People have been modifying Rega's classic RB series tonearms for some time now, but never have we come across such a dramatic transformation as the one achieved by the Audiomods Series III tonearm.

It uses the arm tube, lift mechanism and rest clip from an RB250 and replaces everything else with machined aluminium parts that, like the tube, are polished for a perfect finish.

If that weren't enough, Audiomods adds a micrometer to the system that allows precise VTA adjustment on-the-fly. The arm is also presented in a padded wooden box and comes with alternative counterweights.

In fact, how this can be done for the asking price is a bit of a mystery.

Double helix technology

The most striking thing about the arm are the holes drilled into it, these run down the arm in two spirals to form a double helix. The purpose is to reduce mass without undermining stiffness, as would be the case with a straight line of holes.

Audiomods also inserts press-fit discs inside the arm to increase radial stiffness and reduce resonant peaks.

The biggest change to a standard RB250 is in the bearings, which are ceramic hybrid types in a machined yoke. Interestingly, the same type of bearing is also used for horizontal movement and both are decoupled from the base.

It comes in two wiring variants: one terminates the arm cables in a five-pin plug in the base (£625) and the option shown above, which has a continuous 900mm-long loom that ends in a pair of Nakamichi phono plugs. The wire used is silver litz and terminates in silver tags at the cartridge end.

Audiomods also supplys two sizes of counterweight, extensive set up instructions, alignment gauges for different null positions and annealed copper shims to mass load lighter types of cartridge.

Balanced performance

We listened to this arm on a Townshend Rock 7 and the Dr Feickert Analogue Woodpecker (in both instances it supported a van den Hul Grasshopper III cartridge).

The heavier of the two counterweights proved big enough to balance the heavy cartridge and the Townshend damping paddle, but only just. However, this didn't stop the Audiomods from delivering a far more fluid sound than the standard RB300 it replaced.

We also enjoyed the easy adjustment of VTA while the record played, a feature which encourages positioning it where it can be easily accessed from the listening seat.

Beautiful tunes

Moving over to the Woodpecker, the difference between this and the Rega was even more pronounced, the finesse of the shiny arm making the latter seem crude by comparison.

It plays beautiful tunes across the band, but this is most obvious in the bass where the abilities of various musicians is never less than obvious.

The degree to which you can hear what's going on in the mix is quite remarkable and the way it combines this analysis with musicality is extremely engaging.

Impressive build

This impressively built arm has a very calm and clean presentation that makes more expensive alternatives seem brash and up front. Cymbals could not sound more realistic, while kick drums have weight and power.

There have been many attempts at refining what is a very good arm design in the RB250, but this is by far the most comprehensively capable and revealing example we've encountered. The fact that it has been so well thought through and is supplied with every bit of hardware and information you need to get it to sing, shows just how much effort Audiomods has put into the job.

It seems under priced for what you get, but we're not complaining!

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