Acoustic Research AR9LS owners? Just for thought

WOW, thanks for the response guys. Here is another bone to throw at you to chew on. My yamaha has an option on it to run "auto class A" whatever that means. I have done some research on class A power but its confusing to me to say the least. I have noticed no audible difference when i use the class A setting but it does seem to run a lot hotter. Can anyone explain?

What I suspect is occurring - is that most amps operate in class a/b which means that its initial gain is in class a but it switches to class b at a very low levels. This switching from class a to b gives your amp the ability to operate up to a high power output but the switching can cause sonic issues some folks are sensitive to. So enter class A where the amp operates only in class A up to its rated power. No switching distortion, lower power, runs hot(er), and costs a lot of loot. A lot!

What I ASSUME Yamaha has done (remember there is no free lunch - no one is giving pure Class A amps for nothing) is that in 'auto class a' the Yamaha's class a is running up to a higher level before you switch to class b, so if you have efficient speakers you will never encounter the problems switching might intoduce. Its still a Class A/B amp, just smoother at higher power levels.

This is very common in Class A/B amps except most don't usually have an option and the class a power levels vary. Some manufacturers have the level high enuf that they try to pass off the amp by implication as pure Class A.

Hope that helps a bit.

It sure did help Newbee, so would you recomend I just leave the auto class a OFF due to these AR9s not being what you would call efficiant or would you say that the class A power will do better with them. In your opinion

Yep. Especially if you can't hear a difference. That would be the only benefit and you might not be the only person who can't hear it. It is rather subtle.

all the info you need is in the manual. i agree with Newbee, run the Yamaha in Class B mode.