The pricing is on the APS Audio Website
Yes. I saw that. Does the cost of the transformers include the installation?
I donât think so but I could be wrong.
Seems APS is having a Black Friday sale.
From the other forumâŚ
Starting this Friday (11/15) we are giving customers 10% off site wide until the end of November while supplies last. This sale excludes VIP pricing upgrades.
I just received the new Limited Edition. Very happy!
What Dac did this replace, or did you upgrade your existing DSD MkI?
I started out with the MK1. Had it upgraded with the APS transformers and the vocm mod along with some power supply mods. Early this year I purchased a MK2 and decided it wasnât for me. I recently had APS upgrade the modded Mk1 to the Limited Edition. Major improvement in sound quality over all other DACâs I have owned.
This DAC is simply incredible. My speakers totally disappear now unlike all the other DACâs. Just plain awesome and so real sounding. 
I just put my DCS Bartok Apex up for sale.
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I had my DSD mkI upgraded my JK Richards a while back. APS transformer and vocm mod, love it. Deciding whether or not to get the limited edition mod or purchase a new DAC. Considering the Audio Analogue AAdac.
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It was an easy decision for me and also saved some cash. If you are happy with your modded MK1, you will be thrilled with the improvements the Limited Edition brings to the table.
You will have to spend a lot more cash [$10k +] for something better.
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So did you get the Limited Edition Signature series plus?
Yes. That is the best sounding one.
Hi,
after a lonmg time an update: Output buffers [but not finished] + a request for photos of VCOM section done with a bi-polar PSU
Parts:
- ELTIM BinBout-128x,XLR balanced > balanced buffer module with a gain of 0
- Neotech solidcore wire
- XLR terminals
- 3d printer (I will upload the files)
Photos
Are there details about what mods were done in the LE edition?
Here is the info for the Limited Edition Signature Series Plus units.
Are you using a pre amp with your upgraded DSD MkI? Wondering if the upgraded DSD sounds better now without a pre amp?
I use an Audio Research Ref 6SE preamp. I wouldnât consider using it without. I donât care to use the digital volume. My digital playback now sounds as good if not better than my vinyl setup. Amazing stuff.
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Zombie what tubes are you using? I have an AR Ref6 (non SE).
Resistor change:
I am looking at 0.01% 805 resistors. 42⏠per piece from vishay. Is changing the resistors with pricy ones worth it?
Well the way I see (and hear) it is, the transformers are a cork to what can ultimately come out. Caps can be better IME, ie more transparent and less âin the wayâ. Itâs pretty easy to try caps in place of the trafos and see for yourself.
The âregularâ output stage (OPS) with high speed industrial OA is a (significant) cork. IMO thereâs really no point in keeping the trafos if you plan to significantly re-do the OPS. But to get rid of DC blocking output trafos (or caps), you also have to have a bi-polar PSU OPS, which places the DC reference level to 0. So with bi-polar PSU Vocm can then be grounded, if your OPS still has a Vocm input (mine with discrete pro OA doesnât need it or use it, tg).
In sum, to really hear what the DS Mk1 can do you have to a) have the output DC coupled, ie no caps or trafos inline. And b) a very high performance OPS. Then you can really hear the DSD stream coming out basically.
Weâll be looking into trying to do same to the DS Mk2, if itâs possible. Itâs still playing here now and I do like it, even in stock form. Weâll likely dig in and see what we might be able to do in the next few months.
The Studio Mk1 is back to its owner in CA now as of this week. AND lately heâs also expecting the full stack of super expensive top-end Ideon digital gear(!).
He also took delivery of a pair of the pricey Clarisys Audio Minuet Plus speakers today in fact. Those suckers are 250 lb each lol⌠Iâll be heading that way to listen in a few weeks; should be super interesting and a once in a lifetime chance to hear and play with that stuff that I could never afford personally 
In other news, the last few month or so here Iâve tried out some Totem Fire V2 (fascinating) and they made some rather astonishing music with the great analog stack with the Studio Mk1 driving. Wow. And now some Zu DWX are here (yes). Muccch better sounding than I expected, (Iâm half in love already honestly) and weâll listen much more.
My regular speaker is a Focal kanta No3, which is no slouch IME but it also isnât a wideband driver speaker.
Anyway, happy weekend everybody! Keep on solderinâ TK
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Nice work Jannik BTW those Neotech pure Cu solid core wires in teflon are pretty good but you can do better IME Teflon can take awhile to break in as well. Yes, (unfortunately) all that has to be optimized as well for best results 
Itâs a long, expensive processâŚ
I had also been asked for an image of the stock type OPS OA when using a bi-polar PSU. This is about all I had quality wise, but you can see. To clarify I had re-purposed the stock local Vocm bypassing array into â new PSU -Vee local bypassing. The lifted Vocm pin goes to a local ground via of the +Vcc bypass array now with a small jumper.
As well, the OA -Vee pin, lifted from the stock ground pad now jumpers over to the (repurposed) local -Vee bypass array. Those little jumper wires pass through the small vias and are soldered (carefully) on the bottom. Hope that makes sense.
Itâs not easy to do a lot of custom SMD re-work
TK
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Sorry. I have to disagree with your transformer statement. Having a BAT preamp with the option to use ether caps or transformer modules⌠The transformers sound much better. Ted Smith also designed these to use transformers for a reason.
Have you tried any power supply mods?
The DC offset and power supply mods make a huge difference in sound quality on these MK1 DACâs. I have heard mine in stages and I can say for sure a quality power supply is very important. The sound stage is much more open and real sounding. The MK1 now sounds better than my $10K dCS Bartok Apex I have for sale.
Have you considered making a piggyback board for them opamp mods you are doing? The photo you posted doesnât look to reliable.
I sold my DS MK2 as it sounded nowhere near as good as the Modded Signature Series PLUS DAC.
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Iâm using stock matched 6H30. I tried the NOS 6h30 and it didnât sound much different.
I have tried different 6550 tubed in the power supply regulator and it does makes a bit of a difference.
Sorry, I have been super busy lately with the audio e-commerce and other things. Weâll just have to agree to disagree on the trafos. The caps sound more transparent IME; PS Audio uses the trafos to create a balanced OPS with no DC offset, NOT because they are somehow magically superior devices (theyâre not)⌠If they were theyâd be used in many, many audio devices including my own (I promise) (I wish they were, and I tried, truly, but theyâre not). Still the best cap or trafo is simply no cap or trafo. Along the way, FWIW I have even tried the best available transformer volume controls/preamps for example and, well⌠meh. If they were better sonically Iâd be using them, I assure you.
Anyway, que sera and YMMV;. whatever you prefer in your system is best for you at the end of the day. And I donât claim to know all, see all by any means, just sharing my journey/experience.
The DS Mk2 is playing here now in my system and IME it sounds great IMO, even all stock and with the stock trafos. I am yet to try the new fw update but will soon. TBDâŚ
The Studio DS Mk1 sounds amazing, absolutely but I agree with Ted, I do like the improved fw processing of the Mk2 (a lot) and that is where we are at currently. I use a hand built super high perf analog stack, great cabling and a pr of Kanta No3, though several other pr of very high perf and very transparent speakers have been through here lately the last few months as well, and have bested them is some ares⌠Eg Totem Fire V2 with the Torrent wb driver. But The mk2 is playing here now in my system. In 2025 weâll step it up with a super analog OPS and try to create a âStudioâ version, if possible. You simply canât do a better analog stage, and it make a huge difference. Otherwise why bother at all? Getting the analog section as out of the way as that is truly magical IME.
DW is using a pr of very expensive Clarisys Ribbons lately, though maybe not for long. I think he prefers the Gryphon stack overall due to a bass issue. FWIW he does say the TK super pre is a nice step up vs the Gryphon Diablo integrated pre section. He also has the top end full stack of Ideon digital gear currently, along with the top end Shunyata cable loom, which he says is superior to the AQ Dragon loom he had been using.
Iâve also been playing with the Denafrips streamers and it makes a d@mn fine hdw streamer indeed. Especially using the HQPlayer to drive it. I donât know how youâd beat it sonically. It also makes a d*rn good local files streamer (USB or HDD). That might be about ~ the best we can do in fact for digital sourcing, along with a CDT3 for CDâs. You ~ wonât beat the hdw they use to drive out the data including the CLKâing. They do it about as good as can be done, ESPECIALLY when cost is also considered. My ears confirm it is really good.
Also Audience lately has a new upgrade to their top end line of Front Row cables, blending in some silver conductors now (good!) and I will be auditioning a pr of the the XLR very soon. TBD. FWIW Iâve been using Cardas Clear Beyond in my system and like it just fine, along with some DIY pure Ag ribbon speaker cable in air dielectric (ie tubing).
Wishing a VERY merry Christmas and a super happy and prosperous 2025 to everyone! TK
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