What's the Difference: VCAs and Groups

So far in our What’s the Difference series, we’ve considered AFL/PFL and Pre-Fade/Post Fade. Today, we’re going to look at another pairing that I see confused all the time. That is the difference between Groups and VCAs. 

Here we have a couple of VCA's (blue channels), a group (red) and input channels (grey).

Here we have a couple of VCA's (blue channels), a group (red) and input channels (grey).

A Group is a Mix Bus

A group is a place to send channels post-fader. To make this clearer, the LR main output on your console is technically a group. So is the Mono output if your mixer has one. When you send a channel to a group, it is after all processing and the fader, so it is truly the final step on the way out of the console. You can assign channels to as many groups as you want; up to the number of groups you have. The level of the channel going to the groups will always be the same. In this way, groups are different from auxes. With an aux, each aux send goes out at its own level. Sending a channel to two groups sends the same exact signal to both groups. 

A VCA is a Remote Control

A VCA (short for Voltage Controlled Amplifier) is really a way to remotely control the level of a channel or group of channels from a single fader. When you assign a channel to a VCA, you can add and subtract gain from that channel using the VCA fader and/or the channel fader. Moving the VCA master up by 5 dB will have the same effect on the channel as moving the channel fader up 5 dB. Turning off the VCA master will effectively mute the channel(s), making it easy to turn entire groups of channels on and off with one fader move. 

When to Use Them

I wrote a much longer series on this topic some time back, but here’s the shortened version. Groups are useful for applying the same processing to a group of inputs. Clever, huh? For example, if you want to do some parallel compression on the drums, you can assign all the drum inputs to a group and insert a compressor on the group. Mix that with the uncompressed version and you have parallel compression. Or perhaps you want to subtly compress all the BGVs. Same thing. Only don’t assign them to the main LR bus; send them to the group, compress then send the group to the LR mix. 

VCAs are useful for mixing similar types of instruments. On digital consoles,  you may not have the faders on the surface for all your inputs. Really large analog consoles may be a long reach. So, you can combine channels into one to make it easier to manage. For example, you may set up the mix for the drum kit, then assign all the drum channels to a VCA. Because the drums are one instrument, you can adjust the level of the drums with the VCA. Some engineers like to put the bass and kick on a VCA and move their level together. Others will assign all the keys to a VCA and all the guitars to another. 

It’s important to note that a VCA is not better than a group, nor is a group better than a VCA. They are different. Not all mixers—especially small ones—have VCAs so you have to make do with groups. But when you have both, use them for what they are good at. 

VCAs and DCAs

On some digital consoles, Yamaha for example, VCAs are called DCAs. DCA stands for Digitally Controlled Amplifier. The function is the same, but the underlying technology is different. For all practical purposes, they are the same. 

This is a pretty simplified explanation. For a lot more detail, check out some of the posts below. 

Other posts with more detail:

CTA Classroom: Understanding VCAs and DCAs

CTA Classroom: Defining Auxes, Groups, VCAs & Matrixes Pt. 1

CTA Classroom: Using Groups

Groups, VCAs and DCAs

Groups, VCAs and DCAs Part Two

Roland

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CTA Classroom: Making Mono Sources Sound Stereo

This is a video I've wanted to do for a long time. I finally got around to getting it done. You'll want to listen on headphones or decent studio monitors to really hear the effects; it won't really sound much different on laptop speakers. 

“Gear

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My Sabbatical

Photo courtesy of https://www.flickr.com/photos/oliverkendal/

Photo courtesy of https://www.flickr.com/photos/oliverkendal/

It shouldn’t be a surprise to anyone that I’m no longer working at Coast Hills, or any other church for that matter, as a TD any longer. I wrapped up in May and have begun a whole new adventure as system designer/project manager for Flexstage, which is part of the architecture firm, Visioneering. Several people have asked me recently, “So, what does your Sunday morning look like now?” When a question comes up more than a few times, it usually becomes a blog post. So here you go.

I’m on Sabbatical

Usually it’s the pastoral staff that gets to take sabbatical. Every few years, pastors often take a month, two or several off to refresh, pray and study. It’s a good concept, and one that I fully support. We all need time to recharge. And that’s pretty much what I’ve been doing. For the last few months, my Sundays have been sleeping in, writing, going for walks and sometimes watching a NASCAR race in my PJs. 

I had originally planned on taking a month off, but it’s turned into more than that. Now, I feel compelled to give some disclaimers at this point. I am not mad at the Church. I don’t feel burned by the Church. I don’t hate the Church. I’m not quitting Church to focus on my business. I just need a break. I will be back.

It’s Been a Long Time

I didn’t grow up going to church. My family and I went once in a while, but in the absence of any meaningful experience, I didn’t stick around. When I met the Lord in 1988 (almost 26 years ago to the week…), I immediately started attending church weekly. Except for a 4-month period in 2002 when I had to work weekends, I’ve attended church pretty much every weekend since 1988. I calculated that by my last weekend at Coast, I had worked approximately 380 of the previous 400 weekends. In that time, I mixed, lit, ran slides for or TD’d well over 1,000 services. 

Along the way, I started equating, at least at a subconscious level, going to church with working. I didn’t even know I was doing it until I stopped. It really wasn’t until a few months ago that I figured it out. So right now, I need to re-program my mind. 

Building New Models

As I write this, I keep thinking back to January when I took Jamie Anderson’s Smaart class. He kept saying, “This is hard because we’re building new models of how sound works in our heads. Building new models is hard. Don’t worry, it gets easier.” That’s what I feel like I’m doing. I have to build a new model in my head of what going to church is. 

Of course, I know what going to church is. But in my mind, I need to get to a place where I’m not critiquing the mix or lighting while I’m there. I need to be able to not feel like I should be working while I’m there. And quite frankly, I need time to rest. My new job has been great, but because I’m learning and refining a whole new skill set, it’s mentally exhausting. Working on staff at a church takes it’s toll even under the best of circumstances. I’m realizing now, three months out, how taxing my time at Coast really was. 

Descriptive, Not Prescriptive

I say this a lot, but I’m telling you what is going on with me, not what you should be doing. I know guys who have been doing the TD thing for many more years than I have and they’re well-adjusted and happy. That is wonderful. This is just what I’m doing right now, nothing more. Like I said, I’m not mad and I will be back. I just don’t know when. 

I remember my first pastor, Ron Boehm, going on vacation one time and saying that he didn’t go to church that weekend just to prove to himself that he could do it. I think it’s important that we know why we’re going to church. Do we do it because we work there? Do we go because we need to get our card punched for the week? Is it to see our friends or social circle? Is it just our habit? Or do we go because we can’t be anywhere else? Because we are compelled to go. Those are important questions. 

Right now, I’m experiencing my time with the Lord in a new way. It’s a lot less programmed and more organic. And it’s very refreshing. I look forward to going back when I’m ready. Until then, I will continue to serve the church through this blog, the podcast and my work with Visioneering. It’s what I feel called to right now. And it’s good.

Roland