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Hiss not Hum help

Hi all,

I have been on my "audiophile"  journey for several years and my main goal is to reach great instrumental separation and clear voice with a wide soundstage.

I mixed and matched many brands such as Anthem, Onkyo, Parasound, Emotiva, Furman, APC, Audioquest, Kimber Cable, Oppo, Ifi, and even DIY, and in general, liked the sound of the latest system, however, there is a hiss coming out of any tweeter, and overall for music is fine since I am 10 feet away from my front towers but If I turn on the Home theater the aggregation of all speaker makes the hiss unbearable.

My attempts to solve the "problem"  include replacing receivers and preamps like switching from Onkyo to Oppo network streamer and recently to Anthem AVM60, and also from RCA to XLR cables, which I used basic cheap RCA, to AudioQuest Red, Acoustic Research Master series, and currently Mogami Gold, cables and cable type made no difference.

On the power line, I started with a regular cyber power AC filter, moved to an APC H15 AC filter, then a Furman Elite PF15, and also tried an Emotiva CMX2 and an Ifi AC purifier, all of this made little to no difference.

Does anyone here experience similar hissing, and has any budget suggestions to attempt to solve this issue?

thanks for everyone's help.
badgod86

Showing 3 responses by auxinput

auxinput
2,920 posts
 
The "hiss" problem is usually because of a preamp that has an extremely "high gain" stage combined with ultra-efficient speakers.  I'm not sure that your Focal would be considered ultra-efficient.  These are typically the really high 98-99db speakers such as Tekton or Klipsch. 

I'm also wondering why you would get this hiss problem from the Anthem AVM60.  Typically these HT processors have a resistor ladder volume adjuster on the output which would reduce any hiss as you turn down the volume.  I would almost think something is wrong with the AVM60.  It's too bad you don't have the ability to try a different preamp.

You could try getting some RCA or XLR attenuator adpaters to put between your AVM60 and the amplifiers if you wanted.  These will drop the signal level going into the amplifiers by something like 6db or 9db.  I cannot guarantee that this would solve the problem, but it is something that people do when they have an ultra-efficient speaker.
auxinput
2,920 posts
 
The attenuator will basically reduce the entire signal level (which does include the hiss).  The result is that you will have to turn up the volume control higher than normal on your preamp equipment to get the same amount of sound out.  As long as you are able to get enough loudness out of your speakers to make you happy, this is a great solution.
auxinput
2,920 posts
 
In a lot of preamps, the "amount of gain" is fixed and is not really affected by the volume control.  The volume control is a potentiometer or a resistor ladder circuit that lowers the signal level.  The the signal is sent through a resistor circuit which drops the signal level again (this could be a large amount like 100 db).  The it gets sent through the "gain circuit" which re-amplifies the signal and provides current to drive the output to the amplifier.  On some preamps, there is a very large amount of gain in this analog circuit.  When you combine it with a very effecient speaker, you will get a lot of hiss.

It's weird that it would occur on your Focal speakers since they are a more conventional speaker, but maybe something is happening.  In any event, it looks like you have resolved the problem.
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