In article <7f8j24tbsh7grb75t8jpiomohmfo0hvhn2@[EMAIL PROTECTED]
>,
flipper <flipper@[EMAIL PROTECTED]
> wrote:
> On Tue, 13 May 2008 08:22:52 -0500, John Byrns <byrnsj@[EMAIL PROTECTED]
>
> wrote:
>
> >In article <kk4i24t13io43j65n6jgmbjnpbr7juna56@[EMAIL PROTECTED]
>,
> > flipper <flipper@[EMAIL PROTECTED]
> wrote:
> >
> >>
> >> Btw, the OTL doesn't 'require' the 120 ohm resistor and it works just
> >> fine as a 'low impedance' output.
> >>
> >> You could just remove the 120 ohm, and then adjust the FB resistor
for
> >> the changed Vo, but there's also a nice trick can be played. Instead
> >> of the FB R and blocking cap. as shown, put a 12ohm under the
existing
> >> Rk on V2A and take the headphone return to that junction. That
> >> eliminates the DC blocking cap.
> >
> >If I am following your description of this mod correctly, doesn't that
> >convert the negative feedback from voltage feedback to current
feedback,
>
> Yep
>
> >with the expected effect on source impedance?
>
> Yes, but then a moving coil device is actually current driven so I'm
> not sure what the 'net effect' would be.
The common "dynamic" loudspeaker is also a moving coil device and people
seem to feel they need to be driven from a voltage source. They talk of
"damping factor" and such. Can I assume that "damping" isn't a factor
with headphones, at least if they are driven from a 120 Ohm source?
Regards,
John Byrns
--
Surf my web pages at, http://fmamradios.com/
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