Steve,

as I have problems picturing what you write, I ask you to draw a circuitry.

Best

Alex

Am 11.10.2012 19:47, schrieb Steve Smith:
> First' it's a long time since I did audio but the phantom power was appli=
ed
> to both cores of a microphone (balanced pair) to power the mic. This was
> injected through a pair of 47K resistors
>
> Second standard audio level a pair of pots to a point of common coupling.
> Simplest
>
> Better a virtual earth mixer one TL071 and three resistors all 47k will d=
o
> fine. Bipolar +/- 9v and earth the non inverting input. Feed back resisto=
r
> from output to inverting input. The other two resistors to the two (pot
> wipers) signals.
>
> Steve
>
>
> -----Original Message-----
> From: piclist-bounces@MIT.EDU [mailto:piclist-bounces@MIT.EDU] On Behalf =
Of
> Alexander Winnig
> Sent: 11 October 2012 17:27
> To: piclist@MIT.EDU
> Subject: [EE] Two questions regarding telephones and mixing audio signals
>
> Hello.
>
> First: Which voltage level should not be exceeded between both
> microphone cables(Signal and Mass) *between *a telephone handset and
> it's telephone?
>
> Second: I have two AC signal sources with a maximum voltage of 1.2 Volts
> each. Which circuitry is the one with the least amount of components
> that combines them in an adjustable way without distorting them or
> diminishing the overal volume?
>
> Best
>
> Alex
>

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