Sorry to necro this old thread but am wondering if people are still using/experimenting with the OTAs.
Was re-reading some threads and some have noted that the OTA sounds a bit lifeless compared to other higher priced cables. I would perhaps agree at least that was the case when I got to try out a set of Ridge Street Audio Poiema speaker cables. RSA definitely has more air and warmth.
Previously, I experimented with various gauge cables. And, I found that thicker cable on the return run relative to the signal run will result in a warmer fuller sound. So, I used two 4mm runs on the return on all my OTA ICs. These turned out very well sound wise.
However, they break easy as keeping two runs soldered onto an Eichmann Bullet Plug's return pin is hardly manageable. I've since stopped using OTA wires because I got tired of constantly re-stripping and soldering the cable whenever the solder broke off but am still using them as SC and PC.
On a side note:
Now, I want to double up the speaker cables but think the .65mm runs would work better than two runs of .4mm for ergonomic reasons. I haven't seen the .65mm cables on Sakura System's site in awhile though.