Klark Teknik Mic Booster CT 1 with an SM58: does phantom power reach the microphone? Nobody has published the answer
With a dynamic in front, this chain is fine: 34 dB of the EVO 4's 58 after the booster's +25. With a condenser in front, the answer is unknown — Klark Teknik does not state whether phantom power passes through, and this site will not invent it.
Signal Chain Compatibility Matrix
Select gear and parameters for live gain, impedance and SPL calculations.
Input Equipment Setup
PASS: Optimal Signal Chain
Requires minimum +60dB of clean pre-amp gain. Most budget entry interfaces max out at +50dB to +56dB and introduce hiss at max pot. An inline preamp booster (Cloudlifter CL-1 / FetHead) is strongly recommended.
The interface preamp provides sufficient headroom.
$538
$405
-25%Tonal & acoustic characteristics: Flat, wide-range frequency response for clean music and speech. Smooth, warm acoustic character with air-suspension shock isolation.
Technical advisory: With +69dB max gain, the Gen 4 Solo can drive demanding dynamics like the Shure SM7B natively without requiring an external inline booster.
Physical Interconnect Topology
Shure SM7B
Direct Cable Connection (No Intermediate Box)
1x Shielded Balanced XLR Cable (3-Pin XLR Male to XLR Female)
Focusrite Scarlett Solo (Gen 4)
Host: Apple MacBook Pro (M1/M2/M3/M4)
Short answer: with an SM58 in front this is a good, cheap chain. With a condenser in front, nobody outside Klark Teknik knows whether it works — and that is the honest answer, not a hedge.
The numbers. At 85 dB SPL the SM58's −54.5 dBV/Pa sensitivity puts −61.3 dBu on the cable. The EVO 4 clips at +16 dBu, a high ceiling, so a −18 dBFS take needs 59 dB — one decibel more than the EVO 4's own 58 dB preamp. The CT 1's +25 dB drops the interface's share to 34 dB and leaves 24 dB spare. That single decibel is the whole case for a £40 booster here: without it you are at the stop, with it you are nowhere near it.
The thing that is not published. Klark Teknik's page says the CT 1 “runs on phantom power and needs no external power source” and offers “+25dB of gain to your mic pre's”. It does not say what happens to that phantom power afterwards. Neither does Radial for the McBoost, nor Soyuz for The Launcher. Three boosters, three silences. This is not the same situation as the Cloudlifter, where Cloud writes in print that its box “doesn't pass phantom power” — there the answer exists and is knowable.
Why the guess is dangerous even when it is probably right. Most in-line JFET boosters do terminate phantom power, so “it does not pass through” is the way to bet. But a bet printed in the same typeface as a datasheet stops looking like a bet. This calculator therefore carries a separate phantomPassThroughUnknown state: the chain is not declared dead, and it is not declared healthy either. If your plan depends on a condenser sitting in front of a CT 1, the specification cannot tell you whether that plan works.
The gem. You can settle it yourself in thirty seconds with any multimeter. Plug the CT 1 into the interface, switch +48 V on, and measure DC voltage at the booster's input XLR — pin 2 to pin 1, then pin 3 to pin 1, with nothing else connected. Tens of volts on both pins means phantom passes through and a condenser will run. Near zero means it does not. Two manufacturers could have printed that number and did not; your meter can.
What to do: SM58 → CT 1 → EVO 4 mic input, +48 V on for the booster, interface gain around 34 dB. Do not buy the CT 1 as a step toward a condenser setup until you have measured its input pins.