Modding the PS Audio Directstream DAC MK1 and MK2


I would like to continue discussing all the mods we have created for these two DAC's as it seems PS Audio is no longer allowing discussions about them on their forum.

For reference here is a link to the closed discussion.

https://forum.psaudio.com/t/modding-the-directstream-dac-mki/2680

128x128richardselectronics

Hi Jeff, one of the reasons I'm considering your transformer upgrade for the MKI has to do with connecting the DAC directly to my Pass amp. I seem to recall you saying that your transformer upgrade increases the output voltage, which helps when you connect the DAC directly to a power amp. I haven't noticed anyone talking about this lately so can you please comment on this? 

I don’t recall us making them exact statements. The Custom nickel transformers do in fact increase the output level by 6dB because they are and were designed as a 1:2 transformer instead of the original 1:1 transformer that are installed in the MK1. We did state that The Custom nickel transformers have a much lower output impedance than the MK2 Edcor XS4400 transformers which places the secondary windings in a series configuration in order to achieve a 1:2 output which creates a very high output impedance. This was kind of a cheat as the Edcor XS4400 was not designed to do so. The Custom nickel transformers are designed from the ground up specifically for each model, The MK1 or the Mk2.

The lower impedance is a plus as it in theory should have a lower noise floor going directly into a power amp. We never tested this as we recommend going through a pre-amp.

Thanks Jeff. My takeaway from your response is that you recommend using a pre-amp. I'm good with that.