A Question Sir Joe....

[Northwinds]

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.

With some preamps and receivers I have had in the past, I could hear what your talking about. Like if I was playing a record and lifted the stylus and the cd player was still playing a disc. With the Perreaux, I hear absolutely nothing

The Perreaux is Dual Channel Class A if that helps

 

[Gepetto]

-108dB re rated inputs

Is the "re" mean it could vary based on the source signal?

Don't know Ron, the section of the spec you cited is noise.

 

[laatsch55]

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.

AHA!!! Coherency.....nice way to put that. Now we are getting somewhere....I'm thinking SOUNDSTAGE would be more enhanced with greater separation....correct??

 

[Gepetto]

With some preamps and receivers I have had in the past, I could hear what your talking about. Like if I was playing a record and lifted the stylus and the cd player was still playing a disc. With the Perreaux, I hear absolutely nothing

Turn the volume up and you will...

 

[Gepetto]

AHA!!! Coherency.....nice way to put that. Now we are getting somewhere....I'm thinking SOUNDSTAGE would be more enhanced with greater separation....correct??

Possibly, soundstage is hard to define but having a lot of mono content on both channels will tend to make the signal less stereo and more mono...

Separation is a good thing so that you are limited only to the lack of separation recorded into the original program material (which swamps the specs of most equipment that is used for playback)

 

[Northwinds]

Joe, could you explain these specs then. I don't understand any of it

Specifications:
PRE-AMPLIFIER SECTION Input Sensitivity High Gain (moving coil)............175μVrms @ 1kHz Low Gain (moving magnet).......1.8mVrms @ 1kHz Compact Disc...........................................350mVrms All other inputs........................................110mVrms Input Impedance High Gain (moving coil).................................47kΩ Low Gain (moving magnet)............................47kΩ Compact Disc..................................................20kΩ All other inputs...............................................25kΩ Input Overload High gain...................................120mVrms @ 1kHz Low gain...................................900mVrms @ 1kHz All other inputs.............................................50Vrms Rated Output...............1.5Vrms into 10kΩ or higher Maximum Output........27Vrms into 10kΩ or higher Main Output, Source Impedance..................470Ω Tape Output Level.......................................110mV Source Impedance.............................................2kΩ Minimum Recommended Load Impedance.10kΩ
Distortion (THD and IMD) Phono inputs 0.005% 20Hz-20kHz rising to 0.01% before overload All others less than 0.0009% 20Hz-20kHz at rated output 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 Frequency Response Output stage........................20Hz-50kHz, ±0.25dB Channel Separation All inputs..................................70dB 20Hz-20kHz Phase Accuracy............................±1° 20Hz-20kHz

 

[Gepetto]

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??

The source crosstalk or lack of separation is huge compared with the playback equipment specs. Remember that the source is recorded by microphones with limited amounts of directionality that are picking up all signals at various strength levels.

 

[laatsch55]

Ok, That's kinda what I was thinkin, it is the source being the bottleneck now, not our equipment. With soundstage being subtle in nature (or not, see there's that audio thang again)...it would seem that it could be easily disturbed by lousy separation. If soundstage is the culmination of ever so slight differences in recording levels of the different mic places and their pickup of reflections and reverberations, then crosstalk could have a very debilitating effect on the whole process....

 

[laatsch55]

The source crosstalk or lack of separation is huge compared with the playback equipment specs. Remember that the source is recorded by microphones with limited amounts of directionality that are picking up all signals at various strength levels.

Ok, then isn't soundstage the DIFFERENCES IN LEVELS of those mic signals?

 

[Gepetto]

Joe, could you explain these specs then. I don't understand any of it

Specifications:
PRE-AMPLIFIER SECTION Input Sensitivity High Gain (moving coil)............175μVrms @ 1kHz Low Gain (moving magnet).......1.8mVrms @ 1kHz Compact Disc...........................................350mVrms All other inputs........................................110mVrms Input Impedance High Gain (moving coil).................................47kΩ Low Gain (moving magnet)............................47kΩ Compact Disc..................................................20kΩ All other inputs...............................................25kΩ Input Overload High gain...................................120mVrms @ 1kHz Low gain...................................900mVrms @ 1kHz All other inputs.............................................50Vrms Rated Output...............1.5Vrms into 10kΩ or higher Maximum Output........27Vrms into 10kΩ or higher Main Output, Source Impedance..................470Ω Tape Output Level.......................................110mV Source Impedance.............................................2kΩ Minimum Recommended Load Impedance.10kΩ
Distortion (THD and IMD) Phono inputs 0.005% 20Hz-20kHz rising to 0.01% before overload All others less than 0.0009% 20Hz-20kHz at rated output 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 Frequency Response Output stage........................20Hz-50kHz, ±0.25dB Channel Separation All inputs..................................70dB 20Hz-20kHz Phase Accuracy............................±1° 20Hz-20kHz

That is a mouthful Ron

It does say that the channel separation or L-R crosstalk is >= 70dB regardless of what you are listening to.

It says that for example, the noise on the moving coil input source due to the preamp is 64 dB down from the signal when the input is at 175 uVrms from the MC cartridge at 1kHz and the preamp is outputting 1.5Vrms to the power amp. That is what the 're rated' term that they use means.

Help you?

 

[Northwinds]

Ok, then isn't soundstage the DIFFERENCES IN LEVELS of those mic signals?

Lee, I always though soundstage was different instruments, vocals whatever recorded by the mixing console and then everything is separated into 2 channels for playback. Say a 24 channel board was used, 12 channels per side would make up the soundtage of the actual recording. I did not think mic placement would be a factor if looking at it that way. This is a very interesting conversation

 

[Northwinds]

It does say that the channel separation or L-R crosstalk is >= 70dB regardless of what you are listening to.


Help you?

Is that good and yes, it's a start but I am woefully unknowledgeable about the technical aspects of performance and understanding what those figures actually mean in layman's terms

 

[laatsch55]

I've always been told that "soundstage" is the ability of your system to place the instruments of the recording in 3D space as they were when they were recorded.

 

[Gepetto]

Ok, then isn't soundstage the DIFFERENCES IN LEVELS of those mic signals?

I would think so Lee but soundstage is one of those rather loosely defined audio terms...

We live in an analog world so there is never a true one or a zero, just varying levels approaching that...

If you think that a mono signal has very low sound stage, then more separation in your playback chain, no matter how you get it would tend to be a good thing for better soundstage.

Practically you cannot get better separation than the original source material unless you use some artificial post-processing methods to separate the signals that come from the original source material.

 

[laatsch55]

Practically you cannot get better separation than the original source material unless you use some artificial post-processing methods to separate the signals that come from the original source material.



OK Joe......sure you want to go there tonight.....and artful dodge on the White Oak Pre question...

 

[Northwinds]

I've always been told that "soundstage" is the ability of your system to place the instruments of the recording in 3D space as they were when they were recorded.

I totally agree but it all comes to what is separated by the mixing consoles. If the guitars are on the left then the guitar tracks were mixed in the left channels and vice versa for other instrunments and vocals. You can blend both side to have a vocalist be in the center of the soundstage. What you said makes sense for a live recording though! Guitar players can use a shifter to have the track go back and forth between the channels to create the effect of the guitar passing from left to right. That's all blending of channels purposely right?

In modern recording, there is no band setting. A guy has headphones on when he puts down the guitar tracks in the studio. The rest of the band is usually not recording at the same time so it does not make sense in the "Placement" of instruments. It would have to be artificially done right?

As I said, this is very informative and I look forward to the definitive answers so I can understand performance better

 

[laatsch55]

Yep, me too.


Some of the better "Live" recordings in my opinion contain distinct instrument placements.....

 

[laatsch55]

Nando, what does that Elite gear have for separation Specs?? And that 9800 you have....

 

[Northwinds]

Yep, me too.


Some of the better "Live" recordings in my opinion contain distinct instrument placements.....

Of course they would IMO, there is a mic on either side of the stage??? If not, it would be a mono recording and it would be tough to figure where the instruments are right? I still say the signal has to go to the main console where it's mixed into separate tracks

The drawbacks? You'll get a clear recording, but not always the whole picture. Your sound person has to mix the soundboard feed for the room, not for your recording. The general idea is this: the louder something is in the room and on the stage, the less you'll hear in the board mix. Guitar amps, drums, and anything else that's really loud will be soft in the mix. This doesn't apply in a large venue where everything needs to be mixed in.

[h=3][/h]

 

[Gepetto]

Is that good and yes, it's a start but I am woefully unknowledgeable about the technical aspects of performance and understanding what those figures actually mean in layman's terms

Rough and tough, 70dB means that for that 1.5V output signal from your preamp, you will have approximately 1/3000th of the other channel bleeding through or about 500uV due to the total of all separation shortcomings of the preamp (PS, wiring, volume pot, board layout, IC crosstalk, selector switch, etc.). It is not bad at all.