Germanium Giant help...

[spacefuzz74]

i'm a little confused about the proper way to assemble this germanium giant...attached is the vero layout i used, as well as a shot of the build.

when i hook it up "normal", with the 9v positive going to the DC positive, and the ground going to the DC ground, i get a very unstable effect...it fades in/out, and the volume is so, so low.

in the photo, i have the 9V positive going to the DC ground and the board ground going to the DC positive, which i understand is "positive ground"?

it still does not seem to be working right, it's more stable, but i'm not getting the distortion/fuzz.

can anyone see what i'm overlooking?

[Travis]

What kind of transistor are you using? The layout is for an NPN transistor and normal negative ground

[spacefuzz74]

I'm using a NPN - MP38A transistor.

[spacefuzz74]

here is a shot of the solder side...i'm fairly certain there are no bridges.

[induction]

It's hard to be sure from the picture, but it looks like you're missing the jumper between the two resistors.

[spacefuzz74]

i wish that was the problem, but the jumper if for sure there.  thanks for looking!

[spacefuzz74]

i swapped out the GE D9K diodes for the SI 1n4148, and now it seems to be working, although the clean mix really does not seem to do much from one extreme to the other.

bad D9K diodes?  unlikely, right?    

[rocket88]

what hfe is the MP38 you're using? it may not be high enough.

[spacefuzz74]

if this is the correct pinout, i'm getting over 100 hfe for the handful of MP38's i have.

[rocket88]

what are you using to measure the hfe? i've got about 1000 MP38A transistors and maybe 10% have an hfe of 100 or more. btw, i believe that's the right pinout, but will check mine and get back to you.

[spacefuzz74]

i built another board, hooked it up to my test box, and i'm getting the same results...it's gonna be one of these times where i just have to let it sit for a few days and come back to it.  maybe the issue will reveal itself.

thanks for all the help!