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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*.

SALE! Our new Signature Series upgraded MK1 DAC

Parts, Transformers, Misc.
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We have developed one of the best sounding DAC to date. 


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.

This is a Level 2 upgrade.



For a Level 3 upgrade add the PLUS upgrade below to this Signature Series for the instalation of our internal analog power supply.  This is the best and most expensive however we feel it's worth every penny.


Chose Black or Silver.

These are build to order.

Avalibilty - Pre Order (3 - 21 days delivery)



We can also convert your unit to this Signature Series for only $2495.

Click [Here]


If you are seeking the very best sounding DAC you might be interested in our new Signature Series PLUS.


This PLUS series addition is a Level 3 upgrade. This is the very best and most expensive however we feel it's worth every penny.


It includes everything in the Signature Series PLUS a super high quality internal linear power supply for the analog board.  It includes isolating filters from the digital supply.  This upgrade ads even more fine detail and increased REAL factor.  Percussive instruments sound so real and dynamic.


We have been working on finding the very best supply for this application and we feel we nailed it.

We use the complete bottom of the DAC for the heat sink keeping the internal temperature low. We use only the best capacitors and diodes available as well as using a high quality discrete circuit with a MOSFET (attached to the bottom of the unit) to regulate the voltage. The R-core transformer is icing on the cake and is very low noise especially with the thick copper flux band.

Signature Series $3995 + PLUS $829 = Total $4824 for our Signature Series PLUS (Level 3) The very best!

Click [Here] to Add $829 to the Signature Series order.


Other options include our external power board / Power supply.  Leave us a note if you want the External power options.

One year warranty included with your purchase.

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