[Review] Burson Audio Conductor 3 Reference

This is the second and final part of the review of the Burson Conductor 3 Reference. For those readers who missed the first part, here is a link; Conductor 3 Reference - Part 1. This second part will discuss the sound, the filter settings and the conclusions.

The Sound

Of course, of greatest interest for me was an evaluation of the overall sound quality and characteristics. Three different setups were used for this. First, the preamp output was connected directly to my Canary CA330 mono-blocks. For the second phase of testing, I used the DAC (fixed 2 volt) output into my The Truth pre-stage. The third phase was a head-to-head test between the Burson unit and my Doge 7 tube DAC. For this test, the C3R (DAC output) and my Doge 7 DAC (variable output) were both connected to The Truth Pre-Stage for comparison. It was necessary to use the variable output from the Doge to set the volume level from both sources exactly the same as the DAC output of my Doge 7 is slightly higher voltage compared to that of the Burson unit. Comparison testing required alternately connecting the USB cables from the two DACs to the PC. Note: Just to be thorough, an attempt was made to connect the Pre output from the C3R to The Truth. This was found to be too difficult to adjust and a good sound was never obtained.

Complete, balanced, sophisticated, dare I say "high-end" sound. The C3R is a serious music-maker and not at all out of place when it took over from my Doge 7 DAC. As expected, it has a slightly different overall character, leaning more to the analytical side. Keep in mind that the Doge 7 is 100% tubes in the analog section. The C3R excels in all of what I like to call the "technical" attributes of the sound such as speed, detail, dynamics, sound stage and separation. The width and depth of the sound stage as well as the level of precision of placement of the various instruments and voices was exceptional. At the other end of the spectrum, it doesn't have the velvet finish that I get from the Doge 7. The bass characteristics are worthy of special mention. There were a couple of occasions where I found the bass to be slightly exaggerated, however, generally it was "just right" and most importantly very precise and penetrating. Even at low volume the bass seemed to fill the room and could be felt as well as heard. Quite impressive. Fans of electronic music, techno-pop, synth-pop etc. should really love this unit. It leaves the impression that it can reproduce any imaginable synthesized sound with ease. Playing Yello, Daft Punk and Depeche Mode, and of course Pink Floyd's Dark Side of the Moon was a lot of fun. When it came to artists like Madeleine Peyroux and Miles Davis, I found the tube DAC more to my liking.

DAC Mode test: For this test, the fixed 2.0-volt output was sent to The Truth Pre-stage and then to my Canary amps. This configuration produced the best results. The performance characteristics were as listed in the paragraph above. The head-to-head test of the C3R vs. the Doge 7, both running through The Truth, spotlighted the technical prowess of the Burson unit with its mastery of detail and definition. It also illustrated the qualities of the tube DAC when it comes to jazz and vocal recordings.

Preamp test: The unit performed well when connected directly to the Canary monobloc power amps, however, it didn’t quite attain the performance level that it was capable of running through The Truth. All the detail was there but there was a slight loss of smoothness. It is quite possible that the impedance match between the C3R and the Canary amps less than optimal. On their web site the output impedance is listed as 25 Ohms for the DAC output and I believe that this is the cause of this difference in sound. In a response to one of my emails, Burson did agree that this might be the culprit. Of course, running through The Truth in DAC mode cures that issue as this unit does match up very well with my Canary amps.

Headphones test: As I mentioned earlier, I am not a headphone guy. I did play a few tracks through my $200 Grados and found the results excellent and I suspect that the C3R would be up to the challenge of a pair of $2000. Sennheiser or $4000. Focal headphones.

Filters

This topic is complicated enough to warrant a separate heading! There are 4 filters available to tinker within the Settings menu. These filters are embedded in the DAC chips and Burson decided to give the user access to these adjustments. That's not to say that their functionality is clear and easy to understand! One of them, De-emphasis, gets one line in the manual; "Only turn on if your source is a cassette tape player", so at least this one is reasonably understandable. The other three receive no explanation in the manual, simply a list of the possible settings. There are, however, two links provided in the pdf download of the manual. Accepting the challenge, I did a bit of digging about these filters. The first link brings us to a Forum in which someone has posted graphs comparing the results of different settings of the FIR filter. The second link brings us to a 64-page pdf file of the ESS Datasheet containing several pages of graphs and tables describing the function of the various filters. Beware, this is a very technical document.

Following all this reading, I still didn't know what FIR and DPLL meant so I kept digging; FIR Filter stands for Finite Impulse Response Filter. There is lot of information available on the internet on this subject, being a retired power engineer (not digital electronics), I understood a bit of it, just enough to know it was time to stop reading! The last two filters are called DPLL, one for DSD and the other for PCM. Again, quoting Google search results DPLL stands for Digital Phase-Locked Loop filters, thus, PLL filters modeled in the digital domain. The bottom line was that if I wanted to know how these filters affect the sound and equally importantly, when and why to use them, I would just have to experiment with various settings, and given that are nine FIR settings and four DPLL settings, that makes 32 combinations to try. No thanks, I will pass on that. The filters remained the way they were set when I received the unit, the factory default values, for the whole time that it was in my possession. FYI the default settings are: FIR - AP Fast, DPLL(DSD) - High, DPLL(PCM) - Mid, DE-EMPHASIS - Off.

P.S. In all this research I did find one somewhat useful tidbit; "if your headphones are bright you could try setting the filters to provide some high frequency roll-off".

Conclusions

Clearly this is an engineering dominated design featuring an innovative, possibly unique, audio circuit, power supply, and case design and a multi-tool digital-age functionality. Not forgetting the very techy filter settings. Certainly, a lot of people will enjoy opamp rolling, tinkering with the filter settings, and trying different headphones and digital music formats, while others, will surely be not interested, or even discouraged, by all the settings. There is a reward for those (like me) who just ignored all the settings and played some music. Something for everyone.

I realize that I have written a lot of comments and criticism regarding some of the quirks and issues with this component. I feel that it is my job to give the reader the whole picture. Notwithstanding, the Conductor 3 Reference was not at all out of place in my relatively high-end system. I really like this unit, the sound, the build quality, the multi-use capabilities, and I would not hesitate in recommending it to anyone who is looking for compact, high quality all-in-one system. The C3R is compact, solidly built, has fine fit and finish, and does a multitude of tasks to a high-performance level. Remind you of something? Here we have the Swiss Army Knife of audio components. Of course, I have not had this unit in my possession long enough to make any statements about the reliability and longevity of this design so that is one point where the Swiss Army Knife comparison does not hold up, yet!

Music List

Here is a partial list of music played for this review. Most of the flac files are rips from my CD collection.

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Burson Conductor 3 Reference - Part 2

A Swiss Army Knife!

Introduction

The Sound

Filters

Conclusions

Music List