you think the price is proportionnal to satisfaction
In DirectStream DAC with all other modifications the difference is audible. Itās worth the hassle and the money.
For my $45k amp/pre combo it was no-brainer, too. The difference was huge in this case!
SOLVED! I replaced the transformer with a toroidal one. R-core transformer from audiophonics is probably not suitable for this application: R-CORE Transformer 30VA 18-0-18V - Audiophonics
so the difference is proportionnal
Thatās weird because half (my guesstimation) of the additional PSUs people installed in this particular application have R-core power transformers, and nobody had this issue.
I donāt have an explanation for the issue you had. Maybe you got a defective transformer. But in general, R-core transformers are good for this application.
At the end of the day, what matters is that you donāt have any issues now.
Anyway I want to thank you for the posts in this thread, without them the DIY potential of our DS MkIs would be hidden and that would be a real shame. I would never have thought that I would cut a pcb track inside a ā¬6000 DAC at home. I think itās time to listen to my voluminous CD collection again!
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A quick update- Iāve finally ordered a DS MK2 and it should be here this week. Itās going to be interesting 
The system is performing at an incredibly high level. Significant differences will be immediately obvious. We shall see
TK
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So will be comparing it to an upgraded mk1?
Yes, thatās right. Iām trading in the stock unit I had here.
TK
Which mods have you done to the Mk1 which you use and will compare the Mk2 with?
Sounds like youāre certain the mkII will outperform the upgraded mkI.
No, Iām not certain at all, will have to wait and see Iāve heard a MK2 at the Lone Star audio fest a year or 2 ago but it was in an unfamiliar system. Liked what I heard there with it but too many other unknowns.
What modsā¦ Everything that needs doing to take the MK1 to the best it can be 
Check my older posts if interested. We got the MK1 to the point where about all that could improve further would be an improved PCM to DSD fw algorithm. Ted suggested the MK2 fw is much improved, so thatās one reason we want to try it. Iāll be paying close attention to vocals in particular, hoping it improves there.
Iāve also tried high quality offline conversion of good quality PCM to the native DSD the MK1 outputs and the sound was also improved.
My friend DW still uses the āStudioā version MK1. Itās very good. And I had planned to finally update mine here to a new Studio version using my own discrete analog for the āerror correctingā gain blocks rather than Sparkos Pro OA; the design is ready in simulation and working there. Those gain blocks are essentially the Ultra_EX-B7 front end. But Iāll wait first now to see how the MK2 sounds here. Meanwhile I spent most of the last year creating the Ultra_EX-B7 mono amps (theyāre fabulous) and was too busy to update the DAC. A pair are playing here now.
TK
Early proto development work for the Studio DAC output stage. It also uses a bi-polar PSU so no output device required (no caps, no trafos), DC coupled allowing max transparency. The active devices are an āerror correctingā approach and are sonically ~ invisible. And of course the actual circuit elements used (theyāre underneath the gain blocks) are about as good sonically as I can get. I know of no better approach than this. Essentially we are hearing the audio stream in the DSD with no sonic footprint from the OPS. The OPS is just transparently removing the unwanted high frequency DSD portion. And hearing, it verifies the theory as well. The soundstage size increases by like 100% lolā¦ Indicating there is ~ no dynamic noise floor from the output stage basically. Iād say that much if not most of the perceived sonic āsoftnessā in the design is alleviated as well. Dynamics are about perfect. We were listening with Audio Vectors, R 6 ArretĆ©, well bi-amped and with dual large Rel subs and itās rockinā in there for sure. Sheesh!
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Dear All,
Some time ago Anton_ss recommended to swap the XLR output connectors for better ones and claimed that this results in a significant audible improvement. Back then this sparked a bit of a controversy whether such improvement is credible and realistic.
As I had already performed all so far discussed mods, I thought that I was done and really enjoyed my modded MK1. However, as Antons recommendations have brought so much sonic improvements this XLR thing kept nagging and despite the hassle of tearing the whole DAC apart AGAIN to reach the analog PCB I decided to swap the XLRs to see for myself.
I managed to swap them successfully (also with a bit of tips and tricks from Anton again) and started to burn in the new connectors for some days. Now Iāve started my first listening sessions and although I only expected some minor improvements at best, I was āflabbergastedā about the magnitude of sonic improvement. Iām not easy to impress and I donāt tend to exaggerate on things but I can fully subscribe to Antons report of āsignificantā improvement. I have a very revealing system with Avantgarde Acoustic horns which are described as āacoustic magnifying glassesā. Soundstage and resolution as well as the ability to listen āinto the recording venueā in terms of resolution has really improved drastically. I couldnāt believe that this mod makes such a difference but it does! I can only say that for everybody who has gone through the work of implementing all the other mods, it would be a ācrimeā not to swap the XLR conncetors! Iām so glad that I could motivate me to do this. Highly recommended!
I attribute the sonic changes to two things. One half to me is the usage of the Anton recommended EIZZ tellurium copper sockets and the other half is my selection of the Mundorf Angelique hook-up solid core cable used for connection to the PCB. A friend of mine crafts RCA interconnects with this cable and they sound beautifully. Although the cable section for the XLR is only about 3cm I recognize their sonic signature as Iāve done a lot of critical listening with my friend on his cables. This cable is responsible for the very nice expansive soundstage.
Again, I hope that my report here motivates some modders to also take this step.
Thanks again Anton and best wishes to everyone here
Christian
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Iāve settled with those previous mods for quite a while now. I definitely want to do this XLR mod. Thank you, guys. I will report back later.
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I havenāt upgraded the XLRās on my DSD MkI, but Iāve had other products in the past that I had the XLRās upgraded on and it made a huge improvement in the sound.
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Hey, @Allears,
I donāt know if youāre following the thread, but hereās the follow-up: see posts above.
With a good resolving system, people can clearly hear not only differences in cables but sockets of different quality, too.
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Okā¦ so I have a DSD MKI with the upgraded decor transformers and the APS power board and external LPS. Iām thinking about having some of these upgrades done to push this DAC to the next level. Iāve caught up on this thread but thereās a lot of information here.
Thinking of having APS add their custom transformers and VOCM resister upgrade. Thoughts?
Definitely worth the upgrades. I am extremely happy and excited with the APS upgrades.
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I had APS upgrade my DSD MkI DAC with the custom transformers and VOCM parts, and was more than satisfied with the results. Highly recommended and cost affective upgrade.
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What was the total cost?