Need feedback from Bryston amp owners

What is the definition of an amplifier? It's an electrical circuit that increases the magnitude of it's input signal. To create an exact replica of it's input, it must increase all frequencies equally. What comes in should come out exactly the same, only bigger.

That's the ideal. Of course, reality is usually something different. If you take a look at John Atkinson's amplifier measurements using the dummy speaker load, you will notice that SS amps generally fit the definition stated above. So why don't some people like them?

If you look at the same graphs for reviewed tube amps, you will notice a pretty big spike centered around 1KHZ-2KHZ, followed by a dip in the 3KHZ-8KHZ range. Remember that decibels are logarithmic in nature, so a 1DB difference is about 20%, 3DB around 50%. Note that this frequency range y coincides with a typical tweeter crossover, which is not surprising since the dummy load is supposed to simulate a real world speaker.

So why do people perceive an amp whose high frequency performance is just about perfect as have an "unrefined" top end, especially when compared to other amps that don't really have a top-end, at least into an inductive load? When did omission and non-linearity become synonyms for refinement?

Given the current fads in speakers, i.e. two way monitors with small drivers, my guess is that tube amps don't deliver enough output at the frequencies near the crossover where the mid/bass driver is starting to misbehave for it to be noticable. Maybe that big peak at 1KHZ is masking the errors, some people are just more sensitive to them.

I was using a Bryston 3B-ST to drive a pair of Proac Response 1.5s. I was pretty unhappy, and was looking to change amps. By coincidence, around the same time Dynaudio revamped their Contour line and I ended up picking up a pair of 3.0s which I had been lusting after.

I never looked back at changing the amp, although I would like to play with a little more power. I believe the real difference is that the Dynaudios have a dedicated midrange driver. That little 6.5 woofer had to work too hard to produce bass, and I think it's long travel was screwing up the upper mids. On some tunes with a lot of low bass, you could actually see the thing flexing asymetrically.

I am not trying to invalidate anyone's choices, or even defend Bryston. I just find it amusing that we use wildly inaccurate devices (loudspeakers/ears) to measure the quality of an electronic circuit, when it probably should be the other way around.

Is this the review you are talking about?

http://stereophile.com/solidpoweramps/725/

I don't see where they compared the Bryston to any other amplifiers in terms of dynamic headroom, either in the review or the measurements section. Greenhill does talk about the amp's dynamics on page 4, but not in a negative way. As far as measurements, the amp seemed to meet it's published specs at 4 and 8 ohms. Bryston doesn't provide a 2 ohm rating, but the amp could be said to fall short there. Only 720W with one channel driven.

For what it's worth, I think Bryston has a history of being fairly honest about the performance of their products in terms of driving very low impedances. For example, it is well documented in the owners manual not to use the bridging feature with speakers rated at less than 8 ohms, and have seen them discuss this on the web as well.

I am not sure I understand the comparisons to tube amps. How many of them double into lower impedances? Just taking some random shots in the Stereophile archive, I didn't see any. Is there actually audio tube amps in the marketplace that will deliver 700W into any load? The most powerful amp I saw was the VTL S-400 at 350W, but it costs as much as a Camry.

Again, my comments were more of a metaphysical nature than a defense of Bryston. Basically I am asking when we hear a noise from our systems that we don't like, why do we assume it's the amps fault? Any speaker on the market is tons less linear, but they always seem to be blameless. And nobody ever thinks about changing the room around.

Yes, the amp/speaker interface is important. But the reality is that most amps can coax sound out of most speakers. Yeah, there are those how want to listen to Mahler on Apogee Scintillas at Who concert levels, but they are the exception, not the rule.

To me, listening to reproduced music is like watching a movie or any other type of entertainment. It's all about your willingness to suspend disbelief. If we constantly fret about equipment choices, we are preventing that suspension from happening. My advice is that we all throw our Stereophiles in the trash and spin some tunes.

Another thing I have picked up from participating here and on the Asylum is that human hearing isn't very accurate and no two people hear alike. Guys will alway say they just had a hearing test and scored aces when challenged. Even if that is true, every test I ever had was of the 'raise your hand if you hear that" variety. I haven't had one since I left public school, so I can't remember. Does the doctor show you a graph after one of these?

I have used the same amp to drive four different pairs of speakers. It satisfied my requirements in all cases. Some of these speakers are considered "difficult loads", such as Magnepan and Dynaudio, but I have never really noticed any shortfall. I guess they aren't as difficult as some people think, or I just don't listen loud enough.

I am sure there are better amps out there, but how much money would it cost me to find them by trial and error, and would I be any happier if I did? I am too busy looking for a cue that will let me bust nine ball like Johnny Archer...

Sean: In contrast, I often find it difficult to compare stereo components. Admittedly, my experience is pretty limited. I have done speaker and amp comparisions at dealers, mainly due to logistics. The only home audition involved a couple of CD players.

To be honest, I drove myself crazy. By the time I get the other box hooked up, I have pretty much forgotten what the other one sounded like. My audio memory is just too short. I am not saying I didn't hear differences, because I did. But more than once those perceptions have not been consistent between swaps. Also, it is not always easy for me to say one is necessarily better just because it is slightly different.

Obviously, matching amps to speakers would demonstrate a lot more variation between samples. But once you narrow it down to a couple that meet the requirements, after six months go by does it make that much difference which one you picked?

I am a avid pool player and compete at the regional and national level. I also collect custom pool cues. I can't tell you how many times I have picked up a friend's cue and started playing lights out with it. If I kept the thing a week, I would eventually end up playing the same speed with it as with any other cue I own. Why is that? Well, my brain noticed the different weight and balance, and I started to pay more attention. Once I get acclimated to the differences, I fall back into my comfort zone. I think the same thing happens when you audition stereo equipment.