Hello to everyone,
My son got me as a christmas present a FOSI audio BOX4 phono pre amp.
I am not entirely happy with the sound so I thooght about upgrading the op amp chips. I disassembled the unit today in order to see what op*amps it is using but I don't know if there are any to be honest. The BOX2 model has some socketed TI op amps that could be easily removed but on my unit this is not the case.
Could someone help me understand based on the circuit picture below? Does this unit have op amps? Or is all done by the tubes?
I apologize
in advance for my ignorance.
My son got me as a christmas present a FOSI audio BOX4 phono pre amp.
I am not entirely happy with the sound so I thooght about upgrading the op amp chips. I disassembled the unit today in order to see what op*amps it is using but I don't know if there are any to be honest. The BOX2 model has some socketed TI op amps that could be easily removed but on my unit this is not the case.
Could someone help me understand based on the circuit picture below? Does this unit have op amps? Or is all done by the tubes?
I apologize
All those small 8 legged surface mount chips look like opamps. I think I can make out '5532' on two of them but you would need to list the type numbers of them all to see what they all are,
The NE5532 is a dual opamp (two in one package) and highly regarded. As a straight gain stage or buffer it is pretty much as good as it gets subjectively. It has been around for decades and lots of studio gear has used it.
https://www.ti.com/product/NE5532
The NE5532 is a dual opamp (two in one package) and highly regarded. As a straight gain stage or buffer it is pretty much as good as it gets subjectively. It has been around for decades and lots of studio gear has used it.
https://www.ti.com/product/NE5532