Dynamic Range - the golden key to music nirvana?


Dynamic Range – the golden key to music nirvana?

 

Before I even start I recognize that Dynamic Range (DR) is not the only thing that determines the quality of your musical experience. However, through my journey I will make the argument that chasing dynamic range may set you on the right path to your musical nirvana. Some, such as tube aficionados, have made a conscious (or unconscious) decision to sacrifice DR for other attributes for example. All I can say for now is that it has transformed my listening experience to such a degree that I feel compelled to share my journey.

 

I seriously started my journey in his addictive hobby some 20 years ago, or at least that’s how far back I can recall. I am getting older. It has become something of an obsession, like with many of us, to try to create the best possible system within my means. I think many of us could use Audiophile Anonymous meetings and therapy. It has been a long, sometimes frustrating journey, with many dead ends, stops, starts and fits. To keep up with all the developments in our little universe can be a full time job. The rewards have, however, been worth it overall. Some would maybe call me a gear-head and while that may be true to some degree let’s face it - we can’t make magic without the gear.

 

It all started a couple of years ago when I decided that hi-rez music streaming and streamers had matured enough that it was time to make the migration to this source and abandon the dedicated MiniMac with my CD collection. After buying and returning a number of streamers I was not impressed, That is until I came across an Auralic Femto. It did not take me long to decide that this was a source worth building a system with. So  my next step was to upgrade my beloved Bel Canto (BC) DAC 1.5 to a 2.7. I kept my treasured W4S STP-SE and used a pair of Bel Canto 500 mono-blocks hooked up to a pair of Acoustic Zen Adagios. So far so good – it sounded just as good, if not better, than the best CD player I could recall having in my system – there were many.

 

I had up until this point favored Class D amps more for their small size than anything else. The BC mono-blocks were wonderful, very musical, powerful amps., but I had always wanted to try a Class A/AB amp. Before long there was a Son of Ampzilla II in the house. I will never forget when I first hooked it up and my wife, a trained musician,  walked by and commented that it sounded very good. I could not agree more. The, and I will use this analogy often, silky smooth, dense, analog sound seemed intoxicating. However, after getting over the initial wonder, before long I realized that there seemed to be something missing. The sound stage seemed a little constrained and some details that I was used to hearing seemed muffled or even absent. Something that stood out was that the decay of the cymbals seemed to be cut short. I had, although I did not think of it those terms at the moment, lost the dynamics of the BC monos. Back to the drawing board.

 

After many hours of research I come to find out that Class A/AB typically operate at a maximum of 30V. The significance of this is that this also constrains the maximum DR of these amps to about 100 db as it is related to the operating voltage. So why not just increase the voltage? Problem with his is that then the transformers would have to be even bigger than some of the 200 lb Class A amps already are and the power needed would end up costing more than running your AC. Now the argument goes that a DR of 100 db is more than enough as you will start entering the hearing pain threshold after that. However, the fact remains that the DR of the human ear is 140 db so something seemed awry. I set out to test the theory.

 

Looking at my components the BC DAC 2.7 has a “class-leading” (to quote BC) DR of 124 db so that seemed ok. I could not find anything on the W4S STP-SE explicitly, but if my calculations were right the DR was probably not much above 100 db if that. I love the sound of the STP, but apparently it had to go if I was going to pursue this. Luckily for me, it turns out that the Stage II version has a DR of well above 120 db so one was quickly acquired so I could preserve that characteristic sound that I loved. The amp posed a conundrum though. Maybe I would have to go back to Class D again since the Class A/AB amps seemed limited to around 100 db. After endless research I found two viable options. The Benchmark AHB2 and SPL Performer S800. While they have different approaches to the problem at hand both operate at much higher voltages to get higher DR’s. Quite astounding DR’s at that. The Benchmark is in the mid 130’s and the SPL is well North of 140 db. I am not an electrical engineer so I can not explain how they did it in such small packages. The Benchmark uses THX modules and the SPL uses the proprietary Voltair system, which allows the SPL to operate at 120V or four times that of other Class A/AB amps achieving unprecedented DR in the Class AB category. One was quickly on the way.

 

The results, coupled with acquiring a pair of Marten Django L speakers, was very satisfying. The system exhibited all that silky smooth, dense sound associated with analog amplifiers accompanied by an increase in dynamics, as I had now come to know it, that brought out all the things I was missing before. The cymbals were decaying properly again, or at least I thought so at the time. Life was good!

 

To recap the system at that time:

 

Auralic Aries G1 (forgot to mention the Femto also got an upgrade)

Bel Canto DAC 2.7.        DR 124 db

W4S STP-SE Stage II.     DR 120+ db

SPL Performer S800.     DR 140+ db

Marten Django L

 

So looking at the chain my overall DR, given that no chain is stronger than the weakest link, was on paper in the low 120’s. I was thinking things could not improve much above that in that department at least given that 120 db is truly in the pain threshold to follow the accepted way of looking at it.

 

True to me OCD I could, however, not rest on my laurels. I have always loved the BC house sound, but it was time to try something new. If I was going to get a new DAC true to my recent findings it needed to have the highest DR possible and hence be as quiet as possible. After much research I found that here are not many that break 130 db. However, one stands out at 150 db, now that is dead quiet, the Hegel HD30. I found one from Walter at Underwood HIFI (he is Ok by the way) and the results were impressive. The enthusiastic reviews were pretty much spot on. It is a marvelous DAC. Keep in mind that the STP pre-amp is still potentially limiting the DR in the system to around 120 db, but this still did not seem to be a problem to me although my thoughts were starting to drift in the direction of “what if”. It sounded pretty amazing though so I was really enjoying my listening sessions and the potential issue slowly faded from my mind for the time being.

 

Fast forward about a year to about a month ago. I found myself having accumulated four reference level systems around he house over the years so I decided it was time to downsize and consolidate. I sold off most of two systems and replaced them with much simplified setups in order to still play hi-rez music throughout the house through ROON. Then one late night I was listening to the main system and my mind started down that dangerous “what if’ path again. I need help! This nagging feeling that possibly my beloved STP Stage II might actually be holding me back. Just maybe inserting a pre-amp with an even higher DR could improve things even more. I also had a SPL Phonitor XE in the system so to rationalize all this I thought if I sell both I would have some funds to upgrade. I also have a Phonitor X so I would still have one of their outstanding headphone amps. A man really only needs so many amps, but those rules as we know, don’t really apply to us audiophiles. So ideally, if I could find a pre-amp/headphone combo with an exceedingly high DR like the Phonitor X, but with some added consumer conveniences like HT bypass that I need for the main system I could test this new theory. So back to the drawing board again.

 

It did not take long to figure out that the only real options that could realize outstanding DR’s were the Phonitor X and the highly acclaimed Benchmark HPA4. Both have a DR in the 135-140+ range. The Benchmark seemed to fit the bill perfectly with HT bypass setup possible and a good selection of inputs and outputs that would fit into the system nicely. I was lucky enough to find a lightly used one and soon it was on its way.

 

It arrived after what seemed like an eternity. I unplugged the Stage II and the headphone amp and inserted the rather diminutive looking Benchmark with the recommended balanced cables. After fiddling with the setup for a while it was time to turn on the sound. I played some of my “test tracks” one after the other in quick succession. I was nothing short of astounded. I am not sure how to express it in words but the experience was visceral. I was hearing details on tracks I have listened to for 40+ years that I have never noticed before. The soundstage was immense. I was just getting lost in the music. The experience was so intense I had to immediately share it with someone. I felt like I had uncovered the golden key to music nirvana and that I had finally gotten a taste of what ultra high end audio might sound like. The Benchmark literally unleashed the DR of the Hegel DAC and the SPL amp. It was as if releasing a kink in a water hose the music was just cascading out of the speakers. Truly amazing! I then tried the headphone amp and the results were just as astounding.

 

So in the end I am at least convinced that higher DR has a strong correlation to the quality of the sound and the experience you will have. My system is now approaching a DR of 140 db overall on paper, or the absolute limits of human hearing, and it sounds better than pretty much anything I have heard. I can’t stop listening!

 

So what about the theory that a DR of 100 db should be more than enough? My conclusion is that this is a myth propagated by Class A amplifier manufacturers to justify not being able to do any better.

 

Happy listening!

 

P.S.  This is my experience and I am sure others have different experiences, but just maybe my journey will help someone else find their music nirvana.

 

 

 

 

 

 

 

 

 

 

 

bjorn154

I have both a Son of Ampzilla II and a Benchmark LA4.

I agree that DR is an important metric but only to an extent. The vast majority of music does not have a dynamic range exceeding 100dB.

I don’t find the SOA II lacking in any regard vs the AHB2. I owned the AHB2 for a couple years and while it’s a good amp, I concluded the SOA II is considerably better. It’s nearly as quiet as the AHB2 and certainly quiet and transparent enough for all practical purposes. I suspect it’s even better in some regards than bridged mono AHB2s, because IME, the SOA simply has a more organic sound than a single AHB2, but with better bass, the latter of which is probably the main and possibly only benefit of dual AHB2s.

IMO, the LA4 or HPA4 are THE Benchmark products to own. The DAC3 and AHB2 are certainly good but not world-class. The LA4 makes everything upstream and downstream sound better, that is, with the caveat of requiring good synergy. In many systems there is a risk of the LA4 sounding too “lean,” partially due to its incredibly wide bandwidth and phase accuracy.

IMO, the LA4 or HPA4 are THE Benchmark products to own. 

The HPA4 and LA4 are exactly what I want in a preamp. Connectivity and silence. The LA4 volume control is also my best. I should have kept the HPA4. The AHB2 suffers from the slight deficiency in bass. I love the top end of the AHB2. 

The Holo Serene (which I also have) is very much like the LA4 but without a lot of the nice features the LA4 has. Just a tad warmer than the LA4.

I am using the LA4 with a Magtech amp into Magnepan LRS+ speakers in a small office. This is a very high sonic standard to improve upon. I do not think I can.

 

 

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So I was just looking at the mighty Mark Levinson amplifiers. True Class A. The 534 for example is a $25,000 behemoth weighing in at 100 lbs. I read some of the reviews and every one praises the dynamics and how silent it is. There are very few specs on the site so I pulled up the manual. Not much there either except:

SNR >85 db

THD <0.3%
 

Now this amp may have many admirable traits, and I certainly hope so based on the price, but dynamic and quiet are not attributes I would expect with those specs. Reasonably good HT receivers do better. These Class A amps are falling behind the times in terms of what can be achieved at much lower cost and in much smaller packages, while still maintaining that silky smooth analog sound.