2009 Phoenix Audio DRS-Q4 MK2

This stellar quality recording preamp/eq is like a cross between a NEVE and an API. Discrete transformer-less input, semi-parametric gyrator eq, custom wound output transformers coupled to discrete OP-AMP blocks. The DI inputs have super high impedance and sound great.

This had a bad discrete op-amp and needed it changed out with a brand new one from the factory. This was found by measuring the B+ 24VDC that shorted across the OP-AMP output and was shunting across the OT. Unfortunately you cant change the individual discrete components of the OP-AMP blocks as they literally are blocks! They are encased in a cement like materiel - Those white/grey cubes you see in the pictures. Much harder and impossible to remove compared to the famous black goop used to protect IP of earlier decades. This kind of irks me as a repair tech, but there was nothing to do here except contct the company and have them ship out a pre-made OP-AMP block and install it into it’s friction fit PCB jacks. Not unlike changing out a power tube! This is one of the better pre’s Ive heard and now it’s back in the studio where it belongs.