I've just found the cause of the hissing noise, now I just have to find the solution. This relates to the recorder I've been using for the past 8 years, a Fostex VF160.
After lots of experimenting over the past day or so, I've discovered the noise is caused by the faders on the channels including the master channel. Normally I record my vocal/guitar live on channel 1 and 2 with the faders about half way for earphone monitoring while I play, then I perform the bounce function with the faders set slightly differently to balance the vocal/guitar tracks, and then I master it adding eq and reverb with the faders set high as possible without any clipping, then transfer the master recording to the internal CD.
So, on 3 of the operations I'm using the faders. After experimenting, I've found the background hiss starts to become noticeable when the faders are turned up higher than about 30%. However to get "normal" recorded volume levels the faders need to be turned up WAY higher than that on the Bounce and especially on the final mastering. Result = noticeable background hiss at normal volume levels.
I can get a final CD recording without 95% the hiss, by simply lowering the faders right down throughout the process, but the problem with that is the volume level on the final CD recording is so low that it's totally unusable.
Aside from the background hiss noise I'm 100% happy with the sound I get from the recorder, and I love the sound I get with the eq and reverb. I much prefer the tone I can get with the simple Fostex eq and reverb compared to the tone I've been able to get with many online recorders. So if possible I'd like to continue using the Fostex.
So, how do I get rid of the noise from a fader when it's turned up more than about 30%? The higher up it goes the noisier the recorded hiss sound gets. The hiss sound is on the actual recording itself, and definitely not the result of bad headphones or speakers.
Fostex high fader hiss is the cause of the problem. I wonder what the solution is? I need a genius to help me.