[TD1]

I've got an Acoustic Solutions SP101 (I know, I should have gone for the Sony!) There is always hiss coming through the speakers even though the turntable is grounded to the amp. The hiss is there even when the connected separates are off.
Is this something that can be fixed or is it inherent because of the lack of quality of the amp?

[Mark.Yudkin]

If it's a hiss, then it's probably the amp. If it's a 50Hz hum it may be a ground loop or an improperly seated interconnect. Your mentioning turntable grounding means you're thinking along the lines of grounding, but your symptom description is at odds with this.

What happens if you physically unplug all leads (all equipment) except power and speakers from the back of the amp?

[BlueWizard]

What Mark is trying to do is isolate the problem. Are you hearing a problem with one of your signal sources (CD, Turntable, etc...) or is it a problem with your amp? Or is it some interconnect interference between the source and amp? If you unplug all the inputs, and it is gone, then the problem is probably originating in one of your signal source. If it continue with your sources unplugged, then it is probably the amp.

Questions -

1.) With no input signal, meaning no music playing, does the intensity of the 'Hiss' vary with the volume control, or is it constant, independent of the volume control?

2.) Does the level of hiss vary with the tone controls, if you turn bass up and down, or treble up and down, so the 'Hiss' go up and down with it.

3.) Is it really hiss similar to what you hear between FM radio stations, or is it hum, as in 50hz or 60hz hum? That matters.

4.) Does the Hiss come and go with input selection? For example, is it there when TAPE is selected but gone when PHONO is selected, or some other combination? Or, is it the same on all inputs?

5.) If volume control dependent, how loud to you have to have the volume control for the hiss to be noticeable?

Also, remember to do as Mark suggested, disconnect the inputs (with the amp and source turned off, of course) one by one, and see if it is one of them that is adding the Hiss.

Steve/bluewizard