Mosfet booster volume

[sopapo]

Hello to all,I built the amz mosfet booster in vero,  I did it twice, one my layout and other using torchy's layout and the problem is the same,when I turn down the gain pot, there is still sound I mean the pot not turn down to zero volume when I completely turn tothe left....
why is this? its normal that the volume dont drop absolutelly when the pot is in min.position?

Also there is very little gain...it supossed that the mosfet booster has until 20 db or more itisnt?

I changed seven BS170 but the problem continue and doubled checked the components with an meter and capacimeter and all is fine....also the voltage in bias point is is right.

What happened?

Do you guys have find something similar?

Thanks to all
Best regards

[Bernardduur]

It is normal; in the "off" position there is a 3dB increase in gain. In the max position there is an 35 dB increase in gain.

I really like mine; I use it as a input buffer just before my bass hits my amp (and before my effects; they are in a seperate pre-preamp FX-loop). It really brightens up my signal.

Just get used to it I guess...... Have you biased yours? Or make a box with two of em behind another for more gain

[Stevo]

 
pinouts correct
Go to mouser.com and look up bs170 and bring up the data sheet

[TheBigMan]

Wot Stevo said.  That's how mine behaved when I first built it.  A swift reversal and all was well.

[sopapo]

Thanks for your answers stevo, bernard and bigman 
I dont knew that this booster have 3 db of level even at minimum pot's position...ooopss fault of mine, dont read well the entire article
But I afraid that there is equally something wrong cause dont look to have to much boost in the middle positions...to fell the signal really boosted (at least somethind that sound near 20 db) I have to turn up too much the pot and then the sound is distorted...

The pinout is right if not it didt work at all, it isn't right? big man what is swift reversal?

It has to do with trying to get the real right tension of bias, apart of the teorically good point (4.5v to 5.5v ) I didnt do the pot thing until find the correct value?...

Or it has to dowith the non linear tracking of the pot that it do a fast bump in the finish that dont let fell the gain? its advised to tweak the pot until it have a more linear tracking ?

Thanks for all , your help is very appreciated.

[ryanscissorhands]

The pot on the AMZ Mosfet is for "boost," not volume. If you do want a volume option, just add a pot to ground at the output. I made my dual AMZ mosfet booster into a two-channel FX loop box, and so I needed to be able to set the booster at unity gain--so I added a 100k pot to ground to both channels.

[sopapo]

Hello Ryan,yes Ryan you are right,but an increase of gain is perceived too as an increase of volume and this the point with the mosfet booster in that is a booster but clean it can boost the signal without tonal change  in the sound until certain degree....the thing is too boost the signal level-wise but without too much change in the sound ot the gain of your amp nor distorting it toomuch...
Its clear that if you crank the boost up the limit you are overdriven the imput section of the amp....

[petemoore]

  Serious amounts of boost, more than I ever really need to use, in fact I should go in and tame it down because it could cause serious 'toomuch' if turned on if the knob got turned up somehow.
 

[sopapo]

why then I am having this issue? I dont see that the boost have 30 db of gain,  it have certain gain when putting the pot in high positions but not that high and the boost of gain is less progressive

It dont work as well as the minibooster in this term, the minibooster have to me more gain

What is wrong?

[transient]

One thing about the Mosfet Booster is, it works even with the wrong pinout, but you get very low volume. If you've socketed the MOSFET, the solution might be as simple as turning the Mosfet around.

.
e

[TheBigMan]

One thing about the Mosfet Booster is, it works even with the wrong pinout, but you get very low volume. If you've socketed the MOSFET, the solution might be as simple as turning the Mosfet around.

.
e

A swift reversal. 

[MartyMart]

One thing about the Mosfet Booster is, it works even with the wrong pinout, but you get very low volume. If you've socketed the MOSFET, the solution might be as simple as turning the Mosfet around.

Or ....... swopping two pins over also, as in "D_S_G" or "D_G_S"  !!

Marty.