Upon installing these upgrades, the unit sounds like a totally different piece of equipment. Gone is all the graininess. Gone are the digital artifacts. Gone are the harsh highs. It's like someone pulled a blanket off my speakers. The clarity and soundstage are absolutely incredible. The noise floor is dead silent. It makes this 20 year old DAC sound as good as modern high-end options.

The Stage 2 for the 540P was fantastic, but A/B testing against the PhonOh! shows the former mod was a touch too sparkly. Whereas the PhonOh has it perfect. Instrument separation, space, placement, nothing overpowering whatever the focus should be. I cant fault it so far. Tomorrow I will get a bit more Rock and metal to see what it brings to the party, but overall, Its been running 5 hours now and I love it!

In short, this DAC is an absolute revelation. The highs are higher, the lows are lower, the instrument separation is a lot more, well, separate. Things shimmer.

Awesome, just awesome; I am, to quote Sister Sledge, lost in music. Scott has delivered exactly what he promised, a more involving and live-sounding DAC.

This is a niche upgrade, but if you were looking at buying (say) a Musical Fidelity M6x DAC, you could have this for half the price. And, dare I say it, you’d have the better and more involving sound. It really is that good.

I received the upgrade and after 10 mins had installed it. Immediately the music sounded crisper, more dynamic, present and with a more forward sound stage. Elements of songs (Spirit of Radio) that I had never noticed before were suddenly present and part of the mix. Another song that had an undampened bass drum in the intro really allowed the space of the room to be heard from the ambient recording. Probably the most telling thing I can say though is that my wife (who does not normally notice the upgrades) noticed the difference between the 551p and the upgrade saying that it is a lot crisper and more detailed. Also, I love the PhonOh! name.

Just to let you know, I have been doing some critical listening to the A5 during the past week. I came to the conclusion that the maudifi A5 outshines my Hegel H390 (a $6000 unit that is also a streamer and a DAC and that is highly praised). I thought you would be happy to know..

Starting this morning, it operates as my main system. It's all there – dynamics, soundstage, segregation of musical instruments and timbre. So it’s a success. Thank you for that.

Amazing sound upgrade! I couldn’t believe my ears when I played the first record! Don’t think about it — just dive into this upgrade and enjoy the music!

I received the amp back safely earlier today and would like to thank you your amazing work. I knew the amp would need burn in but already it has blown my mind. I never expected such an improvement. The expansion of the sound stage, voice and bass is music to my ears. Astonishing really!

You have given me a dilemma though. I know I would need to send you my pre-amp for you to apply your magic soon but I have to change my source. You have awoken that bug I used to have years ago after having my first hifi.

the difference was amazing. The sound stage really opened up, and there was such an improvement with the clarity of sound. The bass was so much more tighter, clear and controlled, and the detail in the other frequencies became really 3 dimensional.

It just feels a lot more immersive, and really organic.

The difference is huge! It is more musical and 3-dimensional with more low volume clout. Up to modern standards, but at a much lower cost.