MayDus, PCM2706/CS4398 USB DAC

Here I’ll post about the d/a converter I’m going to build.
The MayDus will be used between my PC and my Lehmann Black Cube Linear Clone headphone amplifier.
I’ll update this page as the build progress.


I’ll post some pics of the DAC PCB, not mine though as I haven’t gotten mine yet.

The ABS box that’ll hopefully fit the MayDus arrived today, here compared to my iphone4.


Ordered two Edcor XSM 10K/10K from Edcorusa.

Not mine, but an example picture of an Edcor XSM transformer.


Got the DAC board today, still waiting for the Edcor’s and I might need to get another box for the MayDus.

I’ll de-solder the SMD resistors on the CS4398 outputs and solder the wires to the Edcor XSM 10K/10K to the pads.


The 4 resistors that will be removed are circled in in this picture.

I will also remove the rca-connectors from the PCB since I won’t need them.

Should I one day decide to go with an opamp instead of the edcors I can always solder wire from the PCB to better connectors.


I’ve decided to go with an identical enclosure as I used for my B1 preamp.
Ordered it today(though it’s really very early morning, just not asleep yet) and with some luck I’ll get it sometime late next week.


I’ll get the edcor transformers at noon today 🙂
I’ll post pics as soon as I get them.

Pics as promised, also got the new enclosure I ordered for this project, it’s the same one I used for the B1 preamp.

Transformers from Edcor.

Box and DAC-board.

Box and transformers.


A first draft of how to hook the edcors to the dac, pin nr’s on the transformers in the schematics don’t match the ones on the edcors, I’m aware of that.


Got some work done today.

Removed the RCA-sockets.

Some different layouts.


Nr2(but with the power transformer to the left).

And Nr3 (the one I’m leaning towards).

Layout nr4, hopefully the best one.


Got a bit of work done before noon, hopefully I’ll get some more work done today.

Starground and removed resistors where I’ll solder the wires to the signaltransformers.

Started doing the internal wiring.

Both channels done from PCB to Edcor XSM 10K/10K signal transformers.


More or less done with the MayDus. Just waiting for the valued opinions from a few friends who has helped me with this project.

MayDus is playing!

To soon to say too much about the sound, but it’s promising 🙂

First impression (20 or so minutes after I switched it on).

The first thing to say about the sound is that it’s honest, crap in – crap out.
A bit on the bright, somewhat sharp side yet, but then it hasn’t had time to settle.
Honest, dynamic, detailed…but no mercy for bad recordings what so ever.
The LF is very tight and dynamic, so is HF, but those are the areas I believe will improve the most with time as the dac settles.

To be continued…



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