Test time :D (15 questions)


I came across this audio engineering test and scored

Ambitioned Beginner

You’re on the right track!

You already know a few things about audio engineering, but there are many tips and tricks waiting to be discovered. Continue working on your production skills and you’ll soon get much better results.

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I did all my answers, and after hitting the final Submit, it is returning a “server side error” and can’t give me my results. I think I missed four out of fifteen, maybe five… a few I had to just guess, I had no idea.

Same here. I got 4 or 5 wrong also.

Error on the score, but I knew a few. Lot of guessing involved, and I could not tell about the limiter on the master. I don’t think I’m a good engineer!

I got the same error at the end.

I missed a four - one on phase metering, glass mastering, dithering, and the one about the subtractive VCA matrix. I made a wild guess on the XY mic config but got it correct. I didn’t even know what it talking about. The wording on these was terrible. Some of this stuff we all know the answers to, but didn’t recognize the terminology.

Mine actually went through to the results… Semi-Professional… yay! Missed the distance between mics for the one mic technique and kinda blew the master listening test at the end.

This was a total bullshit question. Either LFO in that picture was clearly capable of controlling any of those functions, and the picture was misleading in where it was routed. Since a panner and a filter are both also capable of having a VCA component which can receive a modulation signal from the LFO generator, it COMPLETELY depends on where the signal was routed to.

LFO -> Vca panner = Tremolo
LFO -> Vca oscillator sync 1+2 = vibrato
LFO -> Vca filter = Wah Wah

But based on the answer what we were supposed to assume was that the VCA applied only to AMPLITUDE of Oscillator 1.

Did anyone else miss this question?

This was one I guessed at because I don’t even know what a VCA is. I knew it wouldn’t be reverb, and figured not wah-wah, so blindly picked between tremolo and vibrato. Don’t remember which I picked, but the answer was the other one.

I’ll test my communications skills to use and explain this.

In keyboard land, a ‘voltage controlled amplifier’ is used to give a sound wave motion. Motion like engaging a tremolo or phaser pedal, or physically pitch bending a guitar string. In that analogy, if a voltage controlled amplifier is amplifying your the fingers your left hand, the higher the amplifier signal, the further you bend the string. If a voltage controller amplifier is amplifying your right hand, the higher the signal the faster you strum the guitar. So the VCA controls the amount of whatever it is attached to. In a keyboard, you can attach a VCA to just about anything. You tell the VCA what you wish it to control by using the keyboards routing matrix.

How’d I do?

Voltage controlled amplifier means that you have an amplifier that adjusts it’s gain from an incoming sidechain voltage. From the question, it would definitely be an amplitude change. you can’t really have a VCA filter. that would be called a voltage controlled filter. Amplifier means gain.

I missed 2.

I guessed 15cm for the ortf.

I missed the listening one because I didn’t have any headphones or speaker when I took the test, so I blind guessed.

Yeah, but that VCA must then be routed TO something in order for it to DO anything. Merely routing LFO -> VCA does effect anything until you then say that the VCA is routed to an oscillator (which wasn’t even implied in that test question).

There are many other things that you can route a VCA to besides an oscillator.

Here’s an example. The Moog CP251 is a Voltage Amplifier Controller. At 50 seconds in this video, he can route the voltage amplifier to any assortment of moog pedals including a filter, a wah, and an autopanner. The internal routing matrix on a keyboard works the exact same way. If the LFO is routed the VCA (as stated in the video), then it implies that the LFO (which usually defaults to the modulation wheel on a midi keyboard) is the knob/dial/rotar controlling the voltage attenuation instead of the silver knob on the moog.

??? There are many common examples of when a VCA is patched to a filter for the purpose of control. Let me preface this by saying that I see no need to distinguish between Voltage Controlled Amplifier, Voltage Controlled Attenuator, or Control Voltage Amplifier. Also CV in some cases. So CV == VCA. Same thing. Regardless of what it was called, they used to be modular. Any module with a CV input could receive signal from a CV module including oscillators, envelopes, filters… you can even force a CV to control an LFO if you want to.

The CP251 in the video is a CV generator. It plugs into the side of the moog Phatty 2, and the Voyager like the old one Brandon Drury used to own. Where you plug it in determines what it controls. When I plug it into the control I circled, its definitely controlling the filter.


Some synths have the CV embedded in the filter circuit. Look here:

Instead of an external CV generator being PATCHED to the filter, the Mini V automatically routes it there by default. When the ‘keyboard control’ is switched on, the ‘filter emphasis’ allows the keys to send variable voltage amounts specifically to the filter. When the ‘keyboard control’ is switched off, the position of the ‘filter emphasis’ dial has no effect. So Bob Moog’s implementation of VPO (voltage per octave) didn’t apply exclusively to oscillators and pitch. He and a number of others such as Oberheim, Sequential Circuits, and Roland also applied Voltage Per Octave to the filter section.

This later became known as a VCF. Voltage controlled filter. But all a VCF is is a filter with a “voltage controlled attenuator/amplifier” manipulating it.

I think you are just getting confused over terminology.

The LFO is the voltage, the VCA is the amplifier, which means that the VCA is going to have a tremolo effect. The LFO is determining the gain of the amplifier. The VCA is the thing that is doing the thing. The VCA is not the voltage generator, the LFO is.

Yep, but that’s not a VCA. It’s a VCF.

no, it, it has a voltage manipulating it, not a voltage controlled amplifier.

I see where I messed this up. CV’s can be routed anywhere. VCA’s are specific to Oscillators. Ok. They’re not the same. Got it.

I had confused a VC generator with at VC amplifier. I think this picture straightens everything out and clarifies what you meant by it being a side chain slave :slight_smile:

Funny how thoroughly you can grasp these things, but when terminology and labels get crossed up all hell can break loose when trying to communicate!