In article , Dave Plowman (News)
scribeth thus
In article ,
Don Pearce wrote:
On Wed, 05 Jul 2017 10:11:34 +0100, Jim Lesurf
wrote:

In article , Don Pearce
wrote:
On Tue, 4 Jul 2017 19:23:34 +0100, "Brian Gaff"
wrote:

a single transistor stage with, say an emitter follower would suffice
though these days the over designers would probably use an Ic. Brian

Under-designers, you mean. With an IC you don't have to do any design -
just set two resistors to give you the gain you want.

And that is exactly how I would do this - it's by far the best way.

If it were me I'd probably buy one of the cheap kits I used for
http://www.audiomisc.co.uk/HFN/HeadDAC2/HeadDAC2.html

I don't know if the board is laid out for gain, but your headphone amp
shows a unity-gain circuit only. I can't imagine they failed to make
provision for gain, though.

Something always worries me about using a 5 volt single supply for line
level audio - assuming it is used neat. In the old days, 24v was the sort
of norm for pro stuff. Admittedly line level is higher with that. But when
ICs came along was +/-15v or more.


Remember reading a criticism of the Quad 33 pre-amp citing its 12v as
being too low.


Someone does a modified power supply for that now!...


--
Tony Sayer