Biasing a Rangemaster-like circuit - 7 volt or... ?

[Ivana]

Hi all!
I've made a Rangemaster and i have some questions
1) GEO's theory says 6.6-7.2 volt on the collector.
But voltage are differes from: http://www.rangemaster.de/
Where is the truth? ))))
2) why Robert Keeley uses TWO trimmers for biasing a collector voltage? Not only one from base to ground or in emmiter circuit? What else is need to be in the mind? Robert, can you please explain the details?

Sorry for my English, i am from Russia.
Thanks for your answers!

[Fret Wire]

That's not a true Rangemaster schematic, it's someone's silicon based derivative. If you use a stable, low leakage Ge transistor of the proper gain, you'll find the best sound is around 6-7v, give or take. Usually, around those voltages, your ears will tell you when it sounds best.