A Question Sir Joe....

laatsch55

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Other than idle curiousity....yes. Have you measured crosstalk on any of your pre-amps?
 
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Gepetto said:
That I have not Lee...

I have noticed a lot of bleed through on the 4000 but never measured it.
Click to expand...
Even the Acurus RL11 which is a far superior preamp suffers from victim crosstalk but only with a very large signal on the aggressor channel.
 
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IF.....you have say -65 db crosstalk out of the pre....mono blocs ain't gonna get no better than that correct?
 
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Gepetto said:
Even the Acurus RL11 which is a far superior preamp suffers from victim crosstalk but only with a very large signal on the aggressor channel.
Click to expand...

OK, back up a bit here....crosstalk can be dependent on the signal LEVEL of the other channel regardless of what is happening on the monitored channel??


Time out, Jani says we are out of Bloody Mary Mix......liquor store is onlty 5 blocks away ...back in a jif...
 
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laatsch55 said:
IF.....you have say -65 db crosstalk out of the pre....mono blocs ain't gonna get no better than that correct?
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Even if the monoblocks have -150dB crosstalk separation, they will be degraded to -65dB by virtue of that preamp (you reference) that is driving them if that preamp crosstalk is only -65dB

Weakest link in the system will dictate that.
 
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laatsch55 said:
OK, back up a bit here....crosstalk can be dependent on the signal LEVEL of the other channel regardless of what is happening on the monitored channel??


Time out, Jani says we are out of Bloody Mary Mix......liquor store is onlty 5 blocks away ...back in a jif...
Click to expand...
A man has to know his priorities...
 
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laatsch55 said:
OK, back up a bit here....crosstalk can be dependent on the signal LEVEL of the other channel regardless of what is happening on the monitored channel??


Time out, Jani says we are out of Bloody Mary Mix......liquor store is onlty 5 blocks away ...back in a jif...
Click to expand...
It is usually a relatively constant ratio Lee but it can be non-linear if the common power supply in the preamp reaches a point where it is being dragged down of modulated by the aggressor channel power utilization for example...
 
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I agree an amp can only be as good as the pre or source. What is the primary source of crosstalk?
 
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Is crosstalk the same as channel separation? My Perreaux SA3 shows a channel separation of 70dB from 20Hz-20kHz
 
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Looking at my Spec 1 specs, they don't even list a separation or crosstalk spec. I'm thinkin a phono source is going to be in the -60's for separation, how about a good CD player?
 
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laatsch55 said:
I agree an amp can only be as good as the pre or source. What is the primary source of crosstalk?
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I am sure it varies widely depending on the quality of the preamp. Sometimes it is dual or quad channel op amps that share elements across both channels, sometimes it is one channel talking to the other via the power supply, sometimes it is one channel talking to the other due to wiring proximity or board layout issues, sometimes it is due to a dual channel volume pot or selector switch.

It is likely to be "a death by a thousand cuts" in some cases.
 
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Specs for my phono section

Noise (inputs loaded)
Phono, high gain (unweighted)-64dB re rated input
Phono, high gain (A weighted)
-72dB re rated input Phono, low gain....................
-86dB re 10mV input Phono, low gain (unweighted).-78dB re rated input Phono, low gain (A weighted)..
-86dB re rated input All others (unweighted).......
-104dB re rated inputs

All others (A weighted)........-108dB re rated inputs
 
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laatsch55 said:
Looking at my Spec 1 specs, they don't even list a separation or crosstalk spec. I'm thinkin a phono source is going to be in the -60's for separation, how about a good CD player?
Click to expand...
The cartridge will limit you to less that that Lee. Like 45 dB for a cartridge.

It typically does not matter too much since it is coherent R channel info bleeding through the L channel and vice versa. It is not like listening to an FM radio channel and picking up a faint alternate channel signal which is not coherent to the program material.
 
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Gepetto said:
I am sure it varies widely depending on the quality of the preamp. Sometimes it is dual or quad channel op amps that share elements across both channels, sometimes it is one channel talking to the other via the power supply, sometimes it is one channel talking to the other due to wiring proximity or board layout issues, sometimes it is due to a dual channel volume pot or selector switch.

It is likely to be "a death by a thousand cuts" in some cases.
Click to expand...

OK, That makes sense....so why not mono pre-amps?? Or is the contribution to the total crosstalk negligible compared to the source crosstalk??



AND IS IT TIME FOR A WHITE OAK pre-amp??
 
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-108dB re rated inputs

Is the "re" mean it could vary based on the source signal?
 
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Northwinds said:
Is crosstalk the same as channel separation? My Perreaux SA3 shows a channel separation of 70dB from 20Hz-20kHz
Click to expand...
In most practical cases probably yes, but in other cases, say you have your CD player spinning and pumping out signal but you have your selector switched to phono and you are playing and listening to an LP. The crosstalk from the CD input signal is also crosstalk and not coherent to what you are listening to on the LP.

That is also crosstalk.
 
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