In some ways it reminds me of the difference between a solid state amp and a single ended triode. The triode has a way of extracting every last ounce of details that's mesmerizing.
After I finish the car I believe I am going to resurrect my home theater unity project. I think that the things that make the Unity so special could be well suited to a surround sound system, where timing is so important. At the very least, the extra intelligibility will improve dialog in movies.
And anyways, I got the Summas upstairs, and my home theater speakers are from Costco. I *gotta* rectify that soon
In some ways it reminds me of the difference between a solid state amp and a single ended triode. The triode has a way of extracting every last ounce of details that's mesmerizing.
I got the Summas upstairs, and my home theater speakers are from Costco. I *gotta* rectify that soon
Just buy three Abbeys and some Harpers and you'll be all set
Oh yea and some subs.In my mind its not tubes versus transitors, its crossover versus non. Virtually all transitor amps are AB and thats a recipe for disaster at low level zero crossings which is exactly where things are the most audible.
Dr. Geddes, just wanted to say I appreciate you "dropping some knowledge" where and there on the internet. Just my little experience experimenting with some of your ideas and suggestions has really convinced me that you are preaching the truth. While I don't own any of your products at the current time, I know my next home system will have your products in it.
Are you referring to crossover distortion? And if so, would you say that high sensitivity speakers make such things more audible? Maybe could be some form of harshness?
Thank you very much. Its been a life long pursuit to find the truth in audio and while I may not have all the answers, I think that ones that I do have are pretty well founded in reality.
Yes, crossover distortion, and yes I do believe that high efficiency speakers will accentuate this problem. You are very perceptive. I believe that what audiophiles call "lack of detail" could well be related to this since "detail" means low level signals and the lower the level of the signal the more it is affected by crossover distortion. In my studies of the audibility of distortion crossover distortion was, by far, the most audible and insidious. So much so that it is all I look for in an amp. Curiuosly, the way amps are measured and rated this problem won't show up.
If you look at the spectrun of a 1kHz tone as the signal level is reduced the harmonics should fall with level or stay the same. If they grow, or even worse, the number of orders increases (which is very common) as the signal is reduced then there is crossover distortion and you should throw the amp away. You can't look at THD VS level, because at low signal levels all you are measureing is noise. In a good amp, like I have, the harmonics of the signal should disappear into the noise floor as the signal level is reduced. There are actually ways to measure this using a sychonous signal that will measure below the amps noise floor. This is very revealing.
Which amplifier are you using? It is very hard to find a good amplifier with all the marketing nonsense we see today.
Rgs, JLH
Not at all, there are very good solid state class AB amps out there. The best one that I have tested is my Pioneer receiver, which uses chip amps. Chip amps are inherently better off in class AB because the component matching is ideal (same substrate). My Pioneer has only a second harmonic all the way down into the noise floor, no higher orders at all. NOT SO for most receivers. And you are correct, the spec sheets and advertising are totally meaningless when it comes to audible quality. Unless you measure it yourself you have no way of knowing if its any good.
If everyone got rid of any amp that has crossover distortion, I would guess almost everyone reading this thread would not have an amp left.
So let me get this straight. You have a Pioneer receiver, using chips instead of discrete components, running in class AB, and only cost a few hundred dollars. But has no crossover distortion, and has no odd order harmonics? Sorry, I don't believe that.
Is the volume control analog or digital? Since this is the best you tested, I am curious how many did you test?
I remember in a tread not too long ago, you said
"electronics don't matter that much. They are at a point where they can't get much better. Put most of your focus on the speakes"
But in this thread you seem to be saying that the electronics do matter.
You can believe it or not, but its true. I tested about five amps that I had and the Pioneer was the best.
People always take my statements out of context. Once one has good electronics - and clearly price and "personal perception" don't correlate with good - then the only thing that matters is the speaker and the room (source material being a given). I have never said that any piece of junk electronics is fine. Only that very inexpensive and readily available electronics place the electronics into the "insiginificant errors" category.
I know that this is not a popular position and it's not one that I have always held, but I have studied this problem intensely and this is my conclusion. It is, by the way, the same one as held by Flyod Toole and Lauri Fincham and a whole host of other well know audio researchers. It's amp designers and marketers who seem to hold contrary beliefs.
No, amps and electronics hold no interest to me. They make almost no difference in sound quality, while speakers and rooms dominate the problem. I'm more interested in those things that matter.
From the first 2 post above, I would have guessed that amps matter very much to you. In the last post as you concluded that amps don't really matter, they why did you go to all the trouble to do in depth measurements of over a dozen different amps?
As to the "they [amps] make almost no difference in sound quality", that is just you opinion, and that is fine. But not everyone has the same opinion as you.
Hold whatever opinion you like, but I always back mine up with data. The point is that I bought a $200 receiver that is as good as any amp that I have ever tested and certainly not a limitation to sound quality in my systems. (Ask anyone who has heard them.) Problem solved, end of study, and time to move on. You should too.
I think he is saying amps and electronics matter...to a point. Once you get to that point, then other things clearly matter more- like speakers and the room. I can believe that...but I also know that personal preference can dominate the argument. What is "right" may or may not always be what you find as "good."
Dr. Geddes, how would you do such testing in amps? Is it something that you would need AudioPrecision hardware, or could the average guy measure these things with something more available?
I have a few for my car and want to put the best one on my horns. The only one I have that I know doesn't have crossover distortion is my BIG heavy class A all tube amp (yeah, it's made for automotive applications).
I have a few for my car and want to put the best one on my horns. The only one I have that I know doesn't have crossover distortion is my BIG heavy class A all tube amp (yeah, it's made for automotive applications).