Poor sound from Rega Planar 3

It could be the cartridge(worn out), or it could be the VTA adjustment. If you don't know how old or how much wear is on the cartridge, you need to have someone with experience evaluate it. Do this before playing any more records, since a damaged cartridge could ruin records.

Hi:

Unless the turntable or arm is damaged, it is the cartridge. If you are using Rega's stock felt mat on the platter and a Rega cartridge, the VTA is pre-set and perfect -- you can't adjust VTA anyway with the stock RB-300 arm.

Sounds like the cartridge is dead. Twl is correct -- DO NOT play records or you could damage them. If you replace the cartridge with another Rega cartridge, buy a "Super Bias" or better.

Good luck.

Sold and serviced Rega 3's some years back - I'd agree that it could be a really worn cartidge. Especially as it's used - any chance that there could be a blob of something on the stylus tip? Microscopic inspection should show this.
What are you running the Rega into ? Cables - pre-amp - does the pre-amp have selectible resistance or capacitance ?
Once had a customer extend his tonearm wires by around 30 feet - he returned three differnt tuntables B&O ,Linn Axis and a Rega 2) 'cause they just didn't sound the way they did in the store - this did in fact sound a bit like what you are describing. Any chance somebody improved the RB-300 by modifieng the tonearm wiring or grafting on "better" phono jacks via a really lousy soldering job?
A trully epically worn out stylis tip could be the source of the problem and I sure agree with everyone else - don't play records that you care about untill you're sure this is working right.
I really hope this isn't the case - but how do your records sound on other turntables? I had more than a few customer's over the years who upgraded their system only to realize thier entire LP collection was worn out.