Running an amp at Max??

[Disco_Dave]

I have a Samson amp going into a set of Tannoy Reveals and a friend recently told me that I should keep the volume on the amp at maximum level and then just adjust the volume from the mixer. Could someone confirm whether this is true...I am just wary of pushing equipment to its limits....as i'm sure many are.

[regebro]

Well, it depends. If doing this means that you get hiss and noise, then no. Otherwise it's quite possible to do that, although I don't see that it's a particularily useful general principle.

I would probably set it so that when you have full volume on the monitor outs, the volume is slightly too loud. That way you get a good volume when turning down the monitor outs a bit, and then you have a margin upward if you want to raise the volume, but you still run the monitor outs close to the top level of their capacity.

In bad mixers, and with bad luck, you might actually run the monitor outs *too* hot that way, and then you need to turn down them and crank up the amp to not get distortion. But that shouldn't really happen.

[Disco_Dave]

Doing this gives no discernable extra noise. Not that I could hear above the noise from the mixer anyway!

I couldn't really see the point as with the amp volume on about 1/2 and the mixer volume at similar I can get a perfectly good volume for mixing (for my ears anyway). My friend seemed to think that amps produced a better sound when turned up high , but to me it seems no different really. It didn't make much sense to me because as a bassist I never run my amp at anywhere near full volume...OK I have a powerful rig but in my experience full volume means distortion and speaker damage....

I just asked to see whether it was a well known way to do things but seeing as the way I have it now works I don't think I'll start messing around.

Thanks for your comments.

[KingstonRock]

I was wondering about this before, I have hr824 which have there own amps, pretty big ones, they have no volume control, so they always run full out, the only control they have is a small nob on the back that you need to adjust with a screw driver, but all that does is lower the input signal, not control the amps. So apperantly these amps are designed to run full out, but I like regebro's suggestion, turning the amp down a little can hurt it

[mixsit]

Basically it's just another sensitivty control option to alow you to reduce the gain if you have more than needed. Full open it is out of the circuit, but amp hiss (might) be reduced by turning it down.

[Even]

I'm a little confused. I run my signal into my computer from the board itself via Tape out or channel "inserts". My amp powers my monitors only. All my levels are controlled at the mixer, technically I can shut the amp/monitors clean off and still have a strong and clear signal into my computer.

[Hugh Jazz]

I heard/read somewhere that most power amp manufacturers recommend running the amp wide open and controlling the volume through the board to maximize the S/N ratio. I think they also said it sounds better (in terms of a better frequency response).

[mixsit]

Originally posted by sonusman
Turning down the volume controls of the amp ALSO changes the input sensitivity on most amplifiers. Basically, that means that the input of the amp may more easily "clip".

Ed

Sonusman, I didn't get this part. Could you expotentiate a bit please.
Thanks
Wayne

[Slackmaster2K]

I have absolutely NO idea how this all works, but I'm wondering if this whole "power amp at 100%" thing is another example of a misused fact?

I had assumed that on a power amp, the "volume" knobs were simply input attenuators, and that the amp itself would always be "amplifying" by 100%. Perhaps it is this attenuation that can have a negative impact on the sound? I don't know.

I do know that in the manual for my TA-1600, it said to adjust the inputs such that I would get a slight amount of clipping with my incoming volume at 2/3 to 3/4. This required that I set the knobs on the amp at about 4 (of 10). When I did this, I of course found that it was much easier to adjust volume with my preamp, AND that my noise floor dropped to pretty much nothing (when I first had it at 100% it was definately noisey because of my preamp).

One tip: sonusman convinced me to buy a sound level meter ($35 from radio snack) and it helped a lot with setting up the power amp. I found that "4" on one channel was almost 3db louder than "4" on the other channel. Turning up the quiet channel by just a hair fixed it. I guess that could be expected, as pots are not really "accurate" devices. At any rate, the meter helped me balance the system properly....and learn where that critical 85db level lives at.

Personally I would go with usability over "potential" sound quality in this case...unless turning down the power amp really has a nasty impact on the sound. With my amp at 100% it was not only noisy, but WAY too hard to adjust volume as very small movements on the preamp resulted in HUGE leaps in level....plus the volume knob on my preamp isn't very accurate at low levels (channels become unbalanced under about 15%). Not only was this inconvenient, it was kind of dangerous. It's nice to have a lot of usable room on that volume knob, and even if I accidentally crank it way up I know I'm not going to blow anything.

P.S. I did a minimal amount of searching on deja about this subject and found all sorts of "recommendations"...some even say to set the volume in the middle of the pot because it's more "linear" there. Who knows... In my previous searchings about modding preamps, one common mod was to replace pots with switching resistors....but man, it better have a big impact on the sound to bother with something like that.

Slackmaster 2000

[Pier Calacino]

Hey guys,

I have a samson servo 120, and in the manual it says:
For the best signal to-noise ratio, the servo 120 should normaly be run with the channel input controls at or near maximum (fully clockwise, at the "0 dB" position).

So maybe most amps should be run wide open?

Thanks
Pier

[Lectric_Lab]

I've read lots of different informational posts on this subject too, and thinking on setting the speakers (volume) at 85 dbs and knowing the full potential of each side seems to be the better choice, if you have a db meter. Its also been stated that an amplifier looses its potential power after about 80% of the maximum volume setting (around 8 on the channel) then the volume actually decreases linearally, so I dont have a db meter and I turn my channels wide open and back off 5 detents from full.

[pandamonk]

Originally Posted by Lectric_Lab

I've read lots of different informational posts on this subject too, and thinking on setting the speakers (volume) at 85 dbs and knowing the full potential of each side seems to be the better choice, if you have a db meter. Its also been stated that an amplifier looses its potential power after about 80% of the maximum volume setting (around 8 on the channel) then the volume actually decreases linearally, so I dont have a db meter and I turn my channels wide open and back off 5 detents from full.

Old thread

[boingoman]

Originally Posted by Lectric_Lab

Its also been stated that an amplifier looses its potential power after about 80% of the maximum volume setting (around 8 on the channel) then the volume actually decreases linearally.

Who stated that?