Klark Teknik Mic Booster CT1

Converting 48v phantom power into "clean" gain is ok, but
compared to Behringer UMC202HD's midas preamps, this thing is noisy. However, the noise seems to be not the typical high pitched whine of preamps, but rather a little bit lower one.

You also need a patch cable to connect it directly to the interface, because the male part has a very thick layer of metal around it and would siply not fit. Respectively, if you're ok with plugging it in the back of the mic, then no extra cables are required.

Conclusion:
If you have a decent enough preamp in your interface you dont need it. If you dont, then you probably will not care about a few extra db of background preamp noise. In the end, it does what it advertises to do, and for the price, it is enough.

In comparison to the Triton Audio Fet Head, this is darker in sound because of lower input resistance, so it lacks in "air",
so I have a Fet Head for vocals and acoustic instruments and 2 CT1s for electric guitars or room mics, which was the most value-for-money solution, when the CT1 was 29€. But for 45€, when the FetHead is 66€?

Moving on, handling could be better, the female plug can be a pain to lock and the male plug can only be plugged into cables and not into snakes, consoles or interface inputs.

Conclusion: For 29€ it was definitely worth the money, for 45... I'd definitely buy a Fet Head instead.