Pros: Gives extra power and increased sound quality to low voltage sources
Cons: Non that I can think of
This is a review of the Burson Audio Cable+ RCA to RCA active cable.
The Burson Audio Cable+ was sent to me by Burson Audio for me as a loaner unit to test it out, thanks to Burson Audio for letting me check out the Cable+.
The price at the time for this review is $99 for one 1.2 m cable and $180 for two cables. The Cable+ is available for pre-order on Indiegogo right now:
For more information about the Cable+ you can also check out the Burson Audio website:
I’m not in any way affiliated with Burson Audio.
Short introduction to Burson Audio:
Burson Audio is an Australia based company founded in 1996. They’ve specialized in making headphone amplifier and amp/DAC combos, stereo amplifiers and op amps using discrete circuits.
This is what says themselves about their philosophy:
“Our philosophy is simple; the less our components interfere with the audio signal the more complete your musical experience. This is our core design philosophy since we began in 1996. If our equipment is designed well and transparent enough — and it is — then the pace, rhythm, timing dynamics and tonality becomes a natural expression of the music. We feel this can never be achieved with standard circuit building blocks like IC chip op-amps, IC regulators, or even standard transformers. Instead we research and develop customized discrete circuits specifically to suit their applications. Only then does each and every component in the signal path perform at its peak. And only then will the end result match our expectations.”
About me:Click to show! (Click to show)
I’m a 44 year old music and sound lover that changed my focus from speakers to headphones and IEM’s about five years ago. At that time I realized that it wasn’t realistic for me to have all the different setups that I wanted and still house a family of four children and a wife so my interest turned first to full sized headphones and later also IEM’s.
My preferences are towards full sized open headphones and I believe that also says something about what kind of sound signature I prefer (large soundstage in all directions, balanced and organic sound).
My music preferences are pretty much all over the place (only excluding classical music, jazz and really heavy metal). My all-time favorite band is Depeche Mode although I also listen to a lot of grunge/indie, singer/songwriter/acoustical stuff as well as the typical top 40 music.
I do not use EQ, ever.
I’m a sucker for value for money on most things in life Head-Fi related stuff is no exception.
Demo list:Click to show! (Click to show)
Mark Knopfler – Sailing to Philadelphia
Røyksopp (Feat.Susanne Sundfør) – Save Me
Ane Brun – These Days
Michael Jackson – Dirty Diana
Metallica – Die Die My Darling
The Peter Malick Group – Immigrant
Eva Cassidy – Songbird
Thomas Dybdahl – A Lovestory
Norah Jones – Don’t Know Why
Celldweller – Unshakeable
Jack Johnson – Better Together
Seinabo Sey – Younger (Kygo remix)
Dire Straits- So Far Away
Bjørk - Moon
Lupe Fiasco - Deliver
Morrissey – Earth Is the Loneliest Planet
First of all the retail version of the cable plus will be 1.2 meters long and the box with the active components will be situated about 20 cm from one of the ends. It will be available in the following configurations (with courtesy to the Burson Audio site):
3.5mm input / stereo RCA output (perfect for connection between smartphone, tablet, laptop and the stereo amplifier)
Stereo RCA input / stereo RCA output (perfect for connection between sound-card, CD player, DAC and the stereo amplifier)
3.5mm input / 3.5mm output (perfect for car audio. connect between smartphone, tablet and the car amplifier)
When I was first contacted by Burson Audio and they asked me if I could be interested in testing out and posting my thoughts on the Cable+ here on Head-Fi my answer to them was a lot of questions, I simply couldn’t wrap my head around the concept but they were patient (as always) and explained to me what the intention with the product was and how it works.
The cable itself is smooth and flexible while not feeling too thin. The connectors are nothing spectacular but does still feels sturdy enough that I wouldn’t expect any long term problems to occur with them.
I’ll try my best to give a brief description of what the Cable+ is and how it works. According to Burson Audio there are two bottle necks stopping many of today’s audio sources to sound good. The first is the low voltage output from sources such as phones, tablets and lap tops. The second is the audio cables used that where designed in a time when most audio sources had a high voltage output and therefore the cables where made to work optimal with such sources.
In short the Cable+ is an active audio cable. In addition to the regular pair of RCA cables that we’re used to it also has a small box attached. In this box lies the magic. It contains a 24v low noise, high voltage power supply and one of Burson Audio’s praised SS V5i op amps. This set up needs power to work and that’s supplied through a micro USB port located on the box. The idea is that the “magic” in the box shall give the receiving unit (headphone amp, stereo receiver, HT receiver etc.) a more powerful signal making the overall not only louder but also better.
I’ve got to admit I was skeptical (and slightly confused) myself so let’s find out how the Cable+ works in real life usage.
Real life usage:
I’ve test the Cable plus with several units, all connected to my Conductor V2+ and I’ve been listening with the Hifiman HE400i which are the most revealing headphones that I own.
Since this is the RCA version it's not really useful with most portable gear so to start with I dug out my old Asus BDS 700 blu-ray player from storage and hooked it up with some pretty nice analog Monster cables into one of the analog inputs on my Conductor V2+.
The BDS 700 features the CS4398 dac chips which is pretty well liked but even in the days when I was using this player in my main surround system I wasn't very impressed with its performance with CD playback.
First half hour I was going through some of the tracks on my usual demo list and to cut to the chase this was not a very pleasant experience. The V2+ of course has more than enough power to drive the HE400i but I had to crank the volume up to 46 on it to get enough volume to rock. Even when doing so the sound was flat, metallic sounding and pretty unengaging. In this configuration it was also an audible background noise that I've never heard before when pairing the HE400i with the V2+.
After that I added some y-splits to the analog output of the Asus player and hooked up the same Monster cable to one of the analog inputs on the V2+ and the Cable+ to the other. This way I could use the remote to switch instantly between the two inputs.
The first thing I noticed was that the volume was higher when using the Cable+ connection. I had to lower the volume to 39 on the V2+ to get the same listening level (I used a sound meter app to check that the volume was similar on both, although not perfect scientifically it should still be fairly accurate) and listened to the input fed by the V2+ for about half an hour using the same tracks as before.The second thing that was very easily detected was that the background was now completely black and quiet. Furthermore the sound was fuller, richer and with better dynamics. In all this was a sound quality I could enjoy. When going back to the input fed by the Monster cables after this it sounded even worse to my ears than before and there's no doubt in my mind that the Cable+ makes a significant difference to the sound in this kind of setting.
The second unit I tried with the Cable+ was my Pioneer BDP-51FD Blu-ray player. The BDP-51FD is a pretty good CD player in my opinion and I use it connected to my Conductor V2+ with analog cables to get a different signature when I feel for it. It uses four discrete Wolfson wm8740 chips for digital to analog conversion and also has a built-in jitter reduction circuit. The presentation of the BDP-51FD is quite neutral, maybe even slightly on the cool side, and I'd describe its overall signature as "lean and clean".
The BDP-51FD offer both a stereo analog output as well as analog 7.1 outputs and since the front L/R outputs the same signal as the analog outs so no need for any splitters here. I just hooked up one pair of Monster cables to one of the analog inputs on the V2+ and the Cable+ to the other.
I listened to CD's from Sting, Paloma Faith and Robyn for just short of two hours
The first thing I noticed was that the volume was significantly louder when using the Cable+. After using a sound meter app to match the volume I ended up with 42 respectively 48 on the volume know when having my preferred listening volume with the two cables.
The second thing I noticed was that the input with the Monster cable was noticeable flatter sounding while the one with the Cable+ connected had better dynamics. I also noticed that high hats, cymbals and percussions sounded unnatural and a bit fatiguing without the Cable+ while it was sounding very natural with the Cable+ in the chain. The difference with the BDP-51FD is nowhere near as big as what I experienced with my Asus player as source but the sound is definitely more natural, dynamic and less fatiguing with the Cable+. I'd say that it takes the BDP-51FD from sounding good to sounding great.
Just for fun I also ripped the Robyn album to my laptop (FLAC, highest quality) and compared the two analog inputs to the USB input on the V2+. First of all the volume on the USB input is actually identical to that on the analog input without the Cable+. When comparing the internal DAC on the V2+ to the input using the Cable+ I noticed the following: the dynamics is better and the bass is deeper and more natural sounding when using the DAC on the V2+. The Cable+ input has a leaner presentation with a noticeable subdued mid bass presentation (much like the Mojo, no further similarities between the two though) making it lacking some dynamics but sounding very clean and clear on the other hand.
Like I said initially I sometimes use the BDP-51FD as a CD player (not only transport) connected to the V2+ and the Cable+ does make this even more interesting since it makes the BDP-51FD sounding like a very high quality source and makes it much more enjoyable than it was before. I'll definitely be using this solution more from now on.
The last test I did was to hook up my cable TV set-top box to my Conductor V2+ with the Cable+ today. First I used a couple of RCA splitters to connect the set-top box to both the analog inputs on the V2+, one with a short Van Den Hul cable and one with the Cable+.
Once again I experienced a significant rise on volume from the input with the Cable+. I had to put the volume on the input with the regular cable to volume 48 to get the same listening level as I reached with the volume 42 on the input with the Cable+ connected. Not surprisingly the RCA output on the set-top box is not very impressive and using the input with the regular cable was not a pleasant experience with thin sound and vocals sounding as if they were recorded in a metal box, very hollow. When using the input with the Cable+ the sound was fuller and the overall presentation was quite natural and easily usable.
I then disconnected the regular RCA cable and hooked the set-top box up with the V2+ with an optical cable as well using the internal DAC on the V2+. Listening to the internal DAC the volume was actually about the same as connected with the regular RCA cable and significantly lower than with the Cable+. Apart from that the sound from the internal DAC is quite a bit better sounding, it is more natural, has better dynamics and is less fatiguing but despite this the difference between the Cable+ and the regular RCA cable is actually bigger to my ears than the difference between the Cable+ and the internal DAC on the V2+.
This last set up with my cable set-top box is probably one of the most useful ways to hook up the RCA version of the Cable+. Many people will not have a DAC/amp combo available in connection to their TV and many set-top boxes may not have any more digital outputs free after being hooked up to a surround sound receiver. By using the Cable+ and connect it to a headphone amp you’ll get a more than acceptable sound quality and you can avoid using (the often poor sounding, high output impedance) headphone output on your receiver.
The Burson Audio Cable+ has impressed me more than I thought it would. Being a cable sceptic normally and don’t having any experience with similar products I didn’t really know what to expect. By now I should’ve known and trusted Burson Audio though, the Cable+ may be useful to us hard core Head-Fiers in some settings (mostly to get a higher gain in certain configurations as well as with sources lacking digital outputs or various kinds of amplifiers lacking digital inputs) but I think the really big potential lies with the consumers that doesn’t own a DAC, or maybe don’t even know what it is. The concept of just using a different cable, with the same kind of connectors that you’re already used to, instead of adding more boxes around the house, car, cabin or wherever you are located is truly revolutionary to me and hopefully many others will also come to the same conclusion.
Looking at the other termination options with one or two 3.5mm connectors makes the potential for the Cable+ even bigger given the number of tablets, phones and laptops every household has today. To get significant better sound out of these, often poor sounding devices, in a way that’s easily understandable for most people would indeed be a blessing.