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Topic: low end buzz, NV400 |
Dennis Brown
From:
Gowen, Mi. USA
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Posted 23 Apr 2012 3:50 pm |
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I sold my NV400 here on the forum, It had a couple of dirty pots. I removed the board and sprayed the pots. I reasembled the amp and to my surprise I have this low end buzz. Any ideas as to what I may of done? Needless to say I had to emailed the buyer to let him know I can't sell or send it like this.
Sure could use your help. Thanks you, Dennis |
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Jack Stoner
From:
Kansas City, MO
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Posted 24 Apr 2012 2:07 am
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| Check the Molex connectors, and in particular the one for the reverb. The Reverb connector has caused many Nashville 400 problems. |
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Dennis Brown
From:
Gowen, Mi. USA
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Posted 24 Apr 2012 2:37 am Nv400
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| Thanks Jack. I'll do that. Dennis |
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Curt Langston
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Posted 24 Apr 2012 12:04 pm
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| More likely there is some dust or sand particles in the voice coil gap. The reverb Molex usually only causes reverb related problems. IE: intermittent working of reverb and the like. |
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John Swain
From:
Winchester, Va
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Posted 24 Apr 2012 12:13 pm
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| Dennis, assuming you have a Black Widow speaker,remove the magnet and carefully clean the voice coil and gap.On mine the foam pad had disintegrated.. |
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Jack Stoner
From:
Kansas City, MO
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Posted 24 Apr 2012 1:02 pm
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| Curt, I've had hum problems because of a bad ground connection, even with the reverb control set to zero, on the reverb Molex plug. I also had a NV400 that I worked on have a bad solder connection on a reverb ground pin on the motherboard that caused hum. |
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Dennis Brown
From:
Gowen, Mi. USA
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Posted 24 Apr 2012 2:50 pm low end
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I just disconnected the molex connection to the reverb and no change. The buzz is still there. Is it a big deal removing the magnet or reinstalling?
Thanks guys. Dennis |
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Dennis Brown
From:
Gowen, Mi. USA
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Posted 24 Apr 2012 3:36 pm low buzz
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Well, I removed the magnet. Found a mini junk yard, cleaned it out good. Even the foam pad from behind magnet screen was laying in the dust cover. Cleaned the gap and coil.
It didn't help much. 
Dennis |
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Lee Baucum
From:
McAllen, Texas (Extreme South) The Final Frontier
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Posted 24 Apr 2012 6:17 pm
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Well, Dennis, the good news is, you got that gap cleaned out and prevented a future issue. Sometimes all that garbage in there can cause a fuzzy, buzzy sound, like a blown speaker.
Lee |
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Dennis Brown
From:
Gowen, Mi. USA
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Posted 25 Apr 2012 4:14 am low buzz
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Lee, Thats exactly what it sounds like. (blown speaker)
Thanks everyone for your suggestions. ya'll been very helpful. Maybe I should just send it to Ken Fox.
Dennis |
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Jack Stoner
From:
Kansas City, MO
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Posted 25 Apr 2012 4:37 am
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Dennis, I responded to your e-mail.
Ken Fox posted that he will not be doing solid state amp repair anymore. If it gets to sending it somewhere for repair, Peavey is the best option.
Last edited by Jack Stoner on 25 Apr 2012 9:28 am; edited 1 time in total |
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Ken Fox
From:
Nashville GA USA
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Posted 25 Apr 2012 7:27 am
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Jack, I am no longer repairing solid state amps of any sort, only vintage tube amps (non PC board amps).
I am still doing the intense mods on working steel amps as well as still selling our kits on the website.
Right now we plan to close the buisiness at the end of 2012, due to retirement age coming in June of 2013.
We look forward to attending steel shows and forum activity as we always have
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Tommy Boswell
From:
Virginia, USA
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Posted 27 Apr 2012 4:39 am
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It could be something as simple as cabinet noise. I recently noticed loud buzzing in my 15 inch speaker cab at low frequencies. Thought I had blown speaker, until I was able to examine the cabinet while the low string was plucked (might need a buddy to help). The back panel was loose and just needed some new screws. What a relief!
Hope this helps. |
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Ken Fox
From:
Nashville GA USA
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Posted 27 Apr 2012 5:00 am
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I have fpound several of the older 1502-4 speakers that were buzzing. It was due to the glue having loosen up where the speaker spider glues to the speaker basket. Easy to find, just reve the back and check the spider (The spider is that
yellowish/brown corrugated disk attached to the cone) Rubber cement will fix that. |
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Tommy Boswell
From:
Virginia, USA
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Posted 27 Apr 2012 5:20 am Re: low end buzz, NV400
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| Dennis Brown wrote: |
| I reasembled the amp and to my surprise I have this low end buzz. |
Dennis,
Check for loose hardware; anything will vibrate along with those low frequencies. What are the odds that your speaker went bad at the same time that you put things back together?
Tommy |
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Dennis Brown
From:
Gowen, Mi. USA
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Posted 27 Apr 2012 10:18 am buzz
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| thanks Tommy. I'm wondering the same thing. this is my first time working on a amp. been playing sense 1972 and never fooled with a amp. I might of messed something up myself. Thanks for the help |
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Jerry Overstreet
From:
Louisville Ky
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Posted 27 Apr 2012 10:24 am
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If this condition only started after your pot service, I'd just retrace your steps. Pull the chassis back out and make sure all the connections, chips, etc. are well seated.
I can't tell you the number of times something small like this has caused lots of frustration.
It could be a case of some type of component failure that just coincidentally occurred with your cleaning, it happens, but who knows? Never hurts to go back over your maintenance.
Good luck. |
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Dennis Brown
From:
Gowen, Mi. USA
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Posted 28 Apr 2012 9:37 am buzz
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Thanks Jerry. I'll do that this weekend after the honey do list. it's a good idea.
Ken: Thank you, makes sense. i'll check it also.
Dennis |
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Dave Grafe
From:
Hudson River Valley NY
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Posted 28 Apr 2012 10:38 am
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Are you saying the when you play a low note it buzzes, or are you saying that when you turn the amp on it makes a low frequency buzzing (or humming) sound?
If the former, it could be a problem with the speaker, speaker wires, or a bad connection or component in the signal path.
If the latter it is most likely a poor or missing connection in the ground path, and the speaker itself has nothing to do with it.
Molex connectors are always the first thing to check on these amps, and if you have taken them apart are well worth checking again. Sometimes a pin will slide out of the Molex body and fail to make the intended connection, make cetain that every wire's plug connection is sound and tight.
If you used a dedicated pot cleaner you should be okay but be aware that many commercial "electronics" sprays can actually cause pots or other components to fail due to chemical softening or melting of the plastic pieces within. |
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Dennis Brown
From:
Gowen, Mi. USA
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Posted 28 Apr 2012 11:18 am buzz
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The buzz is most noticed with low tones. It's there on mid tones also. I guess I wasn't certain as how to explain it.
Thank you for the info Dave.
I now have plenty to look for. I will have time to spend on it tomorrow morning. I'll post my findings.
thanks again. Dennis |
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Jack Stoner
From:
Kansas City, MO
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Posted 28 Apr 2012 1:55 pm
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I would call that distortion, rather than buzzing.
I agree, some cleaners (e.g. "contact cleaner") are not really meant for pots and can cause other problems. |
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Dennis Brown
From:
Gowen, Mi. USA
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Posted 28 Apr 2012 3:38 pm buzz
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| Sent you a email Jack. |
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