LaScala AL5 Noise

[babadono]

On 7/6/2023 at 3:41 PM, Coytee said:

Have you *actually* used a shorting plug on your inputs yet?

@Kingdeezie I am going to pick a nit....a "shorting plug" on the input will absolutely reveal what the quietest is possible from your amp/speaker combo. But it is not real world realistic. No electronics up stream of your amp will have zero noise and zero output impedance. A more realistic test is a plug with a 1 k ohm resistor between the center pin and ground.

 

Like these.

[babadono]

26 minutes ago, henry4841 said:

the only thing you want a resistor to do is slow down the flow of electrons

That there is funny..I don't care who you are.

[babadono]

All this talk of THD in amplifiers  Jeesh...your SPEAKERS produce WAY MORE. AND IM distortion and FM distortion and comb filtering..these artifacts are much more perceptible. And are made the least objectionable by HORN loading. That's why we like our horn loaded Klipsch speakers.

Just my $0.02

[OO1]

23 minutes ago, Stephen Buck said:

Yea Google klipsch jubilee demo, 

 who wouda thunk , Google 

[billybob]

Klipsch only sells caps for cold weather...

[babadono]

@Kingdeezie did we ever get an answer..are you using the unbalanced or balanced inputs on the Pass?. The balanced inputs require a different type of "shorting plug".

[babadono]

ahhhh....OK

[henry4841]

2 hours ago, Stephen Buck said:

The OP complained about noise floor not THD anyway.  Audible THD is around 5% for an average ear so all these decimal places are pretty much meaningless.  There are other qualities of amps that are more noticeable once THD is below audible levels.  
 

Here’s a simple discussion of car audio THD.
 

“When the harmonics reach 5%, they are clearly audible. If the tone was music, you would have trouble hearing 5% THD. The 1 % is only barely audible and it's mixed with a continuous, steady tone. With music, it would be inaudible.” https://www.bcae1.com/thd.htm#:~:text=When the harmonics reach 5%%2C they are clearly,steady tone. With music%2C it would be inaudible.

 

People hear noise floor long before they complain of THD.  People also complain of an amp not producing adequate high frequency at low volumes, and then lacking LF slam at higher volumes.  Then there’s the midrange mud.  But some artist sound benefits from lack of reproduction fidelity so there’s that too. 
 I’m always surprised with what people latch onto spec-wise instead of what they have learned to hear and expect out of old and new music. 

Most of the distortion analyzers give THD and THD+noise figures. I have found a noise figure 50db down from primary signal to be quite on my LaScala's and plenty good enough. Noise, hum mostly, not heard. 

[henry4841]

24 minutes ago, Stephen Buck said:

Can your experience be translated into THD+N minimum specs for amp buyers to consider with Klipsch?  Yamaha indicates residual noise at 40 uVrms.  If an amp is audible at zero input there’s voltage that can be measured on speaker cables with meter.  Surely one could just measure that and know if it will be audible on klipsch.  Seems easy enough for a dealer to measure and communicate. 

I do not feel it necessary being modest consumer amplifiers should be quite on our speakers. If you hear hum or noise chances are something is wrong with the device. I am not familiar with comparing uVrms with what I mentioned. I am sure there is info on the net that would do so for those interested. 

[henry4841]

4 hours ago, Stephen Buck said:

Can your experience be translated into THD+N minimum specs for amp buyers to consider with Klipsch?  Yamaha indicates residual noise at 40 uVrms.  

After some thought, the number of .040v's rms needs converting to the more common THD+N just as you said. Companies do this to confuse or for more talented electronic guys than myself. Just how do you get rms into the equation? Above my head. 

 

Best way to be sure is try and find a reviewer that has put that amp into a lab test to get the THD+N number.