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Topic: Cleaning Jacks |
Sonny Jenkins
From:
Texas Masonic Retirement Center,,,Arlington Tx
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Posted 18 Jul 2016 8:17 am |
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| It's been suggested that trouble with NV 400 noise could be caused by dirty pwr amp in - pre amp out jacks,,,or effects jacks. Can these be cleaned by spraying deoxIt into the jacks? Or would that harm the system in some way? |
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Jack Stoner
From:
Kansas City, MO
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Posted 18 Jul 2016 8:46 am
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If those jacks are dirty they are one source, but not the only thing, of noise or intermittent. A dirty Pot can also cause that, along with a Molex connector inside the amp. There are other things that can cause noise, low or no volume, but these are the first things to consider.
Spraying into a jack won't hurt the other components but iffy if that will fix your problem. |
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Larry Dering
From:
Missouri, USA
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Posted 18 Jul 2016 8:55 am
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| Agree with Jack on all points. However to answer your question spraying into the jack will not get to the contact point where it closes. In most cases you need to pull the chassis and work from the inside. The amp must be unplugged and caps drained. Over spraying is not advisable. Just my 2 cents. |
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Sonny Jenkins
From:
Texas Masonic Retirement Center,,,Arlington Tx
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Posted 18 Jul 2016 9:09 am
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The actual problem that I presented to Mike Brown is as follows. I've had a couple of NV 400s put away for several years and I got one out to clean up, check out and possibly sell. Well these old amps sound soooo good (have been playing through a NV 112 for several years),,,and so easy to dial in the sound I like, I quickly decided to keep the 400,,,sell the 112. However, a couple of times, for no known reason like bumping or ??? it will start a very loud buzz or almost a roar. Once I kinda slapped the top of it and it quited down a notch, but still pretty loud. Turned off and on a few times, at some point stopped. When it is working properly it is very quiet. Mike response was,,,,"
The symptom sounds as if it could be a broken solder joint or perhaps the pre eq return jack or the power amp in jack on the rear panel is not functioning correctly..........or they could need cleaning. Try patching a shielded cable from the pre eq send and return jacks on the front panel and another cable between the power amp in and preamp out on the rear panel. This would 'hardwire' these two functions. If the still has this intermittent problem, then the return and power amp in jacks probably need replacing.
I have been playing for several hours now, turned off and on a few times, with a patch cable between the pwr amp and pre amp jacks,,,no problems. I have an RV-3 plugged into effects on front acting as a patch cable. |
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Jack Stoner
From:
Kansas City, MO
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Posted 18 Jul 2016 10:45 am
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| The noise can be the reverb, too. That Molex Connector is a known problem area. First thing, reseat the reverb Molex connector (unplug then plug back in). |
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Mike Brown
From:
Meridian, Mississippi USA
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Posted 18 Jul 2016 1:52 pm Noise/buzz
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| Until the "noise" shows itself again, it is hard to resolve. All that can be done at the point is touch up solder connections/tighten connections. If you had a scope, that would help when tapping on the chassis or a particular part of the circuit board. |
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Sonny Jenkins
From:
Texas Masonic Retirement Center,,,Arlington Tx
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Posted 18 Jul 2016 3:17 pm
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| I've had a patch cable in the back all day,,,off/on several times with no problems. The 400 just seems a lot easier to tweak to the sound I like than the 112. |
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Tony Prior
From:
Charlotte NC
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Posted 19 Jul 2016 3:26 am
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not to take away from anything stated or recommended, but spray cleaning a slightly corroded "metal" may or may not clean the piece or resolve the issue. It needs to be "BURNISHED", which is a slight scraping , a very small file will clean the tip of a jack. Whatever has grown on the tip needs to be removed and brought back to bare metal.
This is why folks put a 1/4 plug in the jack, the 1/4 plug is actually scraping the tip, ever so slightly. They may not realize this.
I love PV amps and I am the worlds #1 fan, but every few years some slight maintenance may be required, such as cleaning and burnishing the connectors.
Don't forget the reverb tank connectors( male and female) , they are also suspect and prone to some slight corrosion.
True...
years back I acquired a Vox Super Beatle, it was really intermittent in the store so they cut the price in half. I decided to buy it. Brought it home and did the typical maintenance, cleaning connectors, jacks and plugs etc, including the RCA plug (M+F) which passed the preamp signal to the Power amp, guess what..that fixed the entire amp. A simple cleaning ( burnishing) of the RCA plug brought the monster back to life.
_________________
Emmons L-II , Fender Telecasters, B-Benders , Eastman Mandolin ,
Pro Tools 12 on WIN 7 !
jobless- but not homeless- now retired 9 years
CURRENT MUSIC TRACKS AT > https://tprior2241.wixsite.com/website |
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