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Topic: NV 400 distortion |
seldomfed
From:
Colorado
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Posted 6 Jan 2005 11:00 am |
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dear all,
I got a used NV400 for a backup. Lovely tone. BUT...
once in a while, after it warms up for 15min. or so, and especially when playing a quiet passage - the vol. drops to a whisper and sounds slightly distorted, then if I play a note or chord with some force it suddenly comes back to full vol. Feels like when I play 'hard', it blows the carbon out so-to-speak. If I lay out or play soft then it will exhibit this vol. drop behavior intermittently.
any thoughts? I exercised the reverb connect already.
Chris
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Chris Kennison
Ft. Collins, Colorado
"There is no spoon" www.book-em-danno.com www.seldomfed.com
[This message was edited by seldomfed on 06 January 2005 at 11:03 AM.] |
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John Daugherty
From:
Rolla, Missouri, USA
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Posted 6 Jan 2005 12:45 pm
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Try cleaning the input jack by putting contact cleaner on a plug and inserting it several times. Also do this to the 1/4" jacks on the rear of the amp(spray cleaner into the jack and insert a plug several times). If cleaning doesn't help, connect a cable from preamp-out to pwr-amp-in and also put a cable from effects send to effects return. Those jacks complete the circuit when there is no plug inserted into the jacks. When the contacts get corroded it can do just what you described.
Of course, It never hurts to try some good guitar cords. You could have a faulty cord. |
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Allen Peterson
From:
Katy, Texas
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Posted 6 Jan 2005 2:08 pm
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John, I have to do exactly what you have described to keep my Nashville 400 from doing what Chris' is doing. Seems to work pretty well. I guess I could spend the money to get the jacks burnished, but the method you describe works for me. My Nashville 400 is over 20 years old, so I guess it has the right to be a little tempermental.
Allen |
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Brad Sarno
From:
St. Louis, MO USA
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Posted 6 Jan 2005 2:54 pm
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Most of those input and send/return jacks are switched. The switching is part of the jack itself and carries the signal. You may want to spray the jacks clean from the inside of the amp and then exercise them (not exorcise) a bit to clean the contact surface. Sometimes it's hard to get the spray into the switch part from the outside of the amp. If that doesn't work, you may want to then exorcise the amp 
Brad Sarno
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Tony Palmer
From:
St Augustine,FL
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Posted 6 Jan 2005 3:14 pm
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I have EXACTLY the same problem with my NV400.
I have tried cleaning all the plug jacks AND running a cord to bypass the in/out but nothing helps it.
As a result, I have a nice amp with great tone, that I cannot ever take to a gig.
I have to say, as extremely helpful Mike Brown is, and apparently the whole Peavey organization, this very problem seems to be quite prevalent with Peavey amps, as I've seen MANY posts about this same symptom and talked to several steel players that have experienced the same problem.
As a result, I've lost confidence in the reliability of these amps and switched to Fender.
Peavey should offer a fix-it kit to retro fit these annoying amp problems once and for all. |
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Ben Slaughter
From:
Madera, California
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Posted 6 Jan 2005 4:00 pm
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| My OLD NV400 was doing something similar then quit altogether. I tried all the tricks Mike suggested. I'm having a local tech look at it now with a STRICT spending limit. It may be time to take it for a long walk (off a short pier). But, if the tech comes up with something, I'll let you guys know (next week hopefully). |
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Larry Robbins
From:
Fort Edward, New York
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Posted 6 Jan 2005 4:30 pm
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Tony,
My Nash did the same and after trying all of the fixes, it still does it once in a while. I take it to gigs as a back up cause they are nice sounding amps. But like you I kinda lost faith and switched to a Fender
(Steelking) love it!Like my PV stuff also.
Not saying one is better than the other, just different. Love that Fender sound though...
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Sho-Bud ProII, Pro III custom,
Fender Steelking,Hilton pedal,Tut Taylor "Virginian"
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John Daugherty
From:
Rolla, Missouri, USA
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Posted 6 Jan 2005 4:41 pm
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| Now, some good words for Peavey. If you get your hands on a copy of the "Peavey Monitor" 40th anniversary edition, read about my old NV400 that has never had a moments problem and performs like new today. I don't know the exact publication date but it is being printed soon.........JD |
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Mike Brown
From:
Meridian, Mississippi USA
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Posted 7 Jan 2005 4:29 pm
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If the problem turns out to be a switching type of jack, the problem can be rectified by changing out the jack or spraying contact spray and inserting a 1/4" jack in and out several times. But, this is not always a sure fix. The solder point that connects a jack(switching or non)to the circuit board could be the problem instead of the jack itself though. If this is the case, naturally a tech can rectify this.
I would chance to state that "every" musical instrument amplifier company has used a switching jack in one or more of their products at one time or another. So, I feel quite sure that other companies experience some failures as well. You just don't hear about them because they are not participating on this Forum.
I don't mind stating that I am the most active member that represents a major amp manufacturer on the Forum(that I am aware of) and I can safely say that Peavey Electronics has been building steel amp models longer than any other manufacturer. So there are more of our steel products on the market than our competitors.
We haven't manufactured a Nashville 400 in at least 5 years. So, it stands to reason that all of the 400's discussed here are at least 5 years old, and I'll bet that many of the amps in question or older than that. Some may be close to twenty years old. I don't know of any electronic piece of gear that is transported in the trunk of a car, set up and used hundreds of times that would not require periodic maintenance. Actually, the Nashville 400 enjoyed a 25 year production run with no changes in the circuit. That in itself is simply amazing for a portable electronic product. When a reputable manufacturer designs and offers a good product to the public, the product will either fail or pass with public approval or disapproval.
As far as its dependability, the Nashville 400 is the most dependable steel amp ever with less than 1% in failures. If an amp gets warm, then quits, that is not a design problem, it's a component failure that can be resolved if in the right tech hands.
I can always be reached between the hours of 8am and 5pm at our toll free number, which is 1-877-732-8391, ext. 1180. This is a North American toll free numbe our office hours are from 8am to 5pm CST. Do any of our competitors offer a toll free number where you can speak directly to the product manager?
If I can be of assistance to you, please feel free to call and thank you for your support of Peavey gear.
Mike Brown
Peavey Electronics Corporation
[This message was edited by Mike Brown on 07 January 2005 at 05:56 PM.] |
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David Spangler
From:
Kerrville, TX USA
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Posted 7 Jan 2005 9:35 pm
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I will defer to Mike Brown's expertise and suggestions.
In the past several years I have worked on several NV400s that, after being put through the normal gigging and transporting, developed cracks in the solder joints on the PC board. Some of these I was able to see with a magnifying lamp and others I detected by running a function generator through the amp and the amp into the speaker and tapped gently on the PC board components with a non-metallic object. Any qustionable solder joints become immediately evident.
However, to do the above tasks, you have to pull the chassis and know which end of a soldering iron to hold.
A friend had an intermittency in his NV400 and he sent it to Peavey for the Peavey Mod and to have it checked over by their shop. It came back better than new for a very reasonable price.
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David Spangler |
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Tony Palmer
From:
St Augustine,FL
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Posted 8 Jan 2005 9:18 am
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I just re-read Brad Sarno's post about spraying and cleaning the aforementioned signal-destroying jacks and realized I cleaned them from the outside only.
Will it make a difference to take the chassis out and open it up and clean and spray them more thoroughly? |
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seldomfed
From:
Colorado
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Carl Williams
From:
Oklahoma
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Posted 8 Jan 2005 6:33 pm
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Mike, I just dropped off my 16 year old N400 with one of your authorized Peavey dealers for service and to add the mod. This is the second Peavey I've owned over the past 30 years and have never had a problem! My first amp which I bought in 1974 was a Peavey Classic w/two 12" speakers and kept it for 15 years. This amp was shipped to Alaska where I used it extensively for two years and then was shipped to Sicily ten years later and never had a problem other than replacing the 6L6 tubes! Granted, I'm not a pro, but for the playing I've done, Peavey has got it done! Mike, I've got to talk with the technician on Monday as to what I want done to the amp (he wasn't in the store today.) I did download the mod info from your website and taped it to the amp as a starter. Could you give me the top two or three items the technician should be checking to insure the amp gets the right service... Thanks for your time, Carl
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Bob Metzger
From:
Waltham (Boston), MA, USA
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Posted 12 Jan 2005 10:18 am
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First off, Peavey (and Mike Brown) do a terrific job for the Steel Guitar community.
Second, all amps have their particular failure mechanisms. With the NV 400, it is the switched jacks and the Molex connectors. These are the weak links in most Peavey amps I've seen and worked on. To say tube amps need constant service and solid state amps never need service is a gross simplification. All amps need routine maintenence (just like tires, belts, wipers on your car).
The metal Switchcraft switched jacks can be cleaned and renewed indefinitely. The plastic jacks should be removed from the amp and professionally cleaned and, occasionally, replaced. They are not, unfortunately, in the Switchcraft league. There are seven jacks in the NV 400 and all need occasional service. One of these on the back panel, is a reverb footswitch jack and needs less maintenence than the other switched jacks. As it has been pointed out, it's the switches within the jacks that carry signal and fail/become intermittent. On my NV 400 I don't use the reverb footswtich jack but instead this is my 'experimenter's port' for whatever improvement/modification I'm working on at the moment.
Also, Molex connectors have shown themselves to be a weak link and these should be carefully re-tensioned and cleaned. Peavey solder joints, over the years, have proven to be completely adequate for the job but like all amps, an occasional solder joint fails or becomes intermittent.
From a tech standpoint, intermittent problems are the most frustrating and I can relate the the posts I've read here but with simple routine maintenence the NV 400 can be a very, very reliable amp and about the best value-for-money in the steel guitar universe. There is no reason that all of your NV 400 amps wouldn't last well into this century with proper maintenence.
Sometimes, spraying into the jack from outside the amp will work and sometimes it won't. Most folks aren't qualified to go 'under the hood' and I've seen many a time more harm than good accomplished from 'user servicing'.
Using a patch cord to get you thru a few gigs might work but it's not really attacking the problem at its root. Peavey parts are priced exceptionally reasonably and I'd recommend all those patch cord folks get some new plastic jacks installed. And, please establish a rapport with your local (and competent) amp tech. That's the real solution!
Bob Metzger[This message was edited by Bob Metzger on 12 January 2005 at 10:29 AM.] |
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Mike Brown
From:
Meridian, Mississippi USA
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Posted 12 Jan 2005 11:59 am
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Thank you very much for your followup comments and suggestions. My intentions of posting my comments was that "any" electronic piece of gear needs occasional maintenance, whether that product is used every weekend or not. And with products that are shipped into varying worldwide marketplaces, our track record is pretty darn good. Otherwise, we would probably not be in business at this time.
I can safely state that every electronic product manufacturer has a product or products that require occasional maintenance. We are no different. Thanks for the backup tech viewpoints and for your support of Peavey products.
Mike Brown
Peavey Electronics Corporation[This message was edited by Mike Brown on 12 January 2005 at 12:01 PM.] |
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Tony Palmer
From:
St Augustine,FL
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Posted 14 Jan 2005 8:59 am
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Thank you Bob for that detailed explanation.
I'm happy to report I removed the chassis from the cabinet and really cleaned every jack from the inside out and now the amp works again!
I guess you just have to go through this procedure every few years to keep them working. |
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Bob Metzger
From:
Waltham (Boston), MA, USA
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Posted 14 Jan 2005 9:37 am
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Tony,
I've been seeing 300 amps a year for over 25 years. I've seen about every type of fault possible but more importantly, I'm able to identify why certain makes/models fail or at least the probability of failure due to their particular design flaws. The ultimately designed amp is one where each link in its chain is equally strong and where design flaws are investigated and upgraded when found.
Within their sonic philosophy and price-point, Peavey amps have always been good bang for the buck but like most amps, it has weak it's links. Understanding that and the value of routine maintenence are the key ideas here.
Bob Metzger |
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Carl Williams
From:
Oklahoma
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Posted 14 Jan 2005 12:54 pm
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Thanks to both Bobs for the detailed info on Peavey amps. I talked with my amp tech yesterday and he's going to do an indepth maintenance check on my NV400. I've not taken the time to have periodic maintenance done like I should have---thanks for the reminder... Carl
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, I'd use it on gig. But for the most part Peavey stuff to me is like having a Goldwing - never strands me in the middle of nowhere!