Four Boosts in One Box

soulsonic · Post by **soulsonic** » 06 Aug 2008, 00:39

I built this the other day for a customer:

It's four boosts all together in one box with individual toggles to switch each one in and out. I was originally going to do it with a four-position rotary switch to select which is active, but I didn't have one on-hand that would fit in the box, so I went with the toggles instead; and that's a good thing, because this way the user can have several on at once for some really cool cascaded overdrives and fuzzes.

The boosts I included are a Rangemaster Germanium Treble Boost, a super-clean opamp boost of my own design, a ZVex SHO, and Jack Orman's MiniBooster. They are wired up in that order, and all I can say is that the RM->SHO->MiniBooster combo is fuzz heaven! I think I might actually throw together a fuzz design based on that because it sounds wicked.
Here's a pic of the guts:

You can see what's going on here plainly enough. One little trick is that I used a MAX1044 to make a negative supply; this gives me a true bipolar supply for the opamp boost, and it has the added bonus of making it easy to wire the Rangemaster up with the negative supply referencing to ground, so I didn't have to wire it "upside-down" or resort to any other compromises. Also note the bias trimmer for the Rangemaster is a 10K pot used as its Emitter resistor - this is definitely the best way to go for biasing. I used an AC128 for the Ge transistor and it can do the Rangemaster thing pretty well when biased up correctly. The opamp boost uses an LF411 in a standard non-inverting sort of configuration. The SHO and MiniBooster are pretty much stock and nothing unusual.
Here is how I wired the toggles:

You might also notice I didn't use any input pull-down resistors (JHS would be proud). With the way I wired the bypass switch, I couldn't hear any noticeable popping when engaging the effect, so I decided not to compromise the "raw" input impedance of the circuits with pull-downs. The SHO sometimes makes a very faint "thunk" when switched, but it's nothing I'm worried about, and the others are very quiet with absolutely no noticeable artifacts when switched while playing.

I didn't include any schematics here because there's already schematics for these boosts all over the place. If anyone is interested in doing a layout for a DIY project, then feel free to do so.

Cow4prez · Post by **Cow4prez** » 06 Aug 2008, 06:39

is that a bit redundant?

great job!

Post by **modman** » 06 Aug 2008, 11:54

Wow very inspirational how a completely whacky idea turns into something you might persue further only because you didn't have a certain part on hand. With a rotary swtich you wouldn't have discovered the fuzz heaven combo

borislavgajic · Post by **borislavgajic** » 06 Aug 2008, 16:33

WOW man!!!!

very nice

RnFR · Post by **RnFR** » 06 Aug 2008, 22:15

thats really cool-
would love to see what comes of the fuzz combo thing.

Silent Fly · Post by **Silent Fly** » 07 Aug 2008, 10:22

It looks very cool Soulsonic!

I like the graphics and the little details like the aligned switches' nuts and the vertical footswitch nut.

RnFR · Post by **RnFR** » 13 Aug 2008, 20:14

would it be possible for you to go into a little bit more detail on how you wired the toggle switches? is it like this except with toggles then you sent the in and out to another stompswitch?

i hope andy doesn't mind me posting this here. if so sorry in advance.

soulsonic · Post by **soulsonic** » 14 Aug 2008, 07:55

Thanks for the comments, guys.

The toggle switches are just individual bypass switches with the footswitch being a master bypass for the whole thing. It's kinda like that diagram you posted, but the switches are wired so that the unused inputs are shorted to ground; this prevents any potential oscillation or noises from the unused parts of the circuit.

RnFR · Post by **RnFR** » 14 Aug 2008, 11:42

cool. that makes sense. thanks for the insight!

LMJS · Post by **LMJS** » 15 Aug 2008, 13:11

"...a super-clean opamp boost of my own design, a ZVex SHO, and Jack Orman's MiniBooster. They are wired up in that order, and all I can say is that the RM->SHO->MiniBooster combo is fuzz heaven! I think I might actually throw together a fuzz design based on that because it sounds wicked."

Very cool stuff.

If you have the time, I would sure be interested in seeing your own op-amp design and what you want to put together for the fuzz design. I am probably not the only curious one on here that would love to see the schematic. Thanks in advance if you can do it!

RnFR · Post by **RnFR** » 17 Aug 2008, 01:00

i started a vero layout for the rangemaster-SHO-minibooster thing because i wanted to try it out, and didn't want to put 3 pcbs in one box, and i'm kinda crappy at perf- it just never looks neat to me and it's not very forgiving when i screw shit up.
when i get it done, should i post it here, or should i put it in another thread?

RnFR · Post by **RnFR** » 17 Aug 2008, 04:49

alright here's what i've got. UNVERIFIED.

i used Doug Hammond's Rangemaster Tweaks simply because i want to hear what it sounds like, and left off the pulldown resistors as per Soulsonics original build. the layout is basically a cobbled together version combining Dragonfly's RM, Igloo's SHO, and Robin Aggleton's MB layouts tweaked for 9x34 holes, common ground, power, and some other adjustments by me.
i was thinking of calling it something completely retarded like the Master of Mini Hard-ons, but then thought differently. maybe.
thanks to all those mentioned above as well as Jack Orman and Mr. Vex.
if any of you geniuses see anything that looks off please let me know because this is the first time i've attempted the vero thing.
cheers!

RnFR · Post by **RnFR** » 17 Aug 2008, 22:56

do i need c2 AND c11 in there? or will c2 do all the power conditioning needed?

i also realized that, depending how big c1 is, you could move it over one row to the right and make everything nice and straight.

soulsonic · Post by **soulsonic** » 18 Aug 2008, 06:38

If you make C2 100uF and maybe include a small (47 ohm) resistor before it, you'll be fine for power filtering.
And you'll probably want to used a 10K trimmer for R3, otherwise the Ge transistor will probably give you a headache if it doesn't bias up rightly with a fixed value.
Also, be sure that you only use a MOSFET like a 2N7000 or BS170 for the SHO - I don't think a JFET will work correctly in that circuit. I also think it will sound best (the way an original does) if you use 10M resistors for R6 and R7.

RnFR · Post by **RnFR** » 19 Aug 2008, 06:37

awesome. thanks alot for the tips. so i should be able to ditch c11 then. i'll try and make the adjustments soon and get a new layout up.

RnFR · Post by **RnFR** » 19 Aug 2008, 07:21

ok, this is what i have. i was able to make it a line thinner as well. is the trimpot hooked up right?

RnFR · Post by **RnFR** » 19 Aug 2008, 11:12

the above layout is 8 rows by x 34 holes, not 32. although if you go without the trimpot you could cut it down another couple.

RnFR · Post by **RnFR** » 19 Aug 2008, 11:46

i think this is how it should look with the trimmer right?

noelgrassy · Post by **noelgrassy** » 19 Aug 2008, 19:16

Great job on this Soulsonic! I especially dig your dual polarity power supply. Always the
clever lad.

Is the basis of your supply described in the PDF file for the MAX1044? Didn't you use this
chip in your seductive Cornish Type Switcher?
I'll check my files.

Always a treat to see your latest creations.

RnFR · Post by **RnFR** » 21 Aug 2008, 01:00

alright i'm REALLY sorry for hijacking this thread. and next time i post a layout, i'll do it via imageshack or some other hosting site so i don't have to keep attaching these bunk layouts. i think i finally got the trimmer right, but DIYLC isn't letting me export files right now so i'll put it up later. if one of the mods wants to split this into it's own thread, i wouldn't be opposed to that either.