Official Mesa/Boogie 400,400+ Club

[Slaymus]

I retubed this summer my 400+ with JJ 6l6 and the 12x7 from Eurotubes.
imo, the sound was a little bit fuller, but it was subtle.
Nothing to be heard at gigging situation.

Last week I also had the bias adjusted by a local tech.
He said he warmed the bias a bit to 32mA to each tube.
Well, the result is impressive !
The sound is more 3D, the treble and high mids are sweeter, the low end is more controlled.
Overall, a significant fuller sound (my wife would disagree, but that's an another story )

Ok, it's still sound like a 400+, bit everything seems more right. No gig at the moment, so I can't say how it will translate in live situation.

I was going to sell this amp because I found it to aggressive, but I think it is now a keeper and maybe the time to have a better cabinet pairing (running a pair of gs112)

The only negative point : 2 power tubes seem to rattle a little bit with cab vibration. Subtle but it's there at bedroom volume.
Nothing to worry at gigging volume. Jay at Eurotubes suggested me to change the position of the tube and that sometimes it can help. He also talk about tube dampers... I'll have a look at this option. Maybe a Gramma pad will help. If not, I can always put the rack on the floor and problem solved !
Question : Is it Ok to let the tube rattle : will it damage them ?

[anderbass]

My Amp tech used to think the JJ 6L6 power tubes were pretty darn good, but lately he's ran across several (that weren't very old) that had became microphonic and also found several others that had severely-drifted throwing the amps bias way off. (he also ran across a new-ish JJ 6l6 that was shorting out/causing the fuse to blow in a 400+)

If the connectors in your powertube sockets have been cleaned/tightened to snugly fit your tubes pins, and your bear-claw clamps have been re-tensioned so they trully grip the tubes base: Those 2 power tubes you have that 'rattle a bit' are prolly defective and you should be demanding that Bruce replace them for free under warranty...

I've still got a full set of JJ's (in my 400+) that I bought from Bruce @ Eurotubes like 6 years ago. I've gigged/played that head a lot since then. The bias on my JJ's have drifted a bit over time, but mine dont rattle at all and still sound great. I think you might have 2 slightly-defective tubes there. And if so, they have a very good chance of completely failing way before the other 10...

[Slaymus]

Thanks for the info.
I'll have a look at the tube socket during the weekend.
Report to follow !

[brotondo]

dug my t-bird out for the first time in a Longtime,because it buzzes so bad and I can't stand it. but anyway,while tone surfing, wound up pluggin into #1 on a whim, which I never ever use cause of the lower headroom. and go figure, the bass don't buzz? I've neglected the bass for years because of RFI problems.

Now my question:Is it possible there is an issue with #2, or is there something special about 1?
the bass buzzes on my little ampeg combo too.
maybe I'm just missing something

[valipe]

Hi! I'm also proud owner of Mesa 400+. I bough it new 5 years ago. I saved one month gig moneys. In Finland Mesas are an were the most expensive amps. So 2000 euroa were gone, but everytime I put power on I feel happiness. I don't mind weigh, but sometimes I take Mesa Big Block instead of 400+. Retubing cost about 600 euros so I transport my bass gear myself if I use 400+.

[themacinator]

How much is 200o Euros in US dollars?

[BillyB_from_LZ]

Originally Posted by themacinator

How much is 2000 Euros in US dollars?

It fluctuates, but today it's about $2632.44

http://www.xe.com/ucc/convert/?Amoun...rom=EUR&To=USD

[mikenel169]

Can i get a number?

Just received this baby a few days ago!

[Caca de Kick]

Welcome to the club!

[themacinator]

#57 goes to miknel169. Sweet Mesa gear, prime 400.

[bikeplate]

Just got an excellent condition 400+. Gigged it last week. Loving it so far

Rob

[LiquidMidnight]

After running both channels concurrently on my 400+ for my last rock band, I decided to just go back to Channel 1 for my current country band this past weekend. Really dug it! I wasn't digging the pinch of wooliness I was hearing the country context with Channel 2 in the mix, but I really like the distinction that Channel 1 by itself is offering.

[mikenel169]

I should prob post this here......I have a question, I noticed a speaker crackling on only a few low notes, only when my eq is on. When it is not on the amp sounds and runs flawlessly. Do i need new preamp tubes, power tubes or are the eq sliders/circuit board dirty and needs a good cleaning. Any advise would help me tremendously.

Thanks!!!

[themacinator]

Gonna leave that to the more technically inclined

[Gringo Starr]

my opinion (and I'm not a tech by any means) I'd say it was something in the eq. My old Bass 400 had an issue with the eq when I first got it. Would work sporadically and make noises. Ended up being just needing a re-soldering in a spot then it was fine. Mind you, the amp was about 20 years old when I got it so who knows what kind of abuse it took before I got it. Anyway sorry for the rambling but I would guess you may have some kind of eq issue and not tube related.

[mikenel169]

Thats what i figured, ill have to open her up and check it out. thanks for the reply

[anderbass]

Mike, something easy you could try first is cleaning your EQ IN/OUT switch with some Deoxit D5.

You can do this without disassembly: Just position (un-plugged) amp with the front pannel pointing upwards, then use the cans straw to slowly spray around the edge of the rocker handle, (gravity will flow the cleaner down inside the switch to the contacts) Then simply work the switch back and forth a couple dozen times to help the cleaning solution work.

[mikenel169]

Great thanks alot i will try that later tonight and see if that works

[BearCave]

Can I join?!? My newly acquired rig......

[mikenel169]

nice BearCave!! you gotta tell me how those 412s sound with the 400+