At the last few pre-pandemic AES conferences I attended, my brief conversations with David Bock centered around his opinions about the classic microphones that were built incorrectly. Most of his comments went over my head, but what I took away was an impression of his passion, talent, and ambition for making microphones sound the best they could. I was excited when Universal Audio announced their David Bock-designed large diaphragm tube microphones, which include the flagship Bock 251 reviewed here, plus the 167 and 187. Yes, please! Send the flagship!
My first surprise was the size of the box the mic kit ships in. Surprise number two was the heavy, two-toned, upholstered, retro-styled microphone suitcase that celebrates the style of the Telefunken case with added flare – the UA version looks ready to be dropped into the trunk of a '57 Chevy for a ride down Route 66. Under normal circumstances I don't get excited about over-the-top aesthetics related to audio gear, but I must admit I was getting pretty stoked. Despite its classic stylings, the mic suitcase has the coolest, super functional, built-in top opening side panel that houses the dedicated Tuchel mic cable! Raise your hand if you are tired of squeezing your custom mic cable into the small space of your crappy case. The mic is further protected by its own custom wooden box. Surprise number three was the light surf green gloss automotive finish of the mic and its linear power supply. We're embracing the old school now.
Many consider the original Telefunken ELA M 251 to be one of the finest production vocal microphones, and with less than 4,000 manufactured, they're extremely rare. Though I've never spent time in the studio with an original ELA M 251, my favorite vocal mics (that I've used on the regular) are Sharkbite Studio's pair of Lucas CS-1s (a take on the AKG C12), which were incidentally repaired / "gone through" by David Bock. I know; 251s and C12s are different (voltage and distance between capsule and tube), so stop yelling at me. Like the Telefunken, the Bock 251 offers three polar patterns (omni, cardioid, and figure-eight) on the mic body. UA's version utilizes a NOS (new old stock) ECC85 tube, while the original ELA M 251 and 251E employ their coveted AC701k and the 6072. The 6-micron German-made all-brass capsule is hand-assembled and tensioned.
As expected, the Bock 251 is an insanely good vocal mic, especially with female (but also male) singers. Three singers with different ranges all agreed that their voices sounded perfect in the headphones during takes, which I know contributed to comfort level and confidence that, in turn, resulted in dynamic and inspired performances every time. I never needed to give instructions on working the mic correctly; it just happened naturally in the moment. From a whisper to a scream, the Bock 251 captured the roundness of the voice's lower register with true-to-life overall reproduction, topped off with that special pre-mixed sparkle. Its proximity effect is addictingly lovely on voice, and the mic takes close-up SPLs in stride (118 dB SPL with 1% THD), recovering quickly when really pushed. In almost all instances, plosives were manageable. Sibilance will happen, and you may need some post-tracking correction depending on the singer and their technique.
The Bock 251 is all business in the studio. Vocals aside, I also achieved excellent results on acoustic guitar that gave me that AKG C12-ish vibe – clarity and stellar harmonic capture, but with less woofiness from lower register fundamentals and overtones. Its custom-designed, multi-sectioned transformers result in smoother low end extension and response – and this mic can take that low end surprisingly well while keeping it in its place without sounding overly pronounced. We're not big on exhaustive mic comparisons, but Tape Op contributor Kirt Shearer can offer deeper insight into the Bock 251, as he owns a Telefunken ELA M 251. -SM
The Bock 251 is certainly designed in the style of the original Telefunken ELA M 251, but seems intentionally intended to be something more than an exact clone. I think you can hear those choices in the character of this mic. The edge-terminated CK12-style capsule unquestionably conveys a recognizable 251 sound, but seems to be contoured slightly differently than its vintage counterparts. Don’t get me wrong, this is a fantastic microphone. It is tremendously detailed and sounds beautiful. Obviously, Bock intentionally designed some sonic differences. While some may think this to be a compromise, or even perhaps blasphemy, it might make the Bock 251 a more versatile mic. Considering that it’s getting tougher to find a solid comparative baseline for a vintage Telefunken ELA M 251, I’ll highlight some of the subtle differences.
Echoing Scott's findings, immediately noticeable is the Bock 251's extended low frequency response. While my vintage Telefunken ELA M 251 isn’t thin on the low end, the Bock is a monster. Its fundamental low end extends deeper than other 251s I’ve used. I found this particularly useful as a drum room mic; there was a different element of depth that my Telefunken didn’t have. This might not always be desirable for vocals, mind you, but for other applications it can be very nice.
The other difference I noticed is the upper midrange. The Bock 251 seemed a little smoother without as much of a presence peak compared to the vintage Telefunken ELA M 251s I know. Again, this is not at all a bad thing, as I personally don’t like mics that are too “peaky” in that range. If you need a bit more in the upper mids, the slightest bit of EQ will get you there. Lastly, the top end of the response seemed pretty much in line with the 251 I use. The Bock 251 certainly has plenty of sparkle on top, but it seemed like it was just a tiny bit flatter – perhaps a dB or so down at 10 kHz compared to what I’m used to.
But again, these differences aren't an issue for me, and perhaps the Bock 251 offers many more uses than some of the vintage options. The slightest amount of EQ will likely get its response into more familiar territory if desired. The Bock 251 is a fantastic mic that absolutely has the vibe of a vintage ELA M 251, with slight differences in the voicing. It excels on vocals, piano, overheads, and room mics at half the price of a new Telefunken. Power cable and fitted shock mount included.
_disp_horizontal_bw.jpg)