110/115v Shaver sockets.

[Gigger]

Hi.. I have a 110v small guitar amplifier i need to test in uk.The output is 8watts.The label on the back says it uses 10 watts if 110v ( which it is ). It has with a two pin flat plug attached as per manufacturer.
Can a standard dual voltage 110/ 240 v shaver socket support the load for about 10mins ( although to be honest the time i dont think is relevent) just to make sure it works ok. Thanks.

 

[plugwash]

Should be ok

 

[ericmark]

Most shaver sockets rated 20va so 10W should be no problem.

 

[Taylortwocities]

Just don't turn the gain up too high!

 

[JohnW2]

Just don't turn the gain up too high!

... and, given the (presumably) floating 110V supply, probably don't be too surprised if there's a fair bit of hum coming out of the speakers.

Kind Regards, John

 

[AdrianUK]

Just don't turn the gain up too high!

Just to be picky (sorry!) you don't change gain of an amplifier ... only the attenuation of its input. The gain will be determined and set at the design stage.

(I'll take my pro audio hat off now ..............)

Adrian

 

[Taylortwocities]

Just to be picky (sorry!) you don't change gain of an amplifier ... only the attenuation of its input. The gain will be determined and set at the design stage.

So this knob marked "gain" will have no effect on what comes out of the speakers?
View media item 67214

 

[JohnW2]

So this knob marked "gain" will have no effect on what comes out of the speakers?

Indeed it will. Adrian's 'picky' point is that such knobs are often incorrectly labelled 'gain', when they are, in fact, up-front variable input attenuators feeding a (factory-optimised) constant-gain amplifier. I'm sure that there are lots of reasons why that is the case. For a start, it avoids 'overloading' the early stages of the amplifier with large input signals (which would cause distortion). Secondly, playing with the gain of the amplifier (rather than having it factory-optimised) is quite likely to have an adverse effect on amplifier performance, and hence the quality of sound ... and there are various other reasons as well.

However, whilst this may well be true in terms of most domestic and 'entertainment' audio amplifiers, if one talks about amplifiers in general, variable gain (and 'gain controls') is a common concept. Electrically-controlled (voltage-controlled) variable gain is common in some applications.

Kind Regards, John

 

[davelx]

All of which is quite correct. However, if you treat an amplifier (i.e. the complete item of equipment) as a black box, and define its gain as the ratio of the output signal level to the input signal level, then that knob, by definition, is a gain control.

 

[JohnW2]

All of which is quite correct. However, if you treat an amplifier (i.e. the complete item of equipment) as a black box, and define its gain as the ratio of the output signal level to the input signal level, then that knob, by definition, is a gain control.

That is also correct, given the self-satisfying definition of gain which you have mentioned. Whether one normally regards 'the gain of an amplifier' as being the gain of the 'black box' (i.e. amplifier gain minus attenuation) or just the gain of the electronic (or whatever, come to that) 'amplifier' is, I suppose, a matter of taste and debate!

Kind Regards, John

 

[Taylortwocities]

<sigh>

Sorry I mentioned it. Just don't give it full wellie, then.

Night all!

 

[ban-all-sheds]

For a start, it avoids 'overloading' the early stages of the amplifier with large input signals (which would cause distortion).

And nobody ever wants distortion out of a guitar amp.....