VinnieRossi Brama Integrated Amplifier Measurements

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

General Information

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

The VinnieRoss Brama was conditioned for 1 hour at 1/8th full rated power (~25W 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 Brama offers five pairs of line-level balanced analog inputs (XLR only), one pair of left/right fixed line-level outputs (XLR), and two sets of speaker-level outputs. The Brama has three gain settings (low/medium/high at 22/28/34dB), unless otherwise stated, the medium setting was used.

Most measurements were made with a 2Vrms line-level analog input. The signal-to-noise (SNR) measurements were made with the default input signal values but with the volume set to achieve the achievable output power of 200W into 8 ohms. For comparison, an SNR measurement was also made with the volume at maximum.

Based on the accuracy and randomness of the left/right volume channel matching (see table below), the Brama volume control is operating in the analog domain. The Brama overall volume range is from -32dB to +27dB (balanced line-level input, speaker output).

Our typical input bandwidth filter setting of 10Hz-22.4kHz was used for all measurements except FFTs and THD versus frequency, where a bandwidth of 10Hz-90kHz was used. Frequency response measurements utilize a DC to 1MHz input bandwidth.

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 VinnieRossi for the Brama compared directly against our own. The published specifications are sourced from VinnieRossi’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 extended to 1MHz, assume, unless otherwise stated, 10W into 8 ohms and 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 line-level analog input (unless specified, assume a 1kHz sinewave at 2Vrms):

For the continuous dynamic power test, the Brama was able to sustain 483W into 4 ohms (~3% THD) using an 80Hz tone for 500ms, alternating with a signal at -10dB of the peak (31W) for 5 seconds, for 247 seconds of the 5 continuous minute before the fault protection circuit engaged due to excessive heat. This test is meant to simulate sporadic dynamic bass peaks in music and movies.

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

In our frequency response plots above (relative to 1kHz), measured across the speaker outputs at 10W into 8 ohms, the Brama is essentially flat within the audi band, and at -3dB right around 200kHz. The Brama appears to be AC coupled, yielding roughly -2.5dB at 5Hz. 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.

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

Above are the phase response plots from 20Hz to 20kHz for the line level input, measured across the speaker outputs at 10W into 8 ohms. The Brama appears to invert polarity (relative to the pin2/3 –  +/- XLR standard), but only yielded +15 degrees of shift at 20Hz, and -15 degrees at 20kHz.

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 line-level input swept from 5Hz 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. Here we see that the deviations between no load and 4 ohms are small at roughly 0.08dB. With a real speaker load, deviations were smaller, at roughly 0.06dB.

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

The chart above shows THD ratios at the speaker-level outputs into 8 ohms as a function of frequency for a sinewave stimulus at the analog line-level input. The blue and red plots are for the left and right channels at 1W output into 8 ohms, purple/green at 10W, and pink/orange at 198W (just shy of the rated output of 200W). The power was varied using the Brama’s volume control. All data are fairly closely lumped together and tell the story of the Brama’s THD performance across most all of our measurements; THD results are dominated and limited by the implementation of a tube per channel in the preamp section. Due to this implementation, varying the conditions at the speaker outputs of the Brama (which utilize transistors) does very little to change the measured THD ratios. Here, we find consistent THD ratios around 0.2% at all frequencies and power levels.

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

The chart above shows THD ratios measured at the speaker-level outputs of the Brama 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. THD ratios into 4 and 8 ohms are close (within roughly 5dB). For the 8-ohm load, THD ratios ranged from 0.005% at 50mW, up to 0.15% at the “knee” at roughly 230W, then up to the 1% THD mark at 255W. For the 4-ohm load, THD ratios ranged from 0.01% at 50mW, up to 0.15% at the “knee” at roughly 420W, then up to the 1% THD mark at 451W.

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

The chart above shows THD+N ratios measured at the speaker-level outputs of the Brama 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). THD+N ratios into 4 and 8 ohms are close (within 3-5dB). THD+N ratios range from roughly 0.05% (50 mW) to 0.15% at the “knees.”

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 Brama as a function of frequency into three different loads (8/4/2 ohms) for a constant input voltage that yields 50W at the output into 8 ohms (and roughly 100W into 4 ohms, and 200W 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. Once again, THD ratios are the same due to the tube in the preamp section, hovering at 0.15-0.2% across the sweep. The 2-ohm data stop at 500Hz due to the protection circuit, which presumably engaged due to excessive heat.

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 Brama 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). Again, all THD ratios are all roughly the same, near the 0.2% mark.

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 Brama 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 was 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). We find that all three IMD traces are essentially the same, again due to the limitations of tube-use in the preamp, and hover around 0.15% across the sweep.

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 Brama 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). We find identical IMD results for all three loads, at 0.4% from 40Hz to 500Hz, then down to 0.006%.

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

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 balanced input. We see significant signal harmonic peaks up to the limits of the FFT (90kHz), ranging from the highest at 2kHz (-55dBrA, or 0.2%) down to the -130dBrA, or 0.00003%, level. Once again, the high THD results are from the use of the tube in each channel of the preamp section. On the right side of the signal peak, we find power-supply-related noise peaks at 60/180/300 Hz, but at relatively low levels. The 60Hz peak dominates at -120/–110dBrA (left/right), or 0.0001%/0.0003%. The other peaks are below -120dBrA, or 0.0001%. This FFT can be characterized as high THD, but relatively low noise.

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

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 balanced input, with the gain set to low and the volume adjusted to achieve the same output. We see essentially the same FFT as with the gain set to medium above.

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

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 balanced input, with the gain set to high and the volume adjusted to achieve the same output. We see essentially the same FFT as with the gain set to medium above.

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 line-level 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) peak is the second (100Hz) signal harmonic at -55dBrA, or 0.2%, and subsequent signal harmonics can be seen down to the -120dBrA, or 0.0001%, level. Power-supply-related noise peaks are the same as the 1kHz FFT above, with the 60Hz peak dominating at -120/–110dBrA (left/right), or 0.0001%/0.0003%.

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 line-level 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 -60dBrA, or 0.1%, while the third-order modulation products, at 17kHz and 20kHz, are at roughly the -70dBrA, or 0.03%, level.

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

Shown above is the FFT of the speaker-level output of the Brama with the APx 32-tone signal applied to the analog 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 are at and below the  -90dBrA, or 0.003%, level.

Squarewave response (10kHz)

Above is the 10kHz squarewave response using the analog line-level 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 Brama’s slew-rate performance. Rather, it should be seen as a qualitative representation of the Brama’s high 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. In this case, we find very clean corners with no over/undershoot.

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

The final graph above is the damping factor as a function of frequency. Both channels track very closely. We can see damping factors of roughly 200 across the entire 20Hz to 20kHz band.

Diego Estan
Electronics Measurement Specialist