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Kurt Ballou
Guest
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 Posted:
Sat Nov 27, 2004 6:14 am Post subject:
schematic and prints for akg 451 pad? |
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there seems to be a big shortage of -20db pads for 451's out there.
especially now that everyone is jumping on the lollipop bandwagon.
i'm suprised the BLUE hasn't started offering pads. i've been
searching for a couple of -20db pads for a couple of years now with no
luck, so i'm thinking of building a bunch myself. my dad is a
machinist who can take care of the metal work. i just need to figure
out what's going on inside. i think it's just a couple of resistors.
does anyone have a schematic, blue print, words of advice, one i could
borrow and reverse engineer, etc?
thanks
kurt
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Predrag Trpkov
Guest
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| Posted:
Sat Nov 27, 2004 12:16 pm Post subject:
Re: schematic and prints for akg 451 pad? |
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"Kurt Ballou" <godcity@aol.com> wrote in message
news:d9baa238.0411262044.471b1b44@posting.google.com...
| Quote: | there seems to be a big shortage of -20db pads for 451's out there.
especially now that everyone is jumping on the lollipop bandwagon.
i'm suprised the BLUE hasn't started offering pads. i've been
searching for a couple of -20db pads for a couple of years now with no
luck, so i'm thinking of building a bunch myself. my dad is a
machinist who can take care of the metal work. i just need to figure
out what's going on inside. i think it's just a couple of resistors.
does anyone have a schematic, blue print, words of advice, one i could
borrow and reverse engineer, etc?
thanks
kurt
|
If the electronic part of it is that simple, building a couple of resistors
and a tiny switch into the body might be less complex a task. Squeezing a
few parts onto the pcb should be far easier than any metalwork.
Predrag |
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Scott Dorsey
Guest
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| Posted:
Sat Nov 27, 2004 6:07 pm Post subject:
Re: schematic and prints for akg 451 pad? |
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Kurt Ballou <godcity@aol.com> wrote:
| Quote: | there seems to be a big shortage of -20db pads for 451's out there.
especially now that everyone is jumping on the lollipop bandwagon.
i'm suprised the BLUE hasn't started offering pads. i've been
searching for a couple of -20db pads for a couple of years now with no
luck, so i'm thinking of building a bunch myself. my dad is a
machinist who can take care of the metal work. i just need to figure
out what's going on inside. i think it's just a couple of resistors.
does anyone have a schematic, blue print, words of advice, one i could
borrow and reverse engineer, etc?
|
It's a capacitive shunt. This is why it affects the sound so substantially.
I really recommend avoiding the things as much as possible, but you can
build one with a single NPO cap shunted across the capsule.
Note that a -20 dB pad on the CK1 is going to have much less than a -20 dB
drop on the BLUE capsules, since they have a larger area and therefore more
capacitance.
If there is any way you can pad down on the output instead of the input
of the electronics, THERE you can use a resistive pad which will have
much less of a sonic effect. But if the mike electronics are clipping,
you're stuck.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis." |
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Mike Rivers
Guest
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| Posted:
Sat Nov 27, 2004 6:07 pm Post subject:
Re: schematic and prints for akg 451 pad? |
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In article <d9baa238.0411262044.471b1b44@posting.google.com> godcity@aol.com writes:
| Quote: | there seems to be a big shortage of -20db pads for 451's out there.
especially now that everyone is jumping on the lollipop bandwagon.
i'm suprised the BLUE hasn't started offering pads. i've been
searching for a couple of -20db pads for a couple of years now with no
luck, so i'm thinking of building a bunch myself. my dad is a
machinist who can take care of the metal work.
|
Maybe you should offer your dad's services to BLUE. They said that the
reason why they didn't make pads (and swivels, too) was because the
machining was too expensive and a new one would cost too much. But if
you can get the machining for free, the rest is easy.
I think it's just a capacitor. If you were to send the mechanical
parts to BLUE, I'm sure they'd put the guts in there for a very
reasonable price and verify that it worked correctly.
--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo |
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Frank Vuotto
Guest
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| Posted:
Sat Nov 27, 2004 6:07 pm Post subject:
Re: schematic and prints for akg 451 pad? |
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On Sat, 27 Nov 2004 09:34:44 -0800, "Richard Crowley"
<rcrowley7@xprt.net> wrote:
| Quote: | All of the cost seems
to be in the low-volume mechanical components. Machining the
relatevly large-diameter, small-pitch threads would appear be the
tricky part
|
Those treads are a pisser. I have one mic that the capsule screws
smoothly into a pad and the pad smoothly into the body but to screw
the capsule directly into the body is next to impossible. I've tried a
few machine shops to see if someone could clean up the threads but no
one had any tap/die that size.
Frank /~ http://newmex.com/f10
@/ |
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Richard Crowley
Guest
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| Posted:
Sat Nov 27, 2004 6:08 pm Post subject:
Re: schematic and prints for akg 451 pad? |
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"Mike Rivers" <mrivers@d-and-d.com> wrote in message
news:znr1101562460k@trad...
| Quote: |
In article <d9baa238.0411262044.471b1b44@posting.google.com
godcity@aol.com writes:
there seems to be a big shortage of -20db pads for 451's out there.
especially now that everyone is jumping on the lollipop bandwagon.
i'm suprised the BLUE hasn't started offering pads. i've been
searching for a couple of -20db pads for a couple of years now with no
luck, so i'm thinking of building a bunch myself. my dad is a
machinist who can take care of the metal work.
Maybe you should offer your dad's services to BLUE. They said that the
reason why they didn't make pads (and swivels, too) was because the
machining was too expensive and a new one would cost too much. But if
you can get the machining for free, the rest is easy.
I think it's just a capacitor. ...
|
The pads I have inspected (not an exhaustive survey, but a few)
look like they are simply small-value capacitors. Can't cost more
than a buck or two worth of components. All of the cost seems
to be in the low-volume mechanical components. Machining the
relatevly large-diameter, small-pitch threads would appear be the
tricky part |
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Scott Dorsey
Guest
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| Posted:
Sun Nov 28, 2004 12:09 am Post subject:
Re: schematic and prints for akg 451 pad? |
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Frank Vuotto <deepthrob@hotmail.com> wrote:
| Quote: | On Sat, 27 Nov 2004 09:34:44 -0800, "Richard Crowley"
rcrowley7@xprt.net> wrote:
All of the cost seems
to be in the low-volume mechanical components. Machining the
relatevly large-diameter, small-pitch threads would appear be the
tricky part
Those treads are a pisser. I have one mic that the capsule screws
smoothly into a pad and the pad smoothly into the body but to screw
the capsule directly into the body is next to impossible. I've tried a
few machine shops to see if someone could clean up the threads but no
one had any tap/die that size.
|
I don't think you can make taps and dies like that, not if you want them
to last long at all. A good shop should be able to chase the threads
on a lathe but they're going to need a small precision lathe because a
typical engine lathe won't do threads that fine.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis." |
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Mike Rivers
Guest
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| Posted:
Sun Nov 28, 2004 12:09 am Post subject:
Re: schematic and prints for akg 451 pad? |
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In article <10qhelmgaepjad1@corp.supernews.com> rcrowley7@xprt.net writes:
| Quote: | Machining the
relatevly large-diameter, small-pitch threads would appear be the
tricky part
|
That's correct. If they had used pipe threads, they'd be cheap. <g>
--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo |
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Kurt Ballou
Guest
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| Posted:
Sun Nov 28, 2004 6:19 am Post subject:
Re: schematic and prints for akg 451 pad? |
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the threads can be cut on a lathe or a milling machine with a 4th
axis. i'm sure dad would whip me up a few for free, but any sort of
volume production couldn't be done cheaply.
any idea how much attenuation different capacitor values would have?
and how are they wired? |
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Kurt Albershardt
Guest
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| Posted:
Sun Nov 28, 2004 11:51 am Post subject:
Re: schematic and prints for akg 451 pad? |
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Frank Vuotto wrote:
| Quote: | On Sat, 27 Nov 2004 09:34:44 -0800, "Richard Crowley"
rcrowley7@xprt.net> wrote:
All of the cost seems
to be in the low-volume mechanical components. Machining the
relatevly large-diameter, small-pitch threads would appear be the
tricky part
Those treads are a pisser. I have one mic that the capsule screws
smoothly into a pad and the pad smoothly into the body but to screw
the capsule directly into the body is next to impossible. I've tried a
few machine shops to see if someone could clean up the threads but no
one had any tap/die that size.
|
That's why they changed the design for the C460/C480 series.
Skipper or Martens (if you're listening) why no lollipops for the newer bodies? |
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hank alrich
Guest
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| Posted:
Sun Nov 28, 2004 6:20 pm Post subject:
Re: schematic and prints for akg 451 pad? |
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Kurt Albershardt <kurt@nv.net> wrote:
| Quote: | Skipper or Martens (if you're listening) why no lollipops for the newer
bodies?
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Bet the monsoon of cheapie import LDC's compared to the number of 480
users out there makes it a risky financial undertaking (so to speak...).
Hell, why not offer one that rides on a CMC6?
--
ha |
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Scott Dorsey
Guest
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| Posted:
Sun Nov 28, 2004 6:21 pm Post subject:
Re: schematic and prints for akg 451 pad? |
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Kurt Ballou <godcity@aol.com> wrote:
| Quote: | the threads can be cut on a lathe or a milling machine with a 4th
axis. i'm sure dad would whip me up a few for free, but any sort of
volume production couldn't be done cheaply.
|
Show him the threads. If he's got an old West Bend, you're going to
be out of luck cutting them, I bet. But on a precision lathe it should
be not too big a deal.
| Quote: | any idea how much attenuation different capacitor values would have?
and how are they wired?
|
They are wired parallel to the capsule, and the degree of attenuation
depends on the capacitance of the capsule. If the capsule has 22 pF
between diaphragm and stator, then a 22 pF shunt will halve the output.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis." |
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Rob Reedijk
Guest
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| Posted:
Tue Nov 30, 2004 12:22 am Post subject:
Re: schematic and prints for akg 451 pad? |
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Kurt Ballou <godcity@aol.com> wrote:
| Quote: | there seems to be a big shortage of -20db pads for 451's out there.
especially now that everyone is jumping on the lollipop bandwagon.
i'm suprised the BLUE hasn't started offering pads. i've been
searching for a couple of -20db pads for a couple of years now with no
luck, so i'm thinking of building a bunch myself. my dad is a
machinist who can take care of the metal work. i just need to figure
out what's going on inside. i think it's just a couple of resistors.
does anyone have a schematic, blue print, words of advice, one i could
borrow and reverse engineer, etc?
thanks
|
It's a good point about getting BLUE to do it since they have already
got some of the machining in place.
But I would be hesitant about using the pads since the connection of
the capsule to the body is a big weak point in the 451. This is a great
source of noise, and you may be adding more. (Though presumably if you
need to pad it down, noise won't be a problem?).
I would also think that it is difficult to create these things since
the body is what conducts the ground and it limits the type of pads
that can be designed. And no matter what, you will have trouble with
how the shunt resistor connects to the body in the pad.
I am not an EE, so, please feel free to shoot me down!
Rob R. |
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Kurt Albershardt
Guest
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| Posted:
Tue Nov 30, 2004 6:22 am Post subject:
Re: schematic and prints for akg 451 pad? |
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Rob Reedijk wrote:
| Quote: |
It's a good point about getting BLUE to do it since they have already
got some of the machining in place.
But I would be hesitant about using the pads since the connection of
the capsule to the body is a big weak point in the 451. This is a great
source of noise, and you may be adding more.
|
Which reminds me: I'd like to leave the A60M thread adapters on my B6's semi-permanently so they threads don't get mangled. I'd much prefer that they unscrew from the C460B amplifiers since those threads are much less subject to damage.
Is there a conductive equivalent to locktite? |
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Richard Crowley
Guest
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| Posted:
Tue Nov 30, 2004 6:23 am Post subject:
Re: schematic and prints for akg 451 pad? |
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"Rob Reedijk" wrote ...
| Quote: | I would also think that it is difficult to create these things since
the body is what conducts the ground and it limits the type of pads
that can be designed. And no matter what, you will have trouble with
how the shunt resistor connects to the body in the pad.
|
All the pads I've seen are simply a single capacitor in
series with the signal path. No connection to the shell. |
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