Turn it up or not?

[midlife]

I have a Crown DC300 for my main power amp. It has L&R gain controls on the front of the amp. I have been told by some in order to get the maximum head room those gain knobs should be run full up regardless of my volume needs (listening levels should be controlled by the preamp gain). What would you do to have it "right"?...........

[SEAWOLF97]

I have a Crown DC300 for my main power amp. It has L&R gain controls on the front of the amp. I have been told by some in order to get the maximum head room those gain knobs should be run full up regardless of my volume needs (listening levels should be controlled by the preamp gain). What would you do to have it "right"?...........

thats the same advise that I got to the same question .... been doing it that way with no problems.

many amps (including some very "high end" ) have no gain control, they just always run wide open.

[midlife]

So too much might just be enough?

[BMWCCA]

It's not correct. They aren't gain controls, they are input attenuators. The simplest explanation is you set them so at the loudest level you play your system your pre-amp volume control is in the "sweet spot" around the three-quarters point, and at "normal" level around the half-way point. This question got asked quite frequently on the Crown forum and was answered by a Crown employee and I re-posted it here. Let me see if I can find the thread:

Here's one mention: http://www.audioheritage.org/vbullet...7&postcount=19

But I think this is the one I was thinking of: http://www.audioheritage.org/vbullet...0&postcount=19

Here's the entire "gain structure" reply from the Crown Forum: http://www.crownaudio.com/forums/ind...indpost&p=4628

[midlife]

It's not correct. They aren't gain controls, they are input attenuators. The simplest explanation is you set them so at the loudest level you play your system your pre-amp volume control is in the "sweet spot" around the three-quarters point, and at "normal" level around the half-way point. This question got asked quite frequently on the Crown forum and was answered by a Crown employee and I re-posted it here. Let me see if I can find the thread:

Here's one mention: http://www.audioheritage.org/vbullet...7&postcount=19

But I think this is the one I was thinking of: http://www.audioheritage.org/vbullet...0&postcount=19

Here's the entire "gain structure" reply from the Crown Forum: http://www.crownaudio.com/forums/ind...indpost&p=4628

I usually try to find the sweet spot among the source (when adjustable), pre-amp and the amp. However I do remember being told that the input attenuators on the DC300 should be run full up to offer the best protection from clipping. Is it a debate or a known quantity??? thanks, every little bit helps, no?

[BMWCCA]

Is it a debate or a known quantity??? thanks, every little bit helps, no?

Uhm, did you read any of the links? Personally, I think I'd trust the Crown rep. But you can do what you want. Pretty much all you can do is introduce more noise. It won't get any louder or produce any more power.

[JBL 4645]

It's not correct. They aren't gain controls, they are input attenuators. The simplest explanation is you set them so at the loudest level you play your system your pre-amp volume control is in the "sweet spot" around the three-quarters point, and at "normal" level around the half-way point. This question got asked quite frequently on the Crown forum and was answered by a Crown employee and I re-posted it here. Let me see if I can find the thread:

Here's one mention: http://www.audioheritage.org/vbullet...7&postcount=19

But I think this is the one I was thinking of: http://www.audioheritage.org/vbullet...0&postcount=19

Here's the entire "gain structure" reply from the Crown Forum: http://www.crownaudio.com/forums/ind...indpost&p=4628

This means input clipping? If set too low a level and the input signal music/movie was many times greater for the input it would start to distort. With the volume being at higher level there is less chances of clipping happening.

BMWCCA
Those links were very helpful.

But if you can attenuate from 11 they wud be much louder, than attenuating from only 8.

that is funny quote "11"

Nigel Tufnel: The numbers all go to eleven. Look, right across the board, eleven, eleven, eleven and...
Marty DiBergi: Oh, I see. And most amps go up to ten?
Nigel Tufnel: Exactly.
Marty DiBergi: Does that mean it's louder? Is it any louder?
Nigel Tufnel: Well, it's one louder, isn't it? It's not ten. You see, most blokes, you know, will be playing at ten. You're on ten here, all the way up, all the way up, all the way up, you're on ten on your guitar. Where can you go from there? Where?
Marty DiBergi: I don't know.
Nigel Tufnel: Nowhere. Exactly. What we do is, if we need that extra push over the cliff, you know what we do?
Marty DiBergi: Put it up to eleven.
Nigel Tufnel: Eleven. Exactly. One louder.
Marty DiBergi: Why don't you just make ten louder and make ten be the top number and make that a little louder?
Nigel Tufnel: [pause] These go to eleven.

I can’t find the old JBL cinema manual in pdf form for the 1993 edition which I have in paper form only.

JBL 4675
108db @ 1m
82db @ 20 meters

Noise floor
24db @ 1 meter
-2db @ 20 meters

The image is from the 2003 edition

Crown SPL db calculator
http://www.crownaudio.com/apps_htm/designtools/elect-pwr-req.htm
SPL db calculator
http://myhometheater.homestead.com/splcalculator.html

[4343]

...

that is funny quote "11"

Nigel Tufnel: The numbers all go to eleven. Look, right across the board, eleven, eleven, eleven and...
Marty DiBergi: Oh, I see. And most amps go up to ten?
Nigel Tufnel: Exactly.
Marty DiBergi: Does that mean it's louder? Is it any louder?
Nigel Tufnel: Well, it's one louder, isn't it? It's not ten. You see, most blokes, you know, will be playing at ten. You're on ten here, all the way up, all the way up, all the way up, you're on ten on your guitar. Where can you go from there? Where?
Marty DiBergi: I don't know.
Nigel Tufnel: Nowhere. Exactly. What we do is, if we need that extra push over the cliff, you know what we do?
Marty DiBergi: Put it up to eleven.
Nigel Tufnel: Eleven. Exactly. One louder.
Marty DiBergi: Why don't you just make ten louder and make ten be the top number and make that a little louder?
Nigel Tufnel: [pause] These go to eleven.

When I worked for Snell & Wilcox, one of the lads in engineering had hand-built a noise generator with a knob where the numbers rotated beneath a little window, 1-10 like normal. One day I had it on 10 and noticed that there was an 11 visible after the 10! The potentiometer would not turn that far, so I guess it would need a special "11" pot to get that far...

[4313B]

I have a Crown DC300 for my main power amp. It has L&R gain controls on the front of the amp. I have been told by some in order to get the maximum head room those gain knobs should be run full up regardless of my volume needs (listening levels should be controlled by the preamp gain). What would you do to have it "right"?...........

Trade it in on an amp without gain knobs and your days of fretting about it are over.

See how easy it can be?

[Robh3606]

Trade it in on an amp without gain knobs and your days of fretting about it are over.

Now where's the fun in that??

Rob