Cambridge Audio EVO 150 Streaming Integrated Amplifier Bench Test Results!

Cambridge Audio EVO 150 DeLorean Edition Introduction

The Cambridge Audio DeLorean Edition Streaming HDMI Integrated Amplifier is a limited edition version of their EVO 150, offering the same performance but with cosmetic upgrades featuring a unique bare metal design inspired by the iconic DeLorean DMC-12. The EVO 150 power section using the Hypex Ncore NC252MP Class D amplifier module and StreamMagic Gen 4 module for what the company claims to be an “unparalleled streaming experience”. The EVO 150 supports Bluetooth aptX HD, Google Home, Apple Airplay and Roon multiroom systems. Analog lovers rejoice as the EVO 150 has an onboard MM phono stage that wasn’t just an afterthought as you will see in our bench test results.

Cambridge Audio EVO 150 Backpanel view

The Cambridge Audio EVO 150 has 2 sets of high quality speaker binding posts in case you want to connect two pairs of speakers simultaneously in parallel or if you want to select between two pairs perhaps located in different rooms from the streaming amp. The EVO 150 has preouts and a sub out that is not bass managed.  The EVO 150 supports 1 HDMI ARC for easy streaming access  from your Display device,  2 toslink, 1 COAX and USB-B for your digital sources, and phono MM and 2 additional analog inputs (1 XLR) for your analog sources.

 

Cambridge Audio EVO 150 Top View

The Cambridge Audio EV 150 is packed to the gills with electronics unlike some high end audio components that often have a lot of empty space in a fancy casing. You can see the SMPS power supply towards the front of the unit with digital circuitry towards the back end.

All measurements were conducted using our Audio Precision APx585 8 Channel HDMI Audio Analyzer. 

For more information about how we measure power amplifiers, please see:

Basic Amplifier Measurement Techniques

Cambridge Audio Preamp

The Cambridge Audio EVO 150 has a very capable preamp section. It delivers a clean 4Vrms output though the power amp section will clip at a much lower drive level. If you plan on using the EVO 150 as a preamp only, I’d suggest turning the speaker A/B to off even if you’re not connecting additional speakers to it.

 

Cambridge Audio EVO 150 Preout Output Voltage vs Distortion

As you can see, the noise and distortion is excellent from the preouts on the EVO 150. The preout can’t be driven to clipping and it produces about 107dB SINDAD at 2Vrms which is impressive.

 

Cambridge Audio EVO 150 1 kHz FFT @ 2Vrms Preout

With a 0dBFs input, and output voltage of 2Vrms from the preouts, the FFT looks very good with the 3^rd order harmonic being 97dB below the 1kHz fundamental. 

 

Cambridge Audio EVO 150 Preout Output SNR (a-wt)

With a digital source of 0dBFs, I measured 111dB SNR (a-wt) at 2Vrms via the analog outputs which is excellent and among the quietest I’ve measured from the best preamps on the market.

 

Cambridge Audio EVO 150 FFT Noise Spectrum (fs = 44.1kHz)

With a 44.1kHz digital input, I checked the stopband rolloff and found it to have a smooth rolloff below ½ Nyquist as expected with no residual out of band nasties other than a rise in noise above 50kHz likely caused by the switching noise from the Hypex Ncore amp module. This is nothing to be concerned about.

Phono In, Pre-Out

The  Cambridge Audio EVO 150 has a Moving Magnet (MM) phono preamp. Using the original 3-time constant RIAA curve, I EQ’ed the APx585 source to get the expected flat response of the phono preamp. The source was driven at 1mVrms and up to 5mVrms to determine frequency response, distortion and linearity.

Cambridge Audio EVO 150 Phono Frequency Response (5mVrms input)

The EVO 150 exhibits extremely linear frequency response with -3dB points of 15Hz and 60kHz, respectively. It appears Cambridge Audio applied a shallow subsonic filter below 20Hz to help prevent turntable rumble.

Cambridge Audio EVO 150 Phono Distortion vs Frequency Response (5mVrms input)

The distortion (< 0.003% THD+N or 90dB SINAD) above 80Hz which is excellent. The slight rise in low frequency distortion is likely due to the subsonic filter but its still below .03% THD+N at 20Hz. Most MM phono cartridges output around 5mVrms so it’s a good idea for the phono preamp to be able to handle inputs of 10mVrms without distortion. The EVO 150 maintained excellent distortion behavior with up to 50mVrms input. I’ve never seen a phono stage be able to accept that high of input which is a testament to it's design. This is a much better phono preamp than what we measured on the Arcam A25 Integrated amp that had problems at low frequency with 5mVrms input.

 

Cambridge Audio EVO 150 Phono SNR @ 1 Watt (a-wt)

With a 5mVrms signal on the phono input, I measured 78dB SNR at 1 watt output. This is about 3dB better than I measured on the Yamaha R-N1000A under the exact same test conditions.

 

Cambridge Audio EVO 150 Sub Out Frequency Response

Unfortunately the Cambridge Audio EVO 150 doesn’t have bass management facilities like some of their competitors. The sub out is ruler flat up to about 1kHz with a -3dB of 2.2kHz. You will need to utilize the LPF built into your powered subwoofer if you decide to connect a sub to this system.

Cambridge Audio EVO 150 Power Amp

 Frequency Response & FFT Distortion Tests

 

Cambridge Audio EVO 150 Frequency Response – no load, 8 ohms and 4 ohms

The Cambridge Audio EVO 150 exhibits flat frequency response from 10Hz to 50kHz (-3dB pt) when driven by an analog or digital source (Fs = 192kHz). The frequency response remains extremely consistent with 8 or 4 ohm loads and even unloaded. This is a true load invariant amplifier and should sound consistent regardless of the loudspeaker load impedance.  

Cambridge Audio EVO 150 1 kHz FFT @ 2.83Vrms (1 watt, 8 ohms)

The Cambridge Audio EVO 150 amp section does show power supply products likely due to internal speaker wiring run too close to the mains wiring. It’s important to note the residual noise and hum is at inaudible levels (-90dB). The dominant 2^nd and 3^rd order harmonics are 97dB below the 1kHz fundamental which is good.

Cambridge Audio EVO 150 Power Sweep Tests

 

Cambridge Audio EVO 150  1kHz PSweep (2CH) - 8 ohms

The Cambridge Audio EVO 150 exhibited impressively low distortion (.002% THD + N or 94dB SINAD) for much of the power band. With 2CH driven, the EVO 150 delivered 130 watts/ch at 0.1% THD+N and 148 watts/ch at 1% THD+N into 8-ohms. Hypex rates power of this amp as 150 watts/ch 2CH driven at 1% THD+N so the EVO 150 falls right in line with this spec under similar test conditions.

 

Cambridge Audio EVO 150  1kHz PSweep (2CH) - 4 ohms

The EVO 150 maintained impressively low distortion even when driving 4 ohm loads. With 2CH driven, the EVO 150 delivered 240 watts/ch at 0.1% THD+N and 268 watts/ch at 1% THD+N into 4-ohms. Hypex rates this amp module at 250 watts/ch 2CH driven at 1% THD+N under similar test conditions.

Full Bandwidth Power Testing

While the EVO 150 performed admirably with 1kHz power sweep testing, it didn’t fair quite as well with full bandwidth power testing.

Cambridge Audio EVO 150  Fullbandwidth PSweep (2CH) - 8 ohms

The Cambridge Audio EVO 150 produced 135 watts/ch with 2CH driven from 10Hz to 20kHz but distortion was above 1% and I could hear the power inductors sing under this load. When I scaled the test back to 110 watts/ch, the EVO 150 delivered very clean full bandwidth power with no stress at under 1% THD+N, both channels driven at 8 ohms.

Editorial Note about Continuous Sweep Testing on  Class D Amplifiers

It’s important to note that it’s often tricky to accurately test full bandwidth amplifier power on some Class D amplifiers, especially designs with lower switching frequencies (fs = 80kHz like the Hypex Ncore module). Fullrange sweeps will usually trip or current limit amplifiers like this on the bench. This is usually done to protect the output filter inductors which are necessary to filter out of band switching noise. In real world applications, this usually have little impact when running music/movie program material on actual loudspeakers.

When I repeated the full bandwidth tests for 4-ohm loads, the EVO 150 would shut down during high power sweeps so I was unable to get accurate results. It’s clear that this amp is well protected against continuous full bandwidth power testing. I will be testing the EVO 150 on a pair of Revel F328be 4-ohm speakers to determine if there are any real world impacts and will report back with my listening test results. 

Editorial Note About Dynamic Headroom

Unfortunately, like most Class D amplifiers I've tested in the past, they often don't produce more power during dynamic burst test signals since they use regulated SMPS power supplies designed for the continuous power rating, not peak power delivery. This is where some linear amp designs rated at the same continuous power can have a 1-2dB advantage in dynamic headroom.

Cambridge Audio EVO 150 Power Table

# of CH	Test Type	Power	Load	THD + N
2	CFP-BW	135 watts	8-ohms	> 1%
2	CFP-BW	110 watts	8-ohms	< 1%
2	1kHz Psweep	148 watts	8-ohms	1%
2	1kHz Psweep	130 watts	8-ohms	0.1%
2	1kHz Psweep	268 watts	4-ohms	1%
2	1kHz Psweep	240 watts	4-ohms	0.1%

Cambridge Audio EVO 150 Power Measurement Table

Signal to Noise Ratio (SNR)

Cambridge Audio EVO 150 SNR @ 1 Watt (a-wt)

I always measure amplifiers at 1 watt so that apples to apples comparisons can be made between different products that have different maximum output capabilities.  If you want to know the SNR at rated power, then you simply take the 1 watt rating and add 20* log (V*R)^1/2 / 2.83) where V = Vrms and R is the load. With a 0dBFs input signal, I measured 89dB (a-wt) at 1 watt (8 ohms) which is  a very good figure. In comparison, the Arcam A25 measured about 5dB better under the exact same test conditions so it’s a little quieter than the Cambridge Audio EVO 150 which is about on par with the Yamaha R-N1000A I also recently measured.

Channel to Channel Crosstalk

 

Cambridge Audio EVO 150 CH-CH Crosstalk

The channel to channel crosstalk isolation of the EVO 150 is excellent at > -90dB at 1kHz, and > -80dB at 20kHz. I like to see at least -60dB of ch-ch isolation at high frequencies and the Cambridge easily exceeded this by +20dB. This translates to very good stereo separation.

Conclusion

The Cambridge Audio EVO 150 offers an attractive, compact, powerfully potent, feature rich streaming amplifier that produced mostly really good measurements on my test bench. It’s low noise and distortion performance and load invariant behavior should translate well to sonic transparency no matter what source you decide to stream and loudspeaker you connect to it. It’s clear that Cambridge Audio put great effort into also providing a great analog experience for vinyl lovers with the well engineered MM phono preamp stage built into this unit. Stay tuned for my listening and user experience impressions to help paint a full picture if this is the right streaming amp for your needs.

Product Feature Update: 5/28/24

Cambridge Audio has introduced VU meters and a clock display to its acclaimed CXN100 network player, via an over-the-air software update.

This update was previously announced for the Evo 75, Evo 150 and Evo 150 DeLorean Edition streaming amplifier models, but due to popular demand has been extended to include the CXN100.

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