[BobM]

I posted a comment on a music forum in an audiophile thread about my recently cleaning the contacts on my stereo. I try and do this annually. The improvement is obvious, no second guessing here. It's free and  though time consuming, relatively easy.

But the reactions I got on that thread were astonishing. I thought this was basic audiophile first grade: a clean contact is a good contact. All metals oxidize over time, some more than others. The people there equated cleaning a contact to using a green pen on a CD, calling it useless.

So, what's the opinion here? What's the scientific justification for needing to do this (to please the engineers)?

Saying just try it, it's free and you will obviously hear the improvement, is getting me nowhere.

[ACHiPo]

I'm a believer, although not an avid enough believer to clean contacts on any type of regular PM program.  When I rearrange or add new gear I try to remember to clean the contacts.  Hard to argue with as you say, although I'm sure there are those that would.  One experience with noisy pots before and after using Caig spray will make anyone a believer (or at least it should).

[srb]

One experience with noisy pots before and after using Caig spray will make anyone a believer (or at least it should).

I agree that it would be impossible to refute that.  (Whether there is also enough actual physical wear that the noise returns sooner than expected requiring re-cleaning is another matter)

I have also had RCA connections that when very gently touched gave some scratchy static, and a subsequent thorough cleaning took that away completely.

Steve

[Wayner]

I posted a comment on a music forum in an audiophile thread about my recently cleaning the contacts on my stereo. I try and do this annually. The improvement is obvious, no second guessing here. It's free and  though time consuming, relatively easy.

But the reactions I got on that thread were astonishing. I thought this was basic audiophile first grade: a clean contact is a good contact. All metals oxidize over time, some more than others. The people there equated cleaning a contact to using a green pen on a CD, calling it useless.

So, what's the opinion here? What's the scientific justification for needing to do this (to please the engineers)?

Saying just try it, it's free and you will obviously hear the improvement, is getting me nowhere.

What do you mean by a contact?

[Steve]

I posted a comment on a music forum in an audiophile thread about my recently cleaning the contacts on my stereo. I try and do this annually. The improvement is obvious, no second guessing here. It's free and  though time consuming, relatively easy.

But the reactions I got on that thread were astonishing. I thought this was basic audiophile first grade: a clean contact is a good contact. All metals oxidize over time, some more than others. The people there equated cleaning a contact to using a green pen on a CD, calling it useless.

So, what's the opinion here? What's the scientific justification for needing to do this (to please the engineers)?

Saying just try it, it's free and you will obviously hear the improvement, is getting me nowhere.

Please don't let them on the thread irritate you Bob. I post on a number of other forums and there are those who claim they are "experts".

Over the years, I have been able to demonstrate to myself, and customers, via a couple of experiments, that our ears are sensitive to 32 udb (micro db) change in frequency response (FR), roughly 95 -100 db down. Of course this will depend upon masking effects of the room, equipment etc. So their perceiving sonic differences may not be that sensitive to some.

Cheers continue PMs Bob.

Steve

[Speedskater]

Steve, haven't you been told a million times not to exaggerate?
"32 udb (micro db)" this needs a reference to measurement scale.

There is a test file out there someplace with a marching band about 60 dB down from classical music, it's real hard to hear the marching band.

There is another test file that drops the music in 20 dB increments, when it gets down to -60 dB it's real hard to hear the music.

That's not to say that having more signal to noise is not a good thing.

[Speedskater]

Thinking about it some more.
Maybe that "32 udb (micro db)" is for 'dBu' or about 0.7746V.
Because a decibel is 1/10 of a Bel, you won't have a micro 1/10.

[Mark Korda]

Bob, the opposition crowd to clean contacts must have never owned a crappy used car, where a clean ,shiny, anode battery terminal finally started you up where the dirty oxided terminal kept you in the driveway going no-where.....Mark Korda

[bummrush]

People have sucessful unhooking and rehooking interconecks just cause of sliding motion also

[Steve]

Steve, haven't you been told a million times not to exaggerate?
"32 udb (micro db)" this needs a reference to measurement scale.

There is a test file out there someplace with a marching band about 60 dB down from classical music, it's real hard to hear the marching band.

There is another test file that drops the music in 20 dB increments, when it gets down to -60 dB it's real hard to hear the music.

That's not to say that having more signal to noise is not a good thing.

Really? When was I told the first time, or any time? 

However, I guess I should have been clearer. Seems I forgot to mention a simple phrase, FR response variations. 32 micro db variation was in reference to frequency response (FR), not total spl across the audio band. I made the necessary correction in my previous post.

The variation in udb is even less as the test involved a cello solo whose lowest FR is 65hz. FR variations are much easier to perceive than total spl variations at it concernes with harmonic structures, which are weighted etc.

By the way, the effects of turn table rumble at -70 or more down is perceived. Just an extra tib bit of information for the public.

Cheers and sorry about confusion.

Steve