Originally Posted by JJinID
It's been a while since I've posted about the status of my Modwright modified Oppo BDP-95 player. I have been in regular contact with Dan regarding the status of the digital input mod, which is what I have been waiting to be finalized for several months now. I have been getting along just fine with my modified BDP-83, so that has allowed me to be patient as time has moved on. Unfortunately Dan is still having technical issues perfecting the digital input mod.
Dan sent out a communication yesterday to all of his customers regarding the status of the digital input mod. I asked him if I could share the content of his email here, and he agreed. I thought it would be valuable to let the members of AA who have been following this thread and/or are interested in the digital input mod know what is going on. Here is what he had to say:
"I am writing this to give a number of you a status report on the digital input mods for the Oppo BDP-95. First of all, the input receiver and DAC board are built and work well. The problem arises when I install them in the Oppo. The problem is grounding related and has to do with ultra-high-frequency ground loops that result in a 3Khz, 6Khz and their upper harmonics tone, that rides on the music. The unit sounds fantastic, but this high-pitch tone that rides on top of the music is obviously not acceptable.
I am working very hard to resolve this and am consulting with everyone I know. I have tried power supply revisions and multiple grounding schemes. Grounding seems to be the key. The noise is either coming from the internal switched mode power supply, or is a harmonic of one of the Mhz clocks. I have proven that the input receiver and DAC, installed in our LS 100 (very similar tube stage), does not exhibit this problem. So, I know that the digital circuitry works. It is a problem that has to do with interaction in the Oppo itself.
I am going to experiment with shielding the switched mode power supply and also with transformer coupling.
If you are tired of waiting, I am happy to complete the other mods and will pay shipping both ways, to install the digital input mods at a later date. If you are willing to wait, I can assure you that I am working very hard on a resolution. This was not expected and is incredibly frustrating. I wanted to communicate the issue and status to you that are waiting, so that you may understand the reason for the delay.
I can't express enough, my gratitude for your patience. As stated above, if you choose to forego the digital input mod and have us complete the rest of the work right away, I am also happy to do so and will pay R/T shipping (domestic) to have the digital input mod installed when complete.
Thank you.
Sincerely,
Dan Wright
President, ModWright Instruments Inc (MWI)"
I will likely take Dan up on his offer. Even though the issue is frustrating both to Dan's customers and to him, I appreciate his communication on status of the troubleshooting and the nature of the issues. I will have the opportunity to pay Dan a quick visit at his location in SW Washington in a couple of weeks, and am greatly looking forward to that trip and seeing his facilities in person!
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