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What's inside the u87 head assembly switch deck? - Gearspace.com
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What's inside the u87 head assembly switch deck?
Old 6th March 2014
  #1
Lives for gear
 
Led's Avatar
 
๐ŸŽง 15 years
What's inside the u87 head assembly switch deck?

Inside the head assembly switch deck there is a resistor but also a small component looking like a choke or cap that has 250 marked on it. Anybody know what it is and does? This is a mid 70's 87.
Thanks.
Old 6th March 2014
  #2
Gear Nut
 
BradL8068's Avatar
 
๐ŸŽง 10 years
The cap is the Pad I believe.
Neumann U 87 | RecordingHacks.com
B
Old 6th March 2014 | Show parent
  #3
Lives for gear
 
SP2016's Avatar
 
๐ŸŽง 10 years
Quote:
Originally Posted by BradL8068 โžก๏ธ
The cap is the Pad I believe.
Neumann U 87 | RecordingHacks.com
B
Yes, it is the capacitor for -10 switching
Old 6th March 2014
  #4
Lives for gear
 
Led's Avatar
 
๐ŸŽง 15 years
Thanks for the replies. I could see it vaguely through the plastic but decided if I took the deck apart to get at it it could be a nightmare to get back together. I have a slight issue where comparing this 87 to an early 80's one I have the output is a bit lower.
I swapped the head assemblies and with the other head on this 70's 87 the output is a lot closer to the 80's 87, so I was wondering if something in the capsule was amiss. Both amp bodies have the R19 and R20 jumped and are set to 200ohms. The capsule that goes with the 70's 87 looks fine visually, so I'm trying to find the difference. The 70's one actually sounds pretty close to the 80's one sonically if I volume match them,
it;s just lower straight out of the mic.
Old 6th March 2014
  #5
Lives for gear
 
SP2016's Avatar
 
๐ŸŽง 10 years
Do not open the plexiglass capsule head !!!
Differences in sound may be caused by the capsule itself.
There were differences in the capsule heads: two capsules with a common back plate and two capsules with insulation.
There were K87 and K870 heads.
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