Gain changes

[RoB]

I need your help please.

When I change my ports on my SQ, the gain always changes to 28 dB. Is there a setting I need to change to prevent this from happening?

So far I haven’t been able to save it in the scenes/shows

Thank you

[Scott]

The gain is associated with the actual preamp port, not the channel, so assigning a different port to a channel will cause you to see that particular port’s current gain setting.

[SQuser]

Could you please describe in more detail what you mean by “change ports” (I/O ports?) and how you do it?

Edit:
Sorry – maybe Scott’s answer has already sorted it out…

[RoB]

For explanation:

I have a band where I sometimes have the desk on stage. I use the local inputs (only need 16)

When I have the console foh, I use the slink port. So if I change this, my gain changes to 28 dB everywhere, no matter what I had previously set.

[Mike C]

That is the default gain when connecting to a stage box input, same thing on the QU.
If you same a scene for each configuration your settings should re call with the scene.
Check that there are no filters / blocks set on the scene recall for the patching and pre amp settings.

[Brian]

There is a common misunderstanding that the channel’s preamp gain setting is tied to the channel. It is not. A preamp’s gain setting is stored in the electronic circuitry of each individual preamp and it will always be tied to that preamp. This means when you change from local input 1 to local input 2, whatever the preamp gain level is set inside the local input 2’s preamp will be automatically recalled into that channel. If you then switch back the local input 1, whatever the gain setting is in the local input 1’s preamp will be recalled in the channel. The same thing applies when you are using stage boxes – the preamp settings are set and stored in each individual input’s preamp circuitry (which is physically inside the stage box). If you switch to SLink input 10 (which is a preamp in a connected stage box), the system will set the channel’s gain to whatever the preamp for that stage box’s preamp is currently set to.

The preamps should retain those gain settings even when the system is powered down or a stage box is unplugged. When you power on the system, the preamp gain settings should not be resetting to 28db but rather it should remain whatever the preamp was set to prior to the shutdown. Similarly, the preamp gain settings should be saved in a scene. If recalling a scene does not load the preamp gain settings that where previously saved, then there is likely a filter (global or scene level) that is preventing those settings from being recalled.

[SQuser]

Now I see an unexpected problem.
Normally RoB’s problem should be solved by using his normal show scene and having two additional scenes with recall filters available, which contain the local patch and the patch on SLink.
He could then load these as needed to patch his show scene back and forth.
Now I would have expected that it would be enough in the recall filter to block everything except the “Inputs Patch”.
But unfortunately this doesn’t work (at least not for me). (
I also have to allow “Preamp” in the recall filter.
Only then is the patch changed, but unfortunately also the gain of the preamp.
Am I thinking wrong or is it a bug?

[Brian]

It’s not a bug. Again, there is no way to change the input’s source to another option that has a preamp (local or via a stagebox) without also loading that new option’s preamp’s gain setting.

Honestly I did not realize that you would have to allow both of those settings (routing and preamp) to be recalled before the system would allow the changes, but it makes sense because it is physically impossible to change
the routing without changing the gain as well. If you block one (or both) of those settings, it would/should naturally prevent the system from completing the routing change/recall.

There are also times where you might want to change the preamp setting without changing the routing, so I can understand why both are included as filter settings. (It would be even better if this was filterable at a per channel basis, but I think both of these settings is an “all or none” type of filter). Although there should be some sort of note/warning stating that you cannot change the routing via a scene change unless the preamp setting is also unfiltered.

[SQuser]

Thanks Brain,

> … it is physically impossible to change the routing without changing the gain as well.
I didn’t expect that – especially with regard to the block diagram, where the input patch clearly seems to be done separately and after the preamps. (

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[Brian]

I realize the block diagram doesn’t specifically address what is part of the pre-amp or not, but anything for an analog input that is prior to the analog to digital conversion (ADC on the block diagram) is really part of the preamp. All of those components are located in the electronics associated with each analog input. For the local inputs those electronics are physically located within the console’s physical frame, but when a stage box is used, those electronics are actually located in the stage box (as represented by the DX Expanders section of the block diagram). The “console” elements really start after the analog to digital conversion which is why it is a represented with a different box surrounding those elements.

[Brian]

I realize my previous comment doesn’t really address your last post. I waited to long to be able to edit the comment as well.

So while it is clear from the block diagram that the routing is physically separate from the preamp and gain setting, the two are still “linked” together when we are talking about analog sources. This is because it is simply impossible to change the source from one analog input to another analog input without also changing the gain. If you have added a filter that blocks changes to the “gain” settings, then this will prevent the system from being able to change to another analog input.

I haven’t tested it, but I suspect this limitation only applies to analog sources. If you allow “routing” changes, but filter out “gain” changes, I suspect you can still change a digital input (USB or I/O port) to another digital input (USB or I/O port) without issues because those sources don’t have a “gain” setting.

[SQuser]

Hmm – I’m still thinking back and forth.
Let’s put it this way: A&H probably deliberately designed it so that the gain level follows the respective physical input.
But the gain level could just as easily be used by the target input, which would be very practical in this case.
A physical separation would only be impossible on consoles where the gain control is a real analogue control, such as the good old 01V… from Yamaha.

But how now to solve this seemingly simple problem?
Actually it should be possible with the Mixing Station app, because here you could always link two channels of the same mic or instrument (MS Channel Links) except for the Signal source and Mute parameters.
Then you could set up a fader bank for the local inputs and a second one for the stage box.
And then you would simply have to mute the entrances to the bank that you don’t need that evening.
Otherwise, all changes to the channels in one bank would also be transferred to the channels in the other bank – including the gain.
And you wouldn’t have to change anything about the routing.

But I hope there is a much simpler method too.
I would probably just readjust the gains during the sound check – or write down the 16 values.
(In the past we used to draw the knobs – with a little line in them.
So back to the roots. 🙂 )

[RoB]

Thank you all so much, I think I’ve made a lot of progress in my understanding.

I have a start scene with which I start the sound check. And in this scene I routed the patching to Local or Stagebox depending on the situation. And that’s definitely my biggest mistake, right?

I would have to save this scene twice, once locally and once in Stagebox. Then I can save to the preamps, which should be approximately the same. After all, the source is always the same

[SQuser]

> And in this scene I routed the patching to Local or Stagebox depending on the situation. And that’s definitely my biggest mistake, right?
When patching by hand in the I/O settings, yes.

> I would have to save this scene twice, once locally and once in Stagebox. Then I can save to the preamps, which should be approximately the same.
That would of course be possible, but any other changes you make during your show, e.g. EQ, would of course always be saved only in the respective scene and not transferred to the other one.

I now think it’s more of a bug that patching doesn’t work with a special scene that only allows patching.

[SQuser]

Hello Brain again,
Your statements unsettled me because they contradicted my experiences, but you have a lot of well-founded knowledge.
So I just tried it out again in practice and (luckily) found the following:

> The preamps should retain those gain settings even when the system is powered down or a stage box is unplugged.
I doubted that because it would mean, among other things, that I wouldn’t be able to prepare a show with a stage box including gains and 48V on the MixPad.
But I can do that, push it into the SQ and after switching on the stage box, the corresponding settings are transferred to the stage box – and fortunately not the other way around.

> the preamp settings are set and stored in each individual input’s preamp circuitry (which is physically inside the stage box).
I would think, the preamp parameters are saved in the console.

Please correct me and sorry, if I should think wrong!
I’m glad to be able to find out things here that I didn’t know yet.

[Author]

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