I was asked by Burson if I was interested in reviewing their product Burson cable+ and after considering it for a bit I thought it would be a fun challenge. The cable+ was provided free of charge. No affiliations.
The Burson Cable + is a bit of a confusing name because as far as I can tell it is really an audio buffer with an opamp disguised as an cable: in addition to the cable it also isolates the source from the amp (impedance matching) plus adds a 6db gain stage. Some of you may remember the Burson buffer that was sold a few years back, and to me this looks like a similar concept only that it now comes with a cable and several hundred dollars cheaper.
The cable (buffer) comes in a couple of different set-ups but the one I tried was with RCA to 3.5mm stereo jack. I wasn’t able to figure out material used for the cable or plugs, but the electronics are housed in a very nice machined aluminum enclosure. It looks really premium. It is powered by an microusb plug by a separate power supply. The included PSU looked like an apple cell phone charger but this can easily be swapped for another psu as I did. I tried both an USB power bank as well as an ifi ipower 5V - especially the ifi helped further refine the sound.
My previous experience with testing interconnect cables has been that I could hear a positive improvement when going from a poor cable to a good cable such as when I went from an entry-level cable to a diy cable I made based on Zenwave’s Neotech wire. However, often when comparing similar style cables I find the differences are sometimes so subtle it is not even worth pointing out and other times I struggle to even reliably identify a difference. So my expectation going in to this review was that I would need to sit and A/B some cables and really strain my ears to try identify any real differences and then struggle even more to determine if I would prefer one set-up better than the other.
But then again, I didn’t really realize beforehand what a powered cable would do to the sound and I was in for a surprise. To give a clue: I liked it a lot in some set-ups.
Since I only had a cable with 3.5mm stereo jack to RCAs I was limited in my testing to the following: computer integrated audio, mobile devices and a chromecast audio.Testing with a computer
Since I don’t use my desktop computer too often I never bothered to get a separate DAC for it so I have just been using the integrated audio on the motherboard. In other words, the audio was poor as in “flat”, not very clear and definitely not engaging. So this would be a perfect first listening experience with the cables taken straight out of the box.
So from just expecting a minor change from using the new cable, I was floored from what I heard. All of a sudden I heard a really solid stereo-image which I had never experienced before in this set-up. The muddy sound was now much clearer and my bookshelf speakers all of a sudden delivered a punchy and textured bass. Just to be clear, we are not talking about the sound quality of a high quality expensive DAC (not even close) but the improvement was so substantial it was not really a need to do any A/B comparisons. But I still did, of course, and since the Burson cable boost the volume a few db, I even adjusted the sound levels to be similar. Probably the best way to describe the sound is that it’s “cleaned up” to be able to show the max potential of the particular DAC.Testing with mobile devices
I doubt many here on AudioCircle uses a cellphone as a DAC in their main system, so these scenarios maybe are not really applicable. But I was curious so here we go:
Using the cable with an old Samsung Galaxy S4 quickly showed the phone’s internal DAC is not very good. Didn’t matter the sound was cleaned-up and that the signal got a boost - it still didn’t sound very engaging. I also had some weird noise issues using the cable the phone - probably due to a dying battery since it didn’t happen with any of my other devices.
Using the cable with my ipad or my iphone showed some improvement and it started to sound ok. The improvements were in more detail and more refined bass. The changes were definitely noticeable, but not as dramatic of an improvement I heard from the computer - probably because they sounded better from the beginning.
Again - while the sound improved a lot it is still no match for a proper DAC. Chromecast Audio
I have been using a chromecast audio with an old Pioneer Elite receiver in my family/TV room. The receiver is used as pre-amp plus power the surrounds and center in a HT set-up. The mains are powered by a CROWN XLS 2000 drivecore amp.
The chromecast can be connected either via spdif optical or rca. Connecting the chromecast via the optical sounds harsh and fatiguing in my system so I have always used RCAs which had the downside it made the sound a bit too dark.
Using the Burson cable and the sound is now starting to approach really good. I’m really bad explaining sound but the darkness disappeared and instead I heard increased dynamics, better defined bass and more details at the top without getting harsh. Cello, piano, guitars had more texture and air while drums and bass had some more details and punch.The no harsh part is really important to me since I’m more than sensitive to fatiguing systems and therefore don’t really enjoy too analytical/clinical systems much. Lucky for me, there was nothing at all of that.
I also tested the cable buffer between my diy Folsom amp (http://www.audiocircle.com/index.php?topic=138229.0
) and the chromecast audio. Again more dynamics, soundstage and an overall improvement of the sound! The only bad thing is that the gain was borderline too much in this set-up.
If you are a chromecast audio user, adding the cable+ will definitely improve the sound quality.
Here comes the bad news...I didn’t expect that I would like this product so much and I’m now regretting that I don’t have one with RCAs on both sides so I can try it with my better DACs. If I can’t get hold of an adapter, I will cut up the cable and solder on my own.Summing it up
So I have to admit that it was fun to review this cable, but I kind of underestimated how much time it would take - partly because it sounded good so I wanted to test it in as many set-ups as I could. This review also opened up my eyes to opamps. The cable+ uses the Burson v5i and I’m now curious to explore replacing opamps in my other set-ups.
What could be better?: I do wish that it would be possible to swap cable set-ups easier such as different length cables and connections. Perhaps a version with female RCAs would be a good option to add. Having a cable requiring a power supply also requires a little bit of planning to make sure you have an extra outlet close by.
So the conclusion so far is that if the source DAC doesn’t have good outputs, the cable+ will make a very nice impact. I do believe the level of improvement depends a lot on the output stage of the source so the benefits will be system dependent.
Hopefully I can get hold of an adapter in the near future so I can test a couple of better dacs. It may take a while but I will then update this review with a part 2. I will also add a few images.
Thanks to Burson for giving me an opportunity to enjoy the Cable+ in my systems.
Edit: added pictures