This is a review and detailed measurements of the Rogue Audio Sphinx V3 integrated amplifier with tube buffer. It is on kind loan from a member and costs US $1,599.
The front panel of the Sphinx portrays a high-end look with its thick metal:
Alas, that thin metal surrounding it, takes that impression away. I liked the very wide apart inputs and output terminals which "should" bode well for crosstalk measurements:
There is good bit of weight to the unit courtesy of power transformer. I like the inclusion of the balance control. As you see in the first picture, I had to use it to get same gain out of both channels.
Protection circuit was well done with automatic recovery and worked great no matter how hard I pushed it.
Internal amplification is provided by a pair of Hypex UCD 180 OEM class D amplifiers. A buffer state made out of tubes completes the picture.
The amplifier has won many accolades as indicated by their mention on the product page:
Let's see if objectively they are right.
Rogue Audio Sphinx V3 Measurements
As usual, I set the gain to 29 dB and feed the amp a 1 kHz tone into 4 ohm at 5 watts and see what we get:
What we get is not very nice. Broad set of harmonics to the tune of -80 dB do away with any notion of "tube sound." Add fair bit of noise and SINAD which is a measure of distortion+noise sinks quite low:
That's 10 dB worse than the media across 140 amplifiers tested so far. Not good. As a reference, Hypex specifications shows a SINAD of 84 dB so 15 dB was lost in the addition of the buffer stage in this amplifier.
Another thing that is not good is signal to noise ratio:
So even at full power your 2 bits short of CD's dynamic range.
The shocker was the normally "innocent" crosstalk test which just about every amplifier does well in:
Then comes Sphinx, losing to our $20 throw-away amplifier! Clearly zero attention was paid to isolation of the two channels.
Frequency response also shows sloppy attention to producing the audible band properly:
Let's measure our power vs distortion:
Definitely much less happy driving 4 ohm load. Here is our peak and max power:
So moderately powerful although without much headroom.
Conclusions
Rogue Audio takes a perfectly serviceable Hypex UcD 180 amplifiers and adds copious amount of noise and distortion with its front-end. Mind you, despite use of the tube, it doesn't give that 2nd harmonic dominant result. It just raises the noise and distortion, robbing you of transparency. But hey, folks buy audio products by how many myths are included in their design and Rogue audio gets there with that tube stage. Perfect marketing, poor engineering. Story of high-end audio.
Needless to say, I can NOT recommend the Rogue Audio Sphinx V3. You can get plenty of better amplifiers for this level of money.
------------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The front panel of the Sphinx portrays a high-end look with its thick metal:
Alas, that thin metal surrounding it, takes that impression away. I liked the very wide apart inputs and output terminals which "should" bode well for crosstalk measurements:
There is good bit of weight to the unit courtesy of power transformer. I like the inclusion of the balance control. As you see in the first picture, I had to use it to get same gain out of both channels.
Protection circuit was well done with automatic recovery and worked great no matter how hard I pushed it.
Internal amplification is provided by a pair of Hypex UCD 180 OEM class D amplifiers. A buffer state made out of tubes completes the picture.
The amplifier has won many accolades as indicated by their mention on the product page:
Let's see if objectively they are right.
Rogue Audio Sphinx V3 Measurements
As usual, I set the gain to 29 dB and feed the amp a 1 kHz tone into 4 ohm at 5 watts and see what we get:
What we get is not very nice. Broad set of harmonics to the tune of -80 dB do away with any notion of "tube sound." Add fair bit of noise and SINAD which is a measure of distortion+noise sinks quite low:
That's 10 dB worse than the media across 140 amplifiers tested so far. Not good. As a reference, Hypex specifications shows a SINAD of 84 dB so 15 dB was lost in the addition of the buffer stage in this amplifier.
Another thing that is not good is signal to noise ratio:
So even at full power your 2 bits short of CD's dynamic range.
The shocker was the normally "innocent" crosstalk test which just about every amplifier does well in:
Then comes Sphinx, losing to our $20 throw-away amplifier! Clearly zero attention was paid to isolation of the two channels.
Frequency response also shows sloppy attention to producing the audible band properly:
Let's measure our power vs distortion:
Definitely much less happy driving 4 ohm load. Here is our peak and max power:
So moderately powerful although without much headroom.
Conclusions
Rogue Audio takes a perfectly serviceable Hypex UcD 180 amplifiers and adds copious amount of noise and distortion with its front-end. Mind you, despite use of the tube, it doesn't give that 2nd harmonic dominant result. It just raises the noise and distortion, robbing you of transparency. But hey, folks buy audio products by how many myths are included in their design and Rogue audio gets there with that tube stage. Perfect marketing, poor engineering. Story of high-end audio.
Needless to say, I can NOT recommend the Rogue Audio Sphinx V3. You can get plenty of better amplifiers for this level of money.
------------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/