Date   : Fri, 30 May 1997 14:56:54 +0100
From   : Paul Theobald <PT@...>
Subject: Re: BBC Questions......

>----------
>From:      Gelfling[SMTP:pjh28@...]
>Sent:      Friday, May 30, 1997 8:55 AM
>To:        Bala Amavasai
>Cc:        bbc-micro@...
>Subject:   Re: [BBC-Micro] BBC Questions......
>
>On Tue, 27 May 1997, Bala Amavasai wrote:
>
>> 2. How do I turn down the sound to my Master? I've used the Control
>>    Panel utility to set the sound to half, but whenever a game takes
>>    control, the volume automatically goes up to full again. I've been
>>    told that there is a hardware switch (potmeter?) inside the BBC. Where
>>    is it located?
>
>The contol panel configuration ("*conf. quiet" or "*conf. loud") only
>controls the default "beep!" sound you get on a reset or from pressing
>COPY. Normal game sounds are unaffected, as you pointed out.
>There are 2 ways to deal with this.
>   1) At the back right of the machine is a phono socket labelled
>"Audio Out". Look at the socket from inside the machine and you'll see
>there's just enough room to stick a medium-sized screw in between the
>terminals. This shorts one of the sound outputs, thus cutting the sound
>drastically with no damage done to the machine (I used it for ages with no
>side effects).
>
>   2) Put a 10K potentiometer in series with the speaker. A
>logarithmic one is probably best, but linear is fine also.

I thought Bala was correct.  I'm sure I remember a small potentiometer
built in to Beebs already, which can be used to change the volume.
There are circuit diagrams on
http://www.acorn.co.uk/ftp/documents/circuits.  Unfortunately I can't
view these at the moment to check.

Paul.