Difference between mesa 400 and 400+

[epic!]

As the title says, whats the difference between these two amps. Also does the 400 go down to 2 ohms? thanks

 

[kayakbass]

I used to own a 400 YEARS ago... As I recall the 400 came with six 6550 power tubes and the 400+ was twelve 5881's. I don't remember my ol'400 going down to 2 ohms though....again it's been a LONG time! Nice finger style tone out of it though....until the transformer blew...

 

[epic!]

Thanks, Im shopping for a 2 ohm tube head for one of my cabs, and came across a relatively cheap 400 for sale. Its either this or a Fender bassman 300.

 

[lorenk]

The main difference is the power tubes, the 400 can use both 6550 and 5881 tubes. Also the plus has one extra band of EQ. I believe they can both operate in two ohm mode but don't quote me.

 

[mikeswals]

The last year of the old 400 did in fact come with 2ohm speaker jacks just like the 400+. That version is harder to find, but do show up.

Other than that I have use my 400 at 2ohms for years

 

[Calaverasgrande]

The bass 400 and 400+

• have the same type of 3 band rotary EQ
• 4 preamp tubes
• have post output transformer DI
• active and passive inputs
• dual effect sends

How they differ;

• 400 has six 6550 (230 watts) or 6L6 (180 watts) 400+ has 12 6L6 at 350 watts or so.
• the 400 has a bit more of a thick grindy mid forward tone to it, the 400+ seem to me to be a lot dryer sounding.
• The 400+ runs its power section with much more headroom than the 400. So you have to really dime the EQ and push the output to get power tube crunch.
• 400 has 6 band graphic, 400+ has 7 band with one extra higher eq slider.
• 400 can only do 4 or 8 ohm loads (I called Mesa about this and they insist you will kill the ouptut transformer if you run 2 ohms). I have never seen a 2 ohm 400 but would love to own one!

 

[epic!]

thanks for the help! since it doesnt run at 2 ohms im going go with the bassman 300

 

[Calaverasgrande]

thanks for the help! since it doesnt run at 2 ohms im going go with the bassman 300

NowI am curious. Do you have a single 2 ohm cab? or are you running two 4 ohm cabs. If its the former it wont happen with the mesa 400. If its the latter you can make a series cable (or series box) and turn two 4 ohm cabs into an 8 ohm load.
Tube heads put out the same watts regardless of whether you are at 4 or 8 ohms so it will be just as good.