I’m not at my computer, but the 3dB point is about 54k. IIRC the gain with 1T ohm output load is about 20.25dB. There is no spike around 100k, but perhaps that’s because I simulate everything from the digital reclocker source at the transistor level, to the output connectors with various loads and have complex Spice models from the manufacturers for everything including the caps (except the transformer, I used its top and bottom 3dB points to get the coupling, used the specs for the winding resistances, etc.) The Spice AC simulation response is a smooth Bessel from sub 1 Hz to beyond the sample rate. The Spice transient simulation matches the AC simulation (except in processing speed) and matches the real output on the scope. FWIW I also simulate the power supplies for the opamps in the big simulation (that takes a while.)
You mentioned 50 Ohms source impedance. It’s 50 source when driving four the opamps in parallel or 200 driving one. Sorry if I confused this earlier somewhere. I always have the four opamps with two in parallel and two antiparallel.
I find it interesting how many have gone to great lengths to modify their Directstream dac with Edcor transformers and external power supplies raving about the sonic gains made than shortly after putting them up for sale saying they are moving in a different direction. In the mean time many like myself have left them alone and continue to enjoy the music. I am looking forward to beta testing the DS MKII when it becomes available.
I am keeping my modded DS. I will be moving it to my office when I get a MKII. It isn’t really a demotion. I listen to it equally with the living room system. The DS is fantastic.
The modified DSD is great. If you only do the Edcor mods the soundstage will open up a lot and it’s a low cost mod imo.
I agree with everything you say, mine is unmodded. In their defence though, I found in the past that when I’ve improved the sound of my system, it makes you want to go and do more. A bit like, if it sound that much better doing ‘a’ then maybe doing ‘b’ will make it sound even better, it’s a bit like an addiction, when we should in-fact not do ‘b’ but just enjoy ‘a’.
I’m probably not going the MKII route. I’m stoked with my modded-DSD and plan to ride it for a long time. Probably until it dies.
I’m loving my modded Directstream dac and Keces P3 power supply also. It matches nicely with my new PST and my Aries G2.1 streamer.
I did not do ANY of the MOD for an entire year waiting for the MK II! Also, I am a lousy handyman. But I fear the MK II will not come anytime soon. Darn, should I start reading from post one? What do you think is the most beneficial improvement (and not too hard) I can do now?
I love my modded DS and hope it never dies.
I would do the 4400 mod first.
I was thinking about that! Thanks! I will just do one and wait for MK II. That should satisfy me for at least three months. Unfortunately, there is a great chance MK II is still far away by then 
Ted, about the actual bit slinger connection to the op amps. Are there separate + and - bit streams coming out of the re-clocker that drive the In+ and In- separately?
Thanks, T
I’m not handy but I was skilled enough to disassemble the DSD and sent the analog board to Wayne @wctaudio he did the solder work (damn fine job if I must say) well worth the investment. For the cost I’d wouldn’t hesitate!
Yes, but also note that the four opamps aren’t all in parallel: Two of them have the opposite connection polarity of the others to help cancel 2nd harmonic power noise.
For a small extra fee, I sent my entire DSD to @wctaudio. The entire cost to ship, install and ship back was very modest and the results beyond worth it.
I did it back when….so I could ride out the initial six months after mkii was released. Little did I know it was going to be so long.
I must think hard if I want to do the Edcor4400 mod. That will be at least two weeks without music, especially since I got the new streamer and a new interconnect still in break-in stage. I will just wait for a few more weeks, I think. The system never sounded better actually.
I am just ranting about the delay on MK II mostly.
Wayne turned my around same day! So 2 days was my down time. I added some money for next day shipping and return.
Thanks! T
That is a quick turnaround! Now I am seriously thinking of doing it. I know it is worth it. Thanks!