ROG Tube Reamer Debug

[Johnny Halo]

Built this circuit and am having some issues.

The output is very low. The volume and the gain both work.

I used this layout -



Deviations from layout are moving Rows M and N points up one to accommodate socketing the diodes (which are 4148s). Using a 500K guitar pot for gain.







There does not appear to be any bad solder joints or bridges. There could be, I just can't find any.

Voltages for the IC are:
Pin 1  4.59
Pin 2  4.60
Pin 3  2.31
Pin 4  0.00
Pin 5  4.60
Pin 6  0.47
Pin 7  1.40
Pin 8  8.84

Diodes are 4.17(A) and 4.20(K)

Also, from pin 8 to the 12k resistor is 8.84. On the other side of (through) the resistor, it goes to 4.38. That reading is the same through the jumper, the next 12k, the Ecap to the 1 meg. On the other side of the 1 meg it drops to 2.31 before going to pin 3.

I have been in contact with Brian from ROG and we thought posting it here might help with finding the issue.

[spaceace76]

it looks like you missed one connection, between the 12k and 51k resistor, on the right side of the board.

there is also a bit of stray solder by the IC legs, you should check that out.

since this layout is kinda tight, you could also do some continuity testing between the rows to make sure there aren't any bridges.

i slapped a photo together to show the two things i mentioned.



hopefully you can get this thing fixed and wailing away soon!   

[DUY1337GUITAR]

If you get this thing working can you post a sound clip?  I'd like to hear how it sounds, been thinking of building this or the Thor
Thanks! 

[CynicalMan]

Soundclips:
http://runoffgroove.com/salvo.html#tubereamer
http://runoffgroove.com/salvo.html#thor

[Johnny Halo]

Thanks, Chris.

I will check out that missed connection as well as the "glop" on the IC legs.

Johnny

[Johnny Halo]

Success! I got it working.

BIG thanks to spaceace76 for his eagle eyes and noticing that I missed the connection between the 12K & 51K. I connected those and cleaned up a few of globs of solder and voila!

All that is left is to put it in a proper enclosure. Can't wait to try different IC's and diodes to see what it can do.

Thanks again!

[spaceace76]

no problem! sometimes all debugging needs is a fresh set of eyes. good to know you're all set. don't forget to post in the pictures thread once it's done!