AUDIO ENGINEERING ASSOCIATES 1029 No. Allen Avenue, Pasadena, CA 91104 Phone: (626) 798-9128 / Fax: (626) 798-2378 E-mail: stereoms@compuserve.com COLES 4038 STUDIO RIBBON MICROPHONE USERÕS GUIDE By Ron Streicher and Wes Dooley QUICK START I F YOU CAN'T WAIT TO USE YOUR NEW COLES 4038, PLEASE READ THESE PRECAUTIONS FIRST SO YOU DON'T ACCIDENTALLY TRASH YOUR NEW TOY. 1 . KEEP YOUR 4038 COVERED BY THE SUPPLIED PLASTIC BAG WHEN NOT ACTUALLY BEING USED. A. THIS KEEPS THE STRONG MAGNET INSIDE THE 4038 FROM ATTRACTING "TRAMP" IRON PARTICLES WHICH POLLUTE THE INSIDE OF THE MIC. B. THIS ALSO PROTECTS THE VERY THIN (.6 micron) AND FAST ALUMINUM RIBBON INSIDE THE 4038 FROM BEING STRETCHED IF THE MIC CASE LID SNAPS SHUT OR IF THE MIC'S STAND IS MOVED TOO QUICKLY ACROSS THE STUDIO. 2 . NEVER PLUG THE 4038 INTO PHANTOM OR "T" POWERED MIC INPUTS. "T" POWER WILL INSTANTLY DESTROY A RIBBON (AND ALSO CAN HURT A DYNAMIC MIC). PHANTOM POWER CAN DO THE SAME IF YOU HAVE A BAD MIC CABLE. IT IS BEST TO PLAY IT SAFE BY TURNING OFF THE MIC POWERING AND WAIT A MINUTE. AFTER THIS IT IS SAFE TO PLUG IN YOUR RIBBON MIC. (THIS WILL ALLOW BOTH OF THE MIC PREAMPS' INPUT CAPACITORS TO DISCHARGE FULLY AFTER YOU TURN POWERING OFF.) 3 . TO INSERT THE CONNECTOR, LINE UP THE PINS AND PUSH IT IN. TO REMOVE THE CONNECTOR, SQUEEZE THE SILVER OVAL-SHAPED RING AT ITS WIDEST POINTS AND PULL THE CONNECTOR STRAIGHT OUT. 4 . WHILE THE COLES 4038 CAN HANDLE VERY LOUD SOUNDS AT HIGHER FREQUENCIES, IT CAN BE DAMAGED BY STRONG AIR GUSTS. SO AVOID KICK DRUMS AND LOUDSPEAKER BASS PORTS BECAUSE THEY CAN STRETCH EVEN A WELL PROTECTED RIBBON. IF YOU CAN FEEL THE AIR MOVE, DON'T PLACE THE MIC THERE. THE 4038 HAS A 1% DISTORTION POINT AT 110 Hz OF 125 DB SPL; AT 55 Hz THIS 1% POINT DROPS TO 110 DB SPL. THUS LOUD HORN SECTIONS ARE NO PROBLEM, BUT ON BASS GUITAR AMPS YOU SHOULD KEEP BACK TWO FEET OR MORE. ALSO REMIND THE PLAYER TO TURN DOWN THE AMP BEFORE CHANGING GUITARS OR SPL AT! (JOE CHICARELLI SUGGESTS THAT ON THE BIG MARSHALL STACKS, IT CAN BE USEFUL TO USE A 6" POPPER STOPPER IN FRONT OF THE 4038 AND/OR SET IT AT AN ANGLE TO THE SPEAKER.) 5 . WHEN USED AS A VOCAL MIC, USE A 6" POPPER STOPPER. THIS HELPS PROTECT THE RIBBON FROM BREATH BLASTING, POPPING, AND MOISTURE. Coles 4038 UserÕs Guide November, 1997 © Page 1 A QUICK TOUR OF THE 4038 It has been said that the railroads built America in the nineteenth century. These Òiron horsesÓ ran on Òribbons of steelÓ and carried commerce from one end of the country to another. In their own way, some of the classic early microphones also helped build America in the twentieth century. From their iron horseshoe magnets and ribbons of aluminum, the sounds they produced traversed the airwaves of the nation. These venerable microphones by such companies as RCA and Western Electric brought us the guiding voices that carried us through the ÒGreat Depression,Ó World War II, and the entertainment that sustained us through these troubles during the ÒGolden Age of RadioÓ in the 1930Õs and Õ40Õs. Thus it comes as no surprise that when in the early 1950Õs the BBC wanted a new microphone for FM broadcast which could continue in this tradition, they chose the principle of the ribbon as the basis for their new design. The proven quality of the ribbon was exemplified by its smooth frequency and excellent transient response, and the ÒrichÓ quality it imparted to both voices and music. However, the BBC also wanted an affordable microphone which would better withstand the rigors of use and would be smaller than its predecessors . The result was the Coles 4038 studio microphone. SO HOW DOES THE COLES 4038 SOUND? Very good indeed for a wide variety of users. In fact, the BBC / STC design team intended the 4038 to become the principal studio microphone for the BBC É and that it did. Functionally this means that, as with a classic Neve console, nothing sounds bad on a 4038 and many things sound just glorious. As with all mics, the choice of a preamp influences the final sound, although it's hard to find a combination that actually sounds bad with the 4038. (Jim Boyk, the artist in residence at California Institute of Technology has gone as far as building a transformerless all tube mic preamp for his pair of 4038's. He reports that he has yet to find 4038's resolution limit; the better he's been able to tweak his mic preamp, the more he hears. As a concert pianist, he records an instrument that is challenging to all microphones.) W h a t o t h e r i n s t r u m e n t s s o u n d g o o d w i t h a 4 0 3 8 ? S a x players (and recordists such as Keith Johnson of Reference Recordings) report that the 4038 is their mic of choice. LA area b rass player Malcolm McNab personally owns several pairs of 4038's, as does the award-winning scoring mixer Shawn Murphy, who has been using as many as ten 4038's at a time on the b r ass sections down at the Sony Pictures Scoring Stage. A comment received from Philadelphia was that the 4038 is the choice for sounds that are bigger than life. D r u m s a n d a m p l i f i e d g u i t a r would fit that description. From way down south in New Orleans came news about capturing the o r i g i n a l B e a t l e s Coles 4038 UserÕs Guide November, 1997 © Page 2 d r u m s o u n d with a good big room and a single 4038 with a tube preamp as the overhead mic. From New York we received an update on that sound, utilizing solid state mic preamps with a pair of 4038's for s t e r e o d r u m overheads, a large diaphragm dynamic for the kick, and a large room to record it in. Bob Rock recently used a pair of 4038's on Metallica as the air mics on a Marshall stack of g u i t a r a m p s . Steve Albini uses the 4038 on single g u i t a r a m p s at a distance of about two feet out. Acoustic instruments in general seem record well with the 4038. When one high end studio in LA got its first pair of 4038's the chief engineer wondered what in the world they sounded like. He had a pair of Avalon mic preamps available and an a c o u s t i c g u i t a r was what he first tried. He became another immediate convert. V i o l i n virtuoso Itzhak Perlmann recently completed a recording at for Telarc Digital, engineered by Jack Renner, where a coincident pair of 4038's were the principal pickup. Michael Bishop, also of Telarc Digital used the 4038's on sax and flute the following week with very pleasing results. Doug Sax of The Mastering Lab used them for a Sheffield direct to disk project to record a brass choir. Voices record well too. One producer was having problems with a female voice on a U47; they liked the midrange, but she was having sibilance problems. Then they tried a 4038, and got exactly the sound they wanted. If you have ever heard a southern gospel quartet and liked that deep, deep sound on the bass voice, you'll want to try a 4038 close up while using a 6" popper stopper. Bi-directional ribbon mics are the king as far as proximity-effect bass boost is concerned. This space reserved for your contribution. Coles 4038 UserÕs Guide November, 1997 © Page 3 AN IN-DEPTH TOUR OF THE 4038 The 4038 has been in continuous production for over 40 years. That's way longer than even the Shure SM58. As they say in the film business, ÒIts got great legs.Ó What has given the 4038 such staying power? Audio quality, reliability and versatility are the key elements. It's a classic that just never went out of production. So let's start with a quick physical tour of the microphone and then think about how to use it on a session. Starting at the bottom, you'll notice that the Coles 4038 uses a different output connector than you are used to. This is the original Western Electric (as in AT&T's manufacturing division) Type-4069 microphone connector. For vintage mic collectors this means there is still a source for this connector; for you it means learning about a new one. If you took the 4069 apart you would find that the three female sleeves are actually individual miniature single-circuit patch bay jacks. This is definitely a legacy from the earlier telephone era. Inserting the 4069 into the base of the microphone is fairly easy: it just slides and snaps in. Releasing it again after use takes a moment's reflection. Look for the silver band around the base of the mic. Notice that a screw holds it in place and that it slightly bulges 90 degrees either side of the screw? By squeezing this band on either side where it bulges out, you'll lift the internal latch pin and then you can slide out the connector. While this can be a careful two handed operation, it's easy to get the hang of it. The BBC owned a number of microphones that employed the 4069 connector and they intended that the connector be permanently left on a mic stand so that it functioned as a quick disconnect mic mounting system somewhat like we use the Atlas LO-2 mic stand quick disconnect adapter. The advantages of the BBC / Western Electric system is that it includes the audio connection and locates the reflective surfaces as far away from the mic element as possible. AEA offers a custom stand adaptor (4069 SA/XLR) for the 4069 connector which provides American standard 5/8"-27 female thread and is wired with a 16" cable and XLR-male connector. Alternatively, the 4070 adaptor directly converts the output to a conventional XLR-male. Up a bit from the silver connector release band, you will find a rotating ring assembly with three eyelets that protrude around the circumference. Two are opposite each other on the ring and the third is offset about 60 degrees. This mounting system is intended for flying or hanging the 4038. The two eyelets opposite each other are for flying the mic in a concert hall or large studio where the cables can come from opposite sides of the room. The eyelets at zero and sixty degrees are intended for hanging the mic from a large studio boom stand such as the Atlas BS 36W. The AEA 4038ES custom elastic suspension mount uses all three of these eyelets to safely and securely isolate the microphone from mechanical shock when boom mounted. Coles 4038 UserÕs Guide November, 1997 © Page 4 AEA also uses this rotating ring assembly for our multipurpose 4038SA stand adapter. This mounts to the 180 degree eyelets using 10-32 Allen head screws. The adapter itself accommodates both a 5/8"-27 mic stand and the European style 3/8" mic stud. The European mic mounts are provided both on the centerline and offset to one side to allow symmetrical stereo setups when using our SMP series of stereo microphone positioners Ñ heavy duty stereo bars specifically designed to securely handle the weight of the Coles 4038. The SMP will also support AKG, Neumann, or other large format microphones Ñ in all standard coincident or near coincident arrays. Next, above the rotating ring, you will find the 4038's yoke assembly. You can use this to adjust the angle of the mic head relative to the connector assembly. While the yoke provides a range of over a 90 degrees from the vertical (it's normal side address mode) all the way to being in line with a mic boom arm, because this is a bi-directional (figure eight) mic, it is generally advisable to angle it to minimize the ÒplumbingÓ in the way of the rear pickup lobe. The front (positive pressure lobe) of the 4038 is the side opposite the yoke assembly. The yoke assembly mounts to the microphone head through two short metal pads that penetrate the microphone's acoustical case. These pads are epoxied directly to the magnet assembly. If the microphone is dropped, these pads can be broken loose from the magnet. The good news is that the mic is designed so that even if things start rattling around, the mic does not fall apart. The bad news is that putting the whole thing back together is tedious bench work and if the yoke's pivot rod has been bent, the only way to fix it, is to replace it. Hint: Be careful and donÕt drop the mic! The yoke supports the mic head which contains the 4038's motor assembly and acoustical case. The unique shape of this acoustical casing was carefully worked out for best high frequency response, both on and off the centerline axis. The center top indentations on the front and rear grilles form an acoustic lens for the ribbon behind it. There is a fine mesh protective metal screen on the inside of the perforated metal outer case. Another fine mesh metal screen is positioned only a tenth of an inch either side of the ribbon to provide more mechanical protection and tame the low frequency resonance peak. Finally, there are acoustical wings inside the 4038's case that help extend the low frequency response down to 30 HZ while reducing the mic's sensitivity to mechanical shock. As with all bi-directional microphones, the principal pickup axes are straight to the front and back. While the amplitude at the rear is the same as the front, it is important to remember that the polarity is reversed. This is equivalent to hitting the "phase swi ...