Hi there,
I was given an AK4390 based DAC by a friend. Unfortunately the DAC came without opamps in output stage. Can someone help me to determine what type of opamp this circuit is suited for, BJT-input or FET-input?
I was given an AK4390 based DAC by a friend. Unfortunately the DAC came without opamps in output stage. Can someone help me to determine what type of opamp this circuit is suited for, BJT-input or FET-input?
My favourites are CMOS TLC/TS 272 or TS912.
Large bandwith, very low power conumption, extremelly high input impedance.
Large bandwith, very low power conumption, extremelly high input impedance.
Given that the cost of suitable opamps is low why not try a few contenders. The LM4562 could be a possibility (the 5532's successor) and I would also definitely try a decent FET input stage type because of their better immunity to (possible) non linearities caused by high frequency noise and hash from the DAC. The OPA2134 might be worth a try. Ultimately there are dozens of suitable devices of whatever type you prefer.
Do you mean this circuit is universal by means of implementation? I'v read that BJT and FET-input opamps require quite a different implementation for the best operation..
Your circuit as drawn is pretty generic and will work pretty much with anything from 1458 (a dual 741) upward.
The differences between FET and BJT input stages are very important to correct operation in some applications but this isn't one of them 🙂 It will work correctly with pretty much any common opamp but you will (or should) find subtle differences in the audio performance.
Do make absolutely sure the opamps you need are duals as drawn on your diagram.
The differences between FET and BJT input stages are very important to correct operation in some applications but this isn't one of them 🙂 It will work correctly with pretty much any common opamp but you will (or should) find subtle differences in the audio performance.
Do make absolutely sure the opamps you need are duals as drawn on your diagram.
Please note the drawn schematics is the most common differential amplifier; but it has a "problem" usually not detected: the input impedance for the non-inverting side is twice the value of the inverting!
