BMP clone... it's ALIVE!!!!

[Danny G]

Hell, yeah!  Go me!  My first build, and it actually works!  It didn't at first, however.  Heh.  Turns out there was a loose connection on the perfboard by the first set of diodes--explains why the effect would only "pop" in when I'd stick my finger on that area, and cut out when I stopped touching it.

I tried it next to my wife's stock Russian BM, and it sounded similar, but different.  I used Tantalum instead of aluminum caps, and used Silver Mica for most of the ceramic caps.  I also used 2N5088 trannies, but have a shipment of 5089's coming in soon.  

Mine seems noisier (when the effect is on, but I'm not playing anything)than hers, especially at high volumes.  I heard that the 88's are noisier than the 89's.  Could this be it?

Have thought about mebbe tweaking the diodes--she uses the BM as a bass overdrive.  LEDs maybe, I have a bunch of Germanium diodes too.  She plays a late 70's SVT, so I'd like to enchance the natural sound of her amp rather than drown it in fuzz (which isn't exactly a bad thing \m/).

Suggestions?  Or should I leave the diodes be?

[nightingale]

very cool~
i've messed around with the clipping in the synthy black sovtec BMP's.. the differences were pretty subtle IMO.. red LED's seemed to make the fuzz a bit nastier, but it wasn't a breakthrough or anything..

look for a BMP thread that mark hammer posted on last week.. he describes an interesting presence mod where you splice a pot into the 2nd gain stage..

also~
check out the wisker bisquit from www.runoffgroove.com it has a bazzfuss gain stage.. i built one and gave it to a friend..
a few months later he emailed me a nd told me it was the best gift anyone has ever given him..
hth,

[jsleep]

If it's noisier, IMO, it's probably not due to transistor noise.  Generally speaking, the noise level is somewhat perportional to the gain setting.  If you adjust the transistor stages for more gain, you get a lot more noise, less gain, less noise.  Sounds obvious, but I'm saying a little gain increase can make a lot of noise.  88 or 89 probably won't make a whole lot of difference.  Also try 2N3904 transistors, I've heard of good results in BMP with those, but I haven't tried that yet myself.

JD Sleep