J
Jacobe Hazzard
- Jan 1, 1970
- 0
Anders said:Hey.
I have this problem with my samick mixer. Well its no
problem when you are making music alone even then the
output must be at a 75% setting.
But when i need to have two headsets connected to the
headphoneoutput the output is just to low.
So Since i got some Opamps laying around. I exchanged the
TL074 that was in the mixer with
Burr Brown OPA134 OPAMPS. Now the noiseratio got MUCH
better. Well anyway, since i had some
opamps left i got this idee.
First of all i can start with that electronics is just a
hobby. I have no education whatsoever but i am planning
to. Ok here we go:
I want to have enough power to drive another headset. So
if i take the headphone output and run
it through the OPAMP witch is in a untiy gain
configuration. I guess it will works as a
buffer so it wont run down the orginal signal....
So the question is: What am i missing? Will this work?
I guess the headphone output voltage may be to much for
the OPAMP.....?
Is this just stupid?
Rough schematic (dident bother to draw the opamp
configuration)
in signal (One channel)
-------
|
|
| |
| |/ potentiometer
| |--------------------- To headphone A
| |\ |
| |
| | ----- To OPA134 (unity gain
configuration) -- To headphone B
|
-----
---
-
OPA134 datasheet.
http://www.elfa.se/pdf/73/731/07312010.pdf
Anders Vinje
There's a problem with this schematic - headphone A is fed by a
potentiometer. This means the output will have some significant impedance,
which will decrease the volume and increase distortion, depending on the
volume setting. Also, connecting/disconnecting headphone A will affect the
volume and sound quality at headphone B. Finally, wouldn't you rather have
two volume settings? If you use different types of phones at the same level
one might be intolerably loud while the other is too quiet.
It would be better to use two buffers, one for each pair of cans (actually
fit thay are stereo you need four buffers). Have the buffer outputs feed the
speaker elements directly - set the volume before the signal goes in to the
buffer and not after.
Do you know anything about the headphones you want to drive, such as
impedance or power handling capability? A 600ohm 3W load looks very
different from a 16ohm 100mW load..
Adam