OT? New tube amp schematic - thoughts?

[mlabbee]

Here's the full-blown version of my pencil pusher - a low power, single-ended, class A amp using 3 triode gain stages and a triode power stage.  The tubes are 6021s and the B+ I estimate will come in between 215 and 250, depending on whether I use a 8VAC or 9VAC wall wart.

http://img.photobucket.com/albums/v514/mlabbee/Pencil%20Pusher%20II/PencilPusherNo.jpg

Any thoughts or suggestions?  The breadboarded version is very noisy, especially when I crank it, but I'm assuming most of that noise will go away when I put it in a shielded enclosure and do point to point wiring with a star ground.

Special thanks to ZVex and Puretube for their suggestions on getting everything working and sounding good.

I will start the final build this week - I'll be putting it in an old wooden tube radio cabinet - it should wind up looking pretty cool. I'll post some pics when it's ready.

[JN]

Looks  great!

To reduce noise, maybe install a (metal film) series resistor ahead of the gate in the final stage.  Dunno, it looks like a lot of gain.

Could you please list what you used for T1 and T2?

Thanks for posting.

Edit**  I forget to suggest the value-- something like 220k, for starters.

[mlabbee]

By gate, you mean grid, right?  I'll give it a try.

For T1, I'm using an Amveco 12/120 toroidal. It has dual primaries that can be run in parallel or serries - I'm runing it in series to double the output from 110 to 220 (pre-rectification) and then running it on 8 to 9 VAC to lower the rectified output to the desired range (probably around 220 V, rectified).  The output transformer is a 3 watt OT used to power the reverb section of Fender amps - you can get them for around 10 at Webervst.com (I don't know the exact model, but it's the only 3 watt OT on the list).

The Amveco is a 62022 from Digikey. Probably bigger than I need, but I wanted to be safe.

[JN]

hehehe... Yes, I meant grid.  Too much time with fets.

Thanks for the info.

You might also try using metal film for all the resistors.

[puretube]

add a ground symbol to the main audio schem  :lol:
(not for me, though - but to avoid upcoming queries...)