Dang it! Trouble with my Massacre build......

[plexi12000]

hey dudes, i built a massacre distortion- (joe davisson.  PNP w/ BS250 trans.)  I downloaded the PCB layout from "Gringo". I'm assuming it is correct.

i'm getting a little bit signal and distortion through, not very loud...but it is squeeling.  Any ideas?

i've learned to be quite thorough and i pay meticulous attention while building...due to past screw ups!  but i musta screwed something up and can't figure it out.

Baah!  I had to 'walk away' from it for a while...but gunna check the trans voltages when i sit down again.  Thanks much!

[Kipper4]

Probe it mate find it 

[plexi12000]

audio probe you mean, Kip?

[Kipper4]

Of course Plexi.
Probe it and see where the trouble starts.

[plexi12000]

yeah.....only prob, is i'm not rreally sure about where the entire signal path is.  i know where it goes in, naturally. but not a lot else! -lol

lemme ask you this....with the BS250, does the signal enter it at the gate lead?  that would maybe me narrow it down to a single stage.

[duck_arse]

(post the schematic so's we can point at it.)

[edit :] parts deleted

[Cozybuilder]

There is another layout posted, input clearly goes through R1 then C1 (100nF) into Q1 gate:

[Marcos - Munky]

This is the signal path:
input>R1>C1>Q1>R5>C3>Q2>R9>C5>Q3>C7>R15>volume pot

BTW, did you noticed it's a positive ground circuit?

[LightSoundGeometry]

perfect pedal to build around halloween haha

[plexi12000]

thanks for chimin in fellas-   yes, i',m aware it's a positive ground circuit.  i have my positive battery lead going to ring lug of input jack....and electro's "reversed".  that's all that needs done, correct?

i'm getting just a tad over 5v at each drain.  about 2.5v at gates.  and around .8 v at the source leads.  does that seem ok?  i believe the drains are good at 5v.

i dont have it boxed up, so 'ive double checked all my wiring....and sucked out solder at two questionable pads...and resoldered just be be sure.

it's too late to fire up the amp...gunna check it out tomorrow.   thanks!

[plexi12000]

This is the signal path:
input>R1>C1>Q1>R5>C3>Q2>R9>C5>Q3>C7>R15>volume pot

BTW, did you noticed it's a positive ground circuit?

forgot---- thank you for taking the time and posting the signal path for me!!!  HUGE help!  if its still fkd up....at least i can try my audio probe tomorrow.

[Cozybuilder]

This looks like an interesting OD, couldn't find a schematic, so I drew this one from the PCB posting above. I guessed on the 2 pot values, and if correct on the Volume, it seems you could sub an audio for the linear/fixed resistor parallel pair. Don't be shy if I screwed this up.

[Marcos - Munky]

thanks for chimin in fellas-   yes, i',m aware it's a positive ground circuit.  i have my positive battery lead going to ring lug of input jack....and electro's "reversed".  that's all that needs done, correct?

No, you should build it the way it is in the layout. You reverse the caps when you want to change the polarity of the circuit (but you need to change the MOSFETs too).

This looks like an interesting OD, couldn't find a schematic, so I drew this one from the PCB posting above. I guessed on the 2 pot values, and if correct on the Volume, it seems you could sub an audio for the linear/fixed resistor parallel pair. Don't be shy if I screwed this up.

It's correct, just the volume pot that's a 100K. Here's the schematic: