This is a review and detailed measurements of the Cambridge Audio Solo Phono Preamplifier. It is on kind loan from a member. The solo costs US $179.99 including free shipping from Amazon.
The solo only supports Moving Magnet (MM) cartridges so there are no controls in front other than a (soft) power switch:
The solo feels and looks good, setting it above typical budget audio products. Love the attention to detail on the back:
Notice the upside down labels so that when you look at it from the top as you often do, you can still read them.
Also great to see is a balance control.
Inclusions of an internal power supply completes a nice picture.
I had previously reviewed the Cambridge Audio Duo. The hope is that the Solo has the same performance as the moving magnet subset of that unit. Let's get into the measurements and see if that is the case.
Phono Stage Measurements
For our dashboard, I now use a 5 millivolt input. The duo was tested at 11+ millivolts so they are not exactly comparable:
Performance is essentially limited by mains noise which is common in phono stages. There are infinite ways to change grounding here and above is my best shot after a few minutes. Key is that there is no distortion products. If you can manage ground loops/hum, the amp is fully transparent to your cartridge. Here is how the Solo ranks:
Speaking of noise, here is our signal to noise ratio:
I was expecting a flat response like the Duo produced. Alas, I did not get that:
I looked up the spec as noted in the graph and indeed, it is twice as bad as the Duo spec. Threshold of hearing for broad frequency response variations in low frequencies is just 0.5 dB so these swings could be audible.
Here is what our noise and distortion looks like relative to input level:
The Schiit Mani is $50 cheaper so good to see the Solo beats it by good margin including not clipping even at high input level of 100 millivolts.
We can run the same test relative to frequency:
These measurements may be hum dominated though so hard to tell if what is shown is distortion or just noise.
Finally here is a new test I am developing. Many times by accident I overdrive these phono preamps and I see them take a while to produces a valid signal even after I have reduced the input level. The goal here is to simulate the same thing happening with a pop/tick from the cartridge against a much lower baseline signal. And do so within the constraints of my analyzer.
The lowest signal my analyzer can generate in 10 Hz. So I set it to that. Then I sample the output at multiples of it (I think 64 times a second) to fully capture that waveform. Then, I program the generator to operate at two levels, one at 0.1 volt and the other 40 dB lower than it. The peaks are very short as to simulate a pop/glitch. Here is what I get:
At the bottom in dashed blue is the Audio Precision analyzer testing itself. We see that it takes it about 0.4 seconds to drop from that peak down to baseline level.
The one in red is the same signal now routed through the Cambridge Solo. The measured time now (shown through two red cursor lines) is 1.6 seconds.
My confidence is not high in this test yet but it is something I am going to run in the future until I figure out its limitations/value.
Conclusions
The Cambridge Audio Solo is an attractive, well-designed phono stage. Alas, it is not a defeatured Duo. Performance is a step down in the important frequency response. So my recommendation is to stretch your dollars and buy the Duo. It supports both MC and MM cartridges and has a headphone amplifier to boot.
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As always, questions, comments, corrections, etc. are welcome.
Google is marking the word "defeatured" above as spelled wrong. Quick search on Google no less, shows it to be correctly spelled. Seems to me, they must not have enough engineers to write a proper spell checker for Chrome browser. I like to act as their agent to collect money for them to hire the right people to remedy this. So please donate generously so that we can all benefit from articles with less typos using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The solo only supports Moving Magnet (MM) cartridges so there are no controls in front other than a (soft) power switch:
The solo feels and looks good, setting it above typical budget audio products. Love the attention to detail on the back:
Notice the upside down labels so that when you look at it from the top as you often do, you can still read them.
Also great to see is a balance control.
Inclusions of an internal power supply completes a nice picture.
I had previously reviewed the Cambridge Audio Duo. The hope is that the Solo has the same performance as the moving magnet subset of that unit. Let's get into the measurements and see if that is the case.
Phono Stage Measurements
For our dashboard, I now use a 5 millivolt input. The duo was tested at 11+ millivolts so they are not exactly comparable:
Performance is essentially limited by mains noise which is common in phono stages. There are infinite ways to change grounding here and above is my best shot after a few minutes. Key is that there is no distortion products. If you can manage ground loops/hum, the amp is fully transparent to your cartridge. Here is how the Solo ranks:
Speaking of noise, here is our signal to noise ratio:
I was expecting a flat response like the Duo produced. Alas, I did not get that:
I looked up the spec as noted in the graph and indeed, it is twice as bad as the Duo spec. Threshold of hearing for broad frequency response variations in low frequencies is just 0.5 dB so these swings could be audible.
Here is what our noise and distortion looks like relative to input level:
The Schiit Mani is $50 cheaper so good to see the Solo beats it by good margin including not clipping even at high input level of 100 millivolts.
We can run the same test relative to frequency:
These measurements may be hum dominated though so hard to tell if what is shown is distortion or just noise.
Finally here is a new test I am developing. Many times by accident I overdrive these phono preamps and I see them take a while to produces a valid signal even after I have reduced the input level. The goal here is to simulate the same thing happening with a pop/tick from the cartridge against a much lower baseline signal. And do so within the constraints of my analyzer.
The lowest signal my analyzer can generate in 10 Hz. So I set it to that. Then I sample the output at multiples of it (I think 64 times a second) to fully capture that waveform. Then, I program the generator to operate at two levels, one at 0.1 volt and the other 40 dB lower than it. The peaks are very short as to simulate a pop/glitch. Here is what I get:
At the bottom in dashed blue is the Audio Precision analyzer testing itself. We see that it takes it about 0.4 seconds to drop from that peak down to baseline level.
The one in red is the same signal now routed through the Cambridge Solo. The measured time now (shown through two red cursor lines) is 1.6 seconds.
My confidence is not high in this test yet but it is something I am going to run in the future until I figure out its limitations/value.
Conclusions
The Cambridge Audio Solo is an attractive, well-designed phono stage. Alas, it is not a defeatured Duo. Performance is a step down in the important frequency response. So my recommendation is to stretch your dollars and buy the Duo. It supports both MC and MM cartridges and has a headphone amplifier to boot.
--------
As always, questions, comments, corrections, etc. are welcome.
Google is marking the word "defeatured" above as spelled wrong. Quick search on Google no less, shows it to be correctly spelled. Seems to me, they must not have enough engineers to write a proper spell checker for Chrome browser. I like to act as their agent to collect money for them to hire the right people to remedy this. So please donate generously so that we can all benefit from articles with less typos using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/