Rattle from 2yr old Vox AC-15

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oceanjaws
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Rattle from 2yr old Vox AC-15

Post by oceanjaws »

Any idea what this rattle is?
It's a Vox AC-15 (bought new 2yrs ago- it's Chinese) and the rattle appears on a Bb note.
The reverb has been cutting in and out, and now doesn't work at all.. could be related?

https://soundcloud.com/brian-acton/vox-rattle
Stevem
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Re: Rattle from 2yr old Vox AC-15

Post by Stevem »

Unplug the rca connector from the end of the reverb pan marked output, does the rattle stop? If so then yes the sourse of the rattle and no reverb is a pan that has failed.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!

Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
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Phil_S
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Re: Rattle from 2yr old Vox AC-15

Post by Phil_S »

I had this experience with a pair of Sovtek EL84's. They buzzed on a particular note. IIRC, it was Bb. I keep them around as "bench tubes."
matt h
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Re: Rattle from 2yr old Vox AC-15

Post by matt h »

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Last edited by matt h on Fri Mar 27, 2015 7:10 am, edited 1 time in total.
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Phil_S
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Re: Rattle from 2yr old Vox AC-15

Post by Phil_S »

No way to know without letting the air in. I assumed it was loose screens, too. Plates certainly look solid enough.
ampdoc1
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Who Knows

Post by ampdoc1 »

I haven't a clue what your trouble is, but I purchased one of the Vox "lunch-box" 15s a couple of years ago. The basic sound was cool, but there was a persistent "ripping" sound as the signal would start to fade.

Checking the internet, I found page after page of comments on the same problem, along with modification suggestions, of which I tried several.
But, while the sound less noticeable, it still wasn't right.

My suggestion...don't buy Chinese equipment (or anything else for that matter) and don't spend a lot of time trying to fix the one you have. Crap is Crap.

Sell that amp or give it to somebody that can't hear the difference. Then go build yourself a good Vox copy.
vibratoking
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Re: Rattle from 2yr old Vox AC-15

Post by vibratoking »

In this case, the first items I check for are physical rattle of the cabinet, bad solder joint(s), and noisy tubes. Plug the amp into a separate speaker cabinet located at least a few feet away and see if the rattle still exists. You can physically try to stop the vibrations with your hand while you feed the offending signal into the amp. Often times I find that the edge of the chassis, could be any edge, is vibrating against the cab at certain freqs. Wedges work well to verify the offending area. Visibly inspect the solder joints or just retouch them all. Only takes a few minutes. Of course, try swapping the tubes or adding dampeners.
Electronic equipment is designed using facts and mathematics, not opinion and dogma.
oceanjaws
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Re: Rattle from 2yr old Vox AC-15

Post by oceanjaws »

Stevem wrote:Unplug the rca connector from the end of the reverb pan marked output, does the rattle stop? If so then yes the sourse of the rattle and no reverb is a pan that has failed.
Opened it up.
Tighten the grips on the RCA connectors.
Seems to have sorted it!
Thanks!
Stevem
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Re: Rattle from 2yr old Vox AC-15

Post by Stevem »

Good deal!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!

Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
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