There is a guy on ebay offering mods to the 7520. The op-amps are already well discussed but he also offers to upgrade the internal power supply.
I quote from an e-mail he sent:
'what i will do is replace the opamps and improve the internal power supply , i will decouple the capacitors, and reduce the noise floor ,if you want a power supply they are £50 extra but if you are happy with your own power supply the other mods will be a great start for you'
I would like to know if this has already been done by anyone, the benefits and any problems?