[Ian Bell[_2_]]

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

[Don Pearce[_3_]]

On Tue, 14 Jul 2009 09:54:30 +0100, Ian Bell
wrote:

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

Use ordinary grommets - about half inch diameter. To mount them stand
them on edge (like balancing a coin) and fix them to both top and
bottom chassis using small P clips. Mount them all at right angles to
each other and they won't fall over and lie flat.

d

[fredbloggstwo]

"Ian Bell" wrote in message
...
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

Ian

a friend of mine had a similar problem on some V72 amps where the existing
mounts had perished. He got some replacements from Maplins - I don't know
the part number though. They are a small rubber mount with a M3 screw in
each end.

Cheers

Mike

[baron]

Ian Bell Inscribed thus:

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

If you only want a few, and are happy with salvage, then a scrap CD rom
drive will provide what you want !

--
Best Regards:
Baron.

[Scott Dorsey]

Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

There are a bunch of possibilities depending on the mass of the board.
The easy one is to take rubber grommets of the sort that appliances use
for power cables, and just run a bolt through them. Those should be
available from a local hardware store.

It gets much fancier from that point, up to suspended shock mounts like
the folks at http://www.gmt.gb.com or Engineering Dynamics in Andover sell.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[DougC]

Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

"Just any rubber" will not dampen vibrations.
What you want is named Sorbothane (at least in the US).


Good luck
~

[Rich Grise[_2_]]

On Tue, 14 Jul 2009 09:54:30 +0100, Ian Bell wrote:

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?


Maybe check with Wallace? ;-)
http://www.wallaceandgromit.com/

Cheers!
Rich

[Dave Platt]

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

There are a bunch of possibilities depending on the mass of the board.
The easy one is to take rubber grommets of the sort that appliances use
for power cables, and just run a bolt through them. Those should be
available from a local hardware store.

It gets much fancier from that point, up to suspended shock mounts like
the folks at http://www.gmt.gb.com or Engineering Dynamics in Andover sell.

One useful possibility: Well-Nuts. They're T-shaped rubber bushings,
with a small nut cast into the end of the stem. Very convenient and
easy to use.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

[Ian Bell[_2_]]

fredbloggstwo wrote:
"Ian Bell" wrote in message
...
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

Ian

a friend of mine had a similar problem on some V72 amps where the existing
mounts had perished. He got some replacements from Maplins - I don't know
the part number though. They are a small rubber mount with a M3 screw in
each end.

Cheers

Mike





Thanks for that. I found this on their web site:

http://www.maplin.co.uk/Module.aspx?ModuleNo=98863


I have asked them what they are mode of and what size they are. Thanks
for the tip.

Cheers

Ian

[Ian Bell[_2_]]

Scott Dorsey wrote:
Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

There are a bunch of possibilities depending on the mass of the board.
The easy one is to take rubber grommets of the sort that appliances use
for power cables, and just run a bolt through them. Those should be
available from a local hardware store.


Yes, that had occured to me but the trouble is the bolt is not really
tightened and may come loose in use or more likely during shipping - and
you know of my recent shipping experience.


I was thinking more of the grommets with a built in cylindrical hollow
metal shaft so you could bolt down tightly to the shaft but the PCB
would be suspended from the outer diameter of the grommet. I am suire I
have seen these in old wireless sets.

It gets much fancier from that point, up to suspended shock mounts like
the folks at http://www.gmt.gb.com or Engineering Dynamics in Andover sell.
--scott


That's more like it. Their miniature buffers look very interesting.
Thanks for that.

Cheers

Ian

[Ian Bell[_2_]]

Dave Platt wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?
There are a bunch of possibilities depending on the mass of the board.
The easy one is to take rubber grommets of the sort that appliances use
for power cables, and just run a bolt through them. Those should be
available from a local hardware store.

It gets much fancier from that point, up to suspended shock mounts like
the folks at http://www.gmt.gb.com or Engineering Dynamics in Andover sell.

One useful possibility: Well-Nuts. They're T-shaped rubber bushings,
with a small nut cast into the end of the stem. Very convenient and
easy to use.



They look really good, but the smallest I have found so far is M5.

Cheers

Ian

[Scott Dorsey]

Ian Bell wrote:
Scott Dorsey wrote:
Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

There are a bunch of possibilities depending on the mass of the board.
The easy one is to take rubber grommets of the sort that appliances use
for power cables, and just run a bolt through them. Those should be
available from a local hardware store.

Yes, that had occured to me but the trouble is the bolt is not really
tightened and may come loose in use or more likely during shipping - and
you know of my recent shipping experience.

Right, you slip a piece of tubing over the bolt, then tighten the bolt down
over the tubing.

I was thinking more of the grommets with a built in cylindrical hollow
metal shaft so you could bolt down tightly to the shaft but the PCB
would be suspended from the outer diameter of the grommet. I am suire I
have seen these in old wireless sets.

It gets much fancier from that point, up to suspended shock mounts like
the folks at http://www.gmt.gb.com or Engineering Dynamics in Andover sell.

That's more like it. Their miniature buffers look very interesting.
Thanks for that.

A lot of that stuff used to show up on the surplus market around here. I
suspect if you can find a place where people still do manufacturing work
that there is a lot of it.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Ian Bell[_2_]]

DougC wrote:
Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

"Just any rubber" will not dampen vibrations.
What you want is named Sorbothane (at least in the US).


Good luck
~



I found their web site, don't seem to have a UK distributor though -
interesting none the less - I downloaded their brochure.

Thanks for the tip.

Cheers

Ian

[Ian Bell[_2_]]

Scott Dorsey wrote:
Ian Bell wrote:
Scott Dorsey wrote:
Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?
There are a bunch of possibilities depending on the mass of the board.
The easy one is to take rubber grommets of the sort that appliances use
for power cables, and just run a bolt through them. Those should be
available from a local hardware store.
Yes, that had occured to me but the trouble is the bolt is not really
tightened and may come loose in use or more likely during shipping - and
you know of my recent shipping experience.

Right, you slip a piece of tubing over the bolt, then tighten the bolt down
over the tubing.


Hmmm, that might work really well. Just make the tubing slightly shorter
than the thickness of the grommet so it gets compressed slightly. Now I
just need a source of tubing.

Cheers

Ian

[GregS[_3_]]

In article , DougC wrote:
Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

"Just any rubber" will not dampen vibrations.
What you want is named Sorbothane (at least in the US).


I don't know if Sorbathane comes in different varieties.
The stuff I know is fairly stiff and not good for
lightweight items. I like using the black foam rubber
used for insulating pipes. Not the Polyethylene stuff,
but the stuff that is very soft and does not spring back
real fast. Kind of gummy. You can cut it up as desired. Try plumbing
or home depts.

greg

[Scott Dorsey]

GregS wrote:
In article , DougC wrote:
Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

"Just any rubber" will not dampen vibrations.
What you want is named Sorbothane (at least in the US).

I don't know if Sorbathane comes in different varieties.
The stuff I know is fairly stiff and not good for
lightweight items.

Sorbothane is a urethane polymer. You can order it in a whole bunch of
different durometers. I don't know that it's better than any other urethane
rubber, but they have outrageously good marketing.

I like using the black foam rubber
used for insulating pipes. Not the Polyethylene stuff,
but the stuff that is very soft and does not spring back
real fast. Kind of gummy. You can cut it up as desired. Try plumbing
or home depts.

That's a urethane foam.... the air in it changes the properties a lot, though.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected][_2_]]

On Jul 14, 7:05*am, (Scott Dorsey) wrote:
Ian Bell wrote:

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

There are a bunch of possibilities depending on the mass of the board.
The easy one is to take rubber grommets of the sort that appliances use
for power cables, and just run a bolt through them. *Those should be
available from a local hardware store.

It gets much fancier from that point, up to suspended shock mounts like
the folks athttp://www.gmt.gb.comor Engineering Dynamics in Andover sell.
--scott

--
"C'est un Nagra. *C'est suisse, et tres, tres precis."

Those shock mounts are easily purchased in Silicon Valley surplus
shops. but I have to say they are not very "wiggly." I would look for
silicone grommets.
http://www.antec.com/Detail.bok?no=328
http://en.wikipedia.org/wiki/File:Si...e_grommets.JPG

[John Larkin]

On Tue, 14 Jul 2009 09:54:30 +0100, Ian Bell
wrote:

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian


Yesterday we had a rep drop by from EAR

http://www.earshockandvibe.com/

who dropped off a really cool sample kit of grommets and pull-through
fasteners for mounting disk drives and fans. He also gave us a golf
ball molded from one of their plastics. Drop it onto a tabletop and it
just goes thud, no bounce. They also have some thin sheets of
dead-soft foam-like fabric.

Try to wrangle their C-1000 sample kit.

John

[[email protected][_2_]]

On Jul 15, 11:01*am, John Larkin
wrote:
On Tue, 14 Jul 2009 09:54:30 +0100, Ian Bell
wrote:

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

Yesterday we had a rep drop by from EAR

http://www.earshockandvibe.com/

who dropped off a really cool sample kit of grommets and pull-through
fasteners for mounting disk drives and fans. He also gave us a golf
ball molded from one of their plastics. Drop it onto a tabletop and it
just goes thud, no bounce. They also have some thin sheets of
dead-soft foam-like fabric.

Try to wrangle their C-1000 sample kit.

John

This looks like a good company. I wish they had that stuff at
Digikey.

The silicone mounts for the hard drives do wonders. Incidentally, the
fans used by Antec in their silent PC are pretty low quality in terms
of how well they are sealed. I've replaced a few after 4 years of
duty. The 3 level speed control they use is good. I can run them on
low and not have any overheating problems. The Silent PC case is
damped a bit. Of course, it is not silent, but it is a vast
improvement over a stock PC case.

If you want a quiet PC CPU fan, go for the Zalman all copper units.

[Rich Webb]

On Wed, 15 Jul 2009 12:17:12 -0700 (PDT), "
wrote:

On Jul 15, 11:01*am, John Larkin
wrote:
On Tue, 14 Jul 2009 09:54:30 +0100, Ian Bell
wrote:

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

Yesterday we had a rep drop by from EAR

http://www.earshockandvibe.com/

who dropped off a really cool sample kit of grommets and pull-through
fasteners for mounting disk drives and fans. He also gave us a golf
ball molded from one of their plastics. Drop it onto a tabletop and it
just goes thud, no bounce. They also have some thin sheets of
dead-soft foam-like fabric.

Try to wrangle their C-1000 sample kit.

John

This looks like a good company. I wish they had that stuff at
Digikey.

McMaster-Carr is the go-to place for this kind of thing. They do carry
electronics-related as well (good price on Kapton tape) but have tons of
mechanical piece parts. Not always the cheapest but reputable and good
stock depth.

http://www.mcmaster.com/ Search on "vibration mounts" and start there.

--
Rich Webb Norfolk, VA

[GregS[_3_]]

In article , Rich Webb wrote:
On Wed, 15 Jul 2009 12:17:12 -0700 (PDT), "
wrote:

On Jul 15, 11:01*am, John Larkin
wrote:
On Tue, 14 Jul 2009 09:54:30 +0100, Ian Bell
wrote:

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

Yesterday we had a rep drop by from EAR

http://www.earshockandvibe.com/

who dropped off a really cool sample kit of grommets and pull-through
fasteners for mounting disk drives and fans. He also gave us a golf
ball molded from one of their plastics. Drop it onto a tabletop and it
just goes thud, no bounce. They also have some thin sheets of
dead-soft foam-like fabric.

Try to wrangle their C-1000 sample kit.

John

This looks like a good company. I wish they had that stuff at
Digikey.

McMaster-Carr is the go-to place for this kind of thing. They do carry
electronics-related as well (good price on Kapton tape) but have tons of
mechanical piece parts. Not always the cheapest but reputable and good
stock depth.

http://www.mcmaster.com/ Search on "vibration mounts" and start there.


That always makes me think of the old boss. He said the MCS website was so
much better at ordering than McMaster Carr. i'm sure he was right for what he was doing,
but I never truely compared the two.

greg

[GregS[_3_]]

In article , (GregS) wrote:
In article , Rich Webb
wrote:
On Wed, 15 Jul 2009 12:17:12 -0700 (PDT), "
wrote:

On Jul 15, 11:01*am, John Larkin
wrote:
On Tue, 14 Jul 2009 09:54:30 +0100, Ian Bell
wrote:

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

Yesterday we had a rep drop by from EAR

http://www.earshockandvibe.com/

who dropped off a really cool sample kit of grommets and pull-through
fasteners for mounting disk drives and fans. He also gave us a golf
ball molded from one of their plastics. Drop it onto a tabletop and it
just goes thud, no bounce. They also have some thin sheets of
dead-soft foam-like fabric.

Try to wrangle their C-1000 sample kit.

John

This looks like a good company. I wish they had that stuff at
Digikey.

McMaster-Carr is the go-to place for this kind of thing. They do carry
electronics-related as well (good price on Kapton tape) but have tons of
mechanical piece parts. Not always the cheapest but reputable and good
stock depth.

http://www.mcmaster.com/ Search on "vibration mounts" and start there.


That always makes me think of the old boss. He said the MCS website was so
much better at ordering than McMaster Carr. i'm sure he was right for what he
was doing,
but I never truely compared the two.


MSC MSC MSC



greg

[Engineer[_2_]]

On Jul 14, 4:54*am, Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

It's not just grommets, it's the overall mass/compliance ratio. You
need enough mass on the "tube (PCB) side" of the compliance so that it
does not move much in "inertial space" when the other side of the
compliance is "bumped". PCB's tend to be a bit light so I'd add some
mass, then use the softest "grommet suspension" confguration you can
find that will still hold up the now heavier PCB assy. The "on edge"
grommet idea looks good to me.
Cheers.
Roger

[GregS[_3_]]

In article , Engineer wrote:
On Jul 14, 4:54=A0am, Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

It's not just grommets, it's the overall mass/compliance ratio. You
need enough mass on the "tube (PCB) side" of the compliance so that it
does not move much in "inertial space" when the other side of the
compliance is "bumped". PCB's tend to be a bit light so I'd add some
mass, then use the softest "grommet suspension" confguration you can
find that will still hold up the now heavier PCB assy. The "on edge"
grommet idea looks good to me.
Cheers.
Roger



You want a natural resonance of a few Hz only. In other words, the board
should move when you blow on it.
2-3 Hz is good.

greg

[GregS[_3_]]

In article , (GregS) wrote:
In article ,
Engineer wrote:
On Jul 14, 4:54=A0am, Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

It's not just grommets, it's the overall mass/compliance ratio. You
need enough mass on the "tube (PCB) side" of the compliance so that it
does not move much in "inertial space" when the other side of the
compliance is "bumped". PCB's tend to be a bit light so I'd add some
mass, then use the softest "grommet suspension" confguration you can
find that will still hold up the now heavier PCB assy. The "on edge"
grommet idea looks good to me.
Cheers.
Roger



You want a natural resonance of a few Hz only. In other words, the board
should move when you blow on it.
2-3 Hz is good.

I am assuming the acoustical path to the board is under control.

greg

[fryzz]

little globs of silcone rubber work well, sort of a "molded in place"
shock mount.

[Ben Bradley[_2_]]

In rec.audio.tubes,sci.electronics.design,rec.audio.p ro, On Wed, 15
Jul 2009 15:25:59 -0400, Rich Webb wrote:

On Wed, 15 Jul 2009 12:17:12 -0700 (PDT), "
wrote:

On Jul 15, 11:01*am, John Larkin
wrote:
On Tue, 14 Jul 2009 09:54:30 +0100, Ian Bell
wrote:

I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

Cheers

Ian

Yesterday we had a rep drop by from EAR

http://www.earshockandvibe.com/

who dropped off a really cool sample kit of grommets and pull-through
fasteners for mounting disk drives and fans. He also gave us a golf
ball molded from one of their plastics. Drop it onto a tabletop and it
just goes thud, no bounce. They also have some thin sheets of
dead-soft foam-like fabric.

Try to wrangle their C-1000 sample kit.

John

This looks like a good company. I wish they had that stuff at
Digikey.

McMaster-Carr is the go-to place for this kind of thing. They do carry
electronics-related as well (good price on Kapton tape) but have tons of
mechanical piece parts. Not always the cheapest but reputable and good
stock depth.

http://www.mcmaster.com/ Search on "vibration mounts" and start there.

The big industrial suppliers (McMaster-Carr, Grangier and MSC)
appear to have everything including good service (well, perhaps it
varies between them but I haven't ordered enough to know), but there's
also Small Parts that would have items like this, perhaps not at as
low prices as the others, but maybe there's something to merit their
mention (I've ordered from Small Parts a few times and got good
service):

http://www.smallparts.com

[Rich Webb]

On Thu, 16 Jul 2009 20:22:03 -0400, Ben Bradley
wrote:

In rec.audio.tubes,sci.electronics.design,rec.audio.p ro, On Wed, 15
Jul 2009 15:25:59 -0400, Rich Webb wrote:

McMaster-Carr is the go-to place for this kind of thing. They do carry
electronics-related as well (good price on Kapton tape) but have tons of
mechanical piece parts. Not always the cheapest but reputable and good
stock depth.

http://www.mcmaster.com/ Search on "vibration mounts" and start there.

The big industrial suppliers (McMaster-Carr, Grangier and MSC)
appear to have everything including good service (well, perhaps it
varies between them but I haven't ordered enough to know), but there's
also Small Parts that would have items like this, perhaps not at as
low prices as the others, but maybe there's something to merit their
mention (I've ordered from Small Parts a few times and got good
service):

http://www.smallparts.com

Ah yes ... Thanks. I've ordered from them in the (rather distant) past
but their bookmark didn't make the transition over to the new box and
I'd forgotten about them. Thanks for the reminder!

--
Rich Webb Norfolk, VA

[DougC]

Scott Dorsey wrote:
GregS wrote:
In article , DougC wrote:
Ian Bell wrote:
I ant to mount a tube mic pre PCB on some anti vibrations grommets to
reduce microphony. Anyone know of a UK source of these?

"Just any rubber" will not dampen vibrations.
What you want is named Sorbothane (at least in the US).
I don't know if Sorbathane comes in different varieties.
The stuff I know is fairly stiff and not good for
lightweight items.

Sorbothane is a urethane polymer. You can order it in a whole bunch of
different durometers. I don't know that it's better than any other urethane
rubber, but they have outrageously good marketing.

I like using the black foam rubber
used for insulating pipes. Not the Polyethylene stuff,
but the stuff that is very soft and does not spring back
real fast. Kind of gummy. You can cut it up as desired. Try plumbing
or home depts.

That's a urethane foam.... the air in it changes the properties a lot, though.
--scott


Other people have mentioned McMaster-Carr, which is where I get it when
I need it. I don't know if they ship outside the US though. They sell it
in various hardnesses; get the softer ones.

Also be aware when using Sorbothane that it is naturally tacky. If it is
clamped between two pieces, over time it will tend to stick VERY hard to
both of them. You need to cover one side with some paper or other
plastic if you wish to prevent it from "bonding".

Sorbothane does dampen a lot better than any other kind I've read of.

One thing it is used for is for vibration-dampening feet under amateur
telescopes--(this is the reason I ended up with some of it)--and in this
use, you can actually SEE how much better it works compared to other
rubbers, by how long the view vibrates after the telescope is lightly
tapped. ....These pads are fairly expensive, so people try to make them
out of whatever other kinds of foam rubber they happen to find--and the
result is always worse. They often don't KNOW that until they can
compare their home-made pads with the real ones side-by-side, but other
rubbers like plain silicone sealant, pipe insulation, latex foam, ect
ect have hardly any noticeable effect at all. Sorbothane telescope foot
pads will cut the "vibration time" about in half, which doesn't sound
like much--but in reality is far better than any kind of other material
will.
~