Here's a tweak for inexpensive MM cartridge fans.

For NZ$65-100 (+ shipping, depending on where you buy from), this RigB solid metal mount-block from Improved Performance Turntables (IPT), is designed to upgrade an AUDIO-TECNICA
AT91 cartridge (or AT3600 OEM versions like the Rega Carbon).

See - eBay or automotivebiz.de.

From all accounts, a decent upgrade - see AUDIO APPRAISAL (18 Aug '20).

" a significant upgrade for a tremendously competent generator held back by its flimsy plastic body....the AT91 variant leaps up into the leagues of the best budget cartridges, and in doing so surpasses a few mid-level models too. "


However, experience tells me that a change from spherical stylus to an elliptical stylus cartridge would be the first upgrade to consider - as AUDIO APPRAISAL also confirm when a 'extended contact' stylus was swapped onto the AT91.

(The AT91 I think is now discontinued & A-T have a new range of 'VM' cartridges.)



(AT91 with RigB metal body mount.)


(Rega Carbon with RigB metal body mount.)


(RigB mount underside)

DarkLantern blog - darklanternforowen.wordpress.com

That looks interesting. I remember I had a client with a spherically-tipped AT91 and I mentioned it would be good to upgrade to an elliptical stylus. So he did and the improvement was very noticeable. The AT91 likes loading above 80k to bring back the otherwise subdued high frequencies.

AMR-iFi R&D

IPT now offer a new RigB 500 body for upgrading the current AUDIO-TECHNICA VM500 series cartridges. Also suitable for the older AT440, AT150 et al.

AudioAppraisal.com reports also that these new bodies are a worthwhile upgrade on the stock metal bodies on the A-T VM700 series cartridges - due to better design, better fit, screw fixing & threaded body.

" The results are immediately clear... Notes start and stop with a precision that the VM740 doesn’t match, let alone the VM540. A decrease in unwanted resonance and the increase in control has a huge impact on detail too. "

" Top-end detail especially is overflowing but in an extremely pleasing manner. But what struck me most about the RigB-equipped 540ML is just how much fun it is. It has a boundless sense of rhythm that revels in a good bass line and sends it thundering forth from the speakers. "

" The VM700 is still a competent cartridge, but the RigB 500 is the body that demonstrates what this generator is capable of. "

Price? (No pricing information can be found anywhere at this time!)




(The IPT RigB 500 cartridge body mount above.)




(Original A-T VM cartridge mount.)

DarkLantern blog - darklanternforowen.wordpress.com