I have recently bought a brilliant (USA made) Musicman SUB with a faulty preamp. To remedy that, I went and bought a JEast MMSR 2 Band premap which I installed myself and now the bass is sounds awesome.
I still have the old, original faulty preamp, which I would like to repair. Having done few checks, it looks like that the op amp IC is faulty and it needs replacing. OP Amp has the following stamped on top of it:
4250d jrc 2004b
I have searched around but could not find much information where to get one.
Any idea?