Article View: sci.electronics
Article #17552Re: need advice on TV sound amplifier
From: Pete Peterson
Date: Mon, 04 May 1987 11:35
Date: Mon, 04 May 1987 11:35
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In article <566@neoucom.UUCP> wtm@neoucom.UUCP (Bill Mayhew) writes:
>
>You can keep the volume at the TV headphone jack high enough for
>person with hearing loss and avoiding 60 Hz buzz by cutting down on
>the volume in the set's speaker.
>
>You might try using an operational amplifier chip to make a notch
>filter for the 60 Hz buzz for the ear phone listener.
>
The original request for this information didn't make it clear whether
the problem occurred at high volume settings (since he mentioned clipping)
or low settings which makes the residual hum ,at zero volume control setting,
significant. In the first case, the attenuator on the output as mentioned
in a previous posting would make sense; if the problem is residual "buzz",
the attenuator on the TV speaker that Bill mentioned would probably help.
Two additional points:
Trying to get rid of "60 hz buzz" (as opposed to 60 hz hum) with a 60
hz notch filter will probably not work out too well since you would still
be left with the harmonics, which are what makes it sound like "buzz"
rather than "hum". You could perhaps use a high-pass filter to cut off
frequencies below 300 hz (telephone-quality sound).
Hearing loss tends to be frequency-dependent; using an amplifier with
some control over the frequency response (at least treble-boost if
not an inexpensive graphic equalizer) might allow for greatly improved
intelligibility without blasting the person's ears.
pete peterson
{decvax,linus,wjh12,mit-eddie,masscomp}!genrad!rep
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!mnetor!seismo!gatech!mit-eddie!genrad!rep From: rep@genrad.UUCP (Pete Peterson) Newsgroups: sci.electronics Subject: Re: need advice on TV sound amplifier Message-ID: <1272@genrad.UUCP> Date: Mon, 4-May-87 07:35:27 EDT Article-I.D.: genrad.1272 Posted: Mon May 4 07:35:27 1987 Date-Received: Tue, 5-May-87 01:19:43 EDT References: <578@stracs.cs.strath.ac.uk> <566@neoucom.UUCP> Reply-To: rep@genrad.UUCP (Pete Peterson) Organization: GenRad, Inc., Concord, Mass. Lines: 30