Hi Christopher, Are you using the U87AI
for drum overheads????
has the capsule powered from about 38v dc (48v less the drop across the blocking resistors). The U87AI
has 60v on the capsule so not only does the capsule in the AI produce about 4db more output but the upper midrange also increases in level a db or two.
has less headroom than a the original U87
and they were headroom challenged. There is definitely a general agreement with seasoned engineers that the U87 does not sound as good with the pad engaged. I have not done any solid testing but I believe this is because of the negative feedback/de-emphasis circuit in the U87 and the pad interact.
Back in the day at Ocean Sound Studios in Vancouver we preferred the AKG 414eb microphones as drum overheads. We had both 87's and 414's.
1) the 414 circuit has 14db more headroom than the U87 and it has a -10/-20db pad that does not seem to degrade the sound like the U87.
2) the 414eb microphones also has less rise in the upper midrange and the low end was tighter sounding. Usually the 414eb has the -10db pad on and at Ocean we had 16' ceiling so we could get a bit of height above the drums.
The maximum output of a U87 before clipping is .39 of a volt RMS (directly from the Neumann specifications). .39 volts is -6dbu.
In my view as a microphone designer this is not enough headroom to use the microphone for drum miking...especially if your room has 8-10' ceilings. Unless its a light Jazz session or folk/rock.
When we built our LDC microphones we used the more elegant 414eb circuit which only cost us $10 more in parts but increases the headroom by 14db.
Drums have a very fast transient attack and the U87 would sound even nastier if it did not have its class "A" transformer coupled circuit. The U87 was designed for spot miking Orchestras and was never designed to be use for close vocals or close drum miking. Now, back in 1968 when the U87 first came out it was only $400 and some change. Large studios of the day bought 10 at a time and they eventually got into the hands of "rock" engineers.
In a big studio with an older U87 then it is possible to use the 87 for drum overheads but you certainly can't get them in as close as a 414eb. However, often drums were dampened more in the 70's and 80's than today. Today's modern snare drums also produce more output level. I use an old 1953 wooden snare as its not as loud as the new metal snares so I can hit the drum a bit harder without it producing a painful drum level.
You would definitely have to Pad the U87AI if you were using it in close for a John Glynn's set-up. You can buy some in-line pads between the microphone and the preamp but if the U87 is being driven into distortion the in-line pad will not help the situation.
When we designed our CM67se which is often used for drum overheads and in front of guitar/bass amps we designed a circuit that can produce 21db more headroom than a U87AI before the pad on the CM67se is engaged.
Nir Z who played drums with Genesis and on the first John Mayer CD uses our CM67se mics for drum overheads they are less than 1/3 the cost of the U87.
I have 9' ceilings in my home studio and with the CM67se set in a John Glynn configuration we usually have the -10db pad in and the Neve 1073
set to -20db of gain. The original API 312 has a 20db pad which need to be engaged when you were close miking drums.
Cheers, Dave Thomas
Originally Posted by Currecubaa
wow, thanks for all help guys.
the neve guys just checked my pre amp and there`s nothing wrong with it. So its probably something with my U87 ai going into Neve. Does anyone know if bying a pad between u87 and neve a good idea?or does it effect the quality?