Modding the DirectStream DAC MKI

Jeff, thanks. Nice stuff, but it looks like it leaves a mess of that bismuth/tin stuff behind on the PCB. That’ll still have to be pulled off, but I guess it can be done at a lower temperature.

That’s easy to resolve. Just use solder wick, flux and some fresh silver content solder.
spread flux then place solder tip on top of solder wick and move around until wick has absorbed the low temp solder. Flux again and add silver content solder. repeat. Ready for new transformers. This way one won’t ruin the board ot the old transformers.

The best tool is the one below however is expensive if one only rarely does this type of work.
This is what I use:


Yep, that’s what I use, too. :smile: But I haven’t used it yet for any large mass removals. What temp do you set it to for the MkII tranny removals?

set it to 2.5 425c. Use the large tip. (about the size of a standard round toothpick) melt, let stand for 3 seconds and then pull the trigger.
gently move each pin away from the edges of the hole with your finger nail or plastic sponger tool. If one does not move, re-solder that pin and repeat the de-solder process.
Sometimes gently twisting the transformer will break the pin loose if it’s slightly stuck.


JK, what is this pad (do you have a link)? Is the blue stuff deviating/transmitting heat? It rather looks like annisolator or n stead of putting a copper plate inbetween?

Thanks Jeff. I’ve thus far used the Hakko only for SMD desoldering.

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Just thought I would share some pictures of a mod I did to my DAC and a firiend of mine. Useing some copper sheet and aluminum tape I decide to craft an enclosure for the analog board to provide some shielding as best I could from other circuits within the DAC. The result was surprisingly good. Before I did my friends DAC we compared both DACs. Both DACS had the same modifications, APS transformers and VOCM mod. The only difference is the enclosure for the anlog board in my DAC. Without hesitation my friend said I needed to modify his. We both agreed there was no way we could live without the mod. I encourage someone who is capable of doing this to give it a try. I think you will come to the same conclusion we did and I hope you share with us your results. In one of the pictures I show the copper before it was completly sandwiched with aluminum tape.


Thanks for sharing this. Can you elaborate on what materials you used to craft this enclosure? Also describe what was the sonic improvement you heard? I have the APS/VOCM mod on my MK1. It’s been a fantastic upgrade, but if there is any gain left on the table, I’d love to give this a go.

What’s the blue sheet between the heatsinks? Is it isolation or heat conductive?

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I don’t want to lead the conversation, I’m hoping someone else will try it and comment. I could say more, but I will start with clarity, detail and sound stage presentation. The system just seems to project the music with such ease. It’s just so comfortable to listen with all the dynamics one could want. I’m really happy with what I’m experiencing. Again, the materials used are copper sheet and aluminum tape.

Heat conductive. It’s from Jkrichard.

Thanks! As JK is no forum member anymore…do you or someone else have a link where to get this stuff? Such heat conductive soft material is new to me.

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A few years ago I searched for transistor thermal pads and found a similar material. It worked great. Search Digikey for thermal pad.

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As posted here:

His email is

Web page is

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So you probably also know about the “brick d*ck” in Ypsi, then? :grin:

Material is m.2 Thermal pad,70x20x1mm for M.2 2280 SSD NVMe Heatsinks. $6 on Amazon. Pardon the late response, but addressed for future reference.

Also have the APS xformer and Vocm mods, so happy.


i ordered 2 Edcor 4400 Transformers and now is see there are already Edcor 4300
installed. As i bought the dac second hand i am a little bit confused. In other Pictures i
have seen Edcor 1412 Transformers as Standard. Can anyone light me up?
Goggle is no help, for Edcor 1412 oder 4300.


Remove and get the Richard’s power supply mod. Then his APS transformers. I think there is another mod that’s easy too while open. That will get you super close to the MKII especially with the I2S input.

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VOCM Mod made the power supply mod obsolete. According to Richard, the LPS makes no discernible difference once you do the APS and VOCM mod. I can concur. My APS+VOCM sounds much better than the EDCOR+LPS mod.


I would say the VOCM and APS or Lundahl transformer mod had much higher impact than the ext. PSU, but when you check the difference between internal and external PSU afterwards, you still hear a clear improvement anyway, maybe depending on the system‘s resolution.