Need help with F-100

[four on six]

On the clean channel, my F-100 has a very loud hiss using normal settings and it doesn't sound like I'm getting 100w of power (with master at 12:00 I could still play in a den and not be too loud). I don't have the same problem with contour channels. Is this normal? I've tried a few different guitars just to see if it's difference in pups, but that doesn't seem to be it. I plan to call Mesa support, but thought I'd check here as well.

 

[Brewski]

Hi There, where is you're gain setting at? Do you have that turned up at all? Also, what are your other settings? (Treble, Mid, Bass) Gain and treble settings affect your volume the most, along with shaping your tone. At 12 noon on the master, you should be pretty darned loud.

 

[four on six]

Clean channel Gain at 12:00, treble 12:00, mid 9:00, bass 11:00. The hiss is quite pronounced even with Master at 9:00. At this setting, I have 40w amps that are much louder and even when I put Master at 12:00, it barely gets any louder. It's sort of like the increased output goes to the hiss rather than any real volume increase. Contour 1 & 2 seem ok.

 

[Brewski]

If you've checked all your pre-amp tubes, then it is probably something that you'll need a tech to look at. Probably something simple, but I would go with plan A and either arrange to have it sent back to Mesa or if you have a certified Mesa tech in your area.

 

[cnumb44]

I had a similar problem with loud hiss on one of the 2 channels of my LSC. It turned out to be a blown screen grid resistor.

First check the V1 preamp tube because that is the first gain stage for the channel and if it is bad, you'll get similar symptoms.

If it is a new amp, Mesa has a great warranty program.

 

[fatboy135]

I´m agree with cnum44, test if your preamps tube are ok, interchange them and hear again