Author Topic: NPN Boost Range Control  (Read 17146 times)

vanhansen

NPN Boost Range Control
« on: September 08, 2004, 01:21:52 PM »
I've looked all over here and have read discussions about Doug's range control and what's needed.  Unfortunately the links to his site don't work anymore and I'm looking for a drawing of how it is all wired up, what value pots to use (I think I saw 5K being used for it, maybe 10K).  Does anyone have diagrams of this added to the NPN boost?  Thanks.

Erik
Erik

aron

NPN Boost Range Control
« Reply #1 on: September 08, 2004, 04:12:30 PM »
Here you go....


vanhansen

NPN Boost Range Control
« Reply #2 on: September 08, 2004, 04:20:31 PM »
Sweet! Thanks, Aron.  I'll do this when I wire up the switch and box it.  I'll post my results/thoughts here.  I'm assuming that the .68uF cap on the drive pot is not electrolytic?  Would axial lead caps be better here (for space)?
Erik

aron

NPN Boost Range Control
« Reply #3 on: September 08, 2004, 05:32:11 PM »
Yes, the .68uF is film. Doesn't really matter about type. Just go out and get a film .68uF if possible.

Let us know how it goes.

GOOD LUCK!  :wink:

Voodoo Blues

Re: NPN Boost Range Control
« Reply #4 on: July 27, 2009, 09:39:09 PM »
Aron, in the diagram above what so you mean by "1uF to 22uF electroltic cap"? Do you mean to get a cap with a value between 1uF and 22uF? What is the difference between chosing  1uF vs 22uF, does one offer more range then the other?
Who put a fog machine in my pedal?

aron

Re: NPN Boost Range Control
« Reply #5 on: July 27, 2009, 10:04:48 PM »
The larger value, the more bass that gets blended in. Note that this is not adding bass, just adding back whatever bass you currently have to the treble signal. .68uF is a treble booster - then you blend in bass to get the bass back. I would use a 22uF (easily found) or 10uF.

Even the range pot isn't critical - 5K, 10K, 25K will be ok.
« Last Edit: July 27, 2009, 10:06:27 PM by aron »

Voodoo Blues

Re: NPN Boost Range Control
« Reply #6 on: July 31, 2009, 03:57:35 PM »
Yes, the .68uF is film. Doesn't really matter about type. Just go out and get a film .68uF if possible.

Will tantalum do? If so, does the negative side go to the outside lug?
« Last Edit: July 31, 2009, 04:34:33 PM by Voodoo Blues »
Who put a fog machine in my pedal?

slacker

Re: NPN Boost Range Control
« Reply #7 on: August 01, 2009, 07:56:12 AM »
Yes and yes :)

Voodoo Blues

Re: NPN Boost Range Control
« Reply #8 on: August 01, 2009, 10:52:20 AM »
Thanks Slacker, after not getting any replies I went ahead and put it in and aside for two small problems she works nicely.  Now I can't decide if I a fuzz type sound or crunch. Decisions, decisions, decisions.
Who put a fog machine in my pedal?

luko-man

Re: NPN Boost Range Control
« Reply #9 on: August 02, 2009, 02:23:34 PM »
what does this doe exactly does it make the boost more powerful or make it more of a drive????
also when you say emmiter of transistor is it dierectly at the emitter or is it wired the same as here on the first picture????
http://www.diystompboxes.com/smfforum/index.php?topic=941.0
« Last Edit: August 02, 2009, 02:26:51 PM by luko-man »
cant think of anything funny to put here

neuman

Re: NPN Boost Range Control
« Reply #10 on: September 14, 2009, 09:54:28 PM »
Just digging around and found this thread; are the 5 K pots audio or linear?

curious.

thanks

aron

Re: NPN Boost Range Control
« Reply #11 on: September 14, 2009, 10:04:31 PM »
Linear is fine.

neuman

Re: NPN Boost Range Control
« Reply #12 on: September 15, 2009, 01:56:08 PM »
Thanks for the advice on linear pots; now, I might be suffering brain-lock, but does this 2 pot mod take the place of the 5 K pot in the original circuit or....

I'm just not seeing it.  Is there a diagram of the whole NPN boost circuit with this mod in it?

Sorry for being dense.

aron

Re: NPN Boost Range Control
« Reply #13 on: September 15, 2009, 05:30:40 PM »
The .68uF cap replaces the original 47uF cap. Then the 5K range pot and the 22uF is an add-on. Now that I think about it, you could probably use the original 47uF cap instead of the 22uF in the "Range" addition.

pazuzu

Re: NPN Boost Range Control
« Reply #14 on: November 12, 2009, 10:00:18 AM »
is there a way to cut treble with this set up? i was thinking of running 2 caps with a spdt center off, and it would be nice to have a treble cut and a bass cut.

<edit>
nevermind. i made that post right after i woke up.
« Last Edit: November 12, 2009, 12:01:36 PM by pazuzu »

1tczx

Re: NPN Boost Range Control
« Reply #15 on: December 11, 2009, 09:54:06 AM »
must it be a .68uf? can a .47uf work? my range knob dun seem like its doing anything/....

.Mike

Re: NPN Boost Range Control
« Reply #16 on: December 11, 2009, 01:39:05 PM »
must it be a .68uf? can a .47uf work? my range knob dun seem like its doing anything/....

When I built my NPN Boost, I added the range control. I find the control to be very subtle, barely having any impact on the tone. I found that there was a minor change if the gain control was up all the way, and found that it did pretty much nothing when the gain was all the way down. If I were to build it again, I would leave it out.

I ended up adding a switch that selects a different input capacitor to cut the bass a bit. Works like a charm. :)

Mike
If you're not doing it for yourself, it's not DIY. ;)

My effects site: Just one more build... | My website: America's Debate.

MBackus

Re: NPN Boost Range Control
« Reply #17 on: July 14, 2010, 02:04:31 PM »
must it be a .68uf? can a .47uf work? my range knob dun seem like its doing anything/....

When I built my NPN Boost, I added the range control. I find the control to be very subtle, barely having any impact on the tone. I found that there was a minor change if the gain control was up all the way, and found that it did pretty much nothing when the gain was all the way down. If I were to build it again, I would leave it out.

I ended up adding a switch that selects a different input capacitor to cut the bass a bit. Works like a charm. :)

Mike
How did you wire that switch?  And what different capacitor did you add? I was thinking 1.0uf? 

.Mike

Re: NPN Boost Range Control
« Reply #18 on: July 14, 2010, 08:09:12 PM »
This is how I wired it. I choose 0.0047uF as the alternate value because it is what is used in the Rangemaster treble booster.



I hope that helps! :)

Mike
If you're not doing it for yourself, it's not DIY. ;)

My effects site: Just one more build... | My website: America's Debate.