HI all...
For a few projects I need some boards of the Phabbtone EQ. So I have been in contact with Phil, and I have been working on the schematic, and this morning even managed to come up with some kind of board:
(http://i39.tinypic.com/211oyaa.png)
The boards are 12 cm long and 8 cm wide. I need 6 myself, and double sided boards are for this size about 15EURO
My question is, if I am going to make boards, are there people interested in buying boards as well? So we can do some kind of group buy to drop the price? I will not make any money with this, just sharing the design as Phil has done a lot as well....
Also, if people could comment on the schematic and or the board, that would be great. I am not particularly good at eagle nor electronics :-)
Input as always appreciated.
Cheers
Erik
I don't see anywhere that the +9V is connected to the board. Should be a connector of some sort or a place to solder a couple of wires. There does not look like there is enough clearance around the mounting holes in each corner. There should probably be 4 or 5 mm from the center of each hole. Are you planning on mounting the pots to the PCB? You will need bigger pads, probably twice as big as the ones you have now.
You are right.. new version.. no led, pots off board... one layer and a +9V pad :-) Tnx!
(http://i43.tinypic.com/j0b0wo.png)
Hi Erik,
Well I admire your enthusiasm,,,, but may I make a few suggestions which I hope will help you and others. You really need to consider HOW the circuit is going to be implemented before committing to making boards.
One size fits all approach will likely lead to wasted boards. :grr
As *Loudthud* has already noted *IF* you are going to hand solder this then you are in for a rude shock. :'(
The Pads on Eagle stuff are far to small to be of much use for the home hobby builder, Especially if you wish to drill holes by hand.
I have no doubt you can edit the library and make those pads much larger but for my needs I hand draw the ink so it matters little as the pcb layout is only used to line up the pots and the DIL socket.
This bypasses all the the messing with photo resist for small production runs,,For such a simple circuit it's not worth the outlay.
Now if you wanted to cram the whole thing into a small case (like boss pedals) then yes you need to go with all the hi teck ideas which means surface mount, double side boards.
Eagle is really more aimed at computer boards and surface mounted stuff and old buggas like me can't even see surface mounted bits. :duh :lmao:
I used Eagle as a guide only.
The board layout I've *shown here* is for a pedal so It should be obvious that if you wish to use this in another situation you have to redesign the layout for the intended purpose.
Example;
*IF* it is part of an on-board circuit in an amplifier then you will not need the diode as it is only there to protect the circuit from reversed battery connections.
*IF* part of an Amplifier circuit then wise to use split supply and then the bias voltage will not be needed.
Sorry if I gave the impression that a quick whip up on eagle will deliver a fully functioning Circuit in a few days. NO sadly it can take weeks and months to perfect even the most simple looking circuits.
YES there are sites where you can D/load and print out a circuit in a matter of a few hours you have a working circuit by sunday arvo BUT be Warned some are full of holes. xP
Example: Build the tonemender (I won't name the site) and then the PhAbbTone?
(both are stand alone tone circuits),,,So take your pick? One will be Horrendously noisy,,,Wink.
And yes I have A/B tested tonemender with Mine,,So I KNOW which one is Low Noise.
(please note some circuits from the above mentioned site are very good and I mean no disrespect to that site,, just pointing out that tonemender is a noise prone design)
@Erik Go purchase a bread board and some small 12VDC plugpaks/wallwarts.
And start experimenting with some circuits.
It will at first look like the hard, long way to build things But you WILL Eventually see that it is in fact the faster way to get a good circuit.
Not only that ,,, YOU will have learned a lot more and Know Why And How the circuit works.
You have a far better chance of fault finding if you have an intricate knowledge of how it works.
The way you are approaching it now you are not learning anything useful and you are walking into a potential nightmare.
Re PCB Software;
Sadly just having a fancy software package can make it all look very easy but in truth it's only the tip of the iceberg. Software can easy give the novice a false sense of professionalism. As mentioned above it looks good on the screen but it will be a nightmare to work with.
I've given up on Eagle ,,, I now use *KiCad* <3) <3) <3)
You can edit the pad sizes *After* the component is laid out the board in a jiffy.
Like all this software stuff,, it is a little tricky to get your head around but I'm getting far better results from KiCad.
With KiCad I'm now at the point where I can look at making more complex circuits,
A special Thanks to our talented member *KMG* for that suggestion,,,,I'm way ahead thanks to his tip off. :dbtu: :dbtu:
Oh Yeah!! *No limitations* any board size. 8)
The other option for small builds is *DIY Layout Creator* which is software setup to help make boards with stripboard or perfboard.
I did try it out but it kept crashing on my old computer but obviously others have no trouble.
*******Bottom line for circuit success*********
Proto 100 times FIRST = one quality build.
If it is built with no testing it will take forever to tweak out all the worms afterwards.
You will end up wrecking the pcb tracks before you ever fix design mistakes.
Phil.
Some old pics,
My proto setup.
(Interesting that the *Active* Para EQ could not deliver the same deep mid notch)
Phil.
Just a tip about EAGLE pad size:
Use DRC to alter the pad size AFTER you have done the layout. Click
DRC icon then in
sizes tab (or
restring tab? Sorry I forget which one) increase
minimum size to about 17-20 mil. Click
apply to see the magic happens. ;)
I'm curious about KiCad, so I'm downloading it now. Thanks Phatt for mentioning it. :tu:
For 6 pcs production I suggest you try the hand drawing method or the toner transfer method (Is this the right term?). It's fairly easy for a newbie like me, and FAR cheaper than ordering. Try it and you won't order anymore. Just remember about the safety factor: safety googles, rubber gloves, air circulation, waste treatment.
Note:
- If you don't have laser printer or magazine paper, you can print your layout on ordinary paper then photocopy it on the thinnest paper available (60 g/m2 will do). I use XEROX photocopier with darkest setting for best result.
- Always remember to balance between your copper trace and the spacing between traces for easy transfer. I use 0.05" for copper trace width.
Happy etching!!! :tu:
Edit: After a quick look, IMHO your traces are too thin. Try 0.05". As for the pad size, try my tips. It's only a few clicks away. ;) Try this tutorial to add a ground plane: http://www.muzique.com/schem/eagle.htm. At least it will speed up the etching process. You also have untraced connection between R9 and R7 (See that yellow line?). I suggest to bevel / chamfer or round / fillet your traces for better electron flow. There are buttons to activate them when tracing. They're just above the drawing panel.
For those who are frustrated with EAGLE's component library (like me), try Gauss Markov's library: http://gaussmarkov.net/wordpress/tools/software/eagle/eagle-2-libraries/. A lot easier to use.
For more tips: http://gaussmarkov.net/wordpress/tools/software/eagle-cad/.
Hope that helps.
Hi all
Thank you so much for your encouragement, warnings and tips! This all has led to:
(http://i41.tinypic.com/wuqzb5.png)
6cm x 3,5 cm board size, no jumpers, bigger pads, bigger traces, smaller caps!
I am also using GM's libraries for a while already... that made a huge difference, definitely recommendable.
@ Phatt: this is the schematic that I ended up using:
(http://i40.tinypic.com/34y1eu8.png)
It will be part of an amplifier system so with a split power supply. Do I have the schematic right for this purpose?
Also, I think I do not completely agree in my case with you on the prototyping of the circuit. If I would have designed the circuit from scratch, then yes. But in this case, it is a proven concept right? So I was kind of hoping that you already had done all the prototyping :-)
Please keep your comments coming though, I really appreciate and read them!
Cheers
Erik
Hello Erik,
I Quote;
""Also, I think I do not completely agree in my case with you on the prototyping of the circuit. If I would have designed the circuit from scratch, then yes. But in this case, it is a proven concept right? So I was kind of hoping that you already had done all the prototyping :-)""
Yes I've proven the circuit works but use outside of the intended purpose may yield differing results.
Just warning you that the result may not be what you expect.
The circuit is slightly tilted to the brighter side as a lot of players can't get the top end they wanted.
Now it delivers stunning results when used in front of;
Fender De-Ville 212.
Crate V30
Fender ProJunior
Fender Pro SS 80 watt
Marshall ValveState 65
Goldentone 40 reverbmaster
And many other obscure names I can't recall.
But I did run into a Peavy oddball Amp (Pre Bandit era) which was extremely bright already. Oh well it had to happen one day :(
but keep in mind I've got a dozen local players using this circuit (who know where I live :trouble) and I've had no complaints. winky.
If you are going to fine tune a full Amp system then you have no choice but to breadboard it all first. As the trick to building good sound is eq balance ALL The WAY down the signal train,,, NOT Just the tone control network.
Mojo tone is a combination of many factors so relying only on a trick tone circuit is only half the story.
If you don't proto and it all works first time then you would be one of the first and Extremely lucky,,, go buy a lottery ticket.
Thanks for the tips on Eagle ,,, but for me a waste of time understanding something that
limits me to a board size??? I can't advance when I'm driving down A dead end street.:(
Phil.
I can't really get into the details at the moment... but there will the next few months very little possibility to do a lot of tuning... but for now I just need the eq boards on a relative short notice. So I would be rally happy if you could at least check if the schematic I used will work... I am especially a bit worried about the power supply. At the moment there is only one pad for power, +9v... is that correct?
Cheers
Erik
Yes your schematic looks fine (for single supply well regulated psu)
If it is for a rack setup with onboard transformer then consider split rail supply.
15-0-15 VDC will give you heaps of headroom.
Just remove R10, R11 and C10. (the Bias/Voltage reference)
Then R4 and R6 go directly to Com (which is now the Zero volts on your regulated split supply).
Also Don't forget that Pin4 on the chip is then connected to the negative rail.
make darn sure you have the supply all sorted out and don't forget the ground plane.
Do it wrong and you may end up with a ground loop hum problem.
Sorry if I'm not making sense but I'm still a bit lost as to what it is you are trying to do?
I would not try to etch a board with the tracks laid down the way you have done.
Running tracks between pins of the chip is asking for trouble.
You only do that when all else fails.
FWIW I spend hours trying to find the best ways to run tracks and place components,, sometimes I'll leave it for a few days and often I see a much better way within minutes of a fresh start.
Cheers from ,, Phil.
Thanks Phil!
Latest version of the board for a single well regulated psu:
(http://i44.tinypic.com/ndpmj8.png)
big pads, big traces, right size caps... 5 x 4 cm
And this should be the board for a split powersupply:
(http://i43.tinypic.com/6r4kra.png)
Looks nice.
The final test is making one, of course, and building a prototype.
Nobody cares if it´s "ugly" so you can draw it on copper with a Shatpie type pen.
I usually buy a small bottle of the original (solvent based) paint and add a couple drops (don't over do it) to the pen, so the paint layer is thicker.
Or you can try the iron on process.
Starts by failing until you practice .
After a couple boards (you don't etch the bad ones, just clean the PCB with paint thinner and start over again) you get the knack of it.
*Or* you can buy a small PhotoPositive board. Results are *impressive* , real professional.
Good luck.
Here's next version:
(http://i39.tinypic.com/1eswb6.png)
I have ordered items for photo positive boards, that looks like fun!
Looks nice. :dbtu: :dbtu:
Be careful with the pad size, though. Reducing it a little won't hurt.
Photo positive boards are impressive.
I have been making PCBs for over 40 years now, and when (sporadically because of $$$) I make one now I can't believe I made it myself, that's *how* good looking they are.
*But* you must set the exposure time right.
Too little, copper does not "clean up", everything is a big short; too much and not traces left.
I suggest you cut a small strip (say, 1/2" x 1") of pcb material, expose it for, say, 5 minutes, and develop it.
According to results, you repeat it exposing 2 minutes more, or 1 less, until you get it perfect.
Only then you make the definitive one(s).
Set up the lamp at a fixed height (say, 10/12") and always use the same in the future.
You must print the PCB design in a good laser printer on a transparency or "vellum" semi transparent drafting paper.
Or photocopy the design on it with a *good* copier.
Look through the print, sometimes there will be small holes or cracks, touch them up with fine point black marker pen (Sharpie).
Best lamp for exposure is one of those garden type pencil quartz lamps.
Good luck.
What for me is still a bit unclear is what exactly to print... just the brd picture?
I take it you are on Eagle?
Under *View* find *Display/Hide layers* Un-click *tplace*
You should then have tracks and pads left on the screen.
Then print it out.
Depending what system you use you may have to mirror the printing.
Have fun ,, Phil.
so that would be something like this:
(http://i41.tinypic.com/fwnjwm.png)
inverted though,...
Excellent tutorial:
http://youtu.be/YJB5PWx9fdA
I would only add:
1) DO use gloves and goggles, this stuff is incredibly nasty.
2) NEVER do this close to any important stuff you care about.
This guy is CRAZY , acid vapors will EAT the insides of all his expensive lab equipment.
How do I know? ... Uh !!! :(
3) It´s not very clear, but since he closed the exposure box lid until he finished mixing his chemicals, he has been exposing the PCB/film sandwich. Almost 4 minutes as he said.
You´ll have to find your own time.
I suggest you sandwich your PCB+film between 2 sheets of glass (or 1 glass + 1 anything else) and use a 250W or 500W quartz halogen lamp at about 40 to 60 cm (18 to 24 inches) away.
Personally I silkscreen PCBs, but it´s worth only for 20 or more PCBs
http://youtu.be/8-WGaAmpfOU
Printing each one takes seconds, but cleaning the paint perfectly (or you lose your screen) , making the screens, etc. can take hours.
Been a really long time.. but I am back on this subject... I made my first pcb and it looks like this:
(http://i45.tinypic.com/30agks8.jpg)
It looks to me that I have to build it slightly larger, since there seem to be some connecting problem area's... especially in the crowded top of the board. No problems though. I am going to start on that now.. but as usual.. comments very welcome!
Cheers
Erik
Cool! 8)
Tip: when doing the artwork, mark the intended length of at least the longest side on the artwork just outside the edge. Also, beware photocopiers because they sometimes slightly change the length in one direction only. As we are stuck with the QWERTY keyboard, so we are stuck with PCB's in inch-by-tenth - don't try to get creative with this.
PCB artworks should have some identification within the board area and should include the name/function of the board, the date for version control, and the name of the creator; e.g. "Phabbtone 121014 erikb1971".
"Oh, I'll remember what that is!" - no, you won't.
Hydrochloric acid (aka Muriatic Acid, "pool acid") as an etchant is just nuts, particularly when he is worried about Ferric Chloride which is relatively harmless. I read that even vinegar from your local supermarket will work {Distilled white vinegar, Hydrogen peroxide, salt}.
http://hackedgadgets.com/2011/04/11/hydrogen-peroxide-distilled-white-vinegar-and-salt-as-a-pcb-etching-solution/ (http://hackedgadgets.com/2011/04/11/hydrogen-peroxide-distilled-white-vinegar-and-salt-as-a-pcb-etching-solution/)
The comments following this Instructable give some clues to the hidden traps with HCL etchant;
http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/ (http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/)
I made the board with photosensitive pcb and a light unit.. works pretty easy.. problem is.. I have not worked on this project for months.. and I have no clue anymore! S I am going back to the last approved schematic, and start all over from there!
Quote from: erikb1971 on October 13, 2012, 12:27:38 PM
I made the board with photosensitive pcb and a light unit.. works pretty easy.. problem is.. I have not worked on this project for months.. and I have no clue anymore! S I am going back to the last approved schematic, and start all over from there!
Oh dear! :-\ QED. Even one-off home builds need good documentation.
and I guess any build needs a thorough understanding of what you are doing.. something which i thoroughly lack.. part of the fun so far!
Cool , but let me comment a couple details:
1) separate parts a little more, some pads and tracks are dangerously close.
2) in the ICs, do not use round pads but oblong/rounded rectangular "IC Pads"
just look at any commercial PCB and you'll se the advantages.
3) add a drill guide hole (say, 28 mils) to every pad center or you will go crazy trying to center thin flexible 1mm drills.
4) *some* labelling is important.
Besides PCB identification as correctly suggested by Roly, try to add (at least a letter) ID to key points, such as "In", "Gnd" , "T/M/B/V" indicating treble mid bass volume, etc.
A + sign on electrolytics positives , an orientation dot for the ICs , etc.