How to make this Boss FA-1 louder?

[Jmkrull]

Hey,

I built this and notice there is a substantial volume cut with the parts listed in this layout. Is there anything I can do/change to boost the output volume up a little bit?

Thanks!

[Mark Hammer]

Replace R6 with 1M.  Stock, it is a 470k feedback resistor.  The 1meg "Volume" control is actually a gain control in parallel with R6.  At max resistance, it is 1M in parallel with 470k, or 320k.  With R5 (15k) as the input resistance, that gives the stage a max gain of 320/15=21x.  If you make R6 1M, that gives you a max gain of 33x.

Whether it can provide that gain cleanly is another matter, but if you want more loud, that ought to do the trick.

[Jmkrull]

Awesome! Thanks! I'll give it a try

[Kipper4]

I built the FA1 from the Ustomp pcb layout and It's plenty loud enough
I dont know if theres anything differant in this layout.
But it should blow the roof off the amp I've used it for direct recording too


http://ustomp.com/?p=6

[Quackzed]

maybee double check that r14 is 470 ohms and not 470k ohms?

[Mark Hammer]

Good call.  Or 47k.  I've seen some resistors where I had to look very closely to tell whether that 3rd band was light brown or dark orange.

[roseblood11]

That ustomp layout still has the "47µF non polar" cap. It's 0.47µF of course...

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I don't rely on color codes anymore. I measure every single resistor before I solder it. Takes a lot of time, but saves a lot of time during debugging!