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Peluso 22 251

Valve Microphone
Published May 2010
By Hugh Robjohns

This mic aims to bring us the sound of a vintage Telefunken — which is a brave choice, since Telefunken are reissuing it themselves! How close have Peluso come to getting it right?

Peluso 22 251

Peluso Microphone Labs are American producers of a range of valve, ribbon and solid‑state microphones all apparently custom designed and hand‑crafted, albeit using a range of internationally sourced components — including PSU, accessories and metalwork for the mic and capsule from China — although there's nothing fundamentally wrong with that. The Chinese have proven themselves very capable at copying vintage capsule designs. The key point, as with many boutique‑mic manufacturers, is that the microphone's design is specifically tailored and optimised, and production and assembly closely controlled to deliver high-quality microphones conforming to Peluso's standards. It is also worth noting that John Peluso has 26 years of experience of working with vintage microphones, and runs a full service and repair laboratory for genuine vintage mics as well as his own products, complete with the ability to repair diaphragms.

The Peluso 22 251 model is very clearly 'inspired by' and styled to closely resemble the classic Telefunken ELA M 251E — itself a variation of AKG's C12 microphone (see 'The Original Telefunken 251' box) — although Peluso also make a closer C12 'homage' in the form of the P12. The 22 251 review model was supplied in a smart composite flightcase complete with power supply module, cat's‑cradle shockmount, seven‑pin mic‑PSU cable and the microphone itself, which is further protected in a foam‑lined wooden case. The mic cable is a woven fabric‑covered design to enhance the vintage look and feel, although it is terminated in Chinese 'Legun' connectors.

The PSU is the familiar Chinese offering, with a hammered‑paint finish. Mains power is applied via the usual fused IEC inlet and associated 115/230V selector switch, while a chunky toggle switch with associated 'jewelled' blue lamp‑cover powers the unit on and off. At the opposite end of the box is a seven‑pin XLR connector for the microphone and a three‑pin male XLR providing the audio output. A large rotary switch with winged knob adjusts the polar pattern in nine steps, from omni, through cardioid, to figure‑of-eight — a significant difference from the original ELA M 251E, which had body‑mounted switching for just three patterns.

The cat's‑cradle suspension follows the familiar Neumann design, and was finished to a good standard, although it lacked a 3/8‑inch thread adaptor for European mic stands. The elastic loops were tensioned appropriately for the mic, allowing a good degree of compliance.

The mic itself measures 50mm (diameter) by 225mm (length), weighs a moderate 620g, and was supplied in a satin‑silver anodised finish with chromed grille. The base ring can be unscrewed to release the body sleeve, gaining access to change the valve when required. A multi‑layer wire mesh protects the 34mm edge‑terminated Braunmühl‑Weber dual‑diaphragm capsule, and I'm told the diaphragms themselves are sourced, gold‑sputtered and tensioned on the Chinese back‑plates within the US. The impedance converter circuitry is built around a 6072A‑M valve (equivalent to the double‑triode 12AY7, although only one triode is used in this circuit), and a silicon‑rubber ring around the valve helps damp any tendency towards microphony. A bespoke CineMag transformer is used for the audio output.

The published specifications claim a frequency response spanning 20Hz to 24kHz, with a sensitivity of 14mV/Pa — which is typical of this kind of microphone. Maximum SPL is given as 138dB and self noise is 15dB (A‑weighted), both being very respectable figures for a valve mic. All Peluso Microphones are protected with a three‑year limited warranty, as well.


The Peluso 22 251 comes with a good‑quality carry case that also accommodates the power-supply unit, a high‑quality mic‑to‑PSU cable, and accessories that include a wooden box for the mic and a cat's‑cradle shockmount.The Peluso 22 251 comes with a good‑quality carry case that also accommodates the power-supply unit, a high‑quality mic‑to‑PSU cable, and accessories that include a wooden box for the mic and a cat's‑cradle shockmount.

When mounted in its shockmount via the screw thread in its base, and suspended above a vocalist, the Peluso 22 251 has that classically imposing and businesslike look of so many vintage mics. I found that it takes about 15 minutes to warm up from switch‑on before it delivers the performance it's capable of, but that shouldn't be an issue for anyone in practice. The ability to switch polar patterns remotely is handy, particularly if you can manage to install the power supply in the control room — but either way, having the full set available at the twist of a switch enables the amount and character of the recording room's ambient sound to be tailored to suit the performance requirements, as well as managing the proximity effect when required.

Obviously, the bass proximity effect is strongest in the figure-of-eight mode, and it is quite prominent when working within six inches or so of the source. Cardioid mode is balanced more evenly at that kind of close‑vocal distance, and the omni pattern is proximity effect‑free, of course. The proximity effect can be used to advantage to warm up a thin‑sounding source, of course, although keeping it under control can be a challenge, especially with very close working. Careful placement of an external pop shield and getting the vocal talent to remain almost touching it generally works well. I didn't experience any problems with popping in normal use, so the mesh grille is reasonably effective.

The 22 251's overall sound character tends obviously towards a rich quality, warm and full at the bottom end with a slightly rounded lower mid-range bloom, and a clear and detailed high end. The original Telefunken 251 is a slightly bright mic in comparison to its contemporaries (and slightly more lightweight than the AKG C12, in fact), and its gentle mid‑range suck-out at around 2kHz was balanced by the fulsome lower mid — the combination of which prevented the mic from appearing thin or edgy. All of those qualities and generic characteristics are largely shared here in the 22 251, although I wonder if the bottom end is actually quite as rounded as the original vintage model on which it is based... or maybe I'm just confusing myself with the sound of the C12, with which I'm much more familiar. I also noticed a mild hint of grittiness at the top end on occasions when the source really let rip, which I don't recall from my (few) past experiences of the 251, although, again, I doubt it will trouble anyone, given all the other positive qualities of this mic.


An original Telefunken ELA M 251 (right) alongside a more modern one made by Telefunken USA.An original Telefunken ELA M 251 (right) alongside a more modern one made by Telefunken USA.Photo: Matthew McGlynn

There is something inherently 'right' about the sound of large-format, large-diaphragm valve mics when it comes to recording vocals, and the 22 251 delivers a lovely bright, clear sound that retains just the right amount of warm, harmonic richness to complement the source nicely, whether a male or female voice. Although noticeably brighter than, say, a U47 (or equivalent), it doesn't expose sibilance in a nasty way, and while some vocalists might benefit from a darker- or fuller‑sounding mic given an expansive mic selection from which to choose, the 22 251 will deliver very usable and attractive results that will sit nicely in a mix with very little effort.

For some, the price (at least, here in the UK) of the Peluso 22 251 may seem unreachably high, yet in comparison with an original ELA M 251 it is the bargain of the century, delivering 95 percent of the sound character for a small fraction of the cost of a vintage model. Highly desirable!  


The flagship competitor is Telefunken Elektroakustik's own stunningly accurate ELA M 251E recreation, although the full‑monty version with a 6072 valve retails for £7072 including VAT in the UK, and the AC 701 valved version is an eye‑watering £9027. There are many other costly 251‑style recreations on the market, of course, such as the Soundelux ELUX 251 (about £3500) and the Lawson L251 (about £1600).

Of far more relevance in the context of the Peluso 22 251 is Telefunken's RFT‑series AR51, which is a lower-cost alternative based on the 251 concept, and has nine polar patterns. It retails for around £1395. Other valve mics worth considering in a similar price range as the 22 251 include its siblings, the Peluso 2247, P12 and VTB. Newmann Retro's NR47 and Retro models can also be considered, as can Rode's Classic II and the MXL Genesis. A slightly off‑the‑wall alternative is the Brauner Phantera, which is a solid‑state mic tuned to sound like a valve mic.

Background: The Original Telefunken 251

Back in the 1950s, Telefunken handled the worldwide distribution of Neumann's studio microphones, including their most popular model at the time, the U47. As part of that arrangement, Telefunken were allowed to re‑badge Neumann's flagship mic as the 'Tele 47' — often referred to by recording artists of the day, such as Frank Sinatra. However, when Neumann decided to manage the worldwide distribution of their products themselves, Telefunken were left without a flagship studio capacitor microphone.

Consequently, around 1959 Telefunken commissioned Austrian microphone manufacturer AKG to produce a bespoke version of their highly revered C12 multi‑pattern capacitor mic, developed by Konrad Wolf. The C12, which used AKG's CK12 capsule, had been in production since 1953 (production stopped in 1963 when solid‑state mics became more popular), and incorporated a clever internal capsule‑suspension system that avoided the need for an external shockmount. It was also the first mic to enable remote control of its (nine) polar patterns, using a rotary switch (S12) on a dedicated control unit, connected between the mic and power supply.

However, Telefunken wanted a pattern selector switch on the microphone itself (similar to the Neumann U47's arrangement), and the result was the Telefunken ELA M 250E (note the correct spacing in 'ELA M'). This switchable‑pattern mic offered cardioid and omni settings, and was constructed in a body that was slightly fatter than the slim AKG original, to accommodate the extra switching and circuitry, with the different grille dimensions affecting the sound quality in small but important ways from the original C12A.

A subsequent but much better‑known variant of the Telefunken microphone, called the ELA M 251E, was released, and this added a figure‑of‑eight polar pattern (essentially combining the facilities of both the Neumann U47 and U48 into a single microphone). Siemens also marketed OEM versions of the ELA M 250 and 251, called the SM203 and SM204.

The most obvious difference between the CK12 capsule and Neumann's M7 used in the early U47s is that the former used an edge‑terminated dual backplate design, as opposed to Neumann's centre‑terminated capsule. However, hidden inside the backplate, the AKG design operates in a fundamentally different way from the Neumann one, although the differences are technical and subtle: the former is based on a resonator design and the latter on the 'aperiodic' concept. The dimensions of the diaphragm to backplate spacing and the chamber labyrinths within the backplates also evolved over the life of the CK12 design, in an effort to increase its sensitivity. Amusingly, the side‑effect of this tinkering was to boost the extreme high‑end response, which subsequently became an integral characteristic of the C12's infamous sound. Also, early C12s employed 10‑micron-thick Styroflex diaphragms, but later versions (and all the Telefunken and Siemens models) used lighter and more responsive 9‑ and latterly 6‑micron Mylar diaphragms.

While the ELA M 250/251 employed the same 6072 double‑triode valve and Haufe T14 (14:1 ratio) output transformer as the AKG C12, the impedance-converter circuitry is significantly simpler. Another variant was also produced for the German and Austrian national broadcasters, differentiated by the absence of the 'E' suffix. For operational flexibility and convenience, these broadcasters had adopted a standardised capacitor‑mic power supply design developed by the IRT (Institute Fur Rundfunktechnic) and called the N52 — part of the 'Brown Book' standard for radio broadcast equipment of the time.

One small but important improvement in the ELA M 250/251's design over the C12 was that the valve was mounted upside‑down at the top of the body. This substantially reduced the length of the wires connecting the capsule outputs to the valve, and brought a worthwhile improvement in both quality and reliability. Perhaps an even more significant design difference, though, was the way the capsule and circuitry could be accessed. The AKG C12 (like the Neumann U47/48) was a fairly fiddly thing to disassemble and repair, but in redesigning the C12 for Telefunken, the AKG boffins introduced the much simpler (and now widespread) idea of locating the body tube with a simple screw collar at the base of the mic. This approach, combined with the design of the electronics module, made field repairs far more practical and speedy, which was a feature much appreciated by broadcasters in particular. Unfortunately, though, it also made the ELA M 251 (and its siblings) rather more expensive than their AKG and Neumann competitors — which is probably why they are relatively rare today.

Published May 2010