CAD Trion Series Microphones

CAD is a company associated with many brand names (Conneaut Audio Devices, Omnitronics, Astatic), with a microphone-building legacy going back to the 1930s.
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CAD is a company associated with many brand names (Conneaut Audio Devices, Omnitronics, Astatic), with a microphone-building legacy going back to the 1930s. The company has primarily been associated with microphones for communication and installed sound applications, but has actively been providing studio mics for the past 20 years or so, the Trion series being their latest endeavor.


FAST FACTSApplications

Studio, broadcast, live sound

Key Features

Condenser element; ships with suspension mount and flight case.


Trion 6000 - $499

Trion 7000 - $479

Trion 8000 - $599


CAD Professional Microphones
The Trion 8000 ($599) and 6000 ($499) are both three-pattern, dual-diaphragm condenser mics with bottle-style bodies - a long cylinder with the capsule on a stalk. The 8000 has tube electronics and an external power supply; the 6000 is solid state, phantom powered. The Trion 7000 ($479) is a ribbon microphone with a short, squatty body and a large ball-shaped grille. All three are supplied with a “cat's cradle” suspension-type shockmount and each comes in a foam-fitted metal case with a carrying handle. The 8000 case - which holds the mic, power supply, and a 25-foot six-conductor cable - looks quite businesslike, and the other cases are functional. Those cases hold the mics very snugly; it takes both hands to remove one. Ballpark street prices are $400 for the 8000, $300 for the 6000, and $270 for the 7000, putting them in line with similar mics such as the Rode NTK tube mic, Studio Projects C3 solid state mic, and a couple of the higher-end Nady ribbon mics.

These are large and heavy mics. With shockmounts, the 8000 tips my kitchen scale at 2 pounds, 13.5 ounces, the 6000 is 2 pounds, 7 ounces, and the 7000 is a trim 1.5 pounds. For each, you'll need a sturdy stand, and particularly for the tube mic. The two condenser mics have different capsules - a 1.2-inch in the 8000 and a 1-inch in the 6000 - both using a traditional center-point connection - and are shockmounted in the head with three rubber blocks. Both mics have a three position mini toggle switch for pattern selection, with the 6000 adding switches for a 10 dB pad and a 100 Hz low-cut filter.

The 6000 is specified for 48V phantom power at 4.7 mA. This was of little concern in the past when phantom power meant 48 volts, but - with several contemporary devices touting phantom power that supply lower voltage - it's good to know. I connected the Trion 6000 to a Mackie Satellite FireWire interface with an open circuit phantom voltage of 38V. The mic didn't seem to be unhappy, but I didn't have anything loud enough to check the maximum SPL level, which is usually the first spec to go when running on reduced voltage.

The power supply for the 8000 is straightforward: solid state diodes and a single regulator IC. The tube filaments are fed with DC - a nice touch. The plate supply for the tube is 120V. The line voltage selector switch is a bit confusing; the notch in the switch slider lines up with the 230V marking on the chassis when it's actually in the 115V position - believe what it says on the switch. CAD agrees, and - beginning with the next production run - the legend will be removed from the case. A ground lift switch on the power supply disconnects Pin 1 of the output XLR connector from the power supply chassis.

The 7000 dual-ribbon assembly consists of two pleated aluminum 1.5-inch long and 0.15-inch wide ribbons, mounted parallel in a frame about 5/8-inch apart. Unlike Beyer's use of dual ribbons to extend the frequency response in their M-160, the goal of CAD's dual ribbon design is to provide higher output level than a single ribbon.

There's a fine mesh screen over the ribbon assembly, but no other blast filtering other than the rather coarse grille. These mics should be used with care. It might also be a good idea to store the mic in its case with the hinge at the bottom to keep the ribbons vertical.

Fit and finish are generally good. The mic bodies have a slightly rubbery feel that's easy to grip. Construction is conventional, with decent (but not really top-shelf) “thru-hole” mounted components, so the curious experimenter might improve low frequency performance or lower the self-noise by selecting premium resistors and capacitors. The impedance converter in the 8000 uses a type 6J1 tube, which is a new one on me. It's not listed in any of my tube manuals, and the only data sheet I could find for it is entirely in Chinese. It's a pentode with similar operating characteristics to the 6AU6, a more common tube used in this sort of microphone. The 6AU6 can indeed be used with a minor wiring change at the tube socket (Tweakers: take note). CAD tests and selects the 6J1 used in the Trion 8000, and they are gearing up to supply tested replacements.

All of the Trions have output transformers, so I suspected that they might be somewhat sensitive to preamp loading. Both of the condenser mics sounded about the same at any load setting between 2,500 and 500 ohms on the Mackie Onyx 800R preamp, with the output level dropping slightly at 300 ohms. The ribbon mic, however, was clearly happiest when loaded with 500 ohms, somewhat lower than the input impedance of most mic modern preamps. At 2,500 ohms, the low end sounded a bit flabby, and at 300 ohms, the high end, which is already kind of shy, became duller. If you were to use these mics regularly, it might be worth a little lab time to find the optimum termination resistor to add to your favorite preamp and build it into an XLR in-line adapter.

There's some magic with a boutique-style pre-amp, however. The 7000 really liked my Great River MP2, possibly because of its transformer input (the Mackie is transformerless), but for consistency and convenience, I did all my auditions using the Onyx 800R with it's input impedance set to 500 ohms for the ribbon mic and 1300 ohms for the condensers.

Mechanical resonances can affect the performance of a mic, so I tapped on the body of each microphone with a pencil to check for ringing. The “bottle” of the condenser mics is a long brass tube, and when removed and hung free, rings like a bell; however, it is substantially damped by the end-to-end clamping when in place. The 8000's housing resonates at around 110 Hz, and it takes about 250 milliseconds to drop 30 dB. The 6000's housing is better damped, decaying 30 dB in about 75 milliseconds, ringing at around 200 Hz. The 7000 is housed in a shallow steel bucket. Its primary resonance is around 180 Hz, but there's a secondary resonance around 40 Hz that continues out beyond 200 ms - this may be the resonance of the shockmount.

In Use

Most of the mics that I use regularly are ones that I've had for upwards of 20 years, and they've served me well. I don't own any modern, mid-priced mics with which to compare the Trions, so my comparisons are to my old standbys, all of which cost much more than these. I was pleasantly surprised at how well they compared.

Since CAD suggests vocals as the primary application for all of these mics (with of course a range of secondary applications), that's what I tried first. I set up the 6000 and 8000 and a Neumann U 87 (my usual go-to vocal mic) in a tight cluster and recorded them with Mackie HDR24/96 multitrack recorder, using the Onyx 800R as a front end. All were initially set to the cardioid pattern.

On both male and female speech, the Trion 6000 sounded remarkably close to the U 87 working both close (four inches) and distant (16 inches), with the exception of a bit of a bit brighter top end: perfectly acceptable as a contemporary vocal sound. The frequency response curve provided by the manufacturer shows a dip at about 7.5 kHz with a hump around 10 kHz, which is likely what I heard. The rise in the 3 kHz to 6 kHz range is similar to the U 87, suggesting the similar sound.

Compared to the U 87, when working close, the Trion 8000 exaggerated the low, chesty vocal range and mouth noises somewhat, suggesting that the bump at 15 kHz in the published curve is legitimate. At about 16 inches, the low end exaggerated by proximity effect smoothed out and the high end boost added an airy quality to the voice. Although the 6000's frequency response curve actually shows a greater low frequency rise than the 8000, this wasn't evident in my listening tests. Perhaps those curves were plotted at different working distances. I think it's a fair assessment that the Trion 8000 offers up the sonic characteristics that we expect from a tube mic today, and that's a good thing.

Both of the Trion condensers sounded close enough to the U 87 on acoustic guitar, banjo, and electric guitar that I'd be happy to use either one in that application. I have a very fat-sounding pedal steel, and the exaggerated low end of the 8000 muddied this up a bit much. On the amplifier, my preference - even over the U 87 - was the Trion 6000.

In the figure 8 configuration, both the 6000 and 8000 had a good null. The 8000 sounded very much alike from both sides, while the 6000 sounded a little brighter on the back side than the front. Several

of today's bidirectional mics advertise this as

a feature (two sounds for the price of one mic), though in truth, perfect symmetry is very difficult to achieve, and just about any dual-diaphragm mic sounds a little different from the back than from the front in the bidirectional mode.

Since I frequently record singing guitarists who aren't comfortable playing without singing, I often use figure 8 mics for both voice and guitar, positioning them so that the null of each mic points at the other source. While there's not always enough isolation to punch in voice or instrument, separation is good enough so that I can EQ each mic without problems due to leakage. I tried this setup with the Trion condensers, selecting (the obvious) tube mic for my voice and the solid state mic for guitar. I was able to get a good guitar sound with practically no vocal leakage, but I had to back far enough away from the vocal mic to lose the proximity effect and couldn't keep much guitar out of the vocal. Working closer and using EQ to cut the low end worked, but the voice really sounded better a foot from the mic than three or four inches.

I tried M/S stereo recording using the 6000 in figure 8 together with an AKG C451/CK1 cardioid mic and found this combination to work fairly well. Mounting the two mics on a single stand was a bit dicey due to the large size of the Trion shockmount, so I wouldn't recommend this as a regular thing unless you have a very heavy-duty mic stand, but it does work. While recording the birds and airplanes in the back yard, I learned that the Trion 6000 was quite sensitive to wind noise, and none of these mics come with a windscreen.

The Trion 7000 ribbon mic is a completely different animal, so it got its own set of listening comparisons alongside a Beyer M 160 and a Beyerdynamic M 260 modified with an RCA 77DX ribbon installed by restorer of RCA ribbon mics Stephen Sank of the Talking Dog Transducer Company. As previously determined, the 7000 sounds best when connected to a 500 ohm input, so that's how I ran it. The two Beyer mics, like many ribbons, prefer being connected to a higher input impedance. The Trion 7000 sounded remarkably like the modified M 260, which, coincidentally, sounds remarkably like a 77DX.

The high end of the Trion 7000 drops off quickly- and is pretty much gone above 10 kHz - but what's there sounds smooth with a pronounced proximity effect when closer than about six inches. It could make a good voiceover mic, and I wish I had one a year ago when I conducted a workshop, “Recording The Plunky Old Banjo.” I really liked it for that. I didn't care for it on acoustic guitar, but that top end rolloff was effective on a scratchy fiddle. The M160 (also a dual ribbon mic) is considerably brighter than the Trion, and while it has a similar low end, it really didn't make for a fair comparison though it's one of my favorites on fiddle.

Checking the sound on both sides of the 7000 proved to be rather interesting. The rear side was somewhat thinner-sounding than the front, but since the acoustic polarity going into the rear is opposite that going into the front, I tried inverting polarity on the console and listened back to the recording. Darn! If the recording from the rear when inverted didn't sound just like the recording from the front! Out of curiosity (and thinking that maybe we'd been fooling ourselves all these years) I tried the same experiment with the Trion 6000, but on that mic, the rear side still sounded brighter than the front even with the polarity reversed.

According to the spec sheets, the 7000 is about 16 dB less sensitive than its condenser brethren, but in practice (with a 500 ohm load) I found that its output was about 20 dB lower. This is a mic that needs a lot of gain unless you're using it on an amplified guitar or some other loud source. I would have liked to try it on tuba or trombone, but one didn't show up during my review period. Also, it's somewhat hum sensitive. The steel case and shielded transformer no doubt helps, but the ribbon assembly still makes a pretty good antenna. In one room with some strange AC hum fields, I needed to turn the mic to null out the hum, but it's good to know that such is possible.


These are all pretty good mics, and I don't feel that it's necessary to add the “for the price” qualifier. CAD has come up with a useful set of microphones that won't break the bank. Don't read into this that Trion condenser mics sound just like a U 87 (they don't, but then my two U 87s don't sound exactly the same either). However, I wouldn't hesitate to try either of these mics for any application where I'd reach for a U 87. The Trion 7000 ribbon is a special case: it's not a mic for everybody, but if you've wanted to experiment with a ribbon mic, it should meet your expectations.