ROG Umble Build Report

[sonbone]

Just wanted to say I'm new here and this is my first build in quite a while.  I was looking for a preamp to build and started off with the ROG Professor Tweed.  In the course of breadboarding and testing, I decided to try a full Fender style tonestack in place of the Professor's single knob tone control.  That worked pretty well, but I became interested in the odd Fender style tonestack of the Umble.  Thought I'd give that a try so, I breadboarded it up and liked it pretty well.  At this point, I decided to change the project completely and breadboarded up the rest of the Umble.  Once  again, I liked it OK, but still not quite what I was looking for, just didn't clean up enough for me.  Also, the  tonestack was just a little too weird.  So I omitted the 4th gain stage and went back to the regular Fender tonestack.  A little more tweaking was done to the first stage, which was basically changed to a Fetzer Valve.  Now in the end I've ended up with something I really like, don't know if it can still be called an Umble, but that's at least were it came from.

In it's final form it's a mild overdrive with a nice warm clean sound, great for a preamp.  I really like the filtering of the second and third stage.  Great for what I play (Country).  Nice spank, but not harsh.  See schematic link below and sound clips.  Boosted sound clip was recorded with a Fetzer Valve in front.  I used 2 different guitars, a '73 Strat with stock Fender single coils and a G&L Asat Thinline also with stock single coils.  Recorded straight into the computer via a SoundBlaster Live 24.





http://www.aronnelson.com/DIYFiles/up/strat_clean.mp3
http://www.aronnelson.com/DIYFiles/up/strat_boosted.mp3
http://www.aronnelson.com/DIYFiles/up/asat_clean.mp3

[zjokka]

Hey, that's a great post, great clips

I also started building the Prof but had trouble biasing and in the end decided to go for the Umble too but mainly for its distortion.
If you're looking for a gritty clean boost with tone control, don't hesistate trying the FAT BOOSTERED. With a good tube amp on low volume and the gain on the booster full up, you get some beautiful harmonic grit in the sound. Maybe like me, you're looking for that edge between clean and overdriven?

I built it for two friends and asked 'you really want the bypass switch, cos I never turn mine off'.
"Yeah, yeah, need that switch" Both came back after two weeks or so saying they don't turn it off anymore

A mate is trying out my Umble now I've got my soundcard sorted out. Will do some clips soon.

zj

[sonbone]

Thanks for suggesting the Fat Boostered.  I haven't looked into that circuit yet.  I'll give it a try.