First impressions

[efung]

efung

The ICEpower 500A uses MC33078 quad opamp in the front end. The input is configured as difference input amplifier for XLR input. The MC33078 is a low-end BJT opamp. You can replace it with BJT input OPA1604. The OPA1604 has low noise and much lower distortion. 

Haven't used SMDs before. I've seen the instructional videos by Dave Jones on YouTube. I don't have a stereo microscope, just a pair of loupes. Everything these days is SMDs, I guess it's time to step up.

efung

DIY 30x gain step up transformer

DIY as in wind your own?

No, I did not. I bought them from ebay. Those were vintage transformers made for moving coil microphone in the old days. They were inexpensive 15 years ago. I searched it again today. They are expensive. If you type "vintage transformer microphone", you will find an inexpensive pairs with impedance ratio 200:49k, step up ratio is about 1:15. However, my pair is older than the Shure's.