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In terms of gain staging...

ARNK

In terms of gain staging...
« on: December 24, 2017, 09:33:18 PM »
Does it make a difference in terms of the signal to noise ratio of a recording depending on what the master volume knob is set to on the Pro 2?

For example, is it better to keep the volume knob at around 75% or more, or depending on your setup, would it make no difference if it were set to only 30% or 40%?

Would the signal into your DAW be just as clean either way as long as it was loud enough?
« Last Edit: December 24, 2017, 09:35:19 PM by ARNK »

Re: In terms of gain staging...
« Reply #1 on: December 25, 2017, 02:17:08 PM »
Hi,

raising the volume can lift up the noisefloor, as long as silence is measured with -85dB or more everything is good. Depending on the on the soundcard or more specific on its impedance or resistatance the position of the knob may vary.
If the amp in the synth distorts at higher levels it may be better to record it with lower Main Volume and amp it a bit afterwards, i remember a user who experienced a "smoother sounds" at lower levels. The one here is about 3/4 so theres a bit room to boost if the programed patch is not yet loud enough. THis gain staging thing as far as i understand starts with source volume (oscs, external in) is multiplied via the VCA and leveled the via Program Volume and then there is Master Volume.

Hope this helps,

Martin3

Re: In terms of gain staging...
« Reply #2 on: December 26, 2017, 05:32:06 PM »
Dave recommends keeping Master Volume at maximum whenever possible for optimum signal to noise ratio. He sometimes jokes he'd rather have no volume knob on the synth, instead having max output as the only option so people always get the best signal but he knows it's not practical for everybody.
Dave Smith Instruments

jdt9517

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Re: In terms of gain staging...
« Reply #3 on: December 27, 2017, 10:30:17 AM »
As a general rule, output of the instrument should be maxed.  Input of the DAW is then adjusted to bring the signal as close to 0 db without over driving.  This will create the best signal to noise ratio.  Depending upon the dynamic range, this could mean that the average input could be -10 db or less.  This was the original reason for the creation of limiters and compressors - limit the dynamic range so more the of signal would record close to 0 db. 
Jim Thorburn .  Toys-  Dave Smith: Prophet 08;
Pro 2; Prophet 12; EastWest Orchestral soft synths; Yamaha S90; Yamaha DX-7; KARP Odyssey; Ensoniq ESQ-1.  All run through a Sonar DAW with a Tascam DM-24 board.

ARNK

Re: In terms of gain staging...
« Reply #4 on: December 27, 2017, 12:09:42 PM »
Dave recommends keeping Master Volume at maximum whenever possible for optimum signal to noise ratio. He sometimes jokes he'd rather have no volume knob on the synth, instead having max output as the only option so people always get the best signal but he knows it's not practical for everybody.

Really!

ARNK

Re: In terms of gain staging...
« Reply #5 on: December 27, 2017, 12:11:33 PM »
As a general rule, output of the instrument should be maxed.  Input of the DAW is then adjusted to bring the signal as close to 0 db without over driving.  This will create the best signal to noise ratio.  Depending upon the dynamic range, this could mean that the average input could be -10 db or less.  This was the original reason for the creation of limiters and compressors - limit the dynamic range so more the of signal would record close to 0 db.

Hmm, should the fader of the input channel be pulled down or should the gain be clipped pre fader?

ARNK

Re: In terms of gain staging...
« Reply #6 on: December 27, 2017, 07:44:12 PM »
Hmm, with the volume set to max, no matter if I pull down the input fader to zero or apply a gain effect before the fader the input meters on my audio interface go straight red to the max.

jdt9517

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Re: In terms of gain staging...
« Reply #7 on: December 27, 2017, 09:18:04 PM »
On your input mixer there should be a gain control.  It is usually near the input.  The gain control is separate from the channel fader.  The gain should be set pretty low since the output of the Pro 2 is pretty high.  What you are doing with the gain control is making the input compatible with the output of the synth (think line level vs. mic level input).  The fader will probably end up being about 1/2 to 2/3 towards the top ("0" db ) after the gain control is properly set.
« Last Edit: December 27, 2017, 09:38:51 PM by jdt9517 »
Jim Thorburn .  Toys-  Dave Smith: Prophet 08;
Pro 2; Prophet 12; EastWest Orchestral soft synths; Yamaha S90; Yamaha DX-7; KARP Odyssey; Ensoniq ESQ-1.  All run through a Sonar DAW with a Tascam DM-24 board.

jdt9517

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Re: In terms of gain staging...
« Reply #8 on: December 27, 2017, 09:55:40 PM »
Hmm, with the volume set to max, no matter if I pull down the input fader to zero or apply a gain effect before the fader the input meters on my audio interface go straight red to the max.

Set the gain control so no signal comes in.  Set your fader to "0" db (usually 1/2 to 2/3 up the fader).  Play the synth while turning up the gain control.  When the meters start going from green to yellow, it's set pretty close.   If you hear clipping, reduce the gain (not the fader) until the clipping goes away.   
Jim Thorburn .  Toys-  Dave Smith: Prophet 08;
Pro 2; Prophet 12; EastWest Orchestral soft synths; Yamaha S90; Yamaha DX-7; KARP Odyssey; Ensoniq ESQ-1.  All run through a Sonar DAW with a Tascam DM-24 board.

Re: In terms of gain staging...
« Reply #9 on: December 28, 2017, 06:02:50 AM »
As a general rule, output of the instrument should be maxed.  Input of the DAW is then adjusted to bring the signal as close to 0 db without over driving.  This will create the best signal to noise ratio.  Depending upon the dynamic range, this could mean that the average input could be -10 db or less.  This was the original reason for the creation of limiters and compressors - limit the dynamic range so more the of signal would record close to 0 db.
Hi,

were you got that information from seems to be not true to me, limiting was done to protect the transmitting towers amplifier afaik. Start of this was the question how to get good signal to noise ratio so please leave the toys out of discussion until most poeple got it that they are boosting the noise. "to get near 0dB"

Hope this inspires or helps,

Martin3

ARNK

Re: In terms of gain staging...
« Reply #10 on: December 28, 2017, 07:30:38 AM »
This might be a question for RME, but I’ve tried reducing the gain in both the audio interfaces mixer as well as my DAW (Cubase). That is with the PRO 2 set to max volume.

No matter how low the gain setting the input meters on my audio interface are immediately red and maxed out/overloaded. The only thing that fixes the issue in the RME interface is reducing the master volume knob on the PRO 2 itself.
« Last Edit: December 28, 2017, 07:33:21 AM by ARNK »

jdt9517

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Re: In terms of gain staging...
« Reply #11 on: December 29, 2017, 07:43:46 PM »
This might be a question for RME, but I’ve tried reducing the gain in both the audio interfaces mixer as well as my DAW (Cubase). That is with the PRO 2 set to max volume.

No matter how low the gain setting the input meters on my audio interface are immediately red and maxed out/overloaded. The only thing that fixes the issue in the RME interface is reducing the master volume knob on the PRO 2 itself.

It's a little difficult to diagnose since I do not know what kind of mixer/interface you are using for your DAW.  However, since the meter pegs when you just crack open the control leads me to believe that you haven't found the gain control yet.

On your interface, there should be two controls per channel - gain and volume.  The gain controls (attenuates) the amount of input coming from your source (Pro 2) into the mixer.  The volume controls the amount coming out of the mixer into your DAW.  Pretty much all gain controls will effectively attenuate the Pro 2's output.  So, it sounds like you may not be finding the gain control or may be mistaking the volume control for gain.

Also, some mixers do not have a gain control but accomplish the purpose by having either two inputs or a switch.  They are usually labeled "Instrument" or "Inst" and "Mic".  If your mixer/interface has that option, use the Inst input. 

Jim Thorburn .  Toys-  Dave Smith: Prophet 08;
Pro 2; Prophet 12; EastWest Orchestral soft synths; Yamaha S90; Yamaha DX-7; KARP Odyssey; Ensoniq ESQ-1.  All run through a Sonar DAW with a Tascam DM-24 board.

Shaw

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Re: In terms of gain staging...
« Reply #12 on: December 29, 2017, 09:32:04 PM »
... limiting was done to protect the transmitting towers amplifier afaik.
True, but I don’t think that was the start of Audio limiters. Langevin bought the patent for the first Audio limiter in the 40s (The tech was developed in the mid 30s), but it wasn’t utilized in radio towers until the late 50s and was part of the reason FM radio came to dominate in the U.S. in the late 50s.
Langevin’s first creations were for telecommunication (through wires back then, remember), but the company marketed limiters for audio recording in the early 50s.
If someone has a different historical account of this, please let me know.


Anyway, when turned all the way up, the Pro 2 doesn’t (or shouldn’t) produce a signal that distorts. That is almost certainly not the source of the problem.   Do you have another synth to test your interface inputs with?

"Classical musicians go to the conservatories, rock´n roll musicians go to the garages." --- Frank Zappa

jdt9517

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Re: In terms of gain staging...
« Reply #13 on: December 29, 2017, 10:58:19 PM »
@Shaw- My understanding is similar to yours.  Experimentation starts in the mid-20's with the first patent about 1940.   Compressors came shortly thereafter (being very similar technology).  For audio work, limiters were used to address the problem of recording engineers having to manually "ride the fader" to keep a signal within a reasonable dynamic range.  Vocalists were the worst offenders.  It wasn't until the 1960's that limiters/compressors started being used for artistic expression. 

I didn't follow the problems in broadcast, but I understand that broadcast engineers faced a similar problem of manually having to limit the signal going to the transmitter.   Limiters addressed that problem as well. 
Jim Thorburn .  Toys-  Dave Smith: Prophet 08;
Pro 2; Prophet 12; EastWest Orchestral soft synths; Yamaha S90; Yamaha DX-7; KARP Odyssey; Ensoniq ESQ-1.  All run through a Sonar DAW with a Tascam DM-24 board.

ARNK

Re: In terms of gain staging...
« Reply #14 on: December 31, 2017, 12:37:14 PM »
Anyway, when turned all the way up, the Pro 2 doesn’t (or shouldn’t) produce a signal that distorts. That is almost certainly not the source of the problem.   Do you have another synth to test your interface inputs with?

Hey there, no it doesn't actually distort the signal - that's the thing. It causes the meters on my audio interface to go all the way into the red when I press a key.

-------
RME Fireface UFX
TotalMix FX

Shaw

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Re: In terms of gain staging...
« Reply #15 on: December 31, 2017, 12:54:31 PM »
Anyway, when turned all the way up, the Pro 2 doesn’t (or shouldn’t) produce a signal that distorts. That is almost certainly not the source of the problem.   Do you have another synth to test your interface inputs with?

Hey there, no it doesn't actually distort the signal - that's the thing. It causes the meters on my audio interface to go all the way into the red when I press a key.

-------
RME Fireface UFX
TotalMix FX
Have you tried other inputs on the RME? Other synths? You need to play process of elimination to somehow narrow this issue down to the fault point.
"Classical musicians go to the conservatories, rock´n roll musicians go to the garages." --- Frank Zappa

ARNK

Re: In terms of gain staging...
« Reply #16 on: January 01, 2018, 06:26:39 PM »
Anyway, when turned all the way up, the Pro 2 doesn’t (or shouldn’t) produce a signal that distorts. That is almost certainly not the source of the problem.   Do you have another synth to test your interface inputs with?

Hey there, no it doesn't actually distort the signal - that's the thing. It causes the meters on my audio interface to go all the way into the red when I press a key.

-------
RME Fireface UFX
TotalMix FX
Have you tried other inputs on the RME? Other synths? You need to play process of elimination to somehow narrow this issue down to the fault point.

I see you have a Minitaur as well, I tested it on Channel AN 5 and cranked the volume knob to 100% and it doesn’t it seems that no matter which patch I choose it doesn’t come anywhere to clipping (or going into the red).

Re: In terms of gain staging...
« Reply #17 on: January 03, 2018, 10:53:16 AM »

Hi,

lets say FM and limiters came a bit before the DAW and talk about fireface UFX and Pro2.

thoughts:

Are you on the Stereo Out or Headphone out on the Pro2-
How are the settings in totalmix.

Shaw

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Re: In terms of gain staging...
« Reply #18 on: January 03, 2018, 11:00:34 AM »
Are you on the Stereo Out or Headphone out on the Pro2...
Yeah, the headphone out would do that for sure, it is WAY hotter than the line out.  And not distorted.
"Classical musicians go to the conservatories, rock´n roll musicians go to the garages." --- Frank Zappa

jdt9517

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Re: In terms of gain staging...
« Reply #19 on: January 04, 2018, 06:05:46 PM »
I went online and looked at the RME UFX manual.  Page 22, Sect. 8.6.   Here is adjustment of the gain for analog inputs:

"The input sensitivity of the rear inputs can be changed in three steps in TotalMix (Input Channel
Settings, Level), assuring the highest signal to noise ratio will be achieved. A further optimization
can be achieved by adjusting the source itself. Raise the source’s output level until the
peak level meters in TotalMix reach about –3 dB."

ARNK, does this help?
Jim Thorburn .  Toys-  Dave Smith: Prophet 08;
Pro 2; Prophet 12; EastWest Orchestral soft synths; Yamaha S90; Yamaha DX-7; KARP Odyssey; Ensoniq ESQ-1.  All run through a Sonar DAW with a Tascam DM-24 board.