Naim’s communication to dealers and distributors was as follows;
Our acclaimed Discrete Regulator Technology was first introduced in 2012, and features across a range of products from power supplies and amplifiers, up to our flagship Statement system.
Since its introduction, and in keeping with an ongoing commitment to the sustainability of Naim hi-fi, we have offered upgrades to the DR spec, from previous, non-DR versions of Classic and 500 series products.
Due to ongoing supply chain challenges, and significant shortages of key components, we have taken the decision to discontinue this service, both in the form of in-house Naim Service performed DR upgrade and DR upgrade kits which can be purchased and installed by our partner service centres.
As it says, the DR upgrades have been offered for 10 years since DR was introduced. That must have given plenty of opportunity for most end users to have had their earlier kit upgraded if they wished to do so. It seems very reasonable to me.