My Monster 3250 (amp) has a 3 displays on the front that show how many watts are being sent to each channel. I leave them off because the lights are a little much, but when I first got the amp it generally was always on 0. If I cranked it up, it might have gotten to 20 or so for explosions or the like.

Not sure if it's accurate, though I know other owners of the same amp have had the same experiences. Some Mcintosh amps have analog readouts, I believe...

Although there's a lot of expensive equipment one could purchase to determine exactly where their amplifiers begin clipping, the simplest and most fun approach might be to hook up a dual channel oscilloscope to the speaker outputs. Additionally, a sine wave generator could be connected to one of the preamp inputs. I'm oversimplifying here, but you would then slowly advance the volume until the point of clipping is reached. This is easily visible on the scope when you begin to see distortion at the top of the sine wave. Crank it up high enough and you'll turn that sine wave into a square wave. A lot of high frequency harmonics are generated at that point.

However, I do not recommend this tactic while your speakers are connected. Although dummy loads don't truly represent the dynamics involved in the interaction between speakers and the amplifier output circuitry, they are a better alternative than the possibility of frying the voice coils in the tweeters of your beloved speakers. I won't even begin to guess at how many burned voice coils I've seen over the years, all caused by cranking that volume control beyond the point at which the amplifier produced clean, undistorted output. No front panel LED's or meters are capable of displaying this amplifier 'red line' accurately.

I have in the past hooked a scope to the outputs of someone's amplifiers to show them just how much clipping takes place at the high volume levels they'd grown accustomed to using during movies. The distortion was obvious to my ears but not to theirs. They believed it was 'just part of the movie.' Once they had a visible picture of the peak output of their amps and about where that peak output occured on the volume settings they understood why the sound seemed to break up at higher settings. Their ears were telling them but they weren't understanding the why.

Although most audiophiles can sense the limits of their equipment, most newbies cannot. A visual demonstration can speak volumes.

On a typical receiver, advancing a round knob volume control past the 11 o'clock point will generally be putting you in the danger zone. However, with modern equipment and electronic controls with linear graph displays it is very difficult to tell. When not using integrated equipment it becomes even more difficult as various amp/preamp combinations can produce a slightly different 'red line'.

A couple of my Carver amps have level controls. If I set these to different positions and recalibrate my 990 the maximum achievable volume reading on my 990 will change. That's because I've changed the maximum power output of one piece of equipment in the chain. Recalibrating reset the maximums. I now leave the amp level controls fully clockwise because the amps without level controls are at that setting by default.

Just because the 990 will advance to +8 doesn't mean that I can safely play my system at that level. If I observe the amp outputs with a scope (and my ears!) visible distortion occurs well before I get anywhere near +8.

The only way I get my money's worth from my equipment to is use it within its limits. Determining those limits can be tricky.

Sorry to be so long-winded.

BobZoom

WOW! A lot of response on a -76 to +8. Didnt think about turning it up with no sound.****. Thanx for the tech. lesson.

I see that this is an older thread but maybe someone can tell me why my 990 goes from -76 to 0 (no "+" volumn, stops at 0).

I'm not certain, but I'd look at the channel trim settings to see if any are into the "+" range to any significant degree.

Just about any mainstream preamp today will put out something in the neighborhood of 7 volts AC maximum. This has nothing at all to do with the "range" of the volume control. This is far away more than enough to drive any home theater amplifier deep into clipping. Most home theater power amps have a target gain of 28db, and require anywhere between 1 and 2 volts to drive them to full power.

Most preamps have a gain roughly in the neighborhood of 20dB, so using this figure, if you have an input voltage of 200 millivolts (far less than most signal sources can supply - most CD players supply 2 volts), then the preamp should have the capability to drive this to 2 volts - enough to drive any amplifier into clipping. Taking the typical output of a CD player of 2 volts, then the preamp would try to amplify this to 20 volts - impossible to do. So in this case the preamp will be deep into clipping - however before this, the power amplifier will be deep into clipping.

By the way, most power amplifiers are around 60% efficient. Using a power consumption meter, you can figure the rough amount of power being made by the amp. Power amplifiers don't "waste" nearly as much energy as your car!

your pre amp must be defective.. mine goes up to +8 on the 990. it's never reached that kind of volume before.. but I have taken it up to about -5 or -3. that was dang loud too.

is this correct zero (0) would be reference level?

Hello skyblazer,

What are you trim levels set to in the speaker calibration menu?

Scott

fronts
Left 0
Center 0
Right 0

right surround +2
Left surround +3
Subwoofer +2

Oops, sorry about that Skyblazer! That questions was actually meant for Uncle Bill.

Uncle Bill,

What are your trim levels for each speaker in the channel configuration menu?

Thanks,

Scott