Console Gain Staging - Yamaha PM2000

[Matt C]

I've been studying the signal flow in my console and wanted to get some opinions on a specific detail.  In the Program/Bus section, there is a switchable 10dB passive attenuation switch (set to -10dB by default), followed by a non-inverting op amp stage set to about 30dB of gain (see schematic below).

I'm curious whether anyone sees a benefit from removing the 10dB  attenuator and adjusting the following op amp for 10dB less gain (around 20dB instead of 30dB).  I tested this out and gave it a quick listen and didn't notice any significant decrease in noise, but it still seems silly to me to throw away 10dB of level just to gain it right back up again. FWIW it would be easy to replace those 33K resistors on the bus channels.

 

[boji]

Are you experiencing noise without the pad you want to reduce?  How old are your lytics?

 

[Matt C]

I re-capped the console within the past year. It's not a particularly quiet console in general and I'm poking around for ideas to quiet things down. I know this specific detail is not gonna make a huge difference, but I was curious to get people's take on it.

 

[abbey road d enfer]

but it still seems silly to me to throw away 10dB of level just to gain it right back up again.

I tend to agree! Is there any explanation in the manual about the purpose of this switch?

 

[scott2000]

Is this relevant???

 

[abbey road d enfer]

Is this relevant???

Yes; it looks like they tried to cater for the needs of some very unexperienced users. I won't debate; the customer's always right.
The example they give of a church with soft-speaking talker is harly practical since 94dB of overall gain (plus about 26-32 dB in the power amps) is bound to generate a lot of feedback.

 

[Matt C]

right, so for my uses I don't need the switch, so bypassing the attenuator and decreasing the gain of the post-fader amp seems only reasonable, even if it doesn't have a major impact on noise or anything else.

 

[JohnRoberts]

That is why pads often have switches associated with them..

Yes, less closed loop gain is always better, all else equal... pads are useful to prevent overload.

JR