GG + Lee,

There’s a slight modification to the above bit already said. Yep, power output is linear (100W is 2x 50W) but loudness is logarithmic (the ear’s a funny thing) and to go from practice combo (70dB) to ear-breaking takes a lot more power (Watts). It’s why all those annoying bass players have a 1200W power amp and complain of ‘lack of headroom’. 😛 Conversely, the “remove two tubes from my 100W so I can crank it in the studio” doesn’t really work. If the full-on 100W is too much, full on 50W will be 97% as much.

HS all T, volume pots are logarithmic, too. By that, I mean that they don’t go “1 = 10W, 2 = 20W”. There are two types of potentiometer; linear and logarithmic (aka ‘audio taper’). A linear pot is useful for tone control (I hate it when a log is put there – it’s like a treble on/off switch) but the volume and channel gains should be a log pot. This is to compensate for the above; so going from 1-10 is at least a bit like steadily increasing the volume. True enough, some are more convincing than others. Ironically, I think my Superlead/bass thing is getting scary after 5, while the similar Laney is running out after 5.

With the Line6, it may be solved by changing the value of the MV pot. If others have complained, maybe Line6 made a bad choice. Suppose it’s a 500k pot; a 1Meg will give you a greater degree of cut/boost, a 250k will give you better fine tuning. It’s hard to say from text which route suits you best – wonder if a search would turn up a juicy thread somewhere in forumland? FWIW, I lean towards halving, not doubling. Think about the warranty, though.

Edit: On an unrelated, I read on “The Bottom Line” of another prob. Bass player did a wedding gig in a barn (with a band of course, even I wouldn’t spend my nuptials just listening to a “yoodeyoo” 🙂 ). Total nightmare; amps cutting out all the time. Turns out the (US) sockets were delivering 70V on one ring, and 130V on another. A complete drag all round, but worst for the guitarist. His Line6 Spider kept returning to factory default each time. Get a surge protector for gigs 😯

I dont think there is a anything wrong with your amp Guitarguy, if you are worried then i would take it in for a checkup, but you get the same kind of setup with other amps, for instance my friend has a Marshall super lead head, it gives a monstrous amount of volume from 0-4 and quickly pans out after that, i had a Fender twin which pretty much did the same thing, but if you feel there is something wrong then maybe you should take it in.

Im tempted to say that 90% of the loudness of an amp lies between 0-5 on the dial with only 10% for the remaining 6-10 (or 11) on the dial, but i’d better not. 😆

I pretty sure this problem was explained a couple of years back in a ‘Dr.Robert’ column in Guitarist (UK) magazine, he is the resident Questions and answers expert and i remember someone had a similar question about a 100 watt head (athough yours is a 150watt). His problem was the same as yours but Robert said when you turn the master volume knob on your amp, it winds the power up from 0 watts, to 100 watts, lets say your amp master volume knob goes from 0-10 (or 11 in other peoples minds) 0 gives you no sound, 1 gives you a 10th of the total output which will be 10 watts, which is very loud in a bedroom, 2 will give 20watts etc, what Robert was saying is that the decibel output volume between 50watts (5 on the dial) and 100 watts (10 on the dial) is’nt twice the volume (Db’s), a 100 watt amp is’nt twice as loud in decibels as a 50 watt amp, it is twice the power output but not twice the volume, so i think you are getting to 5 on the dial and quite rightly noticing that there isnt much happening above that mark. Im sure now i have remarked on your problem there will be plenty of counter remarks coming, and i will of course have to defend my position. 😆