Sensitivity vs Gain

[Noiz2]

Why not? For example Edirol 44 has digital knobs at the front. One of the 2 knobs is I think digital.
If the front knobs arent digital then what is the difference between the menu setting "sensitivity" and the input 1 and input 2 knobs? I'm thoroughly confused now! It would have made sense if the input knobs were attenuation/digital gain, but if not, than what? Another analog gain that further adjusts the voltage of the signal? If this is so, than why have 2 gain setting - one in the menu and one on the knobs?

Edit: I see that Edirol 44 also has gain named under "Sens" ie. sensitivity.

IF it's a menu setting it is almost certainly a digital setting.

Sensitivity is a bad name because it implies more than what it does. You could say I guess that a line input is less "sensitive" than a mic one but it's not really true. Both receive the same signal (ignoring impedance), one just amplifies it a lot more.

Why would you have two? Well generally to do slightly different things. On a mixer that first stage is to optimize the mic pre for that mics signal. THe level is to set the volume you are sending down the line. But don't stop there the mixer probably also has sub masters and a master, so that is four gain stages. Why not just one big knob? They are where they are to optimize the signal path. So that each stage gets what it needs and ideally you end up with the least noise.

 

[Richard Crowley]

I give up. I don't care what KINOKS wants to believe. The circuit is what it is and nothing that KINOS says or imagines will change that. A voltage divider (whether fixed or variable like a potentiometer) CANNOT "boost when set above 50" that is simply fantasy.

I do not agree that the front panel controls could be operating in the digital domain because if they had enough digital dynamic range to handle that, then they could have made a 32-bit recorder! Now it could be that those "Input 1/2" knobs are digitally controlled (fly-by-wire) but they are still ultimately operating on the signal in the analog domain BEFORE the A/D converter. If we want to settle this definitively, somebody can produce a schematic diagram for the gadget and we all can see for ourselves.

In closing, let me repeat that proper operation of an audio system requires proper GAIN STAGING at EACH and EVERY point in the circuit. There are two stages to be adjusted properly in the gadget under discussion, and it makes absolutely no difference in Real World Operation whether the adjustments are digital or analog. And it makes no difference whatsoever what they are named, either.

 

[KINOKS]

I give up. I don't care what KINOKS wants to believe. The circuit is what it is and nothing that KINOS says or imagines will change that.

Richard, I'm not convincing you about anything. I don't get it, what do you think that I want to believe? I want to believe what you guys are willing to explain to me! I just stated that you miss understood that I was talking about the knobs not the menu setting. All else was just me asking questions.

A voltage divider (whether fixed or variable like a potentiometer) CANNOT "boost when set above 50" that is simply fantasy.

I was just thinking out loud. I have little knowledge on this matter. My rationale was that the knobs (not the input gain called sensitivity) are attenuating the signal below the knobs setting of 50 and digitally boosting it when set above 50. The knobs max setting is 100. Edwin pointed out the same thing, he just said that it's usually above 75%. And I said 50% because the noise starts to creep in after 50 and not before.

Anyway... Edwin thanks, you explained it very nice! I see now that this topic is complex and that we can't just guess what and how it is doing. Only one way to find out probably - ask Roland.

And just to be clear: I am in no way advocating the use of the term "sensitivity". I just said that I can understand why Roland, or Edirol for that matter, named it like that.

 

[j1clark@ucsd.edu]

IF it's a menu setting it is almost certainly a digital setting.

Sensitivity is a bad name because it implies more than what it does. You could say I guess that a line input is less "sensitive" than a mic one but it's not really true. Both receive the same signal (ignoring impedance), one just amplifies it a lot more.

Well, I could see using using 'sensitivity' in two ways... one in some sort of bizarre marketing speak to avoid the word 'gain'... The other way is in the idea of 'matching the input amp to the sensitivity of the mic'...

 

[Noiz2]

I give up. I don't care what KINOKS wants to believe. The circuit is what it is and nothing that KINOS says or imagines will change that. A voltage divider (whether fixed or variable like a potentiometer) CANNOT "boost when set above 50" that is simply fantasy.

Well indeed IF it's a voltage divider then you are right. But that is an assumption on your part unless I am missing something. It would also be an unusual choice from my experience but that is me making an assumption.

On a mixer for instance normally you would have the input gain/ trim which is the mic preamp gain control, then you have a level control that controls the gain on the channel amp. Both can add gain to the signal.

So our key difference here is that you are assuming all the gain is in the mic pre and that the level is a passive voltage splitter and I am assuming it's an active amp stage. Either could be the case. I have built both styles of mixers and they both have their plusses and minuses. In the passive mode your fader can't add any gain (or noise) but you have to get all of your gain at the mic pre stage. With the active level you get to add gain later so the trim can be tailored to the mic and the level can compensate for performance, but you have the chance of adding more noise. I've seen the later more often than the former.

 

[Noiz2]

Not that there are any digital level controls here but there certainly could be. A quick search found quite a few products listing them in the features and a whole de=iscusion of the right way to implement digital level controls, turns out you really want a ADC that supports it internally. Anyway it's not an uncommon thing even on non pro gear. But as it relates to the OP it makes no real difference. A properly implemented digital level control should sound the same as a good analog one. A poorly implemented one will have increased noise as you lower the level.