I have a Carver power amp TFM-55 and pre CT-3.
I have been suffering from a significant audible hissing sound through my speakers when I turn up the line level control on the power amp past 65%.
I connected a cd player directly to the power amp to see if it was my pre-amp but I still get the annoying hissing sound through the tweeters. It's like a static hissing sound.
If I disconnect all sources from the power amp and turn up the line level control it is almost dead silent.
I've cleaned all pots, changed interconnects, re-wired and isolated power cables, removed tv's in close proximity etc.
Any ideas what could be causing this? A grounding problem has been mentioned.
Please help.
I have been suffering from a significant audible hissing sound through my speakers when I turn up the line level control on the power amp past 65%.
I connected a cd player directly to the power amp to see if it was my pre-amp but I still get the annoying hissing sound through the tweeters. It's like a static hissing sound.
If I disconnect all sources from the power amp and turn up the line level control it is almost dead silent.
I've cleaned all pots, changed interconnects, re-wired and isolated power cables, removed tv's in close proximity etc.
Any ideas what could be causing this? A grounding problem has been mentioned.
Please help.
I bought a new interconnect but not that good. Maybe I need to try with a more expensive one with very good shielding??
The amp has 380 watts per channel so this is going to pick up every little detail. Also Klipsch speakers with high sensitivity, 93db.
I tried with one pair of shorted plugs, swapping them from each input. Didn.t make any difference. Maybe a pair in every input??
Not sure what you mean here.
Are you referring to the line input for the cdp on the pre-amp?
I have tried shorting plugs on all line inputs on the pre.
If I connect the cdp directly to the power amp and turn up the line level control on the power amp to max then I get the significant hissing.
Also with just the pre-amp connected to the power amp with no cdp connected I still get the hissing when the power is turned up to a high level.
Hi,
Last 2 tests I have tried and noise is present.
First test I have not tried: i was not sure if that was advisable with the power amp.
I did listen to the power without anything attached and the noise was hardly audible (90% improvement). In other words just a very faint sound when I put my ear to the tweeter but this can be normal and does not affect anything.
You recommend to attach the shorting plugs to the inputs of the power?
I can try this when I get back home later.
Hi,
Yes that's what I am doing now but I notice the sound does improve when I use the full power of the Carver but at the expense of the audible hissing noise.
So I'm keeping the line input control at about 65%. Still loads of power as it has 380 watts at 8 ohms but I really want to find out what is causing this noise and to eliminate it if possible.
i'm a member of the Carver club but haven't solved anything with them yet. They mentioned a possible grounding problem but I have no idea how to solve this if this is the case.
When I got home today I tried connecting a different cdp, one of my old walkmans directly to the power amp.
Much much quieter.
So in conclusion the original cdp creates a lot of noise.
Also my pre-amp seems to be creating the noise even without the cdp attached.
I'm planning to buy a much better cdp soon but I want to keep the pre-amp. It's a beautiful piece with receiver and holographic generator.
What is causing the pre-amp to produce this hissing sound?
Much much quieter.
So in conclusion the original cdp creates a lot of noise.
Also my pre-amp seems to be creating the noise even without the cdp attached.
I'm planning to buy a much better cdp soon but I want to keep the pre-amp. It's a beautiful piece with receiver and holographic generator.
What is causing the pre-amp to produce this hissing sound?
actually I have no idea. 
Preamps could be noisy, but common CD-Players shut down their ouput, when not playing music - thats the mute circuit - and therefore have almost no noise contribution.
What puzzles me, is that your amp is quiet with open inputs and noisy with sources connected.
regards
Preamps could be noisy, but common CD-Players shut down their ouput, when not playing music - thats the mute circuit - and therefore have almost no noise contribution.
What puzzles me, is that your amp is quiet with open inputs and noisy with sources connected.
regards
OPEN GAIN STAGE
couuld be that whatever you are connecting that is giving the poor S/N is running an output with no gain reduction(volume control) after it.Some ********consumer stuff has a gain stage last in the signal chain with a gain control at the input of that stage.the result of this is if the stage is noisey then all the noise appears at the output.If your amp has a decent S/N without anything connected then the amp is O.K.A simple fix is to build a small box with some jacks and a dual pot of about 100K to pad the level down to where the noise is not a prob MI-9448
couuld be that whatever you are connecting that is giving the poor S/N is running an output with no gain reduction(volume control) after it.Some ********consumer stuff has a gain stage last in the signal chain with a gain control at the input of that stage.the result of this is if the stage is noisey then all the noise appears at the output.If your amp has a decent S/N without anything connected then the amp is O.K.A simple fix is to build a small box with some jacks and a dual pot of about 100K to pad the level down to where the noise is not a prob MI-9448
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