Best amp for Phono under $500.

Have a Marantz 2230. Plays very good except bass is fair. Don't know why--any ideas? Just playing older Technique Sears tower speakers. Like I said, all else is very good...

Have two vintage semi pro turntables.

Should I go with a newer amp with a sub output?
Will a sub get signals from an LP?
Does the 2230 need a new part?
For any forum participant to help you out they would need more information as to your system and what is lacking regarding bass, and your budget for improvement. Lack of bass can be due to several factors. Source, amplification, speakers.

Is this system new to you ore have you owned it a long time? Did you one have good bass and now it is lacking?

How old is the cartridge? Usually bass is the 1st to go as one ages.

Age of speakers? Are the speaker cone surrounds in good shape?

If the amp is old, I would take it a reputable shop and have it cleaned and checked out. Likely it is fine and could still serve. I take it that the 2230 doesn’t have a sub out. That doesn’t preclude it from driving a sub, one only needs a sub having amplifier speaker output level inputs.

I also recommend that you purchase a copy of “Introductory guide to High-Performance Audio Systems” by Robert Harley. This $20 book is an condensed version of a more complete guide by the same author. The information therein will help you to understand your system, identify areas to improve it, and and solicit help from other in this endeavor.

Good luck!