Page 1 of 1

General amplifier question / food for thought

Posted: Fri Nov 09, 2012 8:35 am
by soundbit
Ok here is the senerio.

4 high end amplifiers. all rated at 100 x 2 wrms. Feeding the same set of compenent speakers and being fed by the same HU.

As each amp was switched out the output voltage of each amp was set the same and the previous. I.e. if amp A read 20 volt unclipped on the output then amp B,C,D would all be set to 20volt unclipped on the outputs.

all amps are therefore putting out the same power. Will there be any audible difference in their sound?

I have more to add to this once I get some responses.

Re: General amplifier question / food for thought

Posted: Fri Nov 09, 2012 9:01 am
by ttocs
if you take the time to scope them to tune them then yes they should all have the same output as long as they all play the same signal. now they can sound different because of speaker location or how it was mounted but in a perfect world if you set them all up for the same output they should match up perfectly.

Re: General amplifier question / food for thought

Posted: Fri Nov 09, 2012 11:10 am
by Eric D
Are you playing these amps around the 20V mark? The closer you get to the point of clipping, the more different amps start to sound different. PG amps have a lot more head room, so they still sound good near the top of their rated output. Other amps like PPIs older offerings can't go beyond their rating, and start to distort.

If you run high end amps at around 50% of their rated power, it will be difficult to tell them apart, but some are different than others.

I have a Focal amp which sounds totally different than any amp I have ever heard, and I have no clue as to exactly why that is.

Re: General amplifier question / food for thought

Posted: Fri Nov 09, 2012 11:15 am
by soundbit
Eric. that is where i am going with this thread actaually.

Why is it that when the output power is kept consistant between all 4 amps they sound the same. Yet when you take each to just before their clipping limit they sound different?

Re: General amplifier question / food for thought

Posted: Fri Nov 09, 2012 2:11 pm
by holmis
A wild throw...

differences in the different components the amp is made from....

Every electronic component has tolerases... that makes them not 100% equal an would under stress meke them act different in a circut...

If every component var 100% equal with 0% tolerance they should act the same under stress too ..

?? or ?? not ??

Re: General amplifier question / food for thought

Posted: Fri Nov 09, 2012 5:36 pm
by Eric D
PPI amps are highly regulated. When you get to clipping, they cut off the signal drastically, and the distortion becomes very audible. And, don't get me wrong, I am not knocking PPI. Being highly regulated is a feature, depending on one's needs.

As for PG, since they are unregulated, and built for a lot of headroom, they don't clip at the max of their rating. If you run them past this, and get to where they start to clip, then the distortion will become significant.

Some amps have so called "soft clipping". When the amp reaches the max, the clipped signal is rounded off on its edges, keeping it smoother than a normal clip. This tends to sound better.

There are other factors as well. The ability of the amplifier to control the speaker near its max output is based on its design. Less control will be more apparent when the amp is near its limits.

IMO, the best plan is to run an amp well below its max ability, and buy a bigger amp if you want more power. Running a 1000W amp at 750W for example makes much more sense to me than trying to get 750W from a 600W rated amp (by clipping the hell out of it).

This is the very reason I ran my modified MS1000TA on my components. 380W a side to components is a lot more than most people, but when the amp probably never exceeded 200W with music, I was left with very clean power, and plenty of control.