Power Sockets on Back of Receivers

[davelee98]

This may be a dumb question, but why on earth do they put power sockets on the back of receivers? Do they expect you to actually plug anything in back there? I would think that after you go through the trouble of getting a receiver with a decent power supply to minimize noise, the last thing you would want to do is add a load by say, plugging your dvd player into the back rather than directly into the wall..

Any ideas?

 

[Leprkon]

originally, it was because we didn't have power strips or multiple power sources back at the end of the 70's... you just didn't have enough places to plug things in. Why they do it now is pretty much a mystery.

 

[MDS]

It's a convenient way to turn on another device at the same time that you turn on the receiver if you don't have a power strip or a macro programmed into a remote control, but yeah they are pretty much useless nowadays.

 

[markw]

This may be a dumb question, but why on earth do they put power sockets on the back of receivers?

I'll try to go through this step by step.

Do they expect you to actually plug anything in back there?

Ummm..., yeah. Why not?

I would think that after you go through the trouble of getting a receiver with a decent power supply to minimize noise, the last thing you would want to do is add a load by say, plugging your dvd player into the back rather than directly into the wall..

Now, it's my turn to ask questions.

1) What do you think is done to the electricity coming out of these sockets and where do you think it comes from?

2) What do you think it "degrades" the electricity from these as opposed to the wall socket?

3) What kind of load do you think these ancillary devices draw, anyway? It's not a power amp, which is a different animal entirely.

Conclusion: As long as you don't plug in a unit which draws more current than these can supply, the electricity coming out of these is just as good as the electricity going into the receiver.

 

[davelee98]

Effects of plugging in to the back of the receiver

Now, it's my turn to ask questions.

1) What do you think is done to the electricity coming out of these sockets and where do you think it comes from?

Since I don't think the engineers are asleep at the designing board, I guess the plugs are literally an extension of the lines coming in, so I suppose it's not that bad.

2) What do you think it "degrades" the electricity from these as opposed to the wall socket?

If I plug a "noisy" device into the receiver directly that draws say, 1 amp average, then the resulting magnetic field will induce all kinds of currents inside the receiver. Worst case, let's assume that for some crazy reason, the load is pushing 240 hz noise directly back out of its power cord. You might then end up actually hearing this coming out of the speakers. I forget most of my electricity and magnetism but I seem to remember that magnetic fields fall off as something like distance cubed. Thus it would be worse than if the power cords were separated by some distance. Although, I suppose you might get a similar effect even if the noisy device was plugged directly into the wall.

3) What kind of load do you think these ancillary devices draw, anyway? It's not a power amp, which is a different animal entirely.

Conclusion: As long as you don't plug in a unit which draws more current than these can supply, the electricity coming out of these is just as good as the electricity going into the receiver.[/QUOTE]

Basically, I was thinking more in terms of the impact on the receiver, not the impact on the ancillary device you have plugged in. Presumably, the piggyback device's own power supply will filter the line anyways.

Maybe I'll try plugging some stuff in back there to see if anything happens...

 

[Tom Andry]

The best use for those outlets on the back of the receiver that I've found is for a fan.

 

[Snarl]

The best use for those outlets on the back of the receiver that I've found is for a fan.

Nice little Lamps aimed down on your Receivers Vents look pretty cool too.... although not very functional it does make for a nice little WoW factor

Cheers

 

[mtrycrafts]

Nice little Lamps aimed down on your Receivers Vents look pretty cool too.... although not very functional it does make for a nice little WoW factor

Cheers

I would think having a LED inside the amp shining out would be a real WOW factor

 

[mtrycrafts]

This may be a dumb question, but why on earth do they put power sockets on the back of receivers? Do they expect you to actually plug anything in back there? I would think that after you go through the trouble of getting a receiver with a decent power supply to minimize noise, the last thing you would want to do is add a load by say, plugging your dvd player into the back rather than directly into the wall..

Any ideas?

As Mark pointed out. And, if you check the rating of those outlets, they are normally about 100 watts, good for an EQ, a CD or DVD player that is about 20 watts or so, etc.
If there is any noise, the receiver's filters will take care of it as the take off is before the filters. So, you'd have the same issue if you plugged them into the wall or a power strip.
A convenient place to plug stuff in.

 

[jzoz01]

I've used them before. I plugged a transformer into the outlet to create a higher power trigger out. The screen we were using was motorized and required a 12v trigger pushing 200ma

 

[mtrycrafts]

I've used them before. I plugged a transformer into the outlet to create a higher power trigger out. The screen we were using was motorized and required a 12v trigger pushing 200ma

Yes, that is a good use of the switched outlet. Some are, some are continuous. Some have one each.

 

[mike c]

if you use the switched outlet as a 12v trigger out (using a 12v adaptor plug with a 1/8" plug at the other end) ... does it continuously supply current or just a burst?

if continuous, wouldnt this damage the external amp/equipment?

 

[mtrycrafts]

if you use the switched outlet as a 12v trigger out (using a 12v adaptor plug with a 1/8" plug at the other end) ... does it continuously supply current or just a burst?

if continuous, wouldnt this damage the external amp/equipment?

If you set it up as was suggested with a step down transformer to 12V, it will supply 12V as long as the receiver is on. Some need a continuous 12V supply, like a screen, to make it work. Some only needs a spike as you asked. So, the supply hookup depends on the need.

 

[JonBaker99]

Switched outlets work great for my old Sony CD player that only has a hard power button. The other outlet works great for powering some low noise computer fans that I connected up using the power supply from an old 12v IR kit. I wouldn't connect any high amperage items up to those outlets but they still definitly serve a purpose.

 

[GlocksRock]

I use one of the outlets on the back of my receiver for a fan to cool the receiver, and the other is used for my leapfrog IR transmitter since my power strip is either full, or doesn't have enough room on it for the large power block. So I'm glad they are there, as they are very handy for me.