New Review in AudioXpress Oct 11, 2017 | Blog AudioXpress’s November issue is out and includes my review of the Ultimate Ears Pro Sound Tap DI box/headphone amp, perfect for on-stage use for headphone monitoring. (photo courtesy of Cynthia Wenslow) 3 Comments Ben on 10/11/2017 at 18:53 Hi Sy. You’re missed over at the forum. Quick question: if I’m using the Equal Opportunity phono preamp for MC use (using the Sowter SUT and a DL-103R) should I stick with the 22K5 resistors or swap then with a pair 3K4 resistors, per the 6K8 figure from His Master’s Noise? FYI, I’m using D3A tubes in the first gain block of the Equal Opportunity. Thank you so much for all you have shared. Reply SY on 10/11/2017 at 19:05 Hi Ben, you’re on the right track. It’s important to optimize the transformer loading, but the values used in the His Master’s Noise probably aren’t appropriate because the HMN’s input stage has 150-200pF of capacitance. By contrast, the input capacitance of the EO is only a couple dozen pF (i.e., pretty negligible). If you don’t have a square wave generator and scope to determine the optimum load experimentally, then use the two 3k4 resistors, and shunt them with a 150pF cap- that should be close. Let me know how this works for you! Reply Ben on 10/11/2017 at 19:46 Thank you Sy. I have a Rigol scope and will probably latch up a 555 as square wave generator when the time comes. Sowter has made the 8055 obsolete in lieu of the 1480 which replaces it (which is what I have). It will be interesting to see how close the loading is. I shouldn’t get too far ahead of myself. I am settled on the EO (have the PCBs) but I have a turntable, tonearm kit & tt power supply to address before I can put the phono preamp to use. Thank you for the hand-holding. I’ll check back in when I’m closer to completion. Reply Submit a Comment Cancel reply Your email address will not be published. Required fields are marked *Comment Name * Email * Website Save my name, email, and website in this browser for the next time I comment.