This magic little box (the size of an MXR phase 45) is for the Purist, whether you're a Guitarist, a Bassist, whether your thing is Jazz, Rock, Acoustic/Electric, or Heavy Rock.
Not a distortion box, the Fat-Boost is a Class A Discrete design offering up to up to 30db of Clean Boost without ANY change to your EQ.... and at the same time it makes your sound Bigger, with more even order harmonics! You Blues players with the vintage-type tube amps will never turn this thing off... and it works great in front of Master-Volume amps to kick them up a notch as well.
The Fat-Boost gives you the feeling that your amp is cranked at living room volumes so clean playing is more dynamic, notes hold on longer without being distorted!
:P ...original copy of...ReplyDelete
Heh, well "original copy" or not, I'm going through a 1590a phase at the moment, and the original seemed to be one of those classics I'd never built before.ReplyDelete
So I can confirm this one works. Only thing to note is the tone control acts as a treble cut as it's turned clockwise. Which may well be how the fulltone one works, I don't know.
Thanks for another neat layout :)
Awesome, thanks for verifying Simon. The pot lugs match the schematic so I'll leave it until someone can say whether the original works the opposite way, and if so I'll swap them. At least we know the layout is right which is the main thing. CheersDelete
"whether you're a Guitarist, a Bassist,", it's mean this layout for bass too?ReplyDelete
Yes I don't see why not, give it a try and see what you think of the frequency response. If you think you're losing any lows it's easy enough to increase some of the cap values to suit.Delete
Increase all the caps value or some caps to get more lows?Delete
And some pics. Actually this one's not great to show off given I couldn't even be bothered painting it! I'm enjoying the sound though, it's working well at the very end of the chain.ReplyDelete
Great build, thanks for the picsDelete
I'm very new to this, this particular pedal looks like an interesting place to begin. I have done a lot of research on many sites, most of them have full on PCB designs.
I love the idea of stripboard, but i can't quite get my head around the off board connections. from looking at the diagram above, how would I know what goes to what? I looked closely at SimonB's finished product to see if i could piece it together, but couldn't quite see enough..
Any help would be so greatly appreciated.
There is information on the offboard wiring here:Delete
This should help
Hi thanks for the quick reply,ReplyDelete
I did look at this but apart from the 9v, ground, in and output, i'm still unsure as to where the rest are going too... the tones, gain and volume? sorry as you can tell i'm a total noob, but hopefully not for too long! :-s
OK, noob here too, but it is quite easy once you get used to it.Delete
If you look on the offboard wiring info, it tells you which pot pins are 1,2 and 3 (there is a little picture). These pin numbers correspond to the wiring given in the layout above.
Gain 1 + 2 means you take the wire to pins 1 and 2 on the Gain pot. Gain 3 is pin 3 on the pot etc. Simples
Where it says Tone 3 & Volume 1, the wire goes to pin 3 on the Tone pot and then there is a link made from there to pin 1 on the Volume pot.
The text note explains that pin 2 on the Volume pot goes to the output (i.e. the pin on the stomp switch output from board)
I think that should get you going :-)
ah thank you so much! unbelievably helpful dbat69. :-)Delete
Thank you! But this is slight different than the previous board... http://tagboardeffects.blogspot.it/2010/02/fulltone-fatboost-v1.htmlReplyDelete
God I thought for a minute I'd done it based on the AMZ schematic but I've just checked and I haven't, I've just got two different schematics for the Fatboost. The original one I did had a gain control in series with the input, and his one has it at Q1 source.Delete
It may well be that both have been used by Fulltone, but I prefer the source method anyway and so would use this layout first. I'll revise or add a new layout if I get to see a V1 or confirmed schematic, but I think any new layout is more likely to be based on the FB2 or FB3 as this one hasn't been available for quite a while.
Thanks for the cool layout! This is my first build. I am anxious to hear it goin. One question is WHERE is the output? I see the INPUT but NO output? Is the OUTPUT at the volume pot no.2? Perhaps help from dbat69? Sorry if i am a noob. But i'll get used to building another one and not be such a novice?! Thanks in advance VinceReplyDelete
The output is from pin 2 on the Volume pot - this wire goes to the stomp switch (follow the offboard wiring guide)
oops meant to say - follow the offboard wiring guide for the stomp switchDelete
Really great, thanks a lot!!! I have a question: the 10 p "orange" capacitor, is ceramic o tantalum?ReplyDelete
10pF capacitor is ceramic. I don't think you'll be able to find tantalums in that value.Delete
thanks a lot!Delete
Built this and its working. Although im getting a heavy hum when effect is engaged... I replaced this with 33pf and 2.2uf.. Dont know if that would cause this. Also using 2n5459's.. Sounds like a grounding issue but everything seems to be connected correctly. Any suggestions?ReplyDelete
hi, this is my first pedal building and looking at your layout i can't figure out what the black stripes and the red spots on the board are . Can you help me ? thank you !ReplyDelete
Hello Luca, red dots are "cuts" in the copper strips, and black lines are "jumpers" from one strip to anotherDelete
These links may help you
There's a learning curve, but once you get the hang of it, vero is very easy to do....good luckDelete
I apologize if this posts twice. I tried to already post and nothing showed up, so doing it again.ReplyDelete
I can't get my pedal working in my test rig. There's just no signal whatsoever coming out.
Here are photos (yeah, it's kind of spiderweby):
I have verified:
1> All 9 pot connects short from the pot pin to where they go on the board and the signal connection of the two jacks, as appropriate (verified with multimeter)
2> All ground connections go to the - on the 9V.
3> I've checked that there are no shorts between adjacent strips on the veroboard.
4> The JFETs are in 3-pin connector slots. I've verified that the 3 legs of each JFET shorts with the appropriate strip on the back of the board.
5> I created a test circuit for the JFETs (they were pulled from an amp, I believe) that has them light a LED (http://amasci.com/emotor/chargdet.html, but who knows?)
I only have a multimeter. No oscope.
What else can I test? Can anyone see anything obviously wrong from the photos?
I didn't have a 3.3uF cap, so I did a 2.2 and 1.0 in parallel.
yes you obviously did it wrong. you did it as all components on the layout are from the bottom of the board...ReplyDelete
make a new on BUT FIRST...
Why does it matter? It's a mirror image. Everything should still be connected the same, Or am I missing something.Delete
This comment has been removed by the author.Delete
"yes you obviously did it wrong." And can you clarify this statement? It's obvious to you, but I wouldn't be here asking if it was obvious to me what's wrong. If it's merely that it's a mirror image, try to keep in mind that different is not the same as wrong.Delete
ok...calm down man. i was just writing thisDelete
"first of all we can't see very clear from that angel your upside of the board. it seems that the long link is not correct even with this mirror build. but after transistors, i can't see anything.
the problem with this reversed building is that the 10pf for example should be connected with the gate of q1. now it's connected with the drain.
but even if you would turn your transistor 180 degrees then you would still have problems cause the small link would connect the source of q1 with the gate of q2.
but you want d of q1 connected with the s of q2...
ahhh!!!!my brain is about to explode with all this opposite thinking!!!
you should build it right cause it's easier for people to "read" it...
hope i helped...
good luck man!"
So you did it in reverse and we should debug it for you in reverse?Delete
How about flipping the JFETs over 180 degrees?
Sorry, I didn't mean to come off harsh.Delete
Okay, I did find a schematic and I noticed the JFETs were in backwards (the mirror image thing screwed me up on that). But once I found a schematic it was clear where the voltage divider was and how the one JFET is biased and the voltages were wrong, so I rotated the JFETs around and that fixes the stuff you pointed out (basically the gates and drains were backwards).
Still not working, but at least there's sound (a slow oscillating noise).
Starting at the top, I have these voltages (the 6 in the middle are measures on the JFET legs):
0 (ground), 9.45 (d), 4.78(s). 4.55(g), 4.78(d), 1.0(s), 0(g), 0(ground)
All of these make sense to me except the 1.0. That looks fishy. With nothing plugged in (except a battery), shouldn't that be 0?
mirosol, I'm asking for help. I'm not demanding it. It's your choice whether or not you want to help me. I'm inclined to get it working this way rather than throwing it out and starting over because I imagine it'll be faster to debug than to rebuild. I could be wrong.Delete
Faster to debug a mirrored board than building it again, being a 11x8 vero with 10 components? Are you sure? How much time have you spent here asking for help and how much would have you used to rebuild an extremely easy board like this? Half an hour?Delete
You guys are sometimes just unbeliable :(
In this case you'd definitely be better off with a rebuild. It'll take you 20 minutes, while i think you've spent at least an hour figuring this board out. You could also use just 2µ2 in place of 3µ3. I bet you won't hear any difference.Delete
And it is very true that it's about a hundred times easier for us to help you when everything isn't in reverse. If this was an opamp circuit, there would be nothing for you to do about it.
And Ksenagos - check your yahoo mailbox :)
Got it. Bad cap, of all things.Delete
Thanks for your help ξεναγός.
it's ok Pedrito.Delete
have fun with your new effect!
it's true that i really wanted to help, but if you had it as we're used to, then we could find the solution much faster by eliminating the "wrong place for this component" stage. if we knew that everything looks fine, and soldering looks clear, then we could tell that you've burned something, or a component is bad
with this way you did it, i wasn't sure even for your voltages.
i mean "which is which". "starting measuring from where?"
hope you understand what i mean.
keep on soldering!
and miro i did it!
check yours too!
Pedrito - as another noob please let explain something vital.ReplyDelete
When you see the picture of where the cuts go you are looking at the NON-copper side of the board, which means that is the side on which you will be placing the components. The picture on the left (with the components showing) is a "see-through" picture to show you where the component go on the other side. They only show the copper in the picture as a reference point - but you are actually looking at the circuit as it is built on the non-copper side.
Here is what I do (and many others) - I look at the pic on the right and I drill a small hole from the NON-copper side so I know where cuts will be when I flip it over. When I flip it over I find those drilled holes and that is where I make the cuts in the copper. Then you flip it back over and start placing the components as you see them in the picture.
Yes, it is confusing at first, but the best way to do it. I am not even sure how you managed to figure out how to build that upside down.
The main thing to remember is that although the picture shows the copper, you are really looking at the other side. So after you make your cuts in the copper - FLIP THE VERO OVER SIDEWAYS - and the build the circuit exactly as you see it in the picture on the left.
The experienced people get understandably irritated when a noob has not done his homework - and that makes it a little tougher on noobs like me how have. I just started a couple months ago, but here are pictures of what i am doing now. You can do it, too...
Mirasols test box (just finished yesterday - works GREAT! Thank You, Mirasol.
The box in use - with 2 circuits (one my first build ever, done before I found this place) and a fuzz from here, connected to gether and powered by the Test Box.
I had actually looked over the How To but I didn't look at it in detail. I realized pretty early on what I had done, but I also realized that, electrically speaking, it shouldn't make a difference. I realized, after I had built the circuit, that you can also just load the layout image into an editor and flip it horizontally. That would have made it easier to put together initially, but it helped me validate that I had everything laid out right. And had it not been for the bad cap and getting the JFETs backwards, I did get it right. I mistakenly flipped the JFETs, but the board was flipped horizontally, whereas the JFETs got flipped vertically and they didn't need to get flipped at all. I just hadn't really thought it through. Just kinda went with my gut. Going with my gut usually gets me in more trouble with electronics, but the circuit survived (unless that's what killed the cap).ReplyDelete
I'm already on to some other pedal (fo-SHO booster)... (The fulltone is the first veroboard thing I've done, but I definitely like it better than single-hole breadboards with some point-to-point. I've done some really hideous stuff).
Thanks for sharing the pics of your test setup. That's pretty sweet. It's been a lot of years since I've built any pedals. I'll probably just build a few, but if I decide to build a bunch, I'll definitely steal some of those ideas for a test rig :-)
Mirosol designed that test box and did a blog about here http://tagboardeffects.blogspot.com/2014/09/test-box-20.htmlReplyDelete
In truth - he said he did not make the blog to show newbies how to build one - he basically did it for more experienced people because he had an idea for an audio probe. But once I got all the parts and traced what he had done, it actually worked without hitch.
Practice definitely helps, here is the challenge as a noob - there is so much to learn that while you can understand it you cannot possibly remember it all - so there will be times when simple things elude you (like how to wire a footswitch).
But after awhile, with redundancy, the more you do it the more you realize certain concepts are in play, and you remember the theory.
For me, the hard ones to master have been; grounding and LEDs. Other people have their own roadblocks. I now know everything needs to be grounded, and for LEDs to work I need a +V, ground, an LED and a resistor - that's it.
The whole thing is actually getting pretty easy. my stuff does NOT look pretty, but it works. I have never (ever) been a craftsman or artist, but I know sound& audio. In time my work will look better, but the concepts are starting to come to me a lot more easily now.
I only my first pedal ever four or five months ago, and it was a kit. Of course, the seller assumed I already knew about footswitches, etc. I didn't, but I do now. I can see the advantage in the PCB route, but this much more interesting and a challenge, and probably cheaper (until I just saw Geiri's man cave) - holy canolli!
I don't have any 3u3 polarized caps. Would 2u2 or 4u7 work in there, or should I just wait and order?ReplyDelete
There´s enough space to solder in a 1uF and a 2.2uF in parallel. Makes 3.2uF which is close enough... :)ReplyDelete
For those of you who actually want the volume pot to work...ReplyDelete
Volume 1 - ground
Volume 2 - from board (labeled volume 3)
Volume 3 - to output
Well I have now built Jack Orman's mini-booster and this one. I really hate to say this but I do prefer this one, and by some margin. It seems to mesh with my gear better, has a fuller sound, and has the mids in just the right place. Damn. I can't stand Mike Fuller!ReplyDelete
I also prefer this to just about every other boost I have built, with the exception of the Red Rooster which is genius. I have also built this with a 220K resistor replacing the gain pot and it works brilliantly as a boost built into an overdrive pedal. IMO the gain pot is fairly redundant. I find the tone control a bit weird but usable.
Thanks for the layout! It's tiny and easy to swap parts around to add the 220K resistor (instead of gain pot) without increasing the size.
Oh, and FWIW the volume wiring works just fine as written on the layout. Not sure what JB is on about! :-)
I hear you, brother. This thing is badass and super useable: the boost range is more than enough (using the first pair of J201's I grabbed) and the tone control works very well, IMO. The gain pot is indeed silly, so I'll probably also swap it for a fixed resistor before it gets boxed.Delete
Hey ! How can I add more gain to this ? Thanks :)ReplyDelete
Hello everyone. I absolutely dig this little thing for guitar and especially for bass. I actually want to convert my bass to active by the help of this. (Gain will be replaced by a trim pot or maybe i use a pot anyways to get onboard distortion) Do you think the power consumption of the 2 JFets will be ok for a long lasting operation? (I don't really know how JFets would compare to the nowadays more common ICs like an Op-Amp or whatever they use in commercial products.ReplyDelete