I've used the Wireworld Electra 7 to good effect, and now Shunyata Venom V12 NR, which does exactly what it is advertised to do with reduced noise. Quite a striking change improvement for a PC on either the TRP GA DAC or the Innuous streamer.
Also, the GA TRP is far from bass shy in my system (Pass labs XA100.8 monoblocks, Von Schweikert VR5 Anni's, Pass XP22 or Benchmark LA4 or latest Don Sachs preamp, Innuous Zenith mkIII streamer, diverse mix of cables), especially with the Tesla el51s and most of the nice rectifiers as recommended in this thread. It can be bass shy with the wrong tubes, especially for the output tubes, however.
Also, it sounds much more dynamic/alive/ballsy with the extra gain (switch on the back) and I wouldn't use it any other way in my system.
This is an Amazing DAC, and an equally wonderful thread going, here, gents. Thanks to all who have contributed!