View Full Version : XLR gain direction


Colin McDonald
January 18th, 2008, 03:26 PM
I keep turning these damn things the wrong way. There's no way of changing the direction of these like the focus and zoom rings is there? I'm I the only stupid old fogey that can't cope with turning pots UP to DECREASE the gain?

Petri Kaipiainen
January 18th, 2008, 04:12 PM
No, and no... =:-)

Bill Pryor
January 18th, 2008, 04:18 PM
Yep, they are totally backwards.

Brian Brown
January 19th, 2008, 05:43 PM
Yes, agreed... totally backwards. What helped me finally be successful in remembering its backwardness is to visualize my thumb moving in a downward direction for lowering the gain and an upward direction for increasing the gain... and paying no attention to those arrows.

Now, I only get it wrong about half the time *grin*.

Brian Brown
BrownCow Productions

Petri Kaipiainen
January 20th, 2008, 02:45 AM
kitchen faucets and nuts, screws in general open counter-clockwise, so maybe the audio was designed by plumbers or mechanical engineers...

Anyways, the QUALITY of the audio is great (over 90 dB S/N ratio from line-in).

Colin McDonald
January 20th, 2008, 07:27 AM
Yes, agreed... totally backwards. What helped me finally be successful in remembering its backwardness is to visualize my thumb moving in a downward direction for lowering the gain and an upward direction for increasing the gain... and paying no attention to those arrows.

Now, I only get it wrong about half the time *grin*.

Brian Brown
BrownCow Productions

I'll try that (while pretending I'm running a bath - thank you Petri). Its OK when I have time to think about it, but with unexpected changes of level it's hard to go against the habit of many years. I've been erring on the side of safety so far since there is such a good S/N ratio, trying to avoid having to change levels if possible during a shot in case I get it wrong and make things worse.

I used to be able to ride a bike with my hands crossed - a similar mental adjustment.

Brian Brown
January 20th, 2008, 01:34 PM
Anyways, the QUALITY of the audio is great (over 90 dB S/N ratio from line-in).

Yes, amazingly clean audio on line-in. When I can feed mine with my mixer, I get beautiful results. And then I don't have to fiddle with those backwards A1 knobs.

And I found that I can even max out the gain knobs on line-in to give me the best dynamic range and almost no noise. Are these your findings, too, Petri?

Thanks,
Brian Brown

Don Palomaki
January 20th, 2008, 01:54 PM
...and paying no attention to those arrows

Think of them not as arrows, but rather that the width of the symbol indicates the resulting the gain (e.g., width of the resulting level bars on the UV meter)

It is consistent with the menu wheel on the GL1/2 is it not? rotating the dial CCW (up viewed from the back) moves the selector UP on the menu.

Of course once you make the mistake in a shoot (as I have) you tend not to forget it again.

Petri Kaipiainen
January 23rd, 2008, 03:36 AM
And I found that I can even max out the gain knobs on line-in to give me the best dynamic range and almost no noise. Are these your findings, too, Petri?

Thanks,
Brian Brown

Yes, I tested my XH-A1 with SD302 and found out that when feeding +20 dB full scale signal to line-ins with the camera pots all the way open I got a sound file where peak samples were exactly 0 dBFS but no clipped samples. The noise bottom was below -90 dBFS!!!!!!!

Can not be more perfect than that with 16 bit system, and easy to adjust, just turn the pots all the way open! With SD302 limiter it is impossible to clip the audio if you understand anything about levels.

These tests were done in SD to find out the true PCM capability of the combination.

I dare to say XH-A1 has perfect audio quality with line in, only that it shoud have more connection/routing options and a limiter also on-cam. And MS on-camera mic system with the possibility of using just the M for ambience with one line-in mic... Well, nothing is perfect.

Brian Brown
January 23rd, 2008, 03:33 PM
Wow, Petri, I knew line-in inputs on the A1 were good, but not that good. Those results are amazing.

I try to shoot with a mixer whenever I can... an AC-powered 12 in/ 4 out Mackie. Nothing as nice as your SD, but its four preamps are pretty clean and the overall sound is much nicer than the mic inputs on the A1. I can get a lot more dynamic range when using the mixer.

I guess now I know why.

Thanks!
Brian Brown
BrownCow Productions

Don Palomaki
January 24th, 2008, 07:53 AM
I knew line-in inputs on the A1 were good, but not that good.

Check for some more details from one set of measurements: http://www.dvinfo.net/conf/showthread.php?t=89879

Jim Burton
January 25th, 2008, 12:53 AM
just to summarize, gain all the way to max, and then automatic gain control is off right?????

Don Palomaki
January 25th, 2008, 05:55 AM
What are the rest of the settings and sources (including their output levels) to go with the above?