Schoeps
- Thread starter abbey road d enfer
- Start date
Help Support GroupDIY Audio Forum:
6AU6 tube SDC mic Manual
Thats an interesting one thanks Tony , I like the way the designer avoids cathode resistor and cap by tapping the heater voltage for grid supply, U47 does something similar and I suspect it may well contribute to the gracious overload .
The late Ing. Dr. Schoeps also used the DC heater voltage biasing on some versions of the M221 mic using the AC701 tube... I like having the bias fixed rather than dependent on the current through the tube... I didn't see any heater voltage regulation...but 6AU6 tubes don't cost as much as a AC701....
I like the Neumann NKM supply...both the heater and HT voltages are regulated. I like the way the HT sees the 150B2 regulator tube first...voltages across the capacitors are held constant... A clean modification to run up the heater voltage slowly and regulate it can be made to those old supplies...
I like the Neumann NKM supply...both the heater and HT voltages are regulated. I like the way the HT sees the 150B2 regulator tube first...voltages across the capacitors are held constant... A clean modification to run up the heater voltage slowly and regulate it can be made to those old supplies...
So what's the beef against cathode bias?
