View Full Version : phase invertor tube?
12-26-2007, 10:50 AM
I was told by a manufacturer that a good matched phase invertor tube could possibly increase lowend headroom.
Now I am learning more and more as I go along my myriad of amps,b ut this is a new one to me.
They also said could be a bad power supply cap. I don't think there is anything wrong persay, as the amps sounds great, but I am just wanting the lows to not be so farty. Yes, I've messed with various power tubes.
12-26-2007, 11:35 AM
Other things to think about for that problem in general are speakers, the type of cab the speakers are mounted in, and power and output transformers. It's hard to be more specific without knowing what kind of amp you're talking about, whether you're talking about using it at all volumes or just cranked, and so on.
12-26-2007, 11:53 AM
Without knowing more about the amp and specific problem it's hard to point to specific cures.
But one fix often used to cure low end farting is decreasing the size of the output stage coupling capacitors. For example if they are 0.1uF, try 0.068uF or 0.047uF or maybe even smaller. It basically rolls off the low end. But it allows one to hear the rest of the frequencies at volume without the annoying farting.
12-26-2007, 12:02 PM
But it allows one to hear the rest of the frequencies at volume without the annoying farting.
Sounds like a holiday dinner thread.
Not sure a phase inverter tube would do it. I find that when I crank my amp (Dr Z Mazerati) I have to roll off a bit of lows to keep it tight. Could be something you could try with amp EQ or your pedals (not sure what you're using). Speaker type would be a factor, too. I like higher-wattage speakers that don't break up much. That seems to keep things tighter.
12-26-2007, 12:28 PM
Starting with a discussion of the amp, speakers and problem would be most appropriate.
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