critique please

[stingray_65]

I've wanted build an octal front 6L6 SE for a harp amp for a while now.

I found an interesting schematic and the modified it to fit my needs.

Fist off I'm using a 6BG6G coke bottle instead of a 6l6 and the pin out is a bit different

second, having just built a 5F2A and toying with the NFB I changed the resitor to a pot ganged to a switch that when turned all the way ccw opens the switch completly cutting the NFB. the 10 meg is to eliminate POPPING when the switch is thrown

third I added a tweed style tone control where the original schematic had a volume only

fourth would a bright circuit with a switch be of any benefit to a Harp amp?

OH! I also added a line out using weber's BALUN xformer. I used it on the 5F2a with HUGE sucsess

I've only done some rudimentary math in the PS section and the dropping resistors may not be correct

It is my intention to build this as a head. If I were to build an extention cab to go along with it, what size speakers would I want to considder?
I really like Webers signature series for thier price and performance.

any comments or concerns would be apreciated

Ray

[tubeswell]

Hi Ray
JM2CW your bright channel won't work unless you switch out the .1uF cap. When you put two or more caps in parallel, it merely sums the capacitances - in this case you'd get .102uF, which is the same as .1uF in terms of what you hear, i.e.; no difference. Why not have just try different value coupling caps there until you find what you like?

[stingray_65]

as always Tubeswell to my rescue!

you know thats a very practical solution.(swapping caps)

I also had concerns that I did not take into account mic impedances.

I want an instument input, but I'm building this mainly for harmonica.

other than that no glaring errors?

Ray