Mesa Boogie 400+ amp

[uyvu_taman]

Dear Friends,

I hope you can help me this issue.

I just bought a used mesa boogie 400+. I uses an active warwick dolphin pro I, 5 strings bass. when I pluged in my bass into an amp, then I turn the channel volume up as well as the master volume up of an amp. However, I did not hear any sound. (Of course, I did turn all the volume up of my bass as well). At that time, the treble, bass, and mid knobs were off (0 position) and EQ was off.

Because in the 400+ amp has two channel (1 & 2), I tried to turn both up as well, but I did not hear anything. I thought it might be wrong with the amp.

However, when I turned the bass knob or treble knob up, then I hear the sound. Do we consider it is a issue with my amp 400+.

Please let me know, I need your feedback..............In order to have a sound come out from my amp, the treble, bass and mid knobs is support to turn it on with the channel volume as well as the master volume......Is it right?

Please help me

 

[uyvu_taman]

Please give me some advice

 

[GaryCleaver]

I also have a 400+, this is usual, because of the way the pre amp and bass mid and treble componants are made, the amp will not produce anything until these are all at least on 1 or higher. There doesnt appear to be anything wrong with the amp if this is your only problem.

Gary

 

[bigbajo60]

This is the classic "Fender Tone Stack" that people talk about...

It sort of acts like a volume control for each individual frequency band.

I switched out the first preamp 12AX7 for a 12AU7 (the infamous Psycho Bass Guy Mod) and found that it made the amp more flexible/suitable for pop, rock, country, etc...