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Topic: Loud Crack on switching off |
Eric Dunlop
From:
Hampshire, UK
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Posted 24 May 2009 1:39 am |
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I have a 75 watt Peavey Studio Pro 112.
It produces a very clean sound for my PSG.
I have this problem.
It produces a vey loud "Crack" like a capacitor discharge, when I switch the amp off.
I have turned down the volume also the reverb and unplugged the jack from the PSG. All to no avail the crack still persists but at a lower volume.
I have stopped using the amp for fear of damaging the speaker.
Can anyone suggest a what I am doing wrong
Regards
Eric |
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Eric Dunlop
From:
Hampshire, UK
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Posted 24 May 2009 4:33 am Loud Crack on Switching Off
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| I have sent an email to "customerservice@peavey.com but as yet have received no reply. |
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Ken Fox
From:
Nashville GA USA
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Posted 24 May 2009 5:06 am
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| If the 16 volts DC voltage rails are not the same this can occur. I have seen it in a Nashville 400 when a 16 volt zener on one rail was only putting out 11 Volts or so. The difference in the two voltages will cause the op amps to have a turn off transient. |
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Earnest Bovine
From:
Los Angeles CA USA
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Posted 24 May 2009 10:07 am
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My Peavey Vegas 400 started doing that a few months ago. Then I heard a hum all the time.
I replaced four capacitors in the power supply (two 1000uF and two 330uF if I remember correctly) and both of those noisy "features" went away. |
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Eric Dunlop
From:
Hampshire, UK
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Posted 24 May 2009 10:16 am Loud Crack on switching off
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Thank you Ken & Earnest,
I am not that technically knowledgable but I will pass on your comments to the repair tech when I locate one in my area. |
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Calvin Walley
From:
colorado city colorado, USA
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Posted 24 May 2009 11:04 am
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Ken
i have a nash 400 pluged into the same ciruit as as a cooling unit,(110 volts) i get a boom when i turn off the cooling unit even tho the amp is turned off
should i be worried ?
_________________
proud parent of a sailor
Mullen SD-10 /nashville 400
gotta love a Mullen!!!
Guitars that i have owned in order are :
Mullen SD-10,Simmons SD-10,Mullen SD-10,Zum stage one,Carter starter,
Sho-Bud Mavrick |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 24 May 2009 11:20 am
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| Pops, clicks, "booms", and other spurious noises will not damage modern amps or speakers. These noises are usually the result of poor design, or possibly, aging components. If they bother you, simply turn down the amp before powering it on or off. |
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Calvin Walley
From:
colorado city colorado, USA
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Posted 24 May 2009 11:42 am
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what i am talking about is , the amp IS OFF but still pluged into the wall
_________________
proud parent of a sailor
Mullen SD-10 /nashville 400
gotta love a Mullen!!!
Guitars that i have owned in order are :
Mullen SD-10,Simmons SD-10,Mullen SD-10,Zum stage one,Carter starter,
Sho-Bud Mavrick |
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Ken Fox
From:
Nashville GA USA
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Posted 24 May 2009 12:50 pm
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The Nashville 400 has a strange on/off circuit! The switch actually does not handle the AC voltage to the primary of the power transformer. Actually the switch is used to fire a TRIAC device that is between the AC and the transformer. I have seen an amp thump with the power off as you say. Not 100 percent sure why. Apparantly the surge is getting thru the TRIAC for a moment and turning the amp on and them back off. Heat pumps start with what is called a locked rotor and pull a whole lot of current on start up! Sometimes that will dim the lights in a house when the pump starts.
I have talked several times with Jimmy at the Peavey Repair Center about some Nashville 400 amps also having a very loud turn on snap. He told me that sometimes it is the DVL caps on the primary side of the transformer that can cause this. I have yet been able to order those caps, as there is part number on the schematic. It would have to be the DVLK caps or the TRIAC causing the noise, in my opinion.
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Calvin Walley
From:
colorado city colorado, USA
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Posted 24 May 2009 2:08 pm
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thanks for replying Ken
but your answer begs the question, is it ok/safe to leave them plugged in 24/7
_________________
proud parent of a sailor
Mullen SD-10 /nashville 400
gotta love a Mullen!!!
Guitars that i have owned in order are :
Mullen SD-10,Simmons SD-10,Mullen SD-10,Zum stage one,Carter starter,
Sho-Bud Mavrick |
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Ken Fox
From:
Nashville GA USA
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Posted 24 May 2009 2:32 pm
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| I can't see a problem with that. |
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Calvin Walley
From:
colorado city colorado, USA
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Posted 24 May 2009 2:36 pm
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thanks ken
that makes me feel better
sorry if i hyjacked the thread
_________________
proud parent of a sailor
Mullen SD-10 /nashville 400
gotta love a Mullen!!!
Guitars that i have owned in order are :
Mullen SD-10,Simmons SD-10,Mullen SD-10,Zum stage one,Carter starter,
Sho-Bud Mavrick |
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John Bechtel
From:
Nashville, Tennessee, R.I.P.
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Posted 24 May 2009 9:01 pm I use two N-112's:
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My Amps. will always give off a loud ‘PoP’ when I turn my Power~Strip OFF, so; I always turn the Master~Volume ‘OFF’ before turning the Power~Strip ‘OFF’!
_________________
<marquee> Go~Daddy~Go, (No), Go, It's your Break Time</marquee> L8R, jb
My T-10 Remington Steelmaster |
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