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Mesa 400 vs 400+ ?

Discussion in 'Amps and Cabs [BG]' started by jock, Jun 22, 2004.


  1. jock

    jock

    Jun 7, 2000
    Stockholm, Sweden
    What is the difference? A 400 is for sale at a great price locally. How does it sound? Compared to the 400+?
    Are these amps reliable?
    Is there any difference on the front panel? Other Eq or anything else different?
     
  2. natrab

    natrab

    Dec 9, 2003
    Bay Area, CA
    If it sounds good, go for it. Both are very reliable, powerful amps that sound excellent. Just make sure it's working right and remember to make sure the tubes are good (A retube can cost you a hefty chunk of change if the tubes are bad).
     
  3. The 400+ uses 4 12AX7 preamp tubes, and 12 6L6GC power tubes. From what I remember, the 400 uses 2 or 3 12AX7's and 6 5881 power tubes. They both put out about 300 watts. The newer 400+'s can handle a 2 ohm speaker load, have 2 speed fans, slave out with level control, and probably a few more push/pull tone tweaking knobs.

    Both are really reliable and sound great.
     
  4. metron

    metron Fluffy does not agree

    Sep 12, 2003
    Lakewood Colorado
    I think the 400+ has two additional graphic eq bands too but Im not sure. Do a search... the difference between these amps has been covered.
     
  5. nsh50a

    nsh50a

    May 11, 2004
    Columbia, MO
    I had no Idea but just found out that the older 400+ models had a 6 band EQ from 90 to around 95 when they changed them to a 7 band EQ. I'm not sure what was on the plain 400's though
     
  6. Rockbobmel

    Rockbobmel Supporting Member

    ...Correct.....
    5881 tubes are similar to 6L6 tubes. What I think you mean is 6550 (50 watt tubes).
     
  7. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    The EQ has nothing to do with it. Mo'Phat nailed it.

    The graphic EQ was actually an option at one time, back when the D180 was in production, and the early days of the Bass 400. First it was a 6 band, then they added one or two along the way.

    Both are rockin. Get it!
     
  8. [Rocky the flying squirrel]

    Thank you, Mr. Knowitall!

    [/Rocky the flying squirrel]


    :D

    What do I know, I play solid state.
     
  9. nsh50a

    nsh50a

    May 11, 2004
    Columbia, MO
    Having only possessed a 400+ for 3 days now I have a couple of questions for you that are more knowledgeable.

    1st: How much noise is this amp supposed to make? With all the volume knobs turned to 0 there is still quite a lot of noise coming through the speakers.

    2nd: More of a comment, let's say I have the master volume at 3 and the pre at 5. When I turn the High Mid and Low knobs all the way to 0 there is no volume at all. As soon as you move at least one of the three knobs above 0 however, you can hear my bass. Is this the way it is supposed to be or is there something wrong with mine.

    thanks
    Nick H
     
  10. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    1st: It should make too much noise. Of course there will be a little hiss, but if you have the volumes all the way down it should just about be dead quiet. Explain "noise".

    2nd: The controls are passive, so when you cut them all down to zero you will get no sound through the amp. The signal hits the treble first (it's the most powerful control, as it shapes the whole sound after it), then mid, then bass, and moves on to the power section. The controls all interact with each other, so EQ with care. What you are experiencing is normal.
     
  11. I had a Bass 400 and it had 6-6550's but I think that it only put out about 220 watts RMS (smaller transformers?). My vintage svt's are much louder. But then again the vintage svt is much louder than the current SLM svt's so go figure.
     
  12. nsh50a

    nsh50a

    May 11, 2004
    Columbia, MO
    Thanks for the help Ben. I was hoping you would answer as it looks like your one of the mesa afficionados on the board. This is my first amp with passive tone controls so that was really worrying me.

    To further explain the noise: There is a constant hum that does not change in quality or volume as the master or preamp is turned up. This does not sound like the classic 60 cycle hum though. On top of this is a hiss which does increase in volume as both the master volume is turned up, or the high's increased. I should note that the amp is hooked up to a power supply with a filter that I thought would remove most line noise. I tried an experiment of hooking up the slave output to a second solid state head I have to see if the noise was in the preamp or poweramp section. The noise was still there through the SS head, but I later found out the slave output of the mesa is taken from the speaker outs and involves the power tubes as well as the preamp tubes in the circuit.

    I ordered a new set of tubes from mesa yesterday (feel like a dufus today as the amp is well out of warranty (3-28-90 build date) and should have went with the JJ6L6 tubes as has been recomended on the board). I hope this helps with some of the noise as one of the preamp tubes (of signal chain 2) was microphonic.
     
  13. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    Try running the FX loop out into your other head. That takes the feed from in between the pre and power amp. Conversely, plug your bass straight into the FX loop in and bypass the pre. It shouldn't be making that humming sound; the hiss sounds normal.
     
  14. nsh50a

    nsh50a

    May 11, 2004
    Columbia, MO
    alrighty. I plugged my bass into the effects return and the noise is still there. When I take a line from the effects send however into a little combo amp, there is no hum and minimal hiss through the combo. So I guess the noise is in the power amp section. Any idea on what could be causing it, or is just the tubes needing to be replaced (which will be done as soon as my order comes)?

    Thanks for the help so far
     
  15. Rockbobmel

    Rockbobmel Supporting Member

    Also, make sure your affects loop and slave out knob are at zero when not in use.
     
  16. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    Sorry, but I have no idea without hearing the actual problem at this point. It's odd that it doesn't change when you turn the volume up. Could it be some sort of grounging problem?
     
  17. Rockbobmel

    Rockbobmel Supporting Member

    This is kinda the same problem I had. It turned out bad tubes. The noise was not really a hum, but like pink noise.
    I thought it was a resistor or cap, but it was a tube or tubes.
     
  18. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    Time to resurect an old thread!

    Ive tried the 400+ and I love it, but Im having trouble finding a used one for sale at a good price. Ive found a couple 400 amps for sale and Im wondering how they differ tonally.

    Im especially interested in the overdriven tone.
     
  19. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    Im already watching that one but it still has 7 days left so Im not holding my breath