Line Mixer - does it perfectly preserve sound?

[tobypearce]

Hi,

Does anyone know if simply passing an instrument through a line mixer has any impact on sound? I wouldn't think so, but it's a very old device so there's just a possibility it does something unfortunately like introduce phase, reduce sample rate etc.

I'd test it with a scope but I'm not really sure what I would be looking for!

[Raveshaper]

As far as I know it does not color the sound. To test this you can split a sound and send it into two mix channels with one of them containing a line mixer in its insert section, then invert phase on one of the mix channels and see if it mutes the sound entirely.

[Ostermilk]

Yes, simply put, they are totally transparent.

A null test is the easiest way to check this.

[Olivier]

Test it yourself.
Take a signal.. Take a spider splitter and split it into 2. Let's call them line a and b. Invert line b using Thor, pipe it into a line mixer (the device you want to test). Now take the output from the line mixer back into a spider merger. Also connect line a to the merger so that line a and b are merged again. Listen to the merged signal. If there is no sound then you know the line mixer didn't change the signal.

[orthodox]

I tested it many times, it is dumb as a rock, it just can't alter the signal by no means.

[selig]

Hi,

Does anyone know if simply passing an instrument through a line mixer has any impact on sound? I wouldn't think so, but it's a very old device so there's just a possibility it does something unfortunately like introduce phase, reduce sample rate etc.

I'd test it with a scope but I'm not really sure what I would be looking for!

Well, besides what the others are saying, which is 100% true according to my testing, you would never see phase or sample rate issues with a gain control device (even a poorly designed one, whatever that would mean). At the extremes, and we're talking HUNDREDS of decibels below nominal level, you may experience some "rounding errors" that might affect the audio quality in some way. But with 32 bit floating point audio we're working with over 1500 dB dynamic range, good luck finding ANY device that can give you enough gain adjustment to ever even come close to seeing any rounding errors.

[tobypearce]

Hi,

Does anyone know if simply passing an instrument through a line mixer has any impact on sound? I wouldn't think so, but it's a very old device so there's just a possibility it does something unfortunately like introduce phase, reduce sample rate etc.

I'd test it with a scope but I'm not really sure what I would be looking for!

Well, besides what the others are saying, which is 100% true according to my testing, you would never see phase or sample rate issues with a gain control device (even a poorly designed one, whatever that would mean). At the extremes, and we're talking HUNDREDS of decibels below nominal level, you may experience some "rounding errors" that might affect the audio quality in some way. But with 32 bit floating point audio we're working with over 1500 dB dynamic range, good luck finding ANY device that can give you enough gain adjustment to ever even come close to seeing any rounding errors.

Thanks - that's exactly the kind of reassurance I was looking for.

What I am wanting to do is create a side chain built in to a combinator using CV from Skope to control the shape of the gain reduction, and get just the feeling from the side chain that I'm after for a track.

Then I'd like to have this available in every track - as a built in default for my combinator patch, with a simple rotary to control strength. Since I want to use this on every track, I'm really pleased to now have the confidence that this won't affect sound quality in any way.

And since you've got in there with a response Selig, and I notice that your own Gain tool has cv in, perhaps I should be using that instead of the line mixer

Presumably it's extremely light on CPU usage?

[riemac]

Hi,

Does anyone know if simply passing an instrument through a line mixer has any impact on sound? I wouldn't think so, but it's a very old device so there's just a possibility it does something unfortunately like introduce phase, reduce sample rate etc.

I'd test it with a scope but I'm not really sure what I would be looking for!

Well, besides what the others are saying, which is 100% true according to my testing, you would never see phase or sample rate issues with a gain control device (even a poorly designed one, whatever that would mean). At the extremes, and we're talking HUNDREDS of decibels below nominal level, you may experience some "rounding errors" that might affect the audio quality in some way. But with 32 bit floating point audio we're working with over 1500 dB dynamic range, good luck finding ANY device that can give you enough gain adjustment to ever even come close to seeing any rounding errors.

Thanks - that's exactly the kind of reassurance I was looking for.

What I am wanting to do is create a side chain built in to a combinator using CV from Skope to control the shape of the gain reduction, and get just the feeling from the side chain that I'm after for a track.

Then I'd like to have this available in every track - as a built in default for my combinator patch, with a simple rotary to control strength. Since I want to use this on every track, I'm really pleased to now have the confidence that this won't affect sound quality in any way.

And since you've got in there with a response Selig, and I notice that your own Gain tool has cv in, perhaps I should be using that instead of the line mixer

Presumably it's extremely light on CPU usage?

I work with a send ducker for sidechaining in this situation, this is the best solution for many tracks and has very low CPU usage.
I still wish there would be a dedicated Rack Extension for volumeshaping. Syncronous comes the closest, but is a little overkill for the task.

[tobypearce]

I hear you reimac.

When I was working in Logic I used volume shaper from cableguys - it did the job perfectly

That's why I am setting up for working with Shape [not Skope, as I said above].
https://shop.propellerheads.se/product/ ... fo-editor/

It's CV, not a volume shaper, but when coupled with a simple gain device, it turns into one. Then you can adjust the curve very precisely to get just the feeling you want from the side chain.

If Llectric Panda (or anyone else for that matter) made a volume shaper that looked just like Shape but passes audio through and ducks it according to the curve, I would buy instantly.

[orthodox]

What I am wanting to do is create a side chain built in to a combinator using CV from Skope to control the shape of the gain reduction, and get just the feeling from the side chain that I'm after for a track.

Then I'd like to have this available in every track - as a built in default for my combinator patch, with a simple rotary to control strength. Since I want to use this on every track, I'm really pleased to now have the confidence that this won't affect sound quality in any way.

By the way, each Mix Channel has a Level CV In.

I don't know how fast you are going to modulate volume level and what is it for, but there's one more thing: the changes of volume knob, mute/solo buttons, just everything are not applied immediately to the signal level. The gain changes are filtered through an attack/release envelope, with the rate of about 10ms/40dB at 44100Hz sampling rate. I guess, it is done in order to prevent clicks.
Not sure if it is really so, I tested it long ago.

[Marco Raaphorst]

Hi,

Does anyone know if simply passing an instrument through a line mixer has any impact on sound? I wouldn't think so, but it's a very old device so there's just a possibility it does something unfortunately like introduce phase, reduce sample rate etc.

I'd test it with a scope but I'm not really sure what I would be looking for!

If you are wondering if something introduces phase, do a phase test: add mine mixer to a paralel channel and invert the phase. Voila, no sound. 100% perfect, no processing going on. (would be weird if a module like that would change something, it's only a gain device)

[selig]

What I am wanting to do is create a side chain built in to a combinator using CV from Skope to control the shape of the gain reduction, and get just the feeling from the side chain that I'm after for a track.

Then I'd like to have this available in every track - as a built in default for my combinator patch, with a simple rotary to control strength. Since I want to use this on every track, I'm really pleased to now have the confidence that this won't affect sound quality in any way.

By the way, each Mix Channel has a Level CV In.

I don't know how fast you are going to modulate volume level and what is it for, but there's one more thing: the changes of volume knob, mute/solo buttons, just everything are not applied immediately to the signal level. The gain changes are filtered through an attack/release envelope, with the rate of about 10ms/40dB at 44100Hz sampling rate. I guess, it is done in order to prevent clicks.
Not sure if it is really so, I tested it long ago.

Here's what I've measured with regards to CV control of Channel Level, which confirms your basic finding:
I used a square wave from Pulsar, which has a CV and Audio level output (making it easy to compare the two).

From silence to full level it takes around 20 ms.
Release time is longer, taking around 120 ms to take the level from full to silence.

[Abstrax]

In my project template I send a copy of my Kick to an mclass compressor. I use the mclass cv out to control the volume of whatever chain I want. It sounds alright, doesn't color the signal, and uses very little CPU.

[selig]

Hi,

Does anyone know if simply passing an instrument through a line mixer has any impact on sound? I wouldn't think so, but it's a very old device so there's just a possibility it does something unfortunately like introduce phase, reduce sample rate etc.

I'd test it with a scope but I'm not really sure what I would be looking for!

Well, besides what the others are saying, which is 100% true according to my testing, you would never see phase or sample rate issues with a gain control device (even a poorly designed one, whatever that would mean). At the extremes, and we're talking HUNDREDS of decibels below nominal level, you may experience some "rounding errors" that might affect the audio quality in some way. But with 32 bit floating point audio we're working with over 1500 dB dynamic range, good luck finding ANY device that can give you enough gain adjustment to ever even come close to seeing any rounding errors.

Thanks - that's exactly the kind of reassurance I was looking for.

What I am wanting to do is create a side chain built in to a combinator using CV from Skope to control the shape of the gain reduction, and get just the feeling from the side chain that I'm after for a track.

Then I'd like to have this available in every track - as a built in default for my combinator patch, with a simple rotary to control strength. Since I want to use this on every track, I'm really pleased to now have the confidence that this won't affect sound quality in any way.

And since you've got in there with a response Selig, and I notice that your own Gain tool has cv in, perhaps I should be using that instead of the line mixer

Presumably it's extremely light on CPU usage?

Well, the Line Mixer doesn't have a CV input for level, only for pan, so it's definitely out of the running! This is why it's best to ask the direct question: what is the best gain control device with a CV input, rather than asking about the audio quality of the line mixer! Selig Gain is designed for this sort of thing (gain control). But might I also recommend using the "Send Ducking" technique if you are wanting to duck audio from a common source (like a kick). If you need independent control over ducking, then the Selig Gain approach in a Combinator is also good - and there are plenty of other REs or native devices that can do this as well, so first check and see if you already have what you need!

Here's the Send Ducking video:

Here's the link to the Combinator needed for this effect:
https://dl.dropboxusercontent.com/u/147 ... er.cmb.zip

[selig]

I hear you reimac.

When I was working in Logic I used volume shaper from cableguys - it did the job perfectly

That's why I am setting up for working with Shape [not Skope, as I said above].
https://shop.propellerheads.se/product/ ... fo-editor/

It's CV, not a volume shaper, but when coupled with a simple gain device, it turns into one. Then you can adjust the curve very precisely to get just the feeling you want from the side chain.

If Llectric Panda (or anyone else for that matter) made a volume shaper that looked just like Shape but passes audio through and ducks it according to the curve, I would buy instantly.

Shape is probably overkill, but I'd still want control over the curve rather than preset shapes - Selig Audio definitely has something in the works that will do all this and more, but there's at least one other RE in the pipeline that will drop before a ducking device. Would be interesting to hear the very basics of what users want for this task to see how close I've come to nailing it…

[selig]

What I am wanting to do is create a side chain built in to a combinator using CV from Skope to control the shape of the gain reduction, and get just the feeling from the side chain that I'm after for a track.

Then I'd like to have this available in every track - as a built in default for my combinator patch, with a simple rotary to control strength. Since I want to use this on every track, I'm really pleased to now have the confidence that this won't affect sound quality in any way.

By the way, each Mix Channel has a Level CV In.

Which would be great if it weren't for the issues we have discussed earlier, plus the fact the OP wants to put this in a Combinator… ;(

[tobypearce]

Selig here goes:

I've attached a self-contained reason file that shows the effect - and control - of different side chain settings.

(This uses Shape and Janitor to achieve the effect - at least until something new comes along )

Notes:
1. There are 7 versions of the same pad - all the same except for different side chain envelopes. Un-mute them in turn, and this shows a whole series of different sounds all based around the simple side chain theme.

2. I've tried to have fun naming the different envelopes - it's great to edit your own but there may be value in having a handful of carefully chosen ones to get people going.

3. The pluck is also side chained. Note how I have used the envelop to delay the start of the ducking to allow the plucky transients through - this would be quite a hassle using a traditional side chain technique.

I hope this helps in the search!

[tobypearce]

Sorry - one more thing.

I used to use the traditional side chain approach: having a silent kick drum going to a spider with multiple outputs to different compressors. It's ok, but I am looking for a way to bake the side chain into the combinator from the get go. Constantly having to press tab and connect the side chain input interrupts workflow, and you also end up with wires all over the back of the rack.

[selig]

Sorry - one more thing.

I used to use the traditional side chain approach: having a silent kick drum going to a spider with multiple outputs to different compressors. It's ok, but I am looking for a way to bake the side chain into the combinator from the get go. Constantly having to press tab and connect the side chain input interrupts workflow, and you also end up with wires all over the back of the rack.

You say that like it's a bad thing (the wires).

I have a few questions: first, are some of these shapes (like the first one that's like a square wave) intentionally off the grid (by 1/32nd note)? I'm guess that if so, you did this by ear rather than by sight or that if by sight it was off because of using the grid at 32 divisions.

As for any dedicated device, should it allow ON and OFF grid drawing for effects like this?

[tobypearce]

Hiya,

I did it by ear. I switched to the maximum 640 resolution and just tuned it by pressing L or R to get it in the sweet spot. Actually, it wasn't so much fun because every time you shift the envelope you get a new high or low bit at the beginning or end of the envelope that you have to take care of. (Easiest just to try it to see what I mean.) All I really wanted to do was change the position of the curve in the middle, not the very end sections. In other words, it would be easier if you could switch wrapping off, and instead just extend the last point with the same value.

Off grid drawing isn't necessary I don't think, so long as the resolution is enough (at least 64 on Shape's measure). Creating a smooth curve would be good though. What is very necessary is to have a rotary to manually change the phase, which would be an easier way to do what I was doing above. Shape has a phase rotary but it's not saved with the patch. This means that you can't use it if you want to quickly audition a series of different envelopes and keep it in time.

Wires is fine but I'm wearing out the K button on my keyboard

[Reasonistas]

When I was working in Logic I used volume shaper from cableguys - it did the job perfectly

Shape is probably overkill, but I'd still want control over the curve rather than preset shapes - Selig Audio definitely has something in the works that will do all this and more, but there's at least one other RE in the pipeline that will drop before a ducking device. Would be interesting to hear the very basics of what users want for this task to see how close I've come to nailing it…

As Giles said, there is a dedicated "sidechain" Rack Extension coming that I believe will satisfy all volume shaping needs and them some. We'll provide more details in a month or so. You won't be disappointed!

[selig]

When I was working in Logic I used volume shaper from cableguys - it did the job perfectly

Shape is probably overkill, but I'd still want control over the curve rather than preset shapes - Selig Audio definitely has something in the works that will do all this and more, but there's at least one other RE in the pipeline that will drop before a ducking device. Would be interesting to hear the very basics of what users want for this task to see how close I've come to nailing it…

As Giles said, there is a dedicated "sidechain" Rack Extension coming that I believe will satisfy of volume shaping needs and them some. We'll provide more details in a month or so. You won't be disappointed!

Hoping I'm not giving too much away…there are actually TWO devices planned for the future that will both seek to address this market gap. The end user always benefits with healthy competition IMO!

[Reasonistas]

Hoping I'm not giving too much away…there are actually TWO devices planned for the future that will both seek to address this market gap. The end user always benefits with healthy competition IMO!

Agreed and I think both devices offer users enough unique features to set them apart. Cheers!