[sdiy] Tube amplifier question

[Motohiko Takeda]

Hi rene, Jürgen and all,

I had learned tube for this 6 month and build some headphone amps by tubes.
6DJ8 is not easy to get here in Japan, But 6922 can be used instead of
6DJ8. it has not only good  sound but also easy price. I like it.
http://www.aleph.co.jp/~takeda/radio/tube/img/6922-schem2.gif
is one of my experiments. You may change the power voltage for FET 5V to
15V or so.
Tubes are not so expensive, IMO. Output Transformer (We need 2 of then for
1 amp )and Power transformer are so expensive, and the Quality of amp
depends on the quality of OPT's.
http://www.aleph.co.jp/~takeda/radio/tube/plan1b.html
is my Japanese Page.
My broken Japanese are hated by this service.
http://babelfish.altavista.com/
but it may help you.
I write so many Japanese local things in this page and I think that
it not good information for the world, but I introduce so many awesome tube
design by Japanese amateur hobbits in this page. please check them.

I also try HeadWize's project named 'Output Transformers Tube Headphone
Amplifier' It works, but not so good. I think that it result depends on impdance
of headphone . Mine is 64 ohm. More high one may get good result I think.
It's page is here
http://www.aleph.co.jp/~takeda/radio/tube/muFolower.html

Mr. kikuchi designed another SRPP one.
http://www.asahi-net.or.jp/~cn3h-kkc/claft/12au7srp.htm
I also build it
http://www.aleph.co.jp/~takeda/radio/tube/12AU7-muFollow/12au7-mufollow.html
we use small transformer for Transistor as matching transformer and it get
so good result. I recommend this methods for headphone amp.

Simple Single ended by 12A6 and 12SL7GT with hi-quarity OPT is also my
recommendation. Now I write page about this now.

cheers!
Motohiko Takeda
Tokyo Japan