Java Boost/Neg Ground Rangemaster

[RobertKeeley]

Thanks for the advice and information RG, can't wait for a great Technology of Grounds paper!
rk

[PharaohAmps]

What I meant by "separating grounds" is that the audio signal gets referenced to ground (here tied to the negative battery terminal) and the power for the transistor is all referenced the other way.  The transistor's collector is tied directly to the -ve (ground) through a resistor, and the biasing for its emitter comes from the +ve supply, also through a resistor.  These biasing currents are all DC, and are basically the same as in a positive ground setup.  Any AC signals are capacitively coupled in, and can be referenced to the -ve (ground) because the DC currents flowing in and out of the transistor are blocked by the capacitors.

I've got two designs that use PNP in a -ve ground circuit, one of which is probably suitable for release now.  I'll put the board layout, parts placement, and schematic on my site later on today (hopefully) and link to them from here.

The other one is kind of still on the breadboard right now, although I do have a PCB layout for it - it's an op-amp input, PNP transistor stage, then an op-amp output.  -ve power is provided by a 1044.  I am probably going to be releasing this design in conjunction with TonePad, since they're really set up to answer questions and provide support to the DIY community.  Stay tuned.

Matt Farrow

[soggybag]

Does the GEO layout for the Netron use a separate signal and power ground?