Cap job on Vibrosonic - pictorial. Update jun5.

A sub forum for our most useful repair, maintenence & upgrade threads.
User avatar
Orang Goreng
Mods
Mods
Posts: 15876
Joined: Tue Sep 12, 2006 5:56 am
Location: Amsterdam, NL - €
Contact:

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by Orang Goreng » Mon Jun 07, 2010 11:58 am

So you know how most of these chassis are suspended by impossibly long bolts which anchor in a nut only accessible through the inside of the cabinet? I don't know if it's just me, but for some reason I always lose grip on a specific one (the one near the pilot light), which then invariably gets stuck between the baffle and the bottom of the chassis. You'd imagine it comes out when you put the chassis back in, but no. Through mystical forces of nature (well, I put the chassis in with the cab face-down, so it's mostly gravity) the nut remains upright and gets trapped when the chassis is returned. I forgot about that and put the other amp's chassis in this cab. This one uses a more clever, later suspension system, so I didn't realise the nut (now needed with the other amp) was still trapped.

So I removed the grille to be able to get to it.

Right.

So one reason why I wanted to service this amp is that at the last gig, it had a strange buzz, which got progressively worse during the night (it was the backline guitar amp of the evening, so it was in use for several hours). Buzes in unsewrviced old tube amps scare me, so I wasn't going to use it until I'd serviced the Dangerous Bits.

Well, I guess I now found the reason for the buzz ;).

Image

Right. I don't notice anything odd when I play at room volume now, but yeah, I can imagine this buzzing at gig/jam session volume; it did sound somewhat mechanical but I could find something that was loose enough to vibrate at the time. Didn't think of looking here.... The chip was lying at the bottom of the cleft between baffle and grill.

Right. So I know it's a dust cap and mainly serves as just that, but also contributes to that "hi-fi" treble of the D130F. I know it's technically possible to just replace them. Is that an easy thing to do, given how they're glued to the cone? Is there a serious consequence to leaving this untouched given how this amp won;t be used for gigs for at least a few months? I have an intact one I could at least in principle cannibalise from my older, broken speaker. Is this where the elusive Black Goop comes in? And, given how the stuff isn't available in Europe AFAIK, do we know an Euro equivalent? Is there perhaps a solid ghetto fix? I can probably live with losing some of those trebles, really ;).


Many questions, once again.
In the land of the blind, the one-eyed man's a freak.

User avatar
Orang Goreng
Mods
Mods
Posts: 15876
Joined: Tue Sep 12, 2006 5:56 am
Location: Amsterdam, NL - €
Contact:

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by Orang Goreng » Mon Jun 07, 2010 12:05 pm

Right, when I'm not busy fucking up other people's threads, I fuck up my own ;D. Show some love for the windows clipboard. Memories you thought you'd lost in Pat's The Wall thread.

Image

Doketer Bibber would be a very feasible explanation for buzz. It shouldn't get much weirder. Away from the internet. Now.
In the land of the blind, the one-eyed man's a freak.

User avatar
Stratelejazzuar
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 6744
Joined: Sun Jul 22, 2007 10:15 pm
Location: K-W, Ontario, Canada

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by Stratelejazzuar » Mon Jun 07, 2010 1:04 pm

lol, the game "Operation"! :D When i was young, a friend had that game; it was so annoying i think i only tried playing once. looking up the original box/packaging for that game... ???

Image

is it just me or does it look like the nurse boy on the left has a crush on the doctor's rear? and said doctor (at a glance) seems to be performing on that red-nosed gentleman's parts. Doctor #2 seems rather devious, and why is the little nurse girl playing with his apple?!?! :wtf: :wtf:

User avatar
Orang Goreng
Mods
Mods
Posts: 15876
Joined: Tue Sep 12, 2006 5:56 am
Location: Amsterdam, NL - €
Contact:

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by Orang Goreng » Mon Jun 07, 2010 2:24 pm

Stratelejazzuar wrote:lol, the game "Operation"!
Yeah, from here: http://www.offsetguitars.com/forums/vie ... ad#p565218" onclick="window.open(this.href);return false;. I still had the link in my clipboard. But it seemed oddly appropriate.
In the land of the blind, the one-eyed man's a freak.

User avatar
øøøøøøø
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 5984
Joined: Sun Jan 06, 2008 8:26 pm
Location: Los Angeles
Contact:

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by øøøøøøø » Mon Jun 07, 2010 6:10 pm

Man, that is weird. Not sure I've seen a dust cap break in exactly that way before! :D

In the meantime, take a piece of masking tape or blue painter's tape or some other easy-to-remove tape, and tape over the hole. That will keep the dust from getting in the voice coil gap.

You can certainly replace that dust cap. That is indeed where the "black goop" comes in. What you do is to use an Xacto blade or some other hobby knife to carefully cut around the dust cap as closely as you can to the edge. BE CAREFUL not to cut the cone. If you want, you can start at your existing hole, and cut an "X" pattern and peel back the 4 sections and cut them from the inside. In any case, you don't have to get too fanatical about cutting too close to the cone. If it leaves a little 'ridge' of aluminum and glue that's perfectly OK. You don't want to leave enough to significantly change the mass, of course, but a tiny little rim will have no real effect.

They make a replacement cap that is ever-so-slightly larger in diameter than the old one, and will cover the "ridge" left by the old one with little/no change in performance. It's here:

http://www.soundspeakerrepair.com/speak ... Dust+Caps/" onclick="window.open(this.href);return false;

You just apply glue to the ridge left from the old one and glue the new one on. Turn the speaker on its back and get a socket from a ratchet/wrench set to use as a weight to hold it down while drying. You're done!

If you really wanted to lose some of the treble, you could always just get a regular 4" paper dust cap from anywhere. The procedure is the same.

User avatar
Orang Goreng
Mods
Mods
Posts: 15876
Joined: Tue Sep 12, 2006 5:56 am
Location: Amsterdam, NL - €
Contact:

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by Orang Goreng » Tue Jun 08, 2010 2:06 am

øøøøøøø wrote:Man, that is weird. Not sure I've seen a dust cap break in exactly that way before! :D
LIke most of them, it was a bit dented to begin with. Those things must be under a lot of stress from the cone moving.
In the meantime, take a piece of masking tape or blue painter's tape or some other easy-to-remove tape, and tape over the hole. That will keep the dust from getting in the voice coil gap.
Ah cool, will do.
You can certainly replace that dust cap. That is indeed where the "black goop" comes in. What you do is to use an Xacto blade or some other hobby knife to carefully cut around the dust cap as closely as you can to the edge. BE CAREFUL not to cut the cone.
I knew those years of microsurgery training would come in handy even after quitting research! ;D. Thanks, I feel confident again.

Does anyone know what makes up Black Goop? Funnily enough, I was having lunch with some field biologists some time ago. One of them was an American guest researcher, and she actually had a minor problem... she used the Black Goop in a research setting, fixing shit to other shit. Not available here anywhere!

I do know there's some speaker repair companies around, I'm sure they'll know an alternative. But if any fellow Europeans have good experience with a local equivalent, I'm all ears :).
In the land of the blind, the one-eyed man's a freak.

User avatar
øøøøøøø
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 5984
Joined: Sun Jan 06, 2008 8:26 pm
Location: Los Angeles
Contact:

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by øøøøøøø » Tue Jun 08, 2010 5:33 am

Any speaker adhesive will do just fine. Should you order the dust cap from the site I linked to above, add this to your cart:

http://www.soundspeakerrepair.com/speak ... Adhesives/" onclick="window.open(this.href);return false;

User avatar
øøøøøøø
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 5984
Joined: Sun Jan 06, 2008 8:26 pm
Location: Los Angeles
Contact:

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by øøøøøøø » Tue Jun 08, 2010 5:34 am

P.S., your buzzing was probably the broken-off piece being bounced around between the cone and the grille!

User avatar
Stratelejazzuar
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 6744
Joined: Sun Jul 22, 2007 10:15 pm
Location: K-W, Ontario, Canada

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by Stratelejazzuar » Tue Jun 08, 2010 5:38 am

øøøøøøø wrote:P.S., your buzzing was probably the broken-off piece being bounced around between the cone and the grille!
heh this buzzing reminds me of how my buddy's TRRI was buzzing - we laid the amp on the floor, took the speaker out that we thought was buzzing, checked it all over, etc. the buzz was gone once we put it back together. then it came back a couple days later... turns out the tilt back leg was vibrating against some other piece of metal and making the noise! ;D ::)

User avatar
Orang Goreng
Mods
Mods
Posts: 15876
Joined: Tue Sep 12, 2006 5:56 am
Location: Amsterdam, NL - €
Contact:

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by Orang Goreng » Tue Jun 08, 2010 6:58 am

øøøøøøø wrote:P.S., your buzzing was probably the broken-off piece being bounced around between the cone and the grille!
There's quite some room between the cone and the grille on a Vibrosonic... I wonder if perhaps it was simply stuck in the dust cap hole..
In the land of the blind, the one-eyed man's a freak.

User avatar
Orang Goreng
Mods
Mods
Posts: 15876
Joined: Tue Sep 12, 2006 5:56 am
Location: Amsterdam, NL - €
Contact:

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by Orang Goreng » Sat Jun 19, 2010 7:05 am

Bleeh, now all of a sudden my reverb stopped working. Never a normal day....
In the land of the blind, the one-eyed man's a freak.

User avatar
andy_tchp
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 8010
Joined: Fri Apr 02, 2010 1:36 am
Location: Brisbane

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by andy_tchp » Sat Jun 19, 2010 5:39 pm

Orang Goreng wrote:Bleeh, now all of a sudden my reverb stopped working. Never a normal day....
Sorry to hear that mate. It's not been a good week for OSG Vibrosonic Reverbs eh? :(
"I don't know why we asked him to join the band 'cause the rest of us don't like country music all that much; we just like Graham Lee."
David McComb, 1987.

User avatar
OffYourFace
Mods
Mods
Posts: 13682
Joined: Thu May 03, 2007 2:59 pm
Location: Los Angeles, CA

Re: Cap job on Vibrosonic - pictorial. Update jun5.

Post by OffYourFace » Sat Jun 19, 2010 11:51 pm

Orang Goreng wrote:Bleeh, now all of a sudden my reverb stopped working. Never a normal day....
it's gotta be something super simple...

Post Reply