Looking for a variable boost

[Wild Zebra]

   Hello looking to build another booster to drive my tube amp.  I already have a rangemaster and was looking for something a little more full.  Then I thought maybe there's a boost that is switchable between Full, bass, mid, treb, clean???  It doesn't have to be so many options.  So any suggestions?

[hendrix2489]

All you do is find the tone capacitor of a design and replace it with a 5-6 position rotary switch that has 5-6 different value caps.  I have done it with a Vox Wah, Brian May treble Boost and a tube-screamer.

depending on what kind of Pups you got i would go with
0.0047, 0.01, 0.022, 0.047, 0.1, 1( in microfarads) which is what i used(sounds great w/lace sensors and hot rails)

but if you have really thin sounding pups maybe   0.022, 0.01, 0.022, 0.033, 0.047, 0.1

that should about do it

[Wild Zebra]

Well I guess I already knew that, but I don't want to mod my Range Master.  So  I could ask what circuit would be a good base for a variable cap set up other than a RM.  Or is there a circuit out there that is like a 3 setting  full, mid, treb??  Guess I'll poke around.  What is the LPB considered full??

[Dragonfly]

you could also check out the ROG "Omega"

[the recluse]

The Dan Armstrong Red Ranger is a Si transistor boost that offers Bass, Full, and Treble boost modes.  The stock circuit is not variable, and from my own experience is very loud, but I don;t think it would be too difficult to wire a volume pot between the output of the circuit and your on/off switch.

[MikeH]

I've always like the AMZ Mosfet Boost and the SHO. 

[John Lyons]

+1 on the Omega.
Goes from high to full range boost variable with a knob.

John

[mnordbye]

The AMZ Mini-booster sounds pretty full and good. It only has a volume control though, so it doesn't have the versatility you wanted. But it's recommended!

Magnus Nordbye

[Auke Haarsma]

you could also check out the ROG "Omega"

Most definately! A very versatile booster, from treblebooster to full boost to even some OD. Love it!

[suprleed]

The AMZ Mini-booster sounds pretty full and good. It only has a volume control though, so it doesn't have the versatility you wanted. But it's recommended!

Magnus Nordbye

I believe Jack has a "fat mod" in his blog for the AMZ mini-booster, so it does have some versatility that you are looking for.

[Wild Zebra]

Thanks guys.  I looked at the omega,  I like that.  So it's a toss up between that and a red ranger with volume control hmmmm, maybe both.

[John M]

While different sounding from the rangemaster (I have a Java Boost with which I A/B'd it), I built the miniboost with the variable input cap selector similar to what Keeley uses on the Java Boost which gives you full/mid and treble/treble as well as Jack's Fat Mod (a voltage reducung mod that adds a bit more grit into the boost) and a presence control so that I can roll the highs off when in the mid and treble mode to have just a mid boost. The more I use this, the more I absolutely adore it. Sound wise compared to the Java Boost it is more dynamic and a bit less gritty. I would recommend using the 2N5457's in it as they sounded best to my ears although the others aren't bad.

John

[Wild Zebra]

John can you point me in the direction of some info on this?

[chillhuman]

you could also check out the ROG "Omega"

+1 - this is a very simple build, and quite versatile ta-boot. Plus, it sounds good.

[John M]

For the input cap switching check out http://www.diystompboxes.com/smfforum/index.php?topic=58484.0 as that is where I got my idea from, but go down a bit. Basically it is switching between those three cap values. For the other two I don't think I am at liberty to tell you the exact details as they come as a freebie when you purchase the PCB from Jack at www.muzique.com, which at 11 Dollars and 1 Dollar shipping makes it not worth the hassle of doing it another way but it is a simple presence control inserted before the output pot and a manner of reducing the voltage to the circuit (I hope I have not offended anyone by passing this on). There are also other cool mods you might want to try which he gives you in that freebie with the PCB purchase, so I would recommend doing it that way.

John