Input impedance

[gutsofgold]

I'm trying to get my Minibooster to sound just the way I want. One of my complaints is it is too "crispy". I understand the Minibooster from AMZ has a high input impedance to give it that sparkle sound. It has a 2.2M and a 1M (both to ground) in parallel at the input which gives about 700k total. Would reducing this to say 90k (1M and 1M in parallel) make much of a difference? I'm trying to get the booster to not alter the sound as much and retain more of "just the guitar" tone. Thanks.

[ClinchFX]

Two 1M resistors in parallel will give 500K.  How it will affect tone will depend very much on the pickups you're using.  If you make the total resistance too low, it will probably sound muddy.  The AMZ Mini-Booster at http://www.muzique.com/amz/mini.htm doesn't have a 2.2M in parallel with the input. 

If you want to see what happens, why not replace the 1M resistor with a 1M trimpot in in series with a 150K resistor and adjust it until it sounds good.

Peter.

[gutsofgold]

There is a spot on the board for an optional 2.2M before the input cap. Would I take into account both R1 and R2 for impedance even though they are seperated by the input cap?

[zyxwyvu]

There is a spot on the board for an optional 2.2M before the input cap. Would I take into account both R1 and R2 for impedance even though they are seperated by the input cap?

Yes, they still act like parallel resistors in this situation.

[bool]

Personally, I'd recommend having a ~560K / 47nF input impendance with fets (or ~220-270K for more "vintage tone" in this case paired with 100nF input cap).

But you can always try paralleling caps at the output to trim excess high frequency content.

[Steben]

Yes, try to swap some caps instead. The smaller a cap, the more low end goes away.

On the other hand, guitars tend to have a tone control. 

[mac]

On the other hand, guitars tend to have a tone control. 

When guitars are new the tone and volume control are tiny appendixes that begin to grow as guitars get old.

mac