Fulltone Fulldrive2 -> Bassdrive

[Bent Penguin]

Hi, I just got a Fulldrive 2 that was made in January 2004 and was wondering if any one knew what the difference between that and the Bassdrive is. I'm quite pleased with the tone but am interested in the extra octave the Fulltone site mentions for the bassdrive.

I found a schematic here

http://www.generalguitargadgets.com/v2/diagrams/fulldrive_2.jpg

But I think that one's too old.

Is it more than just changing the input/output caps? Thanks for any tips.

[cd]

Is it more than just changing the input/output caps? Thanks for any tips.

Amazingly enough - NOPE.  Figure out the RC high pass values and add an extra octave.  That's all.

Any chance you can trace your Jan 2004 model?

[rhinson]

hello there,  does anyone know what the flat mids mod is on this box?  i think i can guess what the comp cut mod is/does but i'm not sure about the flat mids version.  anyone know for sure or have a good educated guess?   thanks     rh

[Steve C]

hello there,  does anyone know what the flat mids mod is on this box?  i think i can guess what the comp cut mod is/does but i'm not sure about the flat mids version.  anyone know for sure or have a good educated guess?   thanks     rh

RG's site has a write up on the subject, as well as Jack Orman's site.

[rhinson]

hello steve,   i looked on both sites but did not see anything about it.  if you could be more specific as to where it's listed on their sites i'd appreciate it.  thanks very much.   rh

[Steve C]

http://www.muzique.com/lab/fatt.htm


about half way down

[Bent Penguin]

Is it more than just changing the input/output caps? Thanks for any tips.

Amazingly enough - NOPE.  Figure out the RC high pass values and add an extra octave.  That's all.

I'm fresh enough to not understand that But I'm under the impression I'll be doubling a cap somewhere.

Any chance you can trace your Jan 2004 model?

I don't see why not, except I don't know what I'm doing. Want to help?

[cd]

I'm fresh enough to not understand that But I'm under the impression I'll be doubling a cap somewhere.

Oops!  OK start here:

http://www.allaboutcircuits.com/vol_2/chpt_8/4.html

A high-pass filters allows highs to pass through, meaning it cuts lows.  So if you want to let more highs through, you can adjust this filter so it cuts off less lows.  The formula for figuring out the frequency at which the high cut starts is:

1/R*C*2*pi

Where R is the value of the resistor in Meg ohms, C is the value of the capacitor in uF.  For example, say you had a .01uf cap and a 100k resistor to ground.  The frequency is:

1/(.1)(.01)(6.28) = 159Hz

If you doubled that .01uf cap to .022uf, the frequency shifts:

1/(.1)(.022)(6.28) = 72Hz

Now the lowest note on a standard guitar is E2, or around 80Hz (I forget the exact number).  The lowest note on a bass is E1, or around 40Hz.  If you want to let ALL the low end through, you flip the formula around to figure out either the value of the cap or the value of the resistor.  So let's say we want a frequency of 40Hz with a 100k (.1M) resistor.  Our formula to figure out the value of the cap becomes:

40Hz = 1/(.1)(C)(6.28)
C = 1/40(.1)(6.28)
C = .039uf (or use the closest standard value, .047uf).

I don't see why not, except I don't know what I'm doing. Want to help?

VERY interesting - do you have a multimeter that can read capacitance, or can you see what the caps (big green things and tubular things) say on them?  The other thing to do is identify the chip type, then measure all the resistors, and measure all the pots.  The other thing to do would be to take a picture of the other side of the board.  This might be tough the way the power jack is arranged, you may have to unsolder it.