Telefunken CU-29 Copperhead
A modern tube condenser that uses the family capsule and a NOS tube. Reviewers who tried it kept reaching for "present" rather than "harsh."
Overview
Its capsule is a single-membrane take on the large-diaphragm design shared with the company's AR-51 and AK-47 MkII microphones. It is paired with a proprietary circuit built around a NOS Telefunken tube and a custom output transformer. One diaphragm instead of two, an old-stock tube, a bespoke transformer. That is why the Copperhead sits below the flagship in the lineup while still carrying the badge.
Owners and reviewers tend to fixate on the voicing. Mix (April 2015, p.24) summed the Copperhead up as a remarkably high-fidelity mic with a character that reads "present" without tipping into "harsh." That matters on vocals, where a bright condenser can turn sibilant fast. The same publication's June 2014 buyer's guide (p.83) placed it alongside classic-design tube mics and described it in similar terms. So the "present but not harsh" reputation wasn't a one-off impression. It's voiced to sit forward in a mix without scratching.
In an Electronic Musician songwriter's-studio roundup, the CU-29 was the splurge vocal mic of the bunch, picked over a small-diaphragm condenser pair and a dynamic. The writer called out big, warm-sounding vocals that flatter just about any singer, plus solid results on acoustic guitar. That's a working-studio verdict rather than a spec-sheet one. Elsewhere it turns up tracked through a Brent Averill 1073 preamp on at least one dance-pop production, a chain an engineer picks when he trusts the mic on a name vocalist.
The price moved, so take care with it. A 2011 EQ NAMM report noted the Copperhead's debut as a new condenser with a vintage NOS tube. By the time Electronic Musician priced it in a studio-build feature it was listed at $1,295. That is considerably less than the company's flagship ELA M 251, but still a real investment. Street pricing on this mic has drifted over the years, and the $1,295 figure is a period snapshot. What's consistent is the positioning: it undercuts the halo model without pretending to be it.
The tube is the long-term issue. A NOS Telefunken tube is a finite resource, and it's the heart of the proprietary circuit. When it ages out, the replacement you drop in will shape the sound as much as the capsule does. That's true of any tube condenser, but the old-stock tube is part of the sales pitch here. Confirm the tube's condition and provenance before handing over money, and expect that a mic this dependent on a single valve will need attention eventually. The custom output transformer is the other service item. It's not an off-the-shelf part, so repairs want someone who knows the model.
For a home or project studio chasing a big, warm vocal sound without stepping up to the flagship, it's a credible answer. Just know you're buying a tube mic with a finite tube, and confirm the price against current listings rather than a decade-old review.
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