Hi, I just had my new DS MKii arrive yesterday, and my hopes were to use it with my Oppo UDP-205, and I am exploring options on how to integrate the two, so I thought I would get some recommendations and advice here. The only cord that I have on hand that works for this setup currently is an optical one, which won’t do the job (I have well over 500 sacd’s), and I see that OppoMod doesn’t seem to make an I2s board for the 205; would the Gearfab D.BOB breakout be the best way to go, or possibly one of the Chinese cards that have been discussed here (still not sure if they work with the 205). Also, if I were to order the breakout box, I want to be sure that I am clear on what type of cables to use; one of my existing hdmi cables to the breakout box, with an hdmi to coaxial (rca plug) cable to my DS MKii?
A new transport seems redundant, particularly with the accumulation of so many separate units and limited space, when the Oppo is still working well. The rest of my system would include the BHK preamp and two BHK 300’s and my Gallo Nucleus Reference 3a’s (with the optional Gally second bass coil amplifier)
Oppomod does not list the 205. The D.BOB is on sale for 699 now. I would go that. Plus at a reputable dealer like B&H you can return it if it does not work right. But it should. I think others here have used it. I tried the cheapo version off ebay, and it was picky. The D.BOB is for more serious listeners like you with 500 SACDs. I was going to say to rip them, but boy thats a ton of work.
I’ve been successfully using this Chinese unit for a few years with my extensive SACD collection and an Oppo 105D with My DS DAC. Don’t see why spending 6x for the same stream would be an advantage.
I’ve got one of those Chinese box converters I use from the Oppo 205 to the DS DAC MKII. Since I have the PST also, I don’t use it for SACDs, however that does work. I use it primarily for Blu Ray audio discs and DVD-A discs so that I can pass the full resolution of those discs to the DAC.
Think I bought that Chinese converter box for about $40 from @brian.fitterman!
When I had a Oppo 203 I used the Oppomod I2S card inside the unit. It worked flawlessly with the MK1. I went to oppomod.com to share the link with you and realized it must not work with the 205 
Oh that guy, don’t trust him.
I was in your shoes, and I was using a Chinese board between OPPO 205 and DS a few years ago. Even though I was using the best AQ HDMI cables, the SQ was subpar. I upgraded to PST and the SQ improvement was monumental! With your large collection of SACD (same here), upgrading to a better SACD transport should be your first priority.
Your OPPO still holds a great value, so upgrading to PST is well worth it (don’t trade in your OPPO205, sell it).
The bad news is that PST maybe out of stock right now.
I went ahead and bought the digital breakout box, and am going to go ahead and order a coaxial cable today. I should be able to use those in a couple days; right now, it’s toslink with cd’s. I’m not interested in selling the OPPO, as I also have a surround sound setup integrated into this with the switch of a few cables, for the multichannel part of the sacd collection, as well as a movie collection.
In that case, it makes sense.
I have an Oppo 103-BDP, used with SACD, DVD, and Blu-ray (video and audio), connected to the DS MK-2 DAC.
When I compared the D.BOB to the OppoMod’s I2S module, the former was superior in sound quality. I use an AQ Coffee Coax cable with the D.BOB.
The D.BOB arrived this evening; now to procure a digital cable for it. I have a Pangea Audio Premier SEMKII HDMI cable, and I am thinking about ordering a Straight Wire Info-Link coaxial cable for the other connection (upgrading the HDMI cord might happen later). Does anyone have any experience with Straight Wire Info-Link cable? I also looked around for Audioquest of various levels, and the only ones that I found available for immediate shipment in a 1.5 meter length were the lower level ones, like Forest and Cinnamon.