Messages

What is the affect / benefit of having a 1uF metal film cap with a 1uF electrolytic cap in parallel on the output, why not just a 2.2uF Cap?

why would you have unconnected pads? if they are not connected, they don't serve a purpose electronically and you should be able to delete them from the schematic/library.

Eagle puts a pad for each component on both the top and the bottom layers, usually my tracks are on the bottom, leaving pads unconnected on the top, these are my 'unconnected pads'  I'm etching at home so I don't have through hole plating, and when drilling the holes out I get a burr on the exit of the hole which I've spent time removing. So if there is a way I can not have the pads, it woudl be a real help.

For the fuzz face you posted I don't quite get why you have the vias to connect the pots. with board mounted pots we usually solder them in from the component side, but you should be able to easily solder them from the solder side too

This is just habit, my first project had five knobs and a switch I decided it would be safest to solder the pots in from the component side as I could have the pots already installed in the enclosure in advanced. I also decided that if I needed to replace a pot I would potentially do less damage to the pad by pushing the leg through the pad rather than pulling it off the pad. But I'm still learning, I only started this around Christmas.

Does anyone know if it is possible to prevent Eagle putting pads on both the top and bottom layers of a double sided board? Or ideally, I'd like to design my PCB and then run a script that deletes all the non-connected pads. Sometimes I'll use a resistor leg as a via so it's helpful to have the pads top and bottom when laying out the design.

Last night I printed 'to PDF' the artwork for the next three projects and took the PDF into a vector program and deleted the unused pads, it's not a huge faff, but I feel there should be something in Eagle that will do this for me, and I've just not found it and my searches have not come up with anything either.

Any help would be great.

I started using Eagle just before Christmas, and my list of pedals has grown as a consequence, three overdrives, a compressor, a delay and a vibe! And today I'm been putting the finishing touches to a fuzz face and another overdrive PCB artwork.

I'm etching my own PCBs and if you plan to do the same then some of the default settings might not be the best. For example in the fuzz face example I've attached I use a track width of 28, a pad size of no less that 60, and a drill hole of 19.86, I drill the board with a 0.8mm drill bit for most components, the 19.86 hole size means the drill bit centers in the hole and also drills a little copper when you go through the PCB.

Regarding layout, I'm still learning, and I'm sure I'm making lots of mistakes that might be making my circuits noisier than they should be. One problem is it's a bit addictive, and takes a lot of time, far more than makes sense when you can buy a prefabricated PCB, but it's also rewarding.

New transistors have just arrived... I seem to be going for bigger components not smaller 

I'm beginning to understand the fascination with the Fuzz Face, I came to it out of a curiosity and with the hope of recreating a couple of tones, but I'm now in a phase of being totally intrigued by it, frustrated with it and captivated by range of the tones and how it reacts to the pick attack and volume knob!

I've been playing around with a straight fuzz face circuit as the beginning point and swapping out transistors, input and output caps and output volume pot, so far I have determined I need about 3 of these as I've yet to stumble upon the holy grail combination.

My amp is not the most traditional, Yamaha THR10C, but it's really the only option currently as I need to keep the overall volume level down, so my aim is to see what I can put together that will work happily with that amp. Generally it takes pedals very well, but I appreciate the fuzz face is picky about what's either side f it.

Anyway, more experimenting to do.

Breadboard and parts have arrived today, and I've been playing around and currently have the 'Axis Face' from Fuzzcentral wired up using a 2N2369A in Q1 and a DB139 in Q2.

It works and I've biased Q2 collector to 4.5V the hfe for the 2N2369A is 100 and 125 for the DB139.

I've had a play with a Big Muff before but this is my first opportunity to play with a fuzz face style circuit and there are a couple of things that I'd just like to know if that's normal for a fuzz face or if I need to tweak something/got something wrong.

If I play a note and let it decay the fuzz is there and sustains for a while then sort of dies off quick like it's gone down a step, the underlying note is still audible, but the major fuzziness has gone.

And my tone pots seem ineffective on my strat which surprised me, as too did the quick sweep from 10-9 on the volume pot before it becomes more gradual, but it does clean up nicely with the volume pot.

Over the weekend I'll redo the bread board with a straight forward fuzz face circuit, I did the axis as it was the last schematic I looked at, but I somehow suspect I may end up with more than just one fuzz!

Thank you somnif & LaceSensor,

So far all my builds have been from well know verified schematics mostly using opamps, which I copy into my computer and designing a PCB layout for, I was trying to approach the Fuzz Face with a similar mind set, but I think the first thing I need to do is buy a breadboard and a load of different transistors and start playing, thankfully it's a simple circuit so I shouldn't get too lost in a load of wires!

I am intending to put a bias trim pot in, and I think I'll also experiment with small value capacitors between the Base and Collector of Q2 if it seems a tad harsh, I guess this is all the stuff that will be so much easier play around with on a breadboard.

Thank you both again for you advice and help.

I spent the weekend, reading many threads on multiple forums and doing general fuzz face research to the extent that on Sunday night I decided I should just drop the whole idea, the issue is that I just could not work out which transistors I should be looking for, once I developed a short list I would go searching for them only to discover they were not available or from an unknown source and potentially rebadged, or I need to buy at least 100 to sort through to find the 2 that will create the magic! I looked at matched sets from SmallBear, but living in the UK if I can find something a little closer to home would be preferable.

I've decided my first foray into the Fuzz Face world would be a silicon Fuzz Face with NPN transistors, I'm looking for something that's probably on the smoother side of the fuzz spectrum, and it's the cleaning up with the guitar volume pot I'm keen to experiment with having heard some really nice tones some players get.

So if anyone could name some transistors I should try that are readily available I would be most grateful. My multi meter can measure hfe, but it's no Fluke, so probably a bit of a crude measurement, but hopefully good enough.

By the way, I'd love to trying germanium transistors, but I get the feeling that's a true minefield! How is it that such a simple circuit is causing me such a head ache?

Sorry for the ramble, but any advice would be wonderful.

Here is an image of the board, I can't seem to get the link to embed

https://www.dropbox.com/s/pof8zuj0c2pag0e/Vibe_01.jpg?dl=0

I ended up using the 5mm diffused yellow LED, I've not tried the other LEDs partly because I completely forgot to socket it! And after trying it I realised it was potentially too bright anyway, and it was the least bright of all my LEDs (200mcd). Don't get me wrong it works and sounds good, but I can distort on the low strings of my strat if the voice knob is wound up high, so I'm currently experimenting moving the LDRs away from the LED, they were touching it to start with, now they are about 1.5mm away, and I think I'll move them further, there is definitely a tonal difference by moving them which I guess it's not surprising as a doubling of the distance will result in 1/4 the intensity, but it's getting too late here to be playing here now.

Okay, I've just ordered:

5mm Diffused LEDs in Yellow, Amber and Green
5mm Water clear LEDs in Yellow, Amber and Green
and 5mm cylindrical water clear LEDs in Yellow, Amber and Green

So that should give me something to play with, both in terms of colour and brightness, and hopefully I'll find something in them that works well with the circuit and the KE-10720.

Thanks midwayfair,

The spec sheets gives a minimum and maximum peak spectral resonance of 550nm and 650mn, and the graph looks to peak at 600mn. The yellow LEDs are 590nm, so I think I'm in the ball park, although I'm adding amber to my list of samples to try as they are 605nm.

Will do Marshall Arts, In my search on here I came across the PCB M.Kresol did... I need to buck up my ideas as he's managed to get it to fit a 125B, my PCB design is a little bigger and will take up a good portion of a 1590BB! in my defense this will be the 4th PCB I'd done the layout for and I'm etching at home.

Putting sockets in sounds to be the way to go.

Thanks again dan.schumaker, I'll add some of Tayda LEDs to my next order.

Thanks, dan.schumaker

I was just lighting up a Red water clear LED and it's are quite directional, so I can see the benefit of the diffused LED. LEDs seem to come in too many flavours, I've just discovered clear super bright diffused LEDs as well as the diffused ones with diffused coloured lenses.

Could you tell me if your LEDs were 'normal' brightness or one of the supper bright variants and what LDRs you used.

Thanks again.

Hello,

Sorry if my searches have not brought up previous discussions about this, but I'm putting together a EQD The Depths that uses LDRs, the ones I've seen recommended are the Tayda's KE-10720 with a Yellow LED, and another suggestion I have read is GL5539s with Green LEDs. I've got some KE-10720s on their way.

What I don't know is what type of LED to use, for example a diffused 5mm Yellow LED has an output of 200mcd and the water clear 5mm Yellow is 2500mcd, quite a difference, and presumably it's important to try and get the right one. From gut shots I've seen it looks like EQD used water clear LEDs, but no idea the colour or what LDRs they used.

Any advice on what LEDs to get in stock would be brilliant, thanks.