Hello

The Yamaha A-S201 is not a high-end amplifier, but the price performance is sufficient.
Now the noise can have the following causes.

1. the source, for example a record player, is not running and could be sending a certain basic signal.

2. the amplifier is connected to a power strip where many digital sources are connected,
These can interfere, but also ballasts of FL lamps.

3. you could install a mains filter, which usually brings peace to the sound.

There are many possibilities, you have to try them out.

Try this one:

When the amplifier is switched on, it can produce some background noise.
Now turn the volume control all the way to the left. If there is still some noise coming through,
you'll have to take the amplifier in for repair.

Or this:

If the amplifier's volume is 1/5 to 1/4 open and the source, e.g. DAC, tape deck or phono, is not playing music, change the source on the amplifier where no source is on. If there is still noise, but it is quiet, it is due to the amplifier, which does not sound as expensive amplifiers do.

In all honesty, I have to say that the old Yamaha amplifiers were better,
but the new expensive amplifiers are not without their problems.

In your case, it could also be the tweeter in your Klipsch speakers,
your Klipsch speakers or your HAMA Internet tuner.

Just test it with another source,
such as connecting an MP3 player with a 3.5mm to 2 x RCA cable to a tape, AUX.

If it still hisses, it's something else.

Remember: Every source can generate a certain amount of background noise.

Greetings Robertange

Quite simply, if the amplifier is not in use, just switch it to standby.
Then check whether a low background noise still comes out.

There are many amplifiers that unfortunately do not mute completely at volume level 0.
However, there may be a few other interference factors:

1. if you have connected the speakers to group A and nothing to group B, the button for group B should be switched off.
2. you may have switched on Pure Direct mode, which could also interfere if nothing is playing.
3. it could be due to a source device, then try switching to another input on the Yamaha A-S201.
4. maybe your Klipsch R-28F are sucking up too much power.
5. it could also be that the amplifier has a defect in which the volume pot does not go all the way back to zero.
6. another variant could be that the source device on the Yamaha, which is still switched on, is transmitting a certain amount of background noise.
7. if the noise is high frequency, it could also be a power supply connected to the same power strip as the amplifier.

A good piece of advice is to separate digital and analogue devices from the same power strip or buy a mains filter, this will solve many problems.

Test whether the amplifier, if close to it, hears a certain hum. Then it could be a mains hum,
that is being transmitted to the speakers.

Another possibility would be if you have a tuner (radio) connected with an aerial cable, then buy a sheath current filter.
These are also available here or from Jumbo or specialist electrical shops.

If the amplifier had a mute button, this would also have been an option.

I once bought this amplifier for a friend and he wasn't too happy with it either.
But the price performance is right.

I wish you good luck with the solution.

I have not this problem, anyway try inverting the polarity of the power supply rotating the plug 180 degrees