Mesa/Boogie 400 and 400+

[klejst]

What is the big difference between these two bass amps? Other than one has a "+" in it's name. I heard the + has more tubes (like 12 where as the 400 has just 6?), is that it? I know this amp is considered by many as a holy grail. Anyone who has either the 400 or 400+ thoughts/comments? Also would the 400 which is rated at 500w @2ohms work with my 900w 4ohm cab?

[Caca de Kick]

The 400 has 6 output tubes, and you can use either 6L6 or 6550 tubes in it. it also has a 6-band eq.

The 400+ uses 12 output tubes, only 6L6. Most had the 7-band eq, although the first year or two of early ones had the 6-band. Overall the + still probably makes 30 to maybe 40 watts more over the 400, but not noticable as both are very loud.

No, these amps did not make 500w.

[klejst]

Thanks man, I guess what I wanted to make sure that this amp being a 2ohm amp would work with my 4ohm cabinet?

[Alex1984]

This amp is 2/4/8 ohms capable. Very stable.

[Caca de Kick]

Originally Posted by klejst

Thanks man, I guess what I wanted to make sure that this amp being a 2ohm amp would work with my 4ohm cabinet?

Well just like any other amp, it is capable of taking different loads, you just don't go below the lowest rated load.

The bogus power ratings on Mesa site was transient power peaks, not RMS. Back in the early 90's, the 400+ was correcty listed at 300w RMS. It actually makes like 270-ish realistically. Still very loud tho.

[klejst]

I have a Mesa PH 6x10 cabinet, so I assume I am alright then with the Bass 400?

[Caca de Kick]

Oh yes, it will be a awesome match to the PH610. I use my Bass 400 connected to my PH810 alot and it's a killer match-up.

[BassmanPaul]

Originally Posted by Caca de Kick

Well just like any other amp, it is capable of taking different loads, you just don't go below the lowest rated load.

This applies to SS amps. With tubes it's best not to go above the selected impedance.

[Grooveman1961]

I don't think that the 400 has a 2 ohm tap. Just a 4 and an 8. The 400plus has all three.

[Caca de Kick]

The last year or two of the 400 did.

[sunbeast]

I had a 400+ for years and played through a 400 many times as well. I mostly used mine through a Bergantino 6x10 cabinet and it is still to this day my favorite amp/cabinet combo I've ever had- it should be equally as nice with the Mesa 610 and incredibly loud as well!

The 400 was the original (well actually there was an earlier amp, the D-180, that preceded both), and was designed around 6550 tubes. The story was that there stopped being a reliable source for 6550s at some point, so they started fitting them with 6L6s instead. The 6L6s only put out around half the wattage of 6550s when they are each biased well, so people were pushing them harder at this point to get to the same volume levels as the original 400s and supposedly they started having more warranty issues as a result. The 400+ was Mesa's response- basically redesigning the amp to get the same amount of wattage from the 6L6s that the 400 got with 6550s, which required twice as many tubes. A 400 fit with 6550s does sound somewhat different than a 400+ with 6L6s, but I didn't find the difference to be huge in the end (I also did not compare the two amps with the same preamp tubes, so it wasn't exactly a well-controlled test!).

I only got rid of my 400+ when my main band bit the dust and I started having to lug my rig around to play in lots of different places with a more diverse group of people again instead of just leaving it in one practice space and then to shows- for me the weight and form-factor were a bit too much to have to move by myself 3 to 4 times a week just for practices (especially with the 610 cab), though it would probably be my #1choice of amp if I was in another steady rock band again.

[Grooveman1961]

Originally Posted by Caca de Kick

The last year or two of the 400 did.

interesting. I must have an early one. I wonder if the wires from the 2 ohm tap are tucked away in the o tranny.

[klejst]

So I should be fine with my 4ohm PH 6x10 then right? I just do not want to blow anything out or not have enough power, etc. I am just a cautious person is all

[sunbeast]

Originally Posted by klejst

So I should be fine with my 4ohm PH 6x10 then right? I just do not want to blow anything out or not have enough power, etc. I am just a cautious person is all

Yes- just make sure to plug it into the 4 ohm speaker tap!

[nepee]

Somebody here run his 400+ with 2 cabs ?

[klejst]

So I am starting to believe buying a 400 would be a great investment and upgrade from my Peavey Tour 450. The only thing is are tube expensive? How often do then generally need to be replaced? I never owned a tube amp before, but I have been hearing the 400 and 400+ are two to look out for and get.

[bacid]

A Mesa tube amp would be a great upgrade to any rig without one. I have a Strategy 400 (the power section of the 400+) and just bought a 400. Power tubes generally need to be replaced every 3ish years depending on how hard you run your amp, or whenever you feel like changing them. Some people never do. A sextet of 6550/KT88 tubes are about the same as a dozen 6L6 tubes, both in power and cost. Prices are different of course depending on what brand you buy. A couple bucks every few years for new tubes is nothing compared to the tone of an all tube bass amp.

[Caca de Kick]

The last time I retubed my 400 was back around late 2003 or early 2004. I will say, the KT88's run alot cooler to the touch than 6L6's...those things really cook.
I retubed it about 3-4 times during the 90's, not because anything 'wore out', but because of my amp always rough riding in the trailer or backs of trucks and getting jarred as well as getting knocked over at gigs sometimes. So I didn't want to eventually have physical damage and just stayed 'ahead of the game' per se.

I've owned many of these now, and my recommendation would simply be when you buy one, to drop in a new set of tubes so you know where you're starting at. Unless you have confirmation the previous owner recently dropped in new ones. Gambling on old unkowns always bit me in the arse.

[sunbeast]

If I remember correctly, I paid around $130 or so for a new set of 12 Shuguang 6L6 power tubes when I had mine. Those were on the cheaper end of the tubes recommended to me, and they sounded MUCH better than the stock tubes that were in the amp when I bought it. As mentioned, a comparable set of 6 6550s to retube a 400 will cost around the same price unless things have changed alot since I last shopped for 'em. I retubed the power section of my 400+ twice over the course of six years, the first time was right after I bought it, and the second time about 4 years later, and only because I felt like I had pushed the amp pretty hard over the course of those 4 years (not because the tubes actually SHOWED signs of wear).

As far as the preamp tubes go- I changed those when I got the amp and then never again. Good preamp tubes can last decades...

Originally Posted by Caca de Kick

I've owned many of these now, and my recommendation would simply be when you buy one, to drop in a new set of tubes so you know where you're starting at. Unless you have confirmation the previous owner recently dropped in new ones. Gambling on old unkowns always bit me in the arse.

+1 to this- I've learned to pretty much just assume the worst from the tubes in used tube amps when I buy them, no matter what the previous owner says about how new they are or how hard they were used. There are many people who will just toss in any old mismatched set of tubes in an amp they are selling in order to hold on to the nicer/newer ones they were using in it when they decided to sell. I've had two seperate amps come to me with tubes so mismatched that the amp would blow a fuse when turned on, and both were described on Ebay as having "barely used matched sets recently installed". That said, you can always try to locate a local tube tech to give the amp and the tubes a once over when you receive it to tell you for sure that everything is kosher (generally a good idea with any expensive used purchase unless you are qualified to look it over critically yourself)!