Turntable sibilance

Beyond VTA, there are two things that would manifest as sibilance (not having heard the actual rig of course):

Mistracking from either VTF or anti-skate set incorrectly. Since you've tried VTF, then it could be anti-skate (although I doubt it). Try playing individually through each speaker--if you notice a tonal difference (or distortion) through one channel vs. the other, that suggests anti-skate could be an issue.

Phono stage loading--if the loading is not matched to the cartridge, the tonal balance will be affected. Either muddy and closed in, or bright, harsh and sibilant. I think this cart should be loaded between 100 and 150 ohms.

Good luck--I'm sure you'll ultimate get the right answers here in the forum!

Kj...vtf maybe...antiskate...no way.

With all due respect, the first two responders must not be familiar with the Nottingham Horizon table. While they are correct that the Rega arm itself does not have adjustable VTA, the arm mount of the Horizon provides that adjustment. There are two small hex head bolts on the side of the round silver colored collet that the arm slides into. When you loosen those you can then raise or lower the tonearm into the desired position and then snug them up to set the VTA. Do not overtighten them, just make them firm enough to hold their position. To reduce high frequency response and sibilance would usually require the arm height to be lowered. Then also recheck alignment and tracking force to ensure they're still set correctly.

Thanks for all your responses. Bill_k, yes I see you're correct about the VTA on the Nottingham. I'll give that a go.

As a separate issue, I purchased an Expressimo Audio Half Moon Heavyweight counterweight. While it made no difference to the pre existing sibilance issue, in every other respect it was a massive improvement. Quite startling actually. Other than upgrading speakers, I've never heard anything make the degree of improvement that this deceptively simple thing has. For once the claims on the website are fully borne out. More focussed midrange, increased soundstage depth, sweeter highs etc.

For the person who asked me to list my system, ok, other than the aforementioned, I have a Lehmann Black Cube phono pre with external psu, Rotel 971 cd player, Korg MR 1000 DSD recorder/player, Brook (Australian) passive preamp, Musical Fidelity X-10 v3 tube buffer, Crown Studio Reference 1 power amp, & Earthworks Sigma 6.2 speakers.

What specific LPs are you testing? Sibilance is often in the recording itself...Hotel CA track great example