I have an ARC SP11 mk2 pre and need to hook it up to a pair of ARC Ref 210s. Pre has unbalanced RCA output and the power has balanced xlr input. Ideally I would upgrade the pre but that am stuck with the SP11 for now. ARC says the 210 will not sound good if I just use a cable or adaptor as it needs a true balanced input to work properly. Quoting a significant reduction in power and increase in distortion.
They say this can be solved by using a transformer based unbalanced to balanced converter or isolation unit to generate the balanced signal. The one they recommended is a PI-2RX from Jensen Transformers but they are quite expensive and only available from the US.
I found a UK based company RCH Audio Engineering who do one with similar specs which works out at about half the cost of the Jenson solution after you factor shipping and import duty/tax. It uses a custom wound transformer to RCH's own specifications. Anyone have any experience with these sorts of converter or RCH?