Bluesbreaker Schematic Differences???

[Guitar_Ninja]

Hey all,

I was just breadboarding a Bluesbreaker from the schematic listed at Tonepad.com and I noticed that it differs from the one listed at GGG.

Specifically, C3 in the GGG schematic runs to ground, while in the Tonepad schematic it runs to the junction of Vb.

I prefer the sound of the pedal with it running to Vb, as it's warmer or smoother sounding, but there's definitely a touch more volume running it straight to ground.

Any idea which is correct, or whether it matters?

Thanks in advance.

Tonepad Schematic:

http://www.tonepad.com/getFile.asp?id=75

GGG Schematic:

http://www.generalguitargadgets.com/pdf/ggg_mbb_sc2.pdf

[DougH]

Theoretically, it shouldn't matter. That is unless the Vb power rail is underfiltered. For example, if that rail used a 4.7u cap to filter it, you might hear a difference. This was one thing I noticed in the Brown Source that affected the overall tone. But with a 100u cap there in the Tonepad Bluesbreaker, it shouldn't affect it. Maybe it's a layout issue on your breadboard? Maybe a long jumper wire running next to something that is causing a parasitic effect?

[Guitar_Ninja]

Could be. I have wires running all over the board to connect everything to Vb. I'll try doing a cleaner layout and see if that helps. Thanks for the assistance.

[Johan]

this one is the correct one....factory schematic.
http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=3818&g2_serialNumber=2
j

[Ice-9]

I have to say , judging by all marshall schematics i have seen and most othe standard op amp schematics c3 would go to ground (the other way works) For me 100% to ground.

I just noticed Johans post above with the factory schematic and it confirms my thoughts.

[Guitar_Ninja]

Good enough for the factory, good enough for me. I rewired the board with C3 going to ground and now everything's working nicely. Just need to finish up the vero layout and then I can start putting it together.