Mola Mola Lupe Phono Preamplifier Measurements

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

General information

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

The Mola Mola Lupe was conditioned for 30 minutes at 1Vrms at the output before any measurements were taken.

The Lupe offers three sets of unbalanced RCA inputs and one set of balanced XLR inputs. Each input is configurable via the Mola Mola app (iOS or Android via Bluetooth to the Lupe), and can be set to MM or MC, with a variety of gain and loading options. There are both unbalanced (RCA) and balanced (XLR) outputs. The balanced and unbalanced outputs offer the same gain (i.e., 1Vrms at RCA outputs is also 1Vrms out of XLR outputs). The balanced input, however, yields half the gain of the RCA input (i.e., if 5mVrms at the RCA inputs yields 1Vrms out, then 10mVrms at the XLR inputs is required for 1Vrms out). We found no appreciable differences in terms of THD and noise between output types, but found significant differences in noise between input types (the XLR input yielded more noise). Comparative FFTs are found in this report for the MM configuration for various input/output type configurations.

Unless otherwise stated, the RCA inputs and XLR outputs were used. The default settings for the MM input were: 45dB of gain (5mVrms in, 1Vrms out), 47k ohms input impedance, and 100pF capacitance. The default settings for the MC input were: 67dB of gain (0.5mVrms in, 1Vrms out), 100 ohms input impedance, 0pF capacitance. The default RIAA equalization was used, but the Lupe offers a plethora of other EQ options. The sub-sonic filter was left off by default, but frequency-response data are provided herein with the filter on and off.

The default bandwidth settings for the analyzer were 10Hz to 22.4kHz, with the exception of FFTs and THD vs frequency sweeps (10Hz to 90kHz), as well as frequency response (DC to 1MHz).

Published specifications vs. our primary measurements

The table below summarizes the measurements published by Mola Mola for the Lupe compared directly against our own. The published specifications are sourced from Mola Mola’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, 1mVrms balanced output into 200k ohms (100k ohms unbalanced) and a measurement input bandwidth of 10Hz to 22.4kHz, and the worst case measured result between the left and right channel. For the MC gain setting measurements, the input impedance was set to 1k ohm.

Our primary measurements revealed the following using the unbalanced MM input (unless specified, assume a 1kHz sinewave, 5mVrms input, 1Vrms output into a 200k ohms load, 10Hz to 22.4kHz bandwidth):

* not possible to exceed 4.7Vrms at output regardless of input magnitude

Our primary measurements revealed the following using the unbalanced MC input (unless specified, assume a 1kHz sinewave, 0.5mVrms input, 1Vrms output into a 200k ohms load, 10Hz to 22.4kHz bandwidth):

* not possible to exceed 11Vrms at output regardless of input magnitude

Frequency response - MM input

Above are our measured frequency-response (relative to 1kHz) plots above for the MM input measured at the balanced output. The blue/red traces are with the subsonic filter disengaged, while the purple and green represent the responses with the subsonic filter.  An inverse RIAA EQ is applied to the input sweep, so that if a device were to track the RIAA curve perfectly, a flat line would emerge.

The Lupe is within +/-0.25dB or so of flat from 20Hz to 20kHz, and about +0.4dB (right channel) up at 5Hz. These data do not quite corroborate Mola Mola’s claim of within +/-0.1dB of RIAA equalization. With the subsonic filter engaged, there is steep attenuation below 30Hz, and the -3dB point is at roughly 20Hz. The worst-case channel-to-channel deviation is between 10kHz and 20kHz, where the left channel is at +0.25dB while the right channel is at -0.2dB. In the graph above and some of the graphs below, we see two visible traces: the left channel (blue or purple) and the right channel (red or green). On other graphs, only one trace may be visible, this is because the left and right channels are tracking extremely closely, so as not to show a difference with the chosen axis scales.

Frequency response - MC input

In our measured frequency-response plot above for the MC input, the Lupe yields virtually the same results as with the MM input above.

Phase response - MM input

Above are the phase-response plots of the Lupe for the MM input, measured at the balanced output. The blue/red traces are with the subsonic filter disengaged, while the purple and green represent the responses with the subsonic filter. The Lupe does not invert polarity. Since phono preamplifiers must implement the RIAA equalization curve, which ranges from +19.9dB (20Hz) to -32.6dB (90kHz), phase shift at the output is inevitable. Here we find -20 degrees at 20Hz, -60 degrees at 200Hz, and -90 degrees at 20kHz. With the subsonic filter engaged, we see +130 degrees of shift at 20Hz.

Phase response - MC input

Above is the phase response of the Lupe for the MC input, from 20Hz to 20kHz. We find the same responses as with the MM input above.

THD ratio (unweighted) vs. frequency - MM and MC inputs

The chart above shows THD ratios as a function of frequency, where the input sweep is EQ’d with an inverted RIAA curve. The balanced output voltage is maintained at the reference 1Vrms. The red/blue (L/R) traces represent the MM input, and purple/green for the MC input. For the MM input, THD values range from 0.02% at 20Hz down to 0.0001% at 20kHz. The MC input yielded higher THD ratios, ranging from 0.2% at 20Hz, down to around 0.0003% at 20kHz. It’s important to emphasize that the limiting factor in these THD measurements is the noise floor (the analyzer cannot assign a THD ratio value for a harmonic peak it cannot see below the noise floor). To truly ascertain the THD ratios of the Lupe, long averaged FFTs must be collected to look for the signal harmonic peaks above the noise floor. These can be seen below in this report for a 1kHz and 50Hz input signal.

THD ratio (unweighted) vs. output voltage at 1kHz - MM and MC inputs

The chart above shows THD ratios as a function of output voltage for the balanced output. The red/blue (L/R) traces represent the MM input, and purple/green for MC. For the MM input, THD values at 100mVrms are at 0.005%, then dip as low as 0.00006% between 6 and 8Vrms, then the “knee” just beyond 8Vrms. For the MC input, THD values at 100mVrms are at 0.01%, then steadily decrease down to 0.0003% at 6-8Vrms. The 1% THD values for both inputs are reached at roughly 9Vrms at the output. It’s important to mention that anything above 1-2Vrms is not typically required for most line-level preamps or integrated amps.

THD+N ratio (unweighted) vs. output voltage at 1kHz - MM and MC inputs

Above we can see a plot of THD+N ratios as a function of output voltage for the balanced output. The red/blue (L/R) traces represent the MM input, and purple/green for MC. For the MM input, THD+N values at 100mVrms are at 0.2%, then dip as low as 0.003% around 8Vrms. For the MC input, THD+N values at 100mVrms are at 2%, then dip as low as 0.02% around 8Vrms.

FFT spectrum, 1kHz - MM input (RCA in, XLR out)

Shown above is a fast Fourier transform (FFT) of a 1kHz input sinewave stimulus for the MM input, which results in the reference voltage of 1Vrms (0dBrA) at the balanced output for the unbalanced input. The second (2kHz) signal harmonic can be seen just above the noise floor at -120dBrA, or 0.0001%. Mola Mola claims that THD could not be measured with their current test equipment; however, with these measurements we can show roughly 0.0001% at 1kHz. On the left side of the signal peak, there is a significant 60Hz power-supply fundamental peak at around -75dBrA, or 0.02%. Subsequent noise-related peaks can be seen at 180Hz (-90dBrA, or 0.003%) and 300Hz (-100dBrA, or 0.001%).

FFT spectrum, 1kHz - MM input (RCA in, RCA out)

Shown above is a fast Fourier rransform (FFT) of a 1kHz input sinewave stimulus for the MM input, which results in the reference voltage of 1Vrms (0dBrA) at the unbalanced output for the unbalanced input. We see effectively the same FFT as above, but for slightly more noise out of the left channel.

FFT spectrum, 1kHz - MM input (XLR in, RCA out)

Shown above is a fast Fourier transform (FFT) of a 1kHz input sinewave stimulus for the MM input, which results in the reference voltage of 1Vrms (0dBrA) at the unbalanced output for the balanced input (note 10mVrms in was required to achieve 1Vrms out). Here we see considerably more noise than with the unbalanced inputs, with the strongest peak at 60Hz at -50dBrA, or 0.3%.

FFT spectrum, 1kHz - MM input (XLR in, XLR out)

Shown above is a fast Fourier transform (FFT) of a 1kHz input sinewave stimulus for the MM input, which results in the reference voltage of 1Vrms (0dBrA) at the balanced output for the balanced input (note 10mVrms in was required to achieve 1Vrms out). Here we see essentially the same FFT as above.

FFT spectrum, 1kHz - MC input

Shown above is an FFT of a 1kHz input sinewave stimulus for the MC input at the balanced output for the unbalanced input. As there is 22dB more gain with the MC setting, predictably the noise floor is elevated compared to the MM input FFT. We can see the second (2kHz), third (3kHz), and fourth (4kHz) signal harmonic peaks at between -100 and -105dBrA, or 0.001% and 0.0006%. The 60Hz power-supply noise peak is more pronounced due to the higher gain, at -55dBrA, or 0.2%. The third (180Hz) and fifth (300Hz) noise-related harmonics also dominate at -70 and -80dBrA, or 0.03% and 0.01%.

FFT spectrum, 50Hz - MM input

Shown above is the FFT for a 50Hz input sinewave stimulus measured at the balanced output for the MM 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 only clear signal harmonic is at 100Hz at -105dBrA, or 0.0006%. Power-supply noise-related harmonics can be seen at the fundamental (60Hz) at around -75dBrA, or 0.02%. Subsequent noise-related peaks can be seen at 180Hz (-90dBrA, or 0.003%) and 300Hz (-100dBrA, or 0.001%).

FFT spectrum, 50Hz - MC input

Shown above is the FFT for a 50Hz input sinewave stimulus measured at the balanced output for the MC 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 signal’s second (100Hz) and third (150Hz) harmonics can be seen at -85 and -95dBrA, or 0.006% and 0.002%. The 60Hz power-supply noise peak is at -55dBrA, or 0.2%. The third (180Hz) and fifth (300Hz) noise-related harmonics also dominate at -70 and -80dBrA, or 0.03% and 0.01%.

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

Above is an FFT of the IMD products for an 18kHz and 19kHz summed sinewave stimulus tone for the MM input measured at the balanced output. The input rms values are set so that if summed (for a mean frequency of 18.5kHz) would yield 2Vrms (Reference or 0dBRa) at the output. Here we find the second order modulation product (i.e., the difference signal of 1kHz) at a very low -105dBrA, or 0.0006%. We can also see the third-order modulation products (i.e., 17kHz and 20kHz) sitting at a vanishingly low -125dBrA, or 0.00006%. This is an exceptional IMD result for a phono preamplifier.

Intermodulation distortion FFT (18kHz + 19kHz summed stimulus) - MC

The last graph is an FFT of the IMD products for an 18kHz and 19kHz summed sinewave stimulus tone for the MC input. Here we find the second-order modulation product (i.e., the difference signal of 1kHz) is at -95dBrA, or 0.002%. We can also see the third-order modulation products (i.e., 17kHz and 20kHz) at roughly the same amplitude as the MM setting, sitting at or just below -120dBrA, or 0.0001%.

Diego Estan
Electronics Measurement Specialist