Pro Audio Design Forum

Using a Deboo configuration, the unavoidable resistor mismatch results in an additional parasitic resistor across the capacitor of a positive or negative high resistance. Use precision resistors or a trim if its that critical. I recall that the resistor mismatch error results in a small static DC o...

There is a catch in the Deboo integrator, differential or single. It is sensitive to resistor mismatch. This can be important or not, depending of the application. When in need for near perfect integrators, one needs capacitors with very high insulation resistors. Using a Deboo configuration, the un...

... Integrated Products, Electronic Design, March 18, 2002. The non-inverting Deboo integrator has a passive input pole which is important for audio servos. Other advantages of the Deboo Integrator are its non-inverting single capacitor topology. https://www.proaudiodesignforum.com/images/pdf/Consider_The_Deboo_Integrator_For_Unipolar_Noninverting_Designs.pdf ...

... I think you can see, in the context of a mic preamp where this may be headed... Over the years I've looked at all kinds of methods to servo-correct gross differential DC offsets at the mic terminals and servo mic preamps in general. Not sure this is a complete list but here are some: ...

... I think you can see, in the context of a mic preamp where this may be headed... Over the years I've looked at all kinds of methods to servo-correct gross differential DC offsets at the mic terminals and servo mic preamps in general. Not sure this is a complete list but here are some: ...

... 245 nA is pretty good. The 80 nA figure, if its really that low, is pure selection luck. Measuring the input offset current requires turning the servo off and visually averaging output Vos readings with Rterm = 0Ω and Rterm= 998Ω and then dividing the delta by the gain. Better accuracy could ...

... it cures it needs to keep being pushed down. https://proaudiodesignforum.com/images/jpg/ZTX851_MC_Preamp_Transistor_Therrmal_Hat.jpg This is the servo response ( at the servo output not the audio output) of one channel without the transistors glued in open air: https://proaudiodesignforum.com/images/jpg/ZTX851_MC_Preamp_Servo_Response_Without_Hat.jpg ...

Just built the second one and it's also measuring about -141 dBu Ein with a 10Ω source. I was wrong about the servo frequency: It's just under 4 Hz based upon measuring the derived high pass response. I'm kinda glad it is lower given that the PTS EQ board has a HP response around ...

Just built the second one and it's also measuring about -141 dBu Ein with a 10Ω source. I was wrong about the servo frequency: It's just under 4 Hz based upon measuring the derived high pass response. I'm kinda glad it is lower given that the PTS EQ board has a HP response around ...

... would be pulled out of the 11V supply. Short C7? Do you mean C6? Not sure what you mean about phase shift at 20 kHz. Both C6 and C7 are in the servo. C6 is a HF bypass for the servo control point and isn't part of the integrator time constant.