In which I take a photo every day that I'm 50, and post it here on this blog, with a bit of related blurb.

Wednesday, 30 April 2014

Day 137 - Not Too Loud Enough

no guitar amps

Before I start, I'd just like to remind you that this is Andy's fault.  

Seriously...blame him!

If you're not blaming him yet, I reckon you might be by the end...

Andy's question was (as I'm interpreting it) broadly about how you can get a decent guitar sound in the house, without annoying the neighbours. 

This probably sounds like a silly question - there's a volume knob, right?

(by the way, gecko know who I'm talking to...)

But it's not that simple... 

The guitar produces a very small, clean signal.  Guitar amps were originally valve amps, which use vacuum tubes to amplify this signal to a level sufficient to drive a speaker, producing a sound loud enough for us to hear.    

When driven through an amplifier at relatively low "gain", an electric guitar sounds smooth and clear - think Hank Marvin (and the Shadows).

However, if you increase the gain up to the point where the valve can no longer cope with it, the signal starts to break up.   In valve amps this signal degradation happens in a smooth, warm way, and if you continue to increase the gain, the signal becomes fuzzy...think Jimi Hendrix on Purple Haze or Voodoo Chile.

Keep applying more gain and you eventually get into Heavy Metal territory.

To keep things simple, I'll just say that gain is closely related to can only get this overdrive effect by turning the amp right up...and valve amps are loud!!

Many professional guitarists would use amps as large as 1-200 Watts.

I have a 30 Watt valve amp, and it's literally unusable in the house!

In order to drive the valves, you need to apply some power...the net effect of which is that the amp makes almost no noise until you turn it up to about 2, and then it's suddenly so loud it seems like the windows might break. 

So how can we get this tone without the volume, for use at home?   The short answer (you'll be relieved to know) is digitally!

There is an ongoing debate over the merits of digital versus analogue signal processing, but if you look at the quality of, say a video on your smartphone, it gives you an idea of how far digital media has advanced over recent years.  The same is true of sound processing, of course, and I think it's fair to say the quality of digital systems is very high now, and it takes an expert ear to detect a difference. 

What this means to me is that I can use a Guitar Effects Processor to fake this fuzzy, over-driven sound before I amplify it, then I can just use normal levels of gain and volume, and get very similar tone to what you'd get from a large'n'loud valve amp. 

From the top in the photo, there's a vocal processor, a power amp, a small mixing desk, a PC on the right, a guitar effects processor, and a pile of assorted cables. 

The trick is to assemble these in the correct order to create sound!

It should go something like;

1a)  Guitar into Guitar Effects Processor
1b)  Microphone into Vocal Processor
2a)  Guitar Effects Processor into Mixer
2b)  Vocal Processor into Mixer
3)    Mixer into PC
4)    PC into Power Amp
5)    Power amp to Hi-Fi speakers

As I was about to start setting this up, I realised that I've apparently lost the power supply for the Mixer, which as you can see, is right in the middle of this signal path!

So, a quick bit of improvisation, ditch the microphone (I wasn't going to sing along anyway!)
and this becomes the much simpler:

Guitar to Guitar Effects Processor to Power Amp to Speakers.

job's a good'un


So, Andy, I don't know why you felt it necessary to subject everyone to that.  I hope you're suitably ashamed of yourself!


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