Turntable sound bad


I have a Rega rb250 with mitchell technoweight, vta adjuster, dnenon dl 103 cartridge. A Rega Planar 3 plinth, with aftermarket steel spiked feet. The problem I am having is setting it up to sound right. After the first few songs play, the voices start to sound hissy, and progressively get worse toward the last song.

I am wondering what would cause this: turntable being out of level, Vta, cartridge overhang, Tracking weight? Obviously I am not doing something right, and this is way beyond my limited knowledge. Oh well I hope someone out there can direct me what to try first. Thank in advance, Jason.
jasonh37
Viridian, agreed, removing the stock feet is a recipe for disaster with this table. Those feet are tuned for the table and provide the best support/isolation for it. I don't think that is the core cause of the problem scribed.

Wendell
Narrod, Viridian, I disagree with both of you regarding the feet. On my Rega 25, I put Cardas blocks under the unit which bypasses the feet, and it made a huge difference for the better.
Stringreen, I'm glad you like it. I've heard that table with about every type of support imaginable and always prefer the stock feet. We all don't hear the same. Whatever works for you is correct.
Narrod, Stringreen, you are probably both right in that rigid feet make the table much more dependent on the resonant signature of the piece of furniture that the table is sitting on. In my experience, I have never heard anything better than the stock feet as well, but that does not invalidate Stringreen's assertions that, in his system, on his furniture, there is an improvement with non-compliant mounting. However, given the complaints that the poster has, I would be looking at the feet. And the arm/cartridge match, and the alignment and probably the step us as well. The Denon likes to see a transformer for MC gain and does not seem to cotton to head amp gain. Methinks the whole setup is pretty wrong.
Agree with Narrod and Viridian on both cartridge alignment and the arm/cartridge match. Here's a link to the HiFi mod . Mandatory reading for most Rega/OL tonearm owners IME.