Modding the DirectStream DAC

Mine shipped out today.

Mine also shipped.

Add me to the list of shipped.

Both new transformers arrived hefty pieces Now to see what my Equipment tech can commit to turn around time for the analog board mod.

I received my transformers yesterday, sadly I may not get time to install them until after the holidays :slightly_frowning_face:

It’s a 1.5 hour DIY job with all the right tools. First impressions… just turned the whole system on, so it’s not all warmed in yet, but…

  1. The midbass is more punchy and I like it. The subbass is more controlled.
  2. Pluck sounds have a more defining leading edge.
  3. All sounds feel more alive with more presence.
  4. Soundstage is deeper and runs further back. Width is similar to before. Instruments in space are more defined.
  5. I’ve been running Snowmass, so will switch to Windom later.

I recently switched to fixed LOW output at 106 and I thought the sound lost some oomph, but it’s now quite alive even with attenuation. The DSD noise floor is practically nil.

Some install notes:

  1. I used 500 degrees on my solder station. The solder cools FAST when extracting, so you really need fast heat and fast extract to prevent damage. I used a medium point tip. Flat tip doesn’t work.
  2. You won’t remove all solder, so when there’s a partial extract, I resolder and tried again until there was 95%+ removed. Then I use the solder iron to push the pin away from the side it’s still soldered to.
  3. Don’t force it when trying to remove the transformer. I used the soldering iron to push pins gently until they came loose from the pad while pulling the transformer gently.
  4. When installing the new former, don’t push. It should slide right in. Clean the pads and holes with wick if you have any resistance.


Beautifully performed Vee, well done!


That looks really well done. Pro tools, pro skills. Did you already determine what you will charge for this? Hope you have lots of time over the holidays because you might just get a few hundred requests… :slightly_smiling_face:


If you could fly over to the uk and do mine as well, that would be good :wink:


Looks great. Please keep is up to date on how it evolves. The other power supply modder mentioned how voices improved. I would like to hear you impressions too of vocals.

Will you please say something more about this “switch”? Just curious and don’t exactly follow. Cheers! Well done, sir.

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It’s in the setup menue of the DS.


Nicely done! Hope it turns out to be worth all of your effort.

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From the manual:

"DirectStream has enough output gain to directly drive most power amplifiers without a preamplifier. DirectStream’s volume control is a no-loss design and may be used at any setting from 1 to 100 without fear of resolution loss.

However, if there is too much gain when you connect directly to a preamplifier or power amplifier, it is possible to select a lower output gain setting. To do so, go to the setup touch screen on DirectStream and choose the lower output option (see the Quick Start guide). You can also turn the output attenuator on or off by pressing the Filter button on DirectStream’s remote control."


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Vocals are one of those that fall in the “more alive” bucket. There was a background voice that I thought was coming from my son’s tablet as he was watching a show next to me, but when I turned to focus on it, it was actually from the piece I was listening to. It felt palpable, close.

Other instruments are popping up like that and I’m finding that really delightful.


The DSD has an attenuation setting in the config panel. When set to LOW, it turns on the attenuator and allows the volume setting to go beyond 100 to 106. With this setting, I believe a few things are happening.

  1. The constant noise floor is pushed to inaudible levels. I test this by turning the BHK Pre volume to 100 when nothing is playing. My speakers are 99dB, so it’s easy to hear whether the noise has gone up, and with this low 106 config, the noise doesn’t fluctuate at all. It’s just a constant BHK Pre noise floor I hear. On HIGH at roughly 65, I can hear noise increasing when the Pre crosses 65. I usually listen to the Pre at 53 because that’s the start of the next volume attenuation ring, which I’ve found to have lowest noise. Also dimming the Pre is required. There’s a different HF buzz the display makes.
  2. I always thought the DSD attenuator dulled the sound in my system, even after breaking in for weeks. I had it on LOW this past week looking for changes in sound because I’m now on a full loom of Iconoclast ICs, but I was planning to switch back to HIGH until the formers showed up in the mail. The new former has really improved the palpability of the sound. I’m hearing presence, realism in sounds I didn’t hear before. Maybe due to the lowered noise floor coupled with the new formers. It feels like a veil was lifted.

Edit: I wanted to qualify the noise floor remark with measurements for LOW / HIGH. Measurements using a Reed R8060 0.5inch at the tweeter, dbA weighted.

For LOW 106, at BHK volume 1, it reads 54dB left, 50dB right. At BHK volume 100, it reads 55dB left, 52dB right. I’m not sure why my left channel is noisier, so I’ll look into that.

For HIGH 100, 54/50 at 1, 67/68 at 100.

Edit #2: for reference, I swapped in a new pair of PSvane 12AU7s into the BHK Pre and at LOW 106, the noise floor is 48/44 dB. That’s roughly 6dB of noise due to the NOS tube. I also found its the daughter boards that cause my level mismatch by swapping them and have an email out to psaudio.


Dear Mr. Vee, infomercials never had any effect on me whatsoever.
But now, you just posted the best infomercial I have ever seen (detailed pictures, best commentaries on sound improvement, …), and this time, I am really interested to buy :grinning:.

I see that you have all the equipment and the tools.

When do you start taking orders?

If I call in the next fifteen minutes, do I get one mod kit free?
(just kidding)


I installed the XS4400 transformers today. Took a couple of hours. I’m amazed at what an upgrade it is. Shocked really. I expected the more substantial bottom end (beefier transformer), but it’s the presence in the mid-range, and the overall fluidity that has been the surprise. It’s like getting a whole new component. I’ve been doing the obligatory re-listen to favorite recordings ever since.

I can’t help but wonder if back when Ted and Paul were first costing out the unit - if maybe the firmware at the time was such that the transformer choice was not quite as significant as it is now. Otherwise, it’s hard to understand why these XS4400s weren’t part of the original build. Could be that the Mc C22 preamp just happens to match up all that much better - and my particular experience is an outlier.

In any event, this is by far the best $90 I’ve spent on audio in a very, very long time.

Thank you Ted, for facilitating this transformation.


I placed my order for the XS4400s today. Is there really a 6 week wait?
I have a nice solder station, silver solder, and a solder sucker just waiting to be used. I’ve already rehearsed the procedure a few times in my head.
I may be a bit ocd about this project. :grin:


Much better than cavalier.