Radial McBoost with a Sennheiser e 835: one of its three load settings is below the microphone's published minimum
The McBoost offers 600 Ω, 2.7 kΩ and 30 kΩ input impedance. Sennheiser specifies a minimum terminating impedance of 1 kΩ for the e 835. One of those three positions is outside the microphone's own specification — and Radial, like two rivals, never says whether phantom power passes on.
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: the chain works, the gain maths is comfortable, and the interesting decision is the load switch — where two manufacturers' published numbers disagree.
The numbers. At 85 dB SPL the e 835's 2.7 mV/Pa — which converts to −51.4 dBV/Pa — puts −58.2 dBu on the cable. The Volt 4 clips at +9 dBu, so a −18 dBFS take needs 49 dB. The McBoost's +26 dB leaves the Volt 4's preamp at 23 dB of its 55. On an iPad mini the Volt 4 asks 6.2 W of the port's 7.5 W — it fits, but this is the tightest bus-power margin in the batch, and a hub with its own supply is the safe move for long sessions.
The conflict worth knowing about. Radial publishes the McBoost's input impedance as 600Ω / 2.7kΩ / 30kΩ — that is the load your microphone sees. Sennheiser's e 835 specification sheet lists Nominal impedance (at 1 kHz) 350 Ω and, on the very next line, Min. terminating impedance 1 kΩ. So the McBoost's 600 Ω position sits below the minimum load the microphone's own maker specifies. Nothing breaks; a dynamic driving too low a load loses level and, with most moving-coil designs, some low end and damping control. But it is a documented mismatch between two published numbers, and it is invisible unless you read both sheets.
The unpublished part. Radial's specification page lists Phantom Power - 48V and says nothing about whether that phantom power continues to the microphone at the input. Klark Teknik and Soyuz are silent in the same way. With a dynamic like the e 835 it does not matter — it needs no power. Put a condenser there and no datasheet in existence answers the question.
The gem. The “min. terminating impedance” line is the most-ignored number on a dynamic microphone's spec sheet, and it is the one that decides whether a load-switching booster helps or hurts. Sennheiser and sE Electronics print it; Shure and Elgato print only the microphone's own output impedance, which tells you nothing about what load it tolerates. That asymmetry means you can check the McBoost's 600 Ω setting against an e 835 and an X1 S, and cannot check it against an SM58 or a Wave DX at all.
What to do: e 835 → McBoost → Volt 4 mic input, +48 V on, interface gain around 23 dB. Use the 2.7 kΩ position as the default; treat 600 Ω as a deliberate tone effect that runs outside Sennheiser's own numbers, not as a neutral setting.