EHX Green Russian Muff - Bass Mods - solved: bad contact on tranny

[negativefx]

Hey all,

I built a green russian and added a split n blend.  Works great... on the D and G strings of my bass.  Playing low on E and A has no fuzz, just clean signal.  Sweeping the blend has very little effect on the lower octave.  Would switching out the two left most 1u electros on the layout for 10u caps improve the low octave response, or should I look at changing something else?  I used BC550CG trannys for every spot, each measuring at 475hfe, tantalum for all the 1u caps.

Thanks!

[Jopn]

Something is amiss with your build.  I put together a stock green russian and it has absolutely no lack of fuzz and grit on any string of any instrument.

I did, however, build a muff once where I accidentally installed all the transistors backwards.  If my memory serves me correctly, it sounded a bit like what you describe...

[Jopn]

Decided to look into this a little more.  If you oriented your BC550s the same way as shown in this vero:
http://tagboardeffects.blogspot.ca/2012/06/ehx-green-russian-big-muff.html

then they are backwards.  See the BC550 pinout here:
http://www.farnell.com/datasheets/727135.pdf

2n5089 and BC550 have the reverse pin order from each other (180 degrees), so I assume the layout was made with the 2n5089 in mind.

[negativefx]

Thanks Jopn... I double checked the pinout of those trannys and reversed their orientation from the layout, but I'll switch em around and also try out some 5089s.

[negativefx]

I had the trannys oriented properly but one of the legs wasn't seated properly in the socket.  All fixed. Thanks for pointing me in the right direction Jopn.