Miniature Tubes

[MicroMinded]

Hello, I am looking to start a build for a small

 

[TheGimp]

Buy Low, sell High.

 

[MicroMinded]

Umm.. I have no idea what happened to the body of my message so I will repeat it.

I am looking to start a build for a <25W headphone pre/amp. The project requires a small footprint so I am looking for tubes. So far I have found 6n16/17b. I would like to be able to set Trebble/Mid/Bass characteristics via potentiometers.

Can anybody recommend some good small tubes?

 

[mastodon]

I assume that's <25W total dissipation, and not output power.

Maybe something like this would be a nice start: Oatley K272 JAN 6418 Valve (Tube) Preamplifier / Headphone Amp Kit It's a hybrid design and lacks the tone controls though.

 

[piano3]

I have seen somewhere a circuit for a headphone amp using directly heated,cheap and common 1P24B at output. The 2 subminiature tubes you mention are very suitable for gain stages.

 

[MicroMinded]

Wow I have read a lot of web pages this weekend. Found quite a few designs and some new tubes such as PL504, 5672, 6418.

I have not done much tube building but I have a 12au7, 12ax7 and a 6v6 on hand I think I will toy with and see what results I get. I found the tube-town.net tube selector guide and it seems pretty handy and diyaudioprojects.com has some simple projects I am going to try out.

I need to learn how to read the tube sheets and properly bias the tubes mentioned above but the ECC81/2/3 tubes seem to be the best and cheapest to start with.

Thanks!