That is not a preamp designed for audio. I would choose a TL072 or one of that range. I don't need almost zero off set etc.
The INA188 is designed for use an industry-standard gain equation: 1 + (50 kΩ/R G).
The INA188 is designed for use an industry-standard gain equation: 1 + (50 kΩ/R G).
I found from Texas Instruments, for microphone preamps: INA163 and INA103.
Same architecture as the 'instrument amplifier'. They are the same as the INA188, but optimized for audio.
What is available today at the performance levels of these TI chips.
Same architecture as the 'instrument amplifier'. They are the same as the INA188, but optimized for audio.
What is available today at the performance levels of these TI chips.
THAT and the former SSM both have parts specifically for mic preamps (also in-amps).
SSM2019 Datasheet and Product Info | Analog Devices
THAT Corporation Introduces Quietest IC Mic Preamp
SSM2019 Datasheet and Product Info | Analog Devices
THAT Corporation Introduces Quietest IC Mic Preamp
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Thanks, do you know, how these:
INA103, THAT 1510, SSM2019 compare with the outstanding Graham Cohen mic preamp, redone by Samuel Groner under the name Montegeneroso.
INA103, THAT 1510, SSM2019 compare with the outstanding Graham Cohen mic preamp, redone by Samuel Groner under the name Montegeneroso.
They are all based on the same topology with slight differences (dates from at least 1968). You can parallel two of the SSM parts and sum the outputs and get down into the .6nV region of the major discrete bipolar low noise diff pairs.
This circuit was originally developed as a precision differential instrumentation amplifier where DC offset and drift mattered and source impedances could sometimes be high unlike microphones.
This circuit was originally developed as a precision differential instrumentation amplifier where DC offset and drift mattered and source impedances could sometimes be high unlike microphones.
How good a mike preamp do you really need?
Samuel is in pursuit of every last tenth-dB of the theoretical ideal.
In almost any practical studio and microphone, the ambient noise is greater than the preamp noise, and the bandwidth is the microphone not the preamp.
The several $10 for-microphone chips are VERY good, until you get to recording harpsichord with ribbons in stone churches far from the city.
Microphone preamps generally call for bipolar-type opamps. The LT1028 offers just about as low noise as you will find anywhere, but they are pricey at ~$6 each. The OPA1611 is a little bit noisier but less THD, faster and about $4 each.
Don't know why you would choose TL072 for a mic application.
No need for very high input Z and there are much quieter FET input amps now in any case.
If going FET type Opamp then I'd suggest OPA134 / OPA2134.
The noise matters when you might have at least 40dB gain.
But with a relatively low source impedance a low noise bipolar type would seem to be a much better fit if going for an op amp based circcuit (as opposed to dedicated mic amps (SSM2019 etc).
NE5534 ? LM4562 (Dual - parallel stages for lower noise).
TLO72 with 2N4403 input hybrid is the best bang for the buck. This arrangement can be designed to rival most mixing boards and with very little cost. I have used INA217 and similar instrumentation amps and they really don't pencil out cost wise and strangely can have more distortion at high gain.
I was just looking the Padless microphone preamplifer (Douglas Self, Small Signal Audio Design, ed 2, p477) this morning. It is a good candidate based on this idea. Both TL072 op-amps are included in the feedback applied to the emitters of the transistors (no reference mentionned).
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