Skreddy Mayonaise - compact layout experiment

[IvIark]

I wondered how much space I'd save if standing resistors wasn't a factor for me and I just wanted to use the minimum number of rows and columns, and so thought I'd do a tester with a reasonable size circuit like a Muff with 4 cascading transistor gain stages.  And decided to use the Mayonaise as the test subject because it was the first schematic I saw

It's funny but avoiding links and using standing resistors doesn't always save space, in this for instance I could have definitely saved rows by avoiding 2 of the links, but there would have been lots more columns to allow multiple connections to a single point, like the transistor collectors in this circuit.  So I used some links still but also used standing resistors wherever possible to save space and this is what I ended up with.  




At 16 x 14 it's pretty compact, but the layout I did with my usual methods was only 3 rows and 3 columns bigger, and I know which one I would prefer to build

Anyway just thinking out loud and I thought I may as well share the layout on here rather than keep it to myself, someone may want to build one in a a little box (although I think this is probably still a bit too big for a 1590A).

[Silver Blues]

Yeah, my Purple Dragon Muff is built on a 20x13 piece of perfboard...

...never again.

I'd rather have the board be a little bigger than have to deal with a situation where almost every axial-lead component is standing. (It's such a pain in the ass to hold down standing components while you solder them, not to mention they protrude up so far off the board... all the resistors in my pedal are bent over to one side just because they have to be. Argh.)

So yeah I agree with you

I might just post the schematic for that pedal here in case anyone wants it. It's really quite cool.

[Surgeon]

Cool! But man will you suffer by tepressing your ocd so much! :D

19x17 vs 16x14, quite an improvement although we would still house it in the same type of enclosure (I assume 1590b is still ad small as it could go) but as usual with layouts, smaller is preferrable for most folks!

thanks ! Mark

[IvIark]

Yeah tell me about it.  It comes to something when your OCD makes you do layouts you wouldn't even build just to confirm to yourself that you wouldn't want to build them

But I agree with Silver Blues (well obviously) :o), more compact is never better for me.  If the layout was small enough to get it in a smaller box then it may have some value, but if the box is going to be the same size anyway then compactness gains you nothing.  In fact quite the opposite, it makes it more awkward because you have to accommodate the standing components and depth can cause more problems than width and height when you have to fit pots and switches behind them, especially when the original was 19 x 17 and so very easily fit in a 1590B in terms of width and height.

Anyway I shaved off a row at the expense of a column and Javi assures me 17 x 13 will fit in a 1590A, so maybe this one does have a little more value over the original layout for some of you.  If you're a total masochist of course

[IvIark]

Silver Blues wrote

I might just post the schematic for that pedal here in case anyone wants it. It's really quite cool.

Yes do post it.  I'm always interested in seeing things like that

[Silver Blues]

All right, will do!

[Lazy Swamis]

Nice one lvlark!  Most anything that is 13 or less in one dimension will go 1590A. I thought I was done building Big Muffs, but here we go again..
Thanks!

[IvIark]

Just noticed that I had the pulldown resistor in the wrong position so have rejigged it

[induction]

Since we're sharing small BMP layouts, here's my hybrid SMD/TH Hoof Fuzz. It's 15x10 and currently unverified, but it sounds great on the breadboard with 2N5089's for Q2 and Q3. (I haven't tried it with the original Ge transistors.) This is my favorite BMP I've ever played. The Shift knob makes all the difference.

I definitely plan to build it, but these days I get about 2.5 minutes of free time every week, so it will be a while. According to the comments above, it will fit in a 1590A, but with 4 knobs I'm not that masochistic. The reason I like small boards because I already have enough trouble fitting circuits into reasonably-sized enclosures.

[Muadzin]

I don't get the obsession with fitting things into 1590B's. Give me the slightly larger 125B any day as those will comfortably allow me to use topmounted jacks. And those are the real pedal board space savers.

So as long as it will fit into a 125B no layout is too big for me.

[IvIark]

125B's are OK too, in fact in some ways they're better for me because it's easy to have top mounted sockets so in my restricted space I can mount them in a rack tray directly next to each other without having to accommodate side mounted patch cables.  But I'll still always aim for 1590B size boxes for a couple of reasons.  Firstly I've got a ton of them and they're half the price of 125B's, I do like the compact size and even when I used a pedal board I preferred that size box rather than VCR sized effects, and also because if I make the layouts suitable for 1590B's, then I know they'll fit in a 125B with a load of room to spare which makes the mounting and offboard wiring that bit easier.

[Freppo]

I guess everyone has their own preference regarding their favourite boxes. I think that the 1590B is the perfect size and has "good looking" dimensions (unlike the 125B..) and it's still possible to squeese complex stuff into it without too much trouble (especially if doing PCB's and/or not using batteries).

I like 1590BB aswell for bigger stuff with alot of knobs, but for big vero layouts with few knobs that require a 1590BB I always look if I can find a smaller PCB layout insted that fits a 1590B. I never understood the 1590A thing.. They are just silly looking and hard to step on and a real pain to work with.. I'm very impressed by people that manage to squeese stuff into those enclosures but for me it's not worth it..

When I'm making layouts myself I always try to have no standing resistors, but I usually end up having a few to keep the size down, so I'm not that picky about it. Caps with odd spacing bothers me more :P

[IvIark]

Yes I think everyone knows I feel the same about box sizes.  If a vero layout will mean putting an effect in a 1590BB unless it's got 6+ pots I'm really not interested and I'd much prefer to use a PCB.

I've thought about posting PCB layouts too, but at the moment it gets things further removed from my idea of DIY.  The one thing I adore about vero is that you can get a schematic and an hour later could be playing the pedal and that just isn't going to be the case for me with the current home PCB fabricating.  No way in a million years am I going to fill the house with chemicals, baths, vats or spare irons for when I break the missus's trying to get a transfer on a blank.  That just isn't fun for me and I'd start to hate the hobby.  And using a fab house or buying a PCB takes the spontaneity away from it.

Maybe my opinion about this will change when the home CNC is more affordable, more integrated, and less complex.  If I could import a trace image and mill a blank with minimal fuss then I'd definitely buy one and not limit circuit sizes the way I do with vero (apart from maybe my support concerns about the hours I'd spend talking someone new to the hobby around debugging and biasing his ADA Flanger)

I'm looking forward to the time I can do that, I'm sure we're not too far away from a user friendly consumer product that won't break the bank being available.

Oh and good look in avoiding oddly spaced caps with vero!
The one great thing about PCBs is that you can have ground and supply points all around you and so can space every components to their perfect pitch.  When you're limited to rows only, you'll know as well as I do that it's impossible to create a layout of a reasonable sized circuit with 5mm pitch for all the caps unless you're prepared to make the board unnecessarily bigger and have more links than you should need.  A better way to avoid odd spacing is to get a set of ceramic multilayer axials which are just like placing 1/8 watt resistors and so any pitch is good.

[Freppo]

Mark, do you have any tip for where to find cheap axial caps?

Thanks
/ Fredrik

[IvIark]

Do you mean just the multilayer ceramic axial or other types too?

Multilayer axial can be bought at good prices from:
http://stores.ebay.com/tiaochongyi/Multilayer-Ceramic-Capacitors-/_i.html?_nkw=axial&submit=Search&_fsub=2242179010&_sid=1021205250
http://stores.ebay.com/electronic-alice/_i.html?_nkw=ceramic+axial&submit=Search&_sid=1067328184
http://stores.ebay.com/yankeeelectronic/i.html?_sid=907190324&_nkw=ceramic+axial&LH_TitleDesc=1#&panel1-3

And some values here at great prices, but postage is now ridiculous to the UK and so he's on my rip off list.  He used to have a lot more values and fortunately I stocked up well on them before he decided to up his profits on international customers:
http://stores.ebay.co.uk/bjkachner?_dmd=2&_nkw=ceramic+axial

For polyester axial I bought lots from here before they stopped shipping to the UK.  Again I seem to have timed this one well and got plenty in over a few months before he stopped shipping:
http://stores.ebay.com/West-Florida-Components/Capacitors-/_i.html?_nkw=axial&submit=Search&_fsub=2&_sid=2639143

And for electrolytic axial I just tend to do an eBay search for the values I want, but I bought a lot of Philips from here at good prices, but there aren't so many packs of 50 or 100 available now, and they also seem to have gone up in price a bit from when I bought them:
http://stores.ebay.com/allshop29/_i.html?_nkw=philips%20capacit*&rt=nc&_sid=868803667&_trksid=p4634.c0.m14.l1513&_pgn=2

[Kinski]

How would I change this compact layout to be the MKIII?
I like this smaller layout, cause I can fit it in a 1590A.

I've been comparing big lists of muff variant values, but its not proving to be very easy with my crappy skills.

[rocket88]

how the hell are you going to fit that into a 1590a?  you must have some sort of witchcraft to be able to do that, i don't even think javi can do that. lol

[Kinski]

Ha! Its actually not too bad. I've fit many board that size (and bigger) into 1590A enclosure. Width has to be 14 rows or less. Length can be 20-some rows. Just lay everything down on top of low profile jacks. And use those small green 9mm pots. Thats it! I also use small tantalum and multilayer ceramic caps when I can.

[rocket88]

hmm, sounds like black magic and voodoo to me.

but, in all honesty, that doesn't sound too bad then. i'll have to pick up some 9mm pots and tantalums and give it a try. still i've done 1 1590a so far and i swear it was the biggest pain in the ass, and it was just an em drive. i blame my big sausage fingers. lol

[Heath]

My experience with 1590As tends to go like this:

1. Build circuit, it works!!
2. Drill enclosure, trying your best to hold onto the tiny thing.
3. Band-aid forehead and retrieve enclosure from next room/neighbor's yard.
4. Check on unconscious cat.  See #3.
5. Fit stuff in enclosure.
6. Curse God.
7. Continue fitting stuff in enclosure.
8. Test.
9. FUCK!
10. Debug.  Uncram.  Find the shit that is touching that should not be touching.
11. Test
12. EUREKA!
13. Do happy dance.
14. Screw back plate on.
15. FUCKING SHIT!
16. Go to step 10 and repeat as necessary.