Beginner's heaphone amp?

[mr_push_pull]

I'm looking for a simple and tested headphone amp design that won't turn me down, as this will be my first valve project, I'm totally new to this domain. I'm thinking about a design using one ECL82 or 86 per channel and I found a few schematics, and a few others that I have at home:
http://www.mcamafia.de/tubes/keksdose/cookiebox.htm
http://www.avanwaarde.freeler.nl/id13.htm
http://www.geocities.com/agalavotti/ecl82.htm
http://www.bonavolta.ch/hobby/en/audio/ecl82_4.htm
http://www.bonavolta.ch/hobby/en/audio/ecl86.htm
http://216.87.144.102/svetlana/TechB...s/No10fig2.gif

What do you suggest?

[Stixx]

I'm looking for a simple and tested headphone amp design

Hi Mr.PP,

not that I am an expert either, but all the afore mentioned schematics are amps to drive loudspeakers..? You could of course drive your (low impedance) cans from these, but why so complicated?
A good selection of dedicated headamps can be found on "www.headwize.com" , including one from A. vanderWaarde that has been built many, many times. A company named wooaudio even sells commercial headamps that look very close.....

rgds,
Oliver

[mr_push_pull]

Hi Stixx,
From what you are saying, one could understand that conventional valve amps can't drive heaphones. I don't understand why would that be, what makes a headphone speaker so special a load? I'm not talking about electrostatics here.

[joensd]

You might wanna have a look here:
http://headwize.com/projects/index.htm
Quite a few tube projects, some being real simple.

[Stixx]

Headphones usually are in the 32-600 Ohms range, and can of course be driven by a tube amp, that has been explained here on the forum.
Most dedicated headphone amplifiers though get rid of the output transformers being otl-designs, making everything a little easier and cheaper to build.....

rgds
Oliver

[Sch3mat1c]

You can build my All-Out Preamp, has tone and bass and four inputs. The cathode follower output is capable of driving my 32 ohm 'phones to a few decibels. Obviously it won't work forever but it'd be a good starting point. 'Specially if you pull out the tone stack and run it straight through instead..(simpler)...

Tim

[fdegrove]

Hi,

Tubecad's Master John Broskie's SRPP+WCF topology using something like a 6SN7 (SRPP) followed by a 6AS7G/6080 as a WCF at around 300V B+ should make for a nice headphone amp capable of driving even the horror of horrors, the AKG 1000 with aplomb.

I should know, I've got one of those monsters with exactly that as an amp so.......

See the Aikido blog:

AIKIDO SUSHI

One caveat, no matter what they say I'd still recommend a good PS with a top quality CLCLC filtering.
You'll be stickin' your "oar" in the can, remember?

Cheers,

EDIT: Oh, BTW, it comes as close to PP you'll probably ever going to get without resorting to tricky phase schplitterzzzz.

[mr_push_pull]

Thaks for the replies, I found some nice amps on the links you gave me. I can get these tubes form Russia (unused of course) for fair prices:

6N2P (ECC83, 12AX7)
6N23P (ECC88, 6DJ8)
6N8S (12SN7)
6P3S (6L6GC)
GU50 (LS50)
GM70

Is any of these valves special? Is there any reason for any of these would be preferred?

[Pentium100]

I have built headphone amp with 3x 6N23P (Stereo). It sounds very well and has enough power to drive 32 ohm headphones.

http://headwize.com/projects/showfil...=cmoy5_prj.htm

[DigitalJunkie]

I've used my PP 6V6 amp with my headphones. I made an adapter to put across the speaker terminals,with an 8ohm resistor across the ouputs,and a headphone jack in parallel. That way the tube amp still has a correct load. It sounds pretty good!

-BUT- Be careful with the volume!

The output from a "normal" amp can and will fry ears and headphones!
The resistor will absorb most of the power,but even 1W with headphones is ear-bleeding-loud.