[build log] 3W tube power amp (my design)

[bancika]

I've planned to build this thing for over a year, but couldn't find time. Finally, I had few weekends to dedicate and it's all done. Some highlights:

* Two 6AK6 (the smallest 6*6 tubes I know of) output tubes in PP
* Output tubes are biased with LEDs, 6 white and two red, wired in two parallel arrays to make sure they can take the current.
* All poly film caps, even in the power supply
* LND150 boost stage for low level input and another input that skips the LND150 stage
* 6021 submini for gain stage and concentrina PI

[img:800:600]http://diy-fever.com/wordpress/wp-conte ... a/guts.jpg[/img]

[img735]http://diy-fever.com/wordpress/wp-conte ... _schem.png[/img]

I turned out exactly as I planned. It's super clean. There's a boosted and "all tube" input. Boosted can get handy when playing with guitar straight into the amp because without the boost it can get loud about as the TV. When using a preamp or hot pedals there's no need for the boost (unless you want to drive the output more) so unboosted input is fine. Boosted channel adds a bit of dirt above half, but not much.

You can find more pics and info here http://diy-fever.com/amps/3w-tube-power-amp

I'll try to post clips soon.

Cheers

[cbass]

Very cool>I had lost track of your website and couldn't remeber the name.So glad I found it again.

[bancika]

Adding some clips. Everything's played clean, guitar into boosted input. I'll record some with pedals in front.

Mini Les Paul -> Nan@ Amp (boosted) -> 1x10" cab -> GLS ES-57 mic -> Tascam DP-008

http://diy-fever.com/wordpress/wp-conte ... od_mic.mp3
http://diy-fever.com/wordpress/wp-conte ... me_mic.mp3

Note that clips recorded with mic have more noise. It's not the guitar or the amp to blame. Since I played relatively quietly, I had to crank the heck out of the mic preamp which added some noise. The amp itself is super quiet.

Mini Les Paul -> Nan@ Amp (boosted) -> dummy load -> Palmer PDI-09 (bright) -> Tascam DP-008

http://diy-fever.com/wordpress/wp-conte ... direct.mp3