New best wide world headphone amplifier

[Nordic]

Thanks for the links.. of course my big goal is also partialy portability... current circuit is about 2 x 2 inch fiting in a case of that with, twice the length and about 3/4" height..... (10x5x2 cm)

[lineup]

Originally posted by Nordic
Thanks for the links.. of course my big goal is also partialy portability... current circuit is about 2 x 2 inch fiting in a case of that with, twice the length and about 3/4" height.....

As told, my circuit is very compact
for 2 channels stereo driving for example 2x32 Ohm
including LIM317 regulator, it is only 47.5 x 62.5 mm.

See picture in Post # 80
http://www.diyaudio.com/forums/showt...720#post995720

You would need a small trafo, though.
Minimum: 3.5 VA 1x12 Volt
Recommended (see my schematic) : ~5.0 VA 15 Volt

I am thinking of building Lineup HeadPhAmp Mk.2
and do it the hardwire way without PCB board!
That would be really something
... when already the old circuit gave me tears of joy
when listening.

[00940]

Originally posted by Nordic
Thanks for the links.. of course my big goal is also partialy portability... current circuit is about 2 x 2 inch fiting in a case of that with, twice the length and about 3/4" height..... (10x5x2 cm)

You might like this : http://www.meier-audio.homepage.t-online.de/headamp.htm Still wall powered though.

[Nordic]

Are all transistor amps so powerhungry or is it just because class a is used?...

[00940]

- for portable amps, opamps are so efficient and good sounding that very few designers see the point of going discrete. Especially when you consider the required quality.

- for desktop amps, class a is a good choice, considered the small power requirements.

[destroyer X]

Kind...and this is enougth.

Is not really needed that forum people agreed in a 100 percent.

Good that our headphone discussion is going on...running, this is nice.

regards,

Carlos

[destroyer X]

And i see that bias can be reduced to intall headphone coil in series..... under 60 miliwatts may work fine without melt the cartridge..... i use try this one someday.

I am imagining how good may be the complete version...hummmm, it may be very good...hummmmm.

regards,

Carlos

[lineup]

that is my new version
notice I changed BD140
and use better BC557 PNP

I dont know why I used BD140, even if result was good
there is no need for it
maybe, the simple fact I had no TO-92 PNP, like BC557, at home this day
and took what PNP I had ....

About resistors in input:
from top:
100k trimmer (can be replaced with ~68k resistor)
150k
47k

and below T1-T2 input pair:
180 Ohm +
180 Ohm
(no big catastrof replace with one 330 Ohm or 390 Ohm)

about transistors:
I would use ( in schematic )
t1-t2 = BC550C ( BC547 )
t3 PNP = BC560C ( BC557 )
t4 NPN = BD139 ( BD139 )

One trafo ~4-5 VA 12-15 Volt
would supply both 2 channels. ( 100mA per channel )

For regulator use something like this:
7812 12V 0.5A ( or 1A ) 3-pin regulator
or
LM317 TO-220 case
12 Volt DC regulators are not difficult to find.
Follow instructions for those regulators when setup.

As this is a
Fully discrete Single End TRUE Class A amplifier
trafo should be able to feed regulator input
with a voltage like 15 Volt or more
at the Class A constant current of 100+100 mA = 0.2A

good luck
if anyone build it - you wont be dissapointed with sound!
I can promise
if your headphones are of same good quality, as my amplifier
/lineup

[destroyer X]

I think i will construct it, as soon as i have more acid to produce boards...or maybe some stripped copper board.

The circuit is very interesting... and now complete with informs and graphics, can be used by everyone around the world..this is something great that our forum provide to anyone.

But if someone have other ideas, please, post the ideas here, as we are searching for multiple ideas, and each one of us will decide the one adequated to construction, based on each one's needs and desires.

Thank you.

regards,

Carlos

[destroyer X]

Watch the picture....mine burned my fingers...so...it is the hottest one!

regards,

Carlos