Overload.

[Dentman]

Today while listening to Supertramp crime of the century CD I noticed my pre/pro had the overload light flashing. Also while listening I noticed the sound was much brighter, bordering on shrill. I was listening at rather high volumes, db meter was spending a good amount of time around 94db with peaks at about 97db.

I picked up the remote and started to dial back the input level until the light stopped flashing. I was surprised by just how much the sound changed. The shrill sound went completely away. Changing this input level plays a dramatic roll in sound quality and really has to be tweaked just right.

So I ask, was I hearing the input signal being clipped, or something else?

I should mention once that input level was dialed back I could raise the volume as loud as I could stand and not get that shrill sound.

 

[Wardsweb]

Over driving the input. Solid state hates it. Tubes don't distort like SS. It changes the sound. Many guitar guys like that tube distortion.

 

[Dentman]

Over driving the input. Solid state hates it. Tubes don't distort like SS. It changes the sound. Many guitar guys like that tube distortion.

So it was clipping ?

 

[Flint]

So it was clipping ?

Yes

 

[Flint]

I remember writing a long screed on the sound of clipping and how when it happens with transistor amps it is usually more likely to blow a tweeter than a woofer because of the significant increase in high frequency output. Not sure it ever made the journey from the original forum, but it was a lively discussion.

Out of curiosity, how is your rig configured that your CD player can clip the input of the Pre/Pro?

 

[Dentman]

I remember writing a long screed on the sound of clipping and how when it happens with transistor amps it is usually more likely to blow a tweeter than a woofer because of the significant increase in high frequency output. Not sure it ever made the journey from the original forum, but it was a lively discussion.

Out of curiosity, how is your rig configured that your CD player can clip the input of the Pre/Pro?

It's a very old low end Sony DVD player. Using analog L + R out. It's not hooked up for video at all.

 

[Dentman]

Also, one of the few things in audio I do know about is amplifier clipping, both tube and solid-state.
I'm just don't know if changing the input voltage is causing clipping, not changing the volume(gain).

 

[Flint]

I guess I don't get it, how are you changing the input voltage?

Yes, the input sensitivity, or input gain, is tied to both changing the gain and the potentially causing clipping.

 

[Huey]

Damn, and hear I thought I was going to see another picture of a receiver on fire.

 

[Dentman]

I guess I don't get it, how are you changing the input voltage?

Yes, the input sensitivity, or input gain, is tied to both changing the gain and the potentially causing clipping.

My pre/pro has adjustable input voltage.

 

[Dentman]

Damn, and hear I thought I was going to see another picture of a receiver on fire.

Very funny!!!!

 

[Huey]

Very funny!!!!

Somewhere, I even have the picture that was posted over at S&V. Must be at home, because I couldn't find it on my work computer. I truly had never seen a receiver on fire like that. lol

 

[Flint]

My pre/pro has adjustable input voltage.

Well, that makes sense.

 

[MakeMineVinyl]

I'm just don't know if changing the input voltage is causing clipping, not changing the volume(gain).

I would be fairly certain that your pre/pro is simply digitizing all analog inputs by default, and that level control is setting the analog level which is being fed to the analog to digital converters inside your pre/pro. The reason a pre/pro would digitize analog inputs is that all processing, including overall volume control from the pre/pro can be done strictly in the digital domain. The digital inputs to the pre/pro go straight through to this processing, the analog inputs get digitized first. This is strictly a cost and convenience move on the manufacturer's part.

If your pre/pro were strictly analog, or if there was a separate analog path through the pre/pro (which would be very expensive to do), it would be relatively difficult to clip the input. An analog to digital converter has very strict limits to the maximum level it can accept before it literally runs out of bits with which to digitize the analog signal, and hard clipping takes place. That is what you were hearing; the analog to digital converter clipping, and the light was telling you that.

 

[Dentman]

I would be fairly certain that your pre/pro is simply digitizing all analog inputs by default, and that level control is setting the analog level which is being fed to the analog to digital converters inside your pre/pro. The reason a pre/pro would digitize analog inputs is that all processing, including overall volume control from the pre/pro can be done strictly in the digital domain. The digital inputs to the pre/pro go straight through to this processing, the analog inputs get digitized first. This is strictly a cost and convenience move on the manufacturer's part.

If your pre/pro were strictly analog, or if there was a separate analog path through the pre/pro (which would be very expensive to do), it would be relatively difficult to clip the input. An analog to digital converter has very strict limits to the maximum level it can accept before it literally runs out of bits with which to digitize the analog signal, and hard clipping takes place. That is what you were hearing; the analog to digital converter clipping, and the light was telling you that.

Thank you, that makes sense. My new DVD player arrives tomorrow. I'll be hooking that with a digital connection. I look forward to seeing if there is any variation in these levels.