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APS audio transformers

Custom audio transformers

We are currently having a sale on our top of the line Signature Series PLUS DAC that includes

our our R-Core APS internal power supply installed in Our Signature Series units. 

The PLUS upgrade normally cost $829.

Signature Series PLUS sale $4,394 less trade in.  We have both Silver and Black units available.

*While supplies last*.

Signature Series Upgrade your unit

Parts, Transformers, Misc.
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We will upgrade your unit to the Signature Series.  You just send us your unit and we will perform the upgrade.  You pay for return shipping.


We have developed one of the best sounding DAC to date.

This is the Level 2 upgrad. $2495

1) Transformer replacement. Replaced the Edcor 150 150 cheap transformers with premium Nickel APS Audio Transformers designed to meet extreme audiophile requirements. These transformers also brings up the gain to standard levels.
2) VOCM upgrade. The VOCM of these units did not have a low enough impedance for the video opamps used. We corrected this by adding very high quality SMD caps. on each opamp power circuit which lowered the impedance the correct amount.
We also replace all 1% thick film resistors with 0.01% thin film resistors as part of our signature series upgrade.
3) RF/EMI shielding was added where needed This lowers any noise from entering critical circuits.
4) Performed DC offset tune. Lowers low frequency distortion.
5) Set of Digital Noise Eliminators. (1-USB-B & 1-HDMI i2s)
6) Tighten re-attach Power Transformer (All come loose at the base)

  We take a stock MK1 and compleatly refurbish it with our new Rev 2 transformers, RF shielding, Power Supply upgrades including Tighten re-attach Power Transformer (All come loose at the base)
, Our Digital noise eliminators.and tune the DC offset.   We even refinnish the lid.  The unit looks brand new.

What you get is an incredable sounding DAC that outperforms even the newest MK2 DAC even with our nickel transformers installed.  The Signature Series can be idenified by the new APS Audio Badging on the front.


For our Level 3 upgrade add the PLUS upgrade $829 to this upgrade. Here

About Us

We have been designing and building custom upgrades for the directstream DAC since 2019


You can read some reviews and find out some more info about our products here and here



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We are located in the

Baltimore / Washington area