC configuration) measured across the speaker outputs at 10W into 8 ohms. We see essentially the same response as with the MM configuration above.

Phase response (MC input)

Above is the phase response plot from 20Hz to 20kHz for the phono input (MC configuration) measured across the speaker outputs at 10W into 8 ohms. We see essentially the same response as with the MM configuration above.

RMS level vs. frequency vs. load impedance (1W, left channel only)

The chart above shows RMS level (relative to 0dBrA, which is 1W into 8 ohms or 2.83Vrms) as a function of frequency, for the analog input swept from 10Hz to 100kHz. The blue plot is into an 8-ohm load, the purple is into a 4-ohm load, the pink plot is an actual speaker (Focal Chora 806, measurements can be found here), and the cyan plot is no load connected. The chart below . . .

. . . is the same but zoomed in to highlight differences. Zoomed in, we can see a maximum deviation within the audio band of just above 0.02dB from 4 ohms to no load, which is an indication of a very high damping factor, or low output impedance. The maximum variation in RMS level when a real speaker was smaller, deviating by about 0.01dB within the flat portion of the curve (20Hz to 10kHz).

THD ratio (unweighted) vs. frequency vs. output power

The chart above shows THD ratios at the output into 8 ohms as a function of frequency (20Hz to 6kHz) for a sinewave stimulus at the analog input. The blue and red plots are for left and right channel at 1W output into 8 ohms, purple/green at 10W, and pink/orange at 250W (rated power). The 10W data exhibited the lowest THD values, 0.0001% from 20Hz to 1kHz, then up to 0.00025% at 6kHz. The 1W data hovered around the 0.0002% across the sweep, and the 250W THD data ranged from 0.0001-0.0002% at 20Hz to 200Hz, then a steady rise to 0.001% at 6kHz.

THD ratio (unweighted) vs. frequency at 10W (MM and MC phono input)

The chart above shows THD ratio as a function of frequency plots for the phono input measured across an 8-ohm load at 10W for the MM (blue/red) and MC (purple/green) configurations. The input sweep is EQ’d with an inverted RIAA curve. The MM THD values vary from around 0.005% at 20Hz then a steady decline down to 0.0003% at 6kHz. The MC THD values vary from around 0.05% at 20Hz then a steady decline down to 0.0005% at 6kHz. The decline in THD values as a function of frequency is a function of the noise floor reduction at higher frequencies due to the implementation of RIAA equalization. The analyzer cannot assign a THD value for a harmonic peak it cannot see below the noise floor.

THD ratio (unweighted) vs. output power at 1kHz into 4 and 8 ohms

The chart above shows THD ratios measured at the output of the Model 10 as a function of output power for the analog line level-input, for an 8-ohm load (blue/red for left/right) and a 4-ohm load (purple/green for left/right), with the volume set to maximum. The 8 and 4-ohm data are closely matched (with 2-3dB). The 8-ohm THD data range from 0.003% at 50mW, down to 0.0002% just before the “knee,” at roughly 220W. The 4-ohm THD data range from 0.005% at 50mW, down to 0.0003% just before the “knee,” at roughly 500W. The 1% THD marks were seen at 340W and 650W.

THD+N ratio (unweighted) vs. output power at 1kHz into 4 and 8 ohms

The chart above shows THD+N ratios measured at the output of the Model 10 as a function of output power for the analog line level-input, for an 8-ohm load (blue/red for left/right) and a 4-ohm load (purple/green for left/right), with the volume set to maximum. The 4-ohm data yielded a consistent 3-4dB higher THD+N result across the sweep compared to the 8-ohm data. The 8-ohm data ranged from 0.03% at 50mW down to 0.0006% at the “knee.”  The 4-ohm data ranged from 0.05% at 50mW down to 0.0006% at the “knee.”

THD ratio (unweighted) vs. frequency at 8, 4, and 2 ohms (left channel only)

The chart above shows THD ratios measured at the output of the Model 10 as a function of load (8/4/2 ohms) for a constant input voltage that yielded 100W at the output into 8 ohms (and roughly 200W into 4 ohms, and 400W into 2 ohms) for the analog line-level input. The 8-ohm load is the blue trace, the 4-ohm load the purple trace, and the 2-ohm load the pink trace. We find increasing levels of THD from 8 to 4 (2-3dB) to 2 ohms (6-7dB). Overall, even with a 2-ohm load at roughly 400W, THD values were fairly low and flat within the audioband, between 0.0004% and 0.001%.

THD ratio (unweighted) vs. frequency into 8 ohms and real speakers (left channel only)

The chart above shows THD ratios measured at the output of the Model 10 as a function of frequency into an 8-ohm load and two different speakers for a constant output voltage of 2.83Vrms (1W into 8 ohms) for the analog line-level input. The 8-ohm load is the blue trace, the purple plot is a two-way speaker (Focal Chora 806, measurements can be found here), and the pink plot is a three-way speaker (Paradigm Founder Series 100F, measurements can be found here). The measured THD ratios for the real speakers were higher than for the 8-ohm resistive load between 20Hz and 400Hz. The highest result, as is usually the case, was at 20Hz into the two-way speaker at 0.01%, compared to 0.0002% into the dummy load. At 100Hz, both speakers yielded THD ratios of 0.0006%, compared to 0.0002% into the dummy load. In the important midrange frequencies of 400Hz to 6kHz, all THD ratios were essentially the same, between 0.0002% and 0.0001%.

IMD ratio (CCIF) vs. frequency into 8 ohms and real speakers (left channel only)

The chart above shows intermodulation distortion (IMD) ratios measured at the output of the Model 10 as a function of frequency into an 8-ohm load and two different speakers for a constant output voltage of 2.83Vrms (1W into 8 ohms) for the analog line-level input. Here the CCIF IMD method is used, where the primary frequency is swept from 20kHz (F1) down to 2.5kHz, and the secondary frequency (F2) is always 1kHz lower than the primary, with a 1:1 ratio. The CCIF IMD analysis results are the sum of the second (F1-F2 or 1kHz) and third modulation products (F1+1kHz, F2-1kHz). The 8-ohm load is the blue trace, the purple plot is a two-way speaker (Focal Chora 806, measurements can be found here), and the pink plot is a three-way speaker (Paradigm Founder Series 100F, measurements can be found here). All IMD results are similar, hovering from 0.0005% to 0.001% across the measured frequency range.

IMD ratio (SMPTE) vs. frequency into 8 ohms and real speakers (left channel only)

The chart above shows IMD ratios measured at the output of the Model 10 as a function of frequency into an 8-ohm load and two different speakers for a constant output voltage of 2.83Vrms (1W into 8 ohms) for the analog line-level input. Here, the SMPTE IMD method was used, where the primary frequency (F1) is swept from 250Hz down to 40Hz, and the secondary frequency (F2) is held at 7kHz with a 4:1 ratio. The SMPTE IMD analysis results consider the second (F2 ± F1) through the fifth (F2 ± 4xF1) modulation products. The 8-ohm load is the blue trace, the purple plot is a two-way speaker (Focal Chora 806, measurements can be found here), and the pink plot is a three-way speaker (Paradigm Founder Series 100F, measurements can be found here). All IMD results are effectively the same, hovering just below 0.002% across the sweep.

FFT spectrum – 1kHz (XLR line-level input)

Shown above is the fast Fourier transform (FFT) for a 1kHz input sinewave stimulus, measured at the output across an 8-ohm load at 10W for the analog line-level XLR input. We see that the signal’s second (2kHz) and third (3kHz) harmonics dominate at -140/-130dBrA (left/right), or 0.00003/0.00001%, and -120dBrA, or 0.0001%. Subsequent signal harmonics can be seen at -135dBrA and below. Below 1kHz, we see traditional noise peaks from the implementation of a linear power supply at the odd-harmonic positions (60/180/300/420/540Hz etc). Given the enormous size of the power supply, however, the peaks are low in level, at -130/-120dBrA (left/right) and below. We also see a rise in the noise floor above 30kHz, indicative of digital amplifier technology.

FFT spectrum – 1kHz (RCA line-level input)

Shown above is the fast Fourier transform (FFT) for a 1kHz input sinewave stimulus, measured at the output across an 8-ohm load at 10W for the analog line-level RCA input. The FFT is almost identical to the balanced FFT above, except for a slightly higher peak at the second (2kHz) harmonic position.

FFT spectrum – 1kHz (MM phono input)

Shown above is the FFT for a 1kHz input sinewave stimulus, measured at the output across an 8-ohm load at 10W for the phono input (MM configuration). We see the second (2kHz) signal harmonic dominating at around -110dBrA, or 0.0003%. Other signal harmonics are difficult to identify amongst the power-supply-related noise peaks. The most significant power-supply-related noise peak can be seen at 180Hz at -90dBrA, or 0.003%. Higher-order power-supply-related peaks can also be seen at lower amplitudes.

FFT spectrum – 1kHz (MC phono input)

Shown above is the FFT for a 1kHz input sinewave stimulus, measured at the output across an 8-ohm load at 10W for the phono input (MC configuration). We see the second (2kHz) signal harmonic dominating at around -100dBrA, or 0.001%. Other signal harmonics are difficult to identify amongst the power-supply-related noise peaks. The most significant power-supply-related noise peak can be seen at 180Hz at -70dBrA, or 0.03%. Higher order power-supply-related peaks can also be seen at lower amplitudes.

FFT spectrum – 50Hz (line-level input)

Shown above is the FFT for a 50Hz input sinewave stimulus measured at the output across an 8-ohm load at 10W for the analog input. The X axis is zoomed in from 40Hz to 1kHz, so that peaks from noise artifacts can be directly compared against peaks from the harmonics of the signal. The most predominant (non-signal) peaks are the signal third (150Hz) signal harmonic and the power-supply-related third (180Hz) harmonic, both around -120dBrA or 0.0001%. Subsequent power-supply-related noise peaks can be seen just below the -120dBrA level.

FFT spectrum – 50Hz (MM phono input)

Shown above is the FFT for a 50Hz input sinewave stimulus measured at the output across an 8-ohm load at 10W for the phono input (MM configuration). The X axis is zoomed in from 40Hz to 1kHz, so that peaks from noise artifacts can be directly compared against peaks from the harmonics of the signal. The most predominant (non-signal) peaks are the signal second (100Hz) harmonic and the power-supply-related third (180Hz) harmonic, at -95dBrA, or 0.002%, and -90dBrA, or 0.003%.

FFT spectrum – 50Hz (MC phono input)

Shown above is the FFT for a 50Hz input sinewave stimulus measured at the output across an 8-ohm load at 10W for the phono input (MC configuration). The X axis is zoomed in from 40Hz to 1kHz, so that peaks from noise artifacts can be directly compared against peaks from the harmonics of the signal. The most predominant (non-signal) peaks are the power-supply-related primary (60Hz) and third (180Hz) harmonics, at -75dBrA, or 0.02%, and -70dBrA, or 0.03%. Signal harmonics are difficult to identify above the higher noise-floor.

Intermodulation distortion FFT (18kHz + 19kHz summed stimulus, line-level input)

Shown above is an FFT of the intermodulation distortion (IMD) products for an 18kHz + 19kHz summed sinewave stimulus tone measured at the output across an 8-ohm load at 10W for the analog input. The input RMS values are set at -6.02dBrA so that, if summed for a mean frequency of 18.5kHz, would yield 10W (0dBrA) into 8 ohms at the output. We find that the second-order modulation product (i.e., the difference signal of 1kHz) is at -120dBrA, or 0.0001%, while the third-order modulation products, at 17kHz and 20kHz, are just below -110dBrA, or 0.0003%.

Intermodulation distortion FFT (line-level input, APx 32 tone)

Shown above is the FFT of the speaker-level output of the Model 10 with the APx 32-tone signal applied to the input. The combined amplitude of the 32 tones is the 0dBrA reference, and corresponds to 10W into 8 ohms. The intermodulation products—i.e., the “grass” between the test tones—are distortion products from the amplifier and below the very low -140dBrA, or 0.00001%, level.

Intermodulation distortion FFT (18kHz + 19kHz summed stimulus, MM phono input)

Shown above is an FFT of the intermodulation distortion (IMD) products for an 18kHz + 19kHz summed sinewave stimulus tone measured at the output across an 8-ohm load at 10W for the phono input (MM configuration). We find that the second-order modulation product (i.e., the difference signal of 1kHz) is at -90dBRa, or 0.003%, while the third-order modulation products, at 17kHz and 20kHz, are just below -110dBrA, or 0.0003%.

Intermodulation distortion FFT (18kHz + 19kHz summed stimulus, MC phono input)

Shown above is an FFT of the intermodulation distortion (IMD) products for an 18kHz + 19kHz summed sinewave stimulus tone measured at the output across an 8-ohm load at 10W for the phono input (MC configuration). We find that the second-order modulation product (i.e., the difference signal of 1kHz) is at -90dBRa, or 0.003%, while the third-order modulation products, at 17kHz and 20kHz, are just below -110dBrA, or 0.0003% (right channel only).

Squarewave response (10kHz)

Above is the 10kHz squarewave response using the analog input, at roughly 10W into 8 ohms. Due to limitations inherent to the Audio Precision APx555 B Series analyzer, this graph should not be used to infer or extrapolate the Model 10’s slew-rate performance. Rather, it should be seen as a qualitative representation of its reasonably extended bandwidth. An ideal squarewave can be represented as the sum of a sinewave and an infinite series of its odd-order harmonics (e.g., 10kHz + 30kHz + 50kHz + 70kHz . . .). A limited bandwidth will show only the sum of the lower-order harmonics, which may result in noticeable undershoot and/or overshoot, and softening of the edges. Due to Model 10’s bandwidth, we can see visible over-shoot in the corners of the waveform. In addition, we can see the 700kHz switching oscillator frequency used in the digital amplifier section visibly modulating the waveform.

Squarewave response (10kHz, 250kHz bandwidth)

Above is the same 10kHz squarewave response using the analog input as seen in the graph above, but this time applying a 250kHz bandwidth filter in the analyzer to remove the effect from the switching oscillator. We find the same visible over-shoot in the corners of the waveform.

FFT spectrum of 700kHz switching frequency relative to a 1kHz tone

The Model 10’s class-D amplifier relies on a switching oscillator to convert the input signal to a pulse-width-modulated (PWM) squarewave (on/off) signal before sending the signal through a low-pass filter to generate an output signal. The oscillator switches at a rate of about 700kHz, and this graph plots a wide bandwidth FFT spectrum of the amplifier’s output at 10W into 8 ohms as it’s fed a 1kHz sinewave. We can see that the 700kHz peak is quite evident at -50dBrA. We also see a clear rise in the noise floor above 30kHz all the way to the 700kHz peak. This very-high-frequency noise is in the signal, but is far above the audio band—and is therefore inaudible—and so high in frequency that any loudspeaker the amplifier is driving should filter it all out anyway.

Damping factor vs. frequency (20Hz to 20kHz)

The final plot above is the damping factor as a function of frequency. Both channels show a relatively constant damping factor from 20Hz to 20kHz. The damping factor for the left channel ranges from just over 1000 down to 700 at 20kHz, while the right channel ranges from 900 down to 600 at 20kHz. These are very high damping factor results, and they explain the Model 10’s exemplary flat frequency-response results into different loads.

Diego Estan
Electronics Measurement Specialist