RCA Shorting Plugs

@almarg

In the related thread mentioned herein, I posted a question worthy (IMO) of your input (no pun intended) :) As that question has gone unanswered there, I thought I might pose the question here.

Might or should there be a theoretical or practical difference when using shorting plugs on an input dependent on the class of amplifier?

Reason I ask is that I’ve obtained and installed these:

https://www.amazon.com/Viborg-Audio-Stopper-Plated-Protector/dp/B017DH76VS/ref=sr_1_1?ie=UTF8&qi....

While I cannot detect a difference in the way my MF M6si (class B or A/B) noise floor emanates the slightest "hiss" or "sizzle" (no music source but volume cranked past 12) with or without the shorting plugs, I can detect a difference when I put them on the LFE input (class D) of my Golden Ear Triton Reference speakers.

Thanks, Al.

EDIT:

I'm aware of the difference in-so-far as the M6si I'm hearing the sound from the tweeter whereas in the T Refs the sound is from the woofer. So perhaps the shorting of inputs effects a particular frequency range more so than others?

Might or should there be a theoretical or practical difference when using shorting plugs on an input of different amplifier classes?

Hi Hal,

I'm doubtful that any such generalizations could be made, as I would expect whatever benefit shorting plugs might provide (with or without resistors) to be highly dependent on the specific design of the component they are used on, as well as on the specific characteristics of noise that may be generated by other components in the system, and that may be present in the surrounding environment.

Best regards,
-- Al

@almarg 

I appreciate the rather prompt response on your part. Very prompt for that matter as I added an edit to my previous post. 

Given what you have just stated, might or should there be difference based on frequency? 

In the case of the M6si I'm hearing the sound from the tweeter, whereas in the T Refs the sound is from the woofer. 

So perhaps the shorting of inputs effects a particular frequency range more so than others? ... In the case of the M6si I'm hearing the sound from the tweeter, whereas in the T Refs the sound is from the woofer.

Hi Hal,

My instinct would be to not extrapolate any general conclusions from your findings. Per my previous comment, pickup of hum or noise at various frequencies will depend on the specifics of the designs that are involved, and on the environment in which they are used, and will tend to have little if any predictability.

Best regards,
-- Al
 

@almarg 
Hi Al, appreciate your feedback. At one point you say

So if the XLR input is being used in those cases and a shorting plug is put on the RCA connector, the output circuit of the preamp or other component providing the balanced signal pair to the amp would have one of the two signals on its XLR **output** shorted to ground.

My AR pre does have both XLR and RCA inputs, I use the XLRs. So if the short to ground you mentioned happens, is that harmful to the unit or would it only result in the muting of the signal (or both?). Would I know right away from using the RCA shorting plug was having a bad effect, if any?

Thanks again.