Apex 460 Tube Condenser

This is the Apex 460 tube condenser microphone, manufactured in China by Alctron Electronics. It is their model T-11A rebadged as an Apex 460. Its design is based on the legendary AKG C12 studio condenser microphone.

A knob on the power supply switches the microphone to 9 individual polar patterns ranging from figure 8 to omni-directional. The Apex 460 comes supplied with a shock mount, a foam windscreen, power supply, cables and molded plastic carrying case. The supplied cable from the power supply to the microphone is about 30 feet long, more than enough for just about any studio or field recording situation. The tube is a Chinese 12AX7B, a very common tube in budget-priced Chinese tube condenser microphones.

The Apex 460 has become a very popular platform for modification. There are a number of websites on the internet that detail component and/or tube upgrades, yielding a microphone rivaling units costing over 10 times the street price of the stock Apex 460. Dave Thomas of Advanced Audio Microphones offers a modification package for the Apex 460, the finished product being on a par with the AKG C12 in terms of response and sound quality. In fact, a good friend who owns a recording studio in California recently tested the Advanced Audio CM-12 and was extremely impressed. He felt it actually sounded better than his Telefunken M16 MkII, another microphone based on the AKG C12.

My personal testing of the stock Apex 460 revealed a microphone with a robust bottom end as well as excellent response on transients in the upper partials. I did notice an emphasis in the upper midrange that might be problematic on some acoustic instruments with a high midrange component to begin with, such as flute; however, on trombone and piano the Apex 460 did a fine job reproducing the subtleties of these instruments. The sound quality and sensitivity of this microphone was very good overall. I found its overall character similar to the Stellar CM-3 reviewed below, but with slightly less midrange emphasis. The microphone already sounds good with the stock tube, but I suspect that a tube swap to a Mullard 12AT7 (or similar) might tend to tone down the midrange emphasis and “warm up” the mic’s sound a bit.

I would recommend this microphone for general field recording of small acoustic jazz groups, rockabilly, or bluegrass ensembles. The Apex 460 would also do well on a 5-piece brass ensemble.

Recently, there was an online exposé revealing that the Apex 460 is identical to the earlier Telefunken R-F-T M16 which sold for $1,200.00 (street price for an Apex 460 is around $200.00). This information generated a lot of controversy and a great deal of embarrassment for Telefunken USA. No link is provided here as the website has since been taken down, no doubt due to pressure from Telefunken. Once it was revealed that the Telefunken R-F-T M16 was, in fact, identical to the Apex 460, Telefunken USA immediately discontinued the R-F-T M16 and released the M16 MKII. Telefunken then offered purchasers of the original R-F-T M16 a free exchange/upgrade to the MKII model. Online reviews of the newer M16 MkII indicate that it is an excellent microphone.

I had the opportunity to test the Apex 460 on a very capable female vocalist and was quite impressed with the clarity with which it recorded her voice.  The slight upper midrange emphasis of the Apex 460 was a benefit in this case as it kept the subtleties of her articulation and enunciation  from getting lost in the mix.

Sterling Audio ST55

This is a Sterling Audio ST55 condenser microphone.  It features a low-cut filter to mitigate proximity effect and low frequency vibration from external sources, as well as a -10 db pad to compensate for louder sound sources.  Its pickup pattern is cardioid-only and is identical to the now-discontinued Groove Tubes GT55.

The capsule of this microphone sports a very thin 3-micron Mylar diaphragm, as well as a resonator disk mounted in front of the diaphragm to improve high frequency response and clarity on transients.  My tests confirm the effectiveness of this system.  Although it gives the microphone a “brighter” sound than one would expect, it is in no way objectionable or “edgy.”  I do not consider this brighter character to be a shortcoming of the microphone.

The ST55 exhibits a very clear sound with an average degree of proximity effect (along the lines of what one would expect of a LDC condenser microphone).  The enhanced high frequency clarity of the ST55 might make it a good choice for a vocalist or speaker with a bass-heavy voice.  I would not hesitate to use this microphone for voice-over work.

I tested this microphone on my own voice, my own instrument (trombone) and also on my 1898-vintage Sohmer upright piano.  In all cases, the ST55 demonstrated a very smooth response across the audio spectrum.  With that being said, I did notice a slightly subdued bottom end response as compared with the MXL 960 tube condenser microphone, the MXL 992 and the TCN Audio ACM-1 ribbon microphone.  This issue is more a matter of personal taste, rather than an undesirable characteristic of the ST55.

Overall, the Sterling Audio ST55 is a quality, budget-priced microphone with a very smooth frequency response and good transient response in the upper partials.  I would personally choose a pair of these to field-record a small string ensemble, harp, classical guitar or an acoustic bluegrass band.

Digital Reference DR-CX1 (Audio Technica AT2020)

The Digital Reference DR-CX1 is a side-address, phantom powered studio condenser microphone made in China.  It is identical to the Audio Technica AT2020.  The specifications for the Audio Techinca AT2020 can be found here:

http://www.audio-technica.com/cms/wired_mics/a0933a662b5ed0e2/index.html

The DR-CX1 feels quite solid in construction.  It has a hefty feel without being so heavy that it would overtax a table mounted scissor microphone stand.

I tested this microphone on a Sohmer upright piano and was very surprised at the overall smoothness of its response across the entire range of the piano.  It rendered a very faithful reproduction of the general sound of the instrument without favoring any particular range of frequencies.  The published response curve shows a very flat response, which bears out the result of my listening tests.

On voice, the DR-CX1 exhibited much less proximity effect than many of the other condenser microphones I’ve reviewed here.  For speakers with deep, boomy voices, the DR-CX1 (Audio Technica AT2020) would be a good choice for a broadcast or podcast microphone.

I’ve not tested this microphone on horns yet, but my initial recording tests on piano indicate that this microphone would likely work well on a variety of wind and string instruments.

MXL 9000

Like the MXL 960 and the Stellar CM-3 microphones reviewed below, the MXL 9000 is a tube condenser microphone that requires a dedicated, external power supply in order to operate. According to MXL, the 9000 uses a 12AT7, a miniature dual triode vacuum tube. I was unable to confirm this visually as the only marking on the tube is “MXL.” The 12AT7 is in the same tube family as the 12AX7; however, the 12AT7 has slightly less gain. My understanding is that the lower gain of the 12AT7 yields a signal that isn’t quite as hot, thus providing a “cleaner” signal.

My tests confirm that this microphone does indeed produce a very clean sound when used on acoustic instruments. Proximity effect is noticeable, but not quite as prominent as the Stellar CM-3 reviewed below (the CM-3 really shouldn’t be used as a vocal mic anyway). I did notice a very slight “eshiness” with the MXL 9000, but it wasn’t objectionable. In fact, this microphone seems to have a fairly smooth overall response. The MXL 9000 possesses a “warm” quality that seems typical of tube condenser microphones.

As with the MXL 960, the MXL 9000 presents a good platform for modification. The microphone is easily disassembled to facilitate tube substitutions, capsule replacement and other circuitry modifications. With that being said, I found the MXL 9000 to be a very good microphone in its stock form.

TNC Audio ACM-4

The TNC Audio ACM-4 ribbon microphone sports a short, dual-ribbon design and is a rebadged ShuaiYin SYR50. It’s exactly the same mic as the Apex 215 and the Alctron HRM-14B.

Ribbon microphones have a very low signal output and the dual-ribbon design of this microphone helps boost its output and sensitivity. When I compared the ACM-4 side-by-side with the ACM-1 and the NADY RSM-4, the ACM-4 definitely produced a noticeably higher output than the others. It also had a slightly brighter response in the upper frequencies; however, it was in no way “edgy” or harsh. In fact, the ACM-4 seemed to have the most balanced frequency response of all the ribbon mics I’ve tested so far. I would still prefer to use the ACM-1 long ribbon mic for baritone sax and low brass; however, if I were going to record flute or piccolo, the ACM-4 would be my choice.

I must admit to a bit of a bias toward ribbon microphones for horns, particularly trumpets. A good ribbon mic can take the brassy edge off a loud, screaming trumpet section in a jazz ensemble and give it just the right timbre in the mix.

TNC Audio ACM-1

This is a TNC Audio ACM-1 ribbon microphone. It has a “long ribbon, short path” ribbon motor design and is manufactured by Shanghai ShuaiYin of China.  It's one of many similar ribbon microphones rebadged for different distributors in the United States. This microphone is essentially the same mic as the NADY RSM-2 and the Alctron HRM-1. ShuaiYin’s version is branded the SYR-14 and is identical to the TNC Audio ACM-1 pictured here.

This microphone sounds amazing on horns, especially trumpets and French horns. It’s reminiscent of the RCA 77DX ribbon mic I used in college. It also sounds terrific on baritone sax.

Although the ACM-1 already sounds great in its stock form, the cool thing about this particular microphone is that it’s an excellent platform for modification. Just replacing the stock transformer with one of higher quality will allegedly yield excellent results. That, plus removing the extra windscreen shielding from the headbasket and adding sound absorbing material inside the microphone base can result in a quality of sound that rivals other ribbon microphones costing 10 times as much.

NADY CM100

The NADY CM100 is marketed as a “measurement microphone” (e.g., calibrating loudspeakers in a particular room space, as well as for tweaking sound system EQ). The NADY CM100 is also sold by Behringer as the ECM8000 and by Audix as the TR-40. They’re all essentially the same microphone.

The CM100 is not really intended for use as a studio recording mic; however, it has an extremely wide and flat frequency response, high definition and an omnidirectional polar pattern that made it very tempting to try as a field recording mic. I must say, I was rather pleasantly surprised at the results. I used it to record a small jazz band and the CM100 showed a very even, uncolored character – with a couple of caveats.

First, the polar pattern of the CM100 is not linear across its entire frequency spectrum. I noticed that the upper harmonics of the off-axis instruments were rather subdued. Second, on very pianissimo passages the microphone’s self (white) noise becomes apparent. On louder sources and passages, this isn’t as much of an issue.