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400+ crapped out at gig

#21
I learned a very important adage in the military years ago when training to be a communications gear repair tech: "take care of your tools, and they'll take care of you".. Meaning of course that in this case, taking care of "tools" can also apply directly to musical equipment. It was quite clear in the OP that you've woefully neglected your amp, and therefore rightfully so, it let you down at a critical moment. This is an important lesson.. I hope your stuff will be treated much better after this.
 
#23
And now for a dissenting point of view. Bands that go on the road store their gear in trucks that get bounced around for thousands of miles in hot weather and almost always arrive at the end of the trip working. I sincerely doubt Mom put as much wear and tear on the amp as a road band does.

However, one thing that the road band does is always mount the amp with support on the bottom rather than letting it dangle from the rack. This causes the amp chassis to flex every time Mom hits a bump. So when you get it working again, make sure there's something firm under it to support it. A good thick but stiff foam padding is good. I used to use a piece of wood wrapped in a towel.
 
#25
Sounds similar to something that happened in my Mesa D-180 (a 400+ predecessor). In my case it was vibration from a rickety cab paired with some fairly crappy tubes, resulting in half of the power tubes blowing out. It still made noise, but was like yours in that the sound was very quiet and distorted. I would make sure that your cab is pretty solid if you play with the amp on top- the vibrations from loud music can be hell on hot tubes and other components. You could also look into a shock-mount case to lessen the shock, or an Auralex Gramma pad to put between the amp and cab and dampen vibration (though the Auralex won't help in the trunk of a car so much). I would suggest never leaving a tube amp anywhere where it will be introduced to alot of shock (ie-trunk of a car!) unless you have a shock-rack. Also, make sure that all of the tubes are seated snugly in their sockets before turning the amp on- I remember reading multiple stories of 400+s blowing fuses when tubes had partially loosened in travel. I'm kinda surprised your amp didn't blow the fuse before blowing whatever else it blew (you must have really hit it with a BIG signal really quickly!). My 400+ has been running strong for a couple years without a shock-rack, but I am extremely careful with it- including how I pack it into vans/ cars/ etc and I never put it on top of any cab apart from my NV-610, which vibrates very, very little even at ridiculous volumes...

Karl
 
#26
wow i would have never thought "bumps" would be so devastating to an amp. i'm definitely learning a bunch just by reading this thread. i have a mesa 400+ and i hope this never happens to me! the top of the amp will occasionally rattle on certain notes but geez now i'm paranoid. :eek:
 
#27
whoatherechunk said:
wow i would have never thought "bumps" would be so devastating to an amp. i'm definitely learning a bunch just by reading this thread. i have a mesa 400+ and i hope this never happens to me! the top of the amp will occasionally rattle on certain notes but geez now i'm paranoid. :eek:
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Just think about how hot tubes get when you are pushing them hard- they will be in their most fragile state at high temperatures (really all the components in the amp will be). At the very least, you should consider some sort of acoustic isolation just for the sake of longer tube life! Its certainly not neccesary- very few people seem to consider it. However, most people that play through tube amps are guitarists- who don't have to worry as much about heavy vibration from the frequencies their instruments are putting out. I believe the earliest SVTs actually had a shock-mount system built in to the chassis of the amp...

Karl
 
#29
sunbeast said:
Just think about how hot tubes get when you are pushing them hard- they will be in their most fragile state at high temperatures (really all the components in the amp will be). At the very least, you should consider some sort of acoustic isolation just for the sake of longer tube life! Its certainly not neccesary- very few people seem to consider it. However, most people that play through tube amps are guitarists- who don't have to worry as much about heavy vibration from the frequencies their instruments are putting out. I believe the earliest SVTs actually had a shock-mount system built in to the chassis of the amp...
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My SVT is one from the very first run, and it's not shock mounted. And tubes really aren't all that delicate. Sure, bumps aren't good for them, but they're not good for SS amps either. And when they're at their hottest, they're always sitting still because they're plugged in, so that's not much of an issue when you're traveling.
 
#30
johnk_10 said:
actually it was the V4's and V4B's that had the shock-mounted chassis. IIRC SVT chassis were always mounted with big bolts directly into the cabinet.
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You don't recall correctly. All of the SVT's before MTI used shock mounted feet. Only the V9 did not have them.

JimmyM said:
My SVT is one from the very first run, and it's not shock mounted.
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Yes it is. If you pull the amplifier chassis out of the head case, you'll see the feet actually float on the same shock suspensions used in the Portaflex amps and are not attached directly to the head case.

BTW, it's not necessarily tubes that get damaged by vibration. Bad solder connections (or even good ones) can break under shock. Mesa is famous for crappy soldering. When I worked at Guitar Center, in the entire 18 months I was there, not a SINGLE Mesa amp worked 100% out of the box. All but one of those failures were due to broken solder joints that happened in shipping. The other one was a custom order Triple Rectifier that had its 5U4's literally fall apart. The glass wasn't broken; the tubes were just so junky that they fell apart.
 
#31
JimmyM said:
And now for a dissenting point of view. Bands that go on the road store their gear in trucks that get bounced around for thousands of miles in hot weather and almost always arrive at the end of the trip working. I sincerely doubt Mom put as much wear and tear on the amp as a road band does.

However, one thing that the road band does is always mount the amp with support on the bottom rather than letting it dangle from the rack. This causes the amp chassis to flex every time Mom hits a bump. So when you get it working again, make sure there's something firm under it to support it. A good thick but stiff foam padding is good. I used to use a piece of wood wrapped in a towel.
Click to expand...

bands in a situation as described also have all thier gear in heavy duty/shockmounted cases too. never to be underestimated.
 
#32
Psycho Bass Guy said:
Yes it is. If you pull the amplifier chassis out of the head case, you'll see the feet actually float on the same shock suspensions used in the Portaflex amps and are not attached directly to the head case.
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Well if I ever get my amp back from the tech (who swears he's just waiting for the caps at this point), I'll be able to see it. But I totally can't remember where they are at this point.
 
#33
JimmyM said:
Well if I ever get my amp back from the tech (who swears he's just waiting for the caps at this point), I'll be able to see it. But I totally can't remember where they are at this point.
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Jim.... is this the SAME samp that you started a new thread about several months ago when you first bought it? Or was I thinking about an older Sunn bass amp? If I'm right about the 'new thread' question, how much longer do ya think before we can see an update on that?.. I know, I know .. the 'caps are on back order' or some other such thing eh? .. :smug: Anyway.. it'd be nice to see that again.
 
#35
Rattman said:
Jim.... is this the SAME samp that you started a new thread about several months ago when you first bought it? Or was I thinking about an older Sunn bass amp? If I'm right about the 'new thread' question, how much longer do ya think before we can see an update on that?.. I know, I know .. the 'caps are on back order' or some other such thing eh? .. :smug: Anyway.. it'd be nice to see that again.
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I didn't first buy it back then but I did post a thread about it. Had no idea it would take 6 months. But to be fair, I did take him a couple amps I needed back quicker in the meantime.
 
#36
Bad solder connections (or even good ones) can break under shock.
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Very true.
The two 400's I have both had the very same broken solder joint at the preamp heater circut, And the D180 I had before also had a broken solder joint elsewhere.

My amps ride in an equipment trailer, so yes they see their fair share of shock. I know I just have to do periodic checks of my heads a couple times a year.
 
#37
Caca de Kick said:
Very true.
The two 400's I have both had the very same broken solder joint at the preamp heater circut, And the D180 I had before also had a broken solder joint elsewhere.

My amps ride in an equipment trailer, so yes they see their fair share of shock. I know I just have to do periodic checks of my heads a couple times a year.
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not to beat a dead horse, but my 400+ would randomly blow fuses as well. I took it into the amp "doctor", he said the same thing bad solder connections, a hundred dollars and 2 days later and it NEVER did that again, and I have used it for 8 years since the repairs were done without failure ( YES I was in the same boat at a gig naturally it failed ) I was just glad I had my Carvin power amp with me in the rack for a backup. now a days I don't even bring that heavy thing, and just use my QSC or CARVIN amps. ( and it saves my rack 60 extra lbs ) an EXTREMELY GREAT AMP, but...weight IS A factor AFTER a show..lol .. last time I used it on stage was a show at PNC PARK here in Pittsburgh last year, driving 4 cabinets. ( 2 stacks ).
 
#38
=/

do not store your amp in a trunk for periods of time!!!!

argh. you should own a solid state amp if you are going to do stuff like this.

anyway, it's either a banged up tube, or a solder joint came un-done. bring it to a tech and have them look it over. and please, never leave your amp or any gear in the trunk of a car!
 
#39
xshawnxearthx said:
=/

do not store your amp in a trunk for periods of time!!!!

argh. you should own a solid state amp if you are going to do stuff like this.

anyway, it's either a banged up tube, or a solder joint came un-done. bring it to a tech and have them look it over. and please, never leave your amp or any gear in the trunk of a car!
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Seriously now, thanks for the reply, but you don't have the right to tell me that. When I was helping everyone pack up for the gig, I wasn't going to put the amp where it ended up. But the guy's mom offered, so I couldn't refuse. The guitarist assured me that he would unload the gear back home (my amp, his Peavey XXX, cab, and his other gear). I was under the assumption that he unloaded everything as soon as he was back home. Well, he didn't. Sure he took out his gear, but for some reason he let my amp live in the back of a mercedes for two weeks. I only found out when I grabbed the amp from his place the day of the gig that he didn't do **** like he said he would. And now you'd probably say something like "well you still should have been on top of that situation and made for sure that the guy did what he said he'd do". This is a guy I trust- I didn't think he'd do something like this.

Thanks for the reply though
 
#40
JimmyM said:
My SVT is one from the very first run, and it's not shock mounted. And tubes really aren't all that delicate. Sure, bumps aren't good for them, but they're not good for SS amps either. And when they're at their hottest, they're always sitting still because they're plugged in, so that's not much of an issue when you're traveling.
Click to expand...


I told a story a couple posts before that one of an experience I had with my D-180 where the tubes went out while playing- this was due to a combination of low quality tubes and setting the amp on top of a vibration-heavy cabinet while playing. So in my case, hot tubes + vibration caused my amp to stop working. I imagine my real-world experience is worth something to this thread... I've never had a solid-state head suffer from vibrations while playing (only from bad power sources or faulty components- both with Ampeg amps).

Karl
 

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