Boss Corporation's biggest lemon - no wonder they discontinued it quickly

I posted this on the SS Guitar forum Well, I just had two more of these abortions in my workshop - both with that nasty buzz/ hum ;) I tried increasing the capacitor at the input of the 10v regulator but unfortunately the buzz was still there, although reduced slightly, SO, i decided to find out wha...

fantastic - thanks so much

amazing

can you measure R4 with a multimeter please
?
cheers
bajaman

I think R2 should be 68k and R4 4k3
cheers
bajaman

something is wrong with the values for R2, R4 and C2 - I suspect R2 is a much larger value or R4 is much smaller and C2 is definitely suspect at 100n !
with those values the input gain is only approximately 2.7 times and has a low pass 3db at 20Hz - perhaps R2 is 750k and C2 10n ?

either D115 or D116 needs to be inverted

I can see at least two mistakes already
Out pin not connected, R6 should be connected to it instead of to C3, and the pot wiring is totally wrong - there should not be a trace between pins 1 and 3 - leave pin 3 not connected like in the picture on the right side !

hmmm - still using this in my two guitars - have not changed the battery as yet

make sure that you run the series tube heaters ground wire on it's own separate connection wire back to the ground connection of the AC input socket. Never mix this ground connection with the signal ground.
cheers
bajaman

very M.E.S.A like

no oscillation problem with my layout

yes

"Guys, can someone explain to me what is the need for multiple gain stages?"
answer: read the first post in this thread

try inserting a 100 ohm resistor in series with the output from the charge pump to the opamp pin 7, and then connect a 220uf (at least 35v) capacitor from pin 7 to ground
cheers
bajaman

anyone tried my SUGGESTION yet ?

"Here’s some one that has done a proper blind test on tone controls

https://youtu.be/817JHiYV_Po"

totally irrelevant to this thread

Please read the first line of my original post and contemplate why I was reticent to share my subjective observations - as Thomas said to Jesus "show me the holes - i want proof"
None so blind as those who will not see, and none so deaf as those who will not hear
cheers
bajaman

Has anyone actually tried my suggestion yet ? I would very much like to hear from you. As I previously stated - I am not interested in proof, recordings measurements etc. If you decide to ACTUALLY TRY my suggestion (with a clean not over distorted signal) then I would be very pleased to hear your th...