Recently, I was asked to repair Matrix Mini-I Pro. It was death. Mute. I quickly found the cause. It was quite easy defect – few electrolytic capacitors were shorted so I replace them all. I gave DAC the second life. Here you can find how looks Matrix Mini-I Pro DAC when cames from factory (official photo):
Meanwhile, the owner of Matrix come up with the idea to upgrade it. I agreed as I got means to do such improvements. So, DAC was given the second and much better life. I decide to do few modifications using as much as possible of original circuit:
- Few better passive components in analog circuit
- Of course my best discrete regulators in most sensitive places
- Better operational amplifiers in analog circuit
Possible to do, but postponed to second level of modifications:
- all resistors to minimelf – circuit is designed to use 0805 resistors, but original pads are able to handle 1206-long resistors
- all regulators to discrete MuzgDIY types
- replace clock generators to MuzgDIY ones or if this couldn’t be done because of space at least Crystek CCHD
Result of modifications: