Clark "mic booster" CT-1 review

[Dilettante]

Purchased at Amazon in hope of obtaining some "free" gain for dynamic microphones.
Admittedly, I was lured by the comment made in the name of Ramesh Singaram:

The Klark Teknik does a great job of boosting the signal without introducing anything adverse - not that I can hear. A clean gain.

Clean gain? Initial voice recording sounded distorted, so I decided to measure the device.
All done via loopback on Audient ID4 mk II using balanced cables and main (speaker) output.
Audient preamp is turned off: knob is set all way to the left, meaning it acts as the line input.

For comparison, raw ID4 measurements can be found here: https://www.audiosciencereview.com/forum/index.php?threads/audient-id4-mk-ii-review.35017/

Multitone​

1K sine

Look at these harmonics...

Sweep

Hmm... What if it does not like loud signals? Let's reduce the output:

Better. Still far from "transparent", but better.

Multitone 32 (averaged 5 times)

Same with the signal reduced under -20 dB

RMAA

Frequency response (from 40 Hz to 15 kHz), dB	+0.03, -0.11​	Excellent​
Noise level, dB (A)	-105.4​	Excellent​
Dynamic range, dB (A)	105.4​	Excellent​
THD, %	2.638​	Very poor​
THD + Noise, dB (A)	-29.2​	Very poor​
IMD + Noise, %	1.696​	Poor​
Stereo crosstalk, dB	-52.3​	Poor​
IMD at 10 kHz, %	1.398​	Poor​

Noteworthy graphs below.

THD+N

IMD

Numbers speak for themselves.