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RCA Shorting Plugs

I am coming to the conclusion that success in home audio reproduction is largely about lowering the noise floor. There are so many different types of “noise”, from so many different sources, that we only really “hear” by their absence.

I have had caps on the unused RCA inputs of my ASL passive autoformer preamp, ever since a friend suggested them way back. I recently got some actual shorting plugs (with resistors), from Hifi Collective in the UK, to replace them. I was surprised by how much difference they made. Transparency, resolution and musical flow all increased, along with the “realness” of instruments and voices. There is also more sense of the space around them.

I know some preamps short the unselected inputs, but, if yours doesn't, these shorting plugs are inexpensive, and definitely worth trying.
tommylion
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ericsch
753 posts
 
OK, thanks!
johnny121
11 posts
 
I tried the shorting plugs as well and they were brilliant, certainly could hear a difference between shorted and non-shorted.The problem it is difficult to get the truth out. When someone like tommylion tries something out and it works, we get people who have never tried this mod before, start putting forward their biased and one-sided point of view.Just because they have some qualification in electronics they feel if something does not fit their textbook opinions then it must be wrong.What lab tests and results of artifically controlled experiments give, and what happens in the real world, can be two very much different things.The shorting plugs reduce the noise floor and allow more detail to come through. Exactly what tommylion described i found the same thing after much listening, and my wife agreed.If you do not have a noise problem you will probably hear little improvement.If you want to learn more try this, then report back:1. Solder a 100 ohm resistor across a working input, not an unused input.2. Listen.3. Post your findings here.
almarg's avatar
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almarg
9,670 posts
 
If you want to learn more try this, then report back:1. Solder a 100 ohm resistor across a working input, not an unused input.2. Listen.3. Post your findings here.
Keep in mind that most source components and most preamps and line stages cannot drive 100 ohms with good or even half-way decent results.  And as you may be aware the manufacturers of many tube-based source components and preamps recommend **minimum** load impedances in the area of 20,000 to 50,000 ohms.

There are some source components and preamps which can do that, and of course 100 ohms would be a reasonable load for many low output moving coil phono cartridges.  But the great majority of components providing line-level outputs can't come close to driving an impedance which is that low, while providing reasonable results.

Regards,
-- Al
  
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