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The story on my whistling Cinema I

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jmschnur

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As you read Jim's response, you will learn the way to vaccum electrostatics.

Joel

From: Joel Schnur [mailto:jmschnur@cox.net]
Sent: Sunday, August 13, 2006 10:46 AM
To: Jim Power
Subject: Whistle from Cinema I

I have an Outlaw 7500 amp.
My Martin Logan Center Speaker (Cinema I) makes a high pitch sound (very low
level) about 2-3 minutes after my system is turned off. It lasts for 5-10 seconds. I assume this is caused by the power being dissipated as the 7500 amp I have turns off (capacitor) discharge. This occurs when the Cinema I speaker is attached to any of the 5 output channels.

I do not hear this from any other speaker in the system (ML Vantages, NHT rear surrounds).

From Jim Power


“I think I recognize this symptom. It is pretty common and also easy to solve.
The cause is a microscopic bit of airborne contaminate that the static charge has drawn into the panel. Once the stuff is inside the panel, it combines with humidity to become slightly electrically conductive and now you are hearing the effects of the static charge leaking away from the film through the stuff. It can cause a hiss, the occasional mosquito-like squeal or a loss of volume.
The solution is easy.
First, unplug the AC power cord and allow the speaker to rest overnight.
This will allow the static charge to completely discharge. Next, use a very powerful vacuum hose over the front of the entire panel. The stronger the better. I don't bother with a brush attachment. Rather I just use the open end of the hose right up against the panel. I do use my finger tips as cushions or bumpers to prevent the hose from scratching the glossy surface.
Especially focus your efforts along the outer edges and along the horizontal spars supporting the film.
That should do it.
Happy listening!”

Vacuuming did not stop the whistle so I wrote to Outlaw Audio.

From Scott at Outlaw Audio

“Hello Joel,

Thanks for contacting the Outlaws!

What you are hearing is the sound of the capacitors discharging. Some speakers are more sensitive to reproducing this sound than others. it is entirely harmless and will not impact your speakers performance.

Please let me know if you have any further questions.

Thanks and regards,

Scott”
 

checkbit

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After reading your post I remembered that I used to have the same issue with my SL3s. I used to use an acurus amp on them and that whistling sound at first worried me. I also contacted acurus at the time and got the same answer of draining caps. I have since upgraded to classe amps and dont have the issue anymore. What do you think of the outlaw stuff? tremendous value.

cb
 

jmschnur

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The Outlaw 7500 sounds very good in my HT system. The Vantages sound quite good. Jazz, Piano etc sound very good in stereo from my Vantages. The amp handles loud DVDs and all my ripped (wma lossless) CD music collection
very well.

I am sure they are not as smooth as a Krell nor any of the Tube class A amps but for $1600 the new Outlaw Amp represents a very good value.

Joel
 
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