clipping and max rated watts/max volume

Depends on the system of course; with power hungry speakers you could go past noon. I've read tho that clipping starts before it's audible, and not near as loud a setting as you'd think.

From my experience it is around 1-2 o'clock position. Remaining travel/rotation allows for playback of low level recordings (or sources).

Clipping has very little to do with the volume control position and everything to do with how strong the signal is.

So you can't rely on the position. If you hear the amp distorting, turn it down.

The easiest way to tell is to listen to the amp.

Huh? Is there no correlation between pre amp output and amp input sensitivity? This is what ultimately determines volume control position in reference to max power output, no? I mean generally speaking, if my pre puts out 2v and my amp has an input sensitivity of say, 1.5v, won't the pot be at around 12-1 o'clock? Is this not a typical scenario? OTOH, would I not be using up the entire pot if I have 2v out and 2v in?

Peter (Csontos), keep in mind that what the preamp puts out is what goes into it plus its gain (which is defined based on its volume control being at max) minus the amount of attenuation the volume control is set to provide.

And what goes into the preamp depends on both the source component and the source material.

So if the amp clips when its input reaches 2 volts, the position of the volume control that will result in the preamp putting out 2 volts will depend on the source component, the source material, and the gain of the particular preamp.

All of those factors can vary widely. So the bottom line is as Ralph (Atmasphere) & ZD stated.

Best regards,
-- Al

Sure, I get that. I'm just surprised the op wasn't given consensus in terms of typical circumstances. It's usually the case in my collection, low and high level recordings being the oddball. I thought pre amps were built to max out the average amp right around half way on the dial. This has been my experience, I think. Except for my Oppo BDP95 at 2v out direct to my LSR&D monos with 2.4v in. But I can get the clipping indicators on the amps to flash. Why would that be? Wrong specs?

I'm just surprised the op wasn't given consensus in terms of typical circumstances.

OK, I'll give it a shot, while reiterating that all of the following can vary widely. Assumptions:

1)All interconnections are single-ended/unbalanced.
2)Onset of clipping occurs at 1.5 volts into the power amp.
3)Source is a CD player.
4)Maximum output of the CD player is 2 volts (which is about 2.5 db greater than the 1.5 volt clipping threshold of the amp).
5)Preamp gain is 12 db. (Note that some widely used preamps, such as some Conrad Johnson models, have gains that are far higher, e.g. 25 db. And many are significantly lower than 12 db).
6)Volume control attenuation (in db) as a function of position is as shown here. (I realize this is a passive preamp, but I couldn't readily find a comparable db-calibrated volume control illustration for an active preamp).
7)Musical peaks on the source material drive the CDP to its 2 volt max output.

Based on those assumptions, the volume control would need to provide 12 + 2.5 = 14.5 db of attenuation to output a level on musical peaks that corresponds to the clipping threshold of the amp. That in turn corresponds to about the 2 o'clock position on the illustrated volume control, which just happens to coincide with what Kijanki said in the initial response above :-)

... my Oppo BDP95 at 2v out direct to my LSR&D monos with 2.4v in. But I can get the clipping indicators on the amps to flash. Why would that be? Wrong specs?

Could be. The manual for the BDP95, btw, indicates 2.1 volts max output. And keep in mind that the difference between 2.1 volts and 2.4 volts is only 1.16 db. Arguably, to use an expression, "good enough for government work." :-)

Also, I'd expect that the exact clipping point may vary somewhat depending on speaker impedance (lower impedance = lower clipping point, for typical class AB amplifiers having unregulated power supplies), on AC line voltage, on whether the amp is being driven hard continuously or just on occasional peaks, etc.

Best regards,
-- Al

Thank you Al. The Kappa 9s are the culprit. They dip below 1ohm at 30hz and 7khz. It was Foxy Lady.

The Kappa 9s are the culprit.

Wow! It's quite a testament to the late Professor Leach that his amp can handle those speakers. As I'm sure you're aware, they are widely known as being "amp killers."

Best regards,
-- Al

I thought pre amps were built to max out the average amp right around half way on the dial. This has been my experience, I think. Except for my Oppo BDP95 at 2v out direct to my LSR&D monos with 2.4v in. But I can get the clipping indicators on the amps to flash. Why would that be? Wrong specs?

Just a FWIW in addition to Al's comments- there is no 'standard' to max out the amp around half way on the dial. Amplifier sensitivity varies from 50 db in some rare cases (The Antique Sound Lab Hurricane being an example) to only about 12db as in the case of some SETs!

In addition, "practical" speaker sensitivities vary over a 20 db range. So its a bit of a dance between wild parameters that a preamp designer must contend with- and likely will either design for specialty concepts (for example, only works with low gain amps) or otherwise might ignore the outlier situations of amplifier gain and speaker sensitivity.

Wow IS the word. I mean in reference to the Kappas. The amps output 375 watts at clipping but capable of 600+ watt peaks @8ohms. I would estimate about 110db out of the Kappas. I managed to round up another pair of identical LSR&D monos which are on their way. I have gone through lots of amps and these are the most transparent non-fatiguing amps I've ever heard. The gut-wrenching drive and slam is astonishing. I also have two 125wpch diy versions I've ordered chassis for so I'll have eight channels for my JBL project.