I love the form factor of the microRendu, I play in office setup and its perfect to use behind the DAC (below/behind monitor) connected to the DAC with an UpTone A>B adapter, and power/ethernet connected in other end. However, its clock (oscillator) is not the best, it was designed before the accurate audio clocks where available (or very expensive). But nowadays, one of the best oscillator available is the Crystek CCHD-575 and it costs $12, and its pin-compatible with the old clock in the microRendu.
So I decided to replace it, ordered a Crystek CCHD-575 24Mhz from mouser, here is the link:
And since its temperature sensitive I also chased around town to get hold of some leaded tin (which in Europe is not allowed to be sold to private persons), because leaded tin has about 40 degrees lower melting temperature (around 180 Celsius).
After some frustration, I got it working, but it was not easy. First of all, everything is very small on the microRendy PCB, and removing the old clock was hard (I ended up removing as much solder as possible and then used pliers + a little force 🙂 ). When soldering the new clock, I pre-tinned one pad and pressed down the clock while heating until it settled down, then soldered the 3 remaining connections normally but with very little solder, and a few minutes break between each soldering to let the clock cool down.
But the result was better than I had anticipated, a completely new sound with more details, air and improved soundstage. So for anyone who feels a little daring, and are prepared that their microRendu might brick (which can easily happen), its a nice little tweak. Easily the best price/performance tweak I have made, but very risky.
Btw, the 1.4 upgrade for microRendu, which isn’t available anymore, is exactly what I described here: change clock to Crystek CCHD-575
I wonder if there are some voltage regulators in there that can be improved upon, or perhaps some caps 🙂