Riddle me this...


Why is it that you cannot seem to purchase a lower-powered solid state amp any more? None of the “names” in solid state amps seem to make any reasonably priced or powered products at all, and most haven’t since about the early 90s. (A few come to mind right off, Levinson no. 29, Rowland Model 1, Krell KSA-80, the family of Pass Alephs). These days, the most modest offering from any of these companies (not to mention everyone else) is many times more expensive, in no small part due to the fact that they are all many times more powerful.

Question is, why? Why should I need 250wpc+ to drive any reasonably designed speaker? What is it about the industry that seems to be in a conspiracy (or, at least, conscious parallelism, for you antitrust geeks) to foist more and more power on the consuming public while, at the same time, doubling or tripling prices for their most modest gear? Why is it that, if I want a really nice amp at less than 100wpc, I have to either go with tubes or with gear that was made at least a decade ago? Why is it that most speakers made these days are either “tube friendly” or “require” an amp with enough power to light a small village to actually go?

Now, don’t get me wrong, I’ve got inefficient speakers and a 250wpc amp which I like the sound of just fine. It just strikes me as preposterous that I (and we, if I may speak for the market) seem to have been conditioned to believe that this is necessary. Why on Earth wouldn’t someone get a reasonably designed, efficient pair of speakers and, say, a Pass Aleph amp for a negligible fraction of ANYTHING built by Pass these days and never look back? I understand there are plenty of legit reasons why more power can be desirable (“never can have too much” yea, yea, I know), but am a bit miffed that, legit reasons or no, the market no longer seems to offer choices. We a bunch of suckers, or what? (Yea, a bit of a rant, but this has been bugging me -- am I the only one? Did I miss something? Can I get a witness?)
mezmo
Brian Miller asked me to comment on this thread from the McIntosh perspective. We have made smaller 100 or 120 watt amps in the past. These were good amps but were slow sellers and have been discontinued. In the case of McIntosh the consumer likes a certain size amp and small ones are not it!
The type of music played and its dynamic range must be a consideration as far as what power is needed. Most music will only require one or two watts at a normal background listening level on average efficiency speakers. I really can not handle Britney Spears at more than 20 watts! If you are using a full symphony orchestra at a realistic playback level you may need hundreds of watts per channel on peaks. 10 times the power doubles the volume so you will run out of watts quickly. Most people are surprised when they use one of our large amps and see how much power they need on the watt meters. It depends on the speakers and how loudly one listens.
We do have consumers use our largest 1200 watt amps on very efficient horn loaded speakers. Why? Because they can I guess.
The challenge is to have a very high signal to noise ratio which our double balanced design will permit, in excess of 124Db. Unless the S/N ratio is high the music will be lost in the hiss.
The new high resolution formats require an increase in signal to noise ratio and higher power to cope with the additional dynamic range.
One solution to the problem is a way to monitor and limit the peak output of an amp which we do with our Power Guard circuit. This looks at the input and output waveform of the signal as it passes through the amp. If the signal starts to show a difference this lights an LED driven by a wave form comparator. The LED's light is received by an optically controlled volume control which will turn the volume down and back up in one 1000th of a second. This will limit the highest point of the peak but allow the amp to continue or be turned up farther. If the amp volume is increased all of the music will get louder except for the highest peaks. This will control overload distortion at the speed of light using light beams.
When an amp clips a burst of distortion is created and by its nature will be sent to the tweeter. This harmonic distortion will be many multiples of the original frequency and the speaker crossover will send it to the tweeter. We are seeing an increase of this type of tweeter failier due to DVD-A, SACD, 96/24 and other high dynamic range recordings since they use more power at same perceived listening level as the older more compressed sources.
A single dome tweeter is hard pressed to handle more than 100 watts. They can only move so far and can dissipate so much heat.
The answer to how much power is determined by the speaker efficiency, listening distance, type of music and the dynamic range of the recording. The definition of high fidelity is the accurate reproduction of the original wave form as it was recorded. For many recordings and cinema soundtracks this will require high powered amps.
Thank you,
Ron Cornelius,
McIntosh
I am surprised no one has mentioned the 47Lab Gaincard - the epitome of the minimalist amp - 25wpc (or 50), small # of parts, very minimalist design and circuit. Sounds great!

-Ed
I think there are many amps out there new and used that
are in the 100 watt range that sound great, that are less than $2500, which translates into around $1500 circa
1988. What in 1988 could you get for around $1500...looking into my handy dandy 1988 Audio Directory:

1.BEL 1001 $1350
2.Belles 450 $1495
3.Boulder 500AE $2795
4. Carver M4.0t $799
5.Classe DR-3B $2995 (25 watts, Class A)
6.Forte 1a $995 (ClassA)
7.Hafler XL280 $650
8.Krell KSA-80 $3700 (Class A)
9.Mark Levinson No.20 $10,700 (100 watts, ClassA)
10.Mark Levinson ML-11 $2100
11.PS Audio PS100C $1195
12.Rowland 3 $4550
13.Sonographe SA120 $895
14.Spectral DMA50 $2495
15.Spectral DMA200 $5995 (200 watts, Class A)
16.Threshold SA/2 $5800 (100watts, Class A)
17.Threshold S/200 $1950

I am not sure about the good old days. Good Amps were not
cheap then either.
Let's not forget about the magazines here. How many times have you read a review of an amp, often fairly powerful amps, where the reviewer tells of how he was listening to some piece of music at insane levels and, lo and behold, the amp clipped. I've seen this on reviews of 300+ watt amps. Always followed by, "but if you listen at normal levels in a normal room you'll be fine". Well, if audio reviewers seem to need power to get their thrills, how do they think their readers will respond. Looking for more and more powerful amps. I realize this doesn't apply to all reviewers but I've seen it in a variety of magazines. Personally, I listen at sane levels and have never needed more than 60-70 watts to drive various speakers.
Ron from McIntosh brings up a very valid point and one that i have "preached" on more than a few occasions. That is, dynamic headroom is king when it comes to clean reproduction. Most people do not realize how much their system is compromised when running low to medium powered amps with low to medium efficiency speakers. That is, until they try an amp with a much greater level of power and power reserve. This is not to say that all "big" amps sound good or are created equal, but that more power is not necessarily a "bad" thing if done right.

While i agree with Trelja that listening nearfield can be very rewarding, requires lower power and provides you with a completely different listening experience, it simply does not work well with a LOT of different types of music and / or speakers. Then again, i would hope that the buyer would have taken their listening environment into consideration when purchasing the components ( especially speakers ) for their system.

Unless you strictly listen to chamber music or use your system for background music, i would recommend begging or borrowing a good sized power amp with fast responding wattmeters on it to try in your system. Taking into account the impedance variables that come into play, i think that most of you would be amazed at how much power is required to reproduce momentary peaks when listening. I am talking about "good" listening levels, not even the levels that one thinks about when "cranking".

Personally, i found this out when i brought home a Yamaha M-80 power amp that i purchased for a friend at the same time that i had a Bryston 4B here. As a point of reference, both amps are rated at 250 wpc @ 8 ohms. While i would not call the Yamaha "reference quality", that specific model is about as good as "mass-fi" gets in my opinion. It is a dual mono design with individual iron core transformers for each channel. It is also capable of well over 1000 wpc on momentary peaks at low impedances, so it is not a "push over" when it comes to tough loads or "more reputable" hi-fi brands.

The point that i'm getting at is that the Bryston had clipping indicators on it. During normal listening sessions, the LED's were coming on VERY frequently. I substituted the Yamaha into the system, which has a very large LED based power meter on the faceplate. Rather than just seeing one led flickering per channel on a regular basis, i was able to track the power demands as a whole. What i found is that i was seeing very regular peaks of appr 900 watts appearing on the wattmeters. I then began scratching my head and thinking that the meters just HAD to be wrong. It simply was not that loud, at least not to me. Then again, the Bryston was going into clipping at the drop of a hat, so that made me think twice.

Substituting over a half dozen amps into that same system, i was able to see that some amps could drive the system with far greater ease and musicality than others of similar power ratings. The one thing that really shocked me was that i was able to drive the system to similar peak levels with some amps that were WAY less powerful. At least on paper and on the bench the amps were less powerful. The only consistent difference that i could find was that amps that remained in Class A bias for a longer period of time always sounded cleaner, clearer and "more powerful" than if i had an amp that was of lower bias and rated for more power. This taught me that it is "okay" to sacrifice power so long as the power that you have is of the utmost quality. You can still run into problems with lack of control, clipping, compression, etc.. with a low powered Class A amp, but the sound that you have the other 90% of the time is FAR superior to what you get out of a high powered low bias AB amp.

Obviously, these are just my thoughts and experiences on the subject. You can take them for what they are worth. Personally, i learned a lot with that group of experiments. I tend to think that others running relatively low powered Class A or very high bias Class AB amps have similar thoughts on the subject. Even though i may have GOBS of high biased AB power in most of my systems, i still love and respect smaller Class A amps to a great extent. Sean
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