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Messages - UsableThought

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Just a follow-up to my own post - one bad thing, one good thing:

1) The bad: I've done a bit more playing around with the current version of CircuitMaker a bit more and it is definitely not for me - it has a serious flaw: If you just want to sketch a schematic, you can't drop in a symbol & give it some values; you are forced to select a real-world component, which requires browsing in a very slow catalog, etc. This is a limitation the old CircuitMaker 2000 didn't have nor do other simulators.

Another big flaw: it is cloud-based, including all your data files! This may or may not explain why it's so slow. Apparently you can't even use if if you are offline  Or so this review of the beta release from this past summer says.

2) The good: I found a download of the old CircuitMaker 2000; this is apparently the version people actually liked. The link I used came from here; I don't know how long it will be good for. It's a RAR file but so far no viruses - I am running a virtual Windows so not too worried about that anyway. And unlike the new CircuitMaker, CircuitMaker 2000 seems quite easy to use.

The Newcomer's Forum / Re: books on amp building
« on: February 05, 2016, 04:50:52 AM »
This is an old thread - but I'd like to add one more book to the list & perhaps suggest that it might be even better for a beginner than "Art of Electronics."

This is "Practical Electronics for Inventors," by Paul Scherz and Simon Monk. The 3rd edition is available in paperback for about $20 from Amazon; a 4th edition is apparently on the way.

For $20 you get a lot of book. It is similar to "Art of Electronics" in having big-format pages crammed full of smallish type with lots of illustrations - a lot of material at 1,000 pages or so. And all of it good stuff in my estimation - speaking as a beginner myself, but one who has looked at enough books to get a sense of what's out there.

As the title suggests, it's aimed at DIY'ers. It is an entirely SS book & very up to date on the technology. It's got plenty of math; but much like "Art of Electronics" it's a book about craft not learning math for math's sake. You are told when the math is and isn't crucial & what shortcuts you can take or tricks you can use to shorten laborious calculations. Like Horowitz and Hill, Scherz and Monk teach you to learn by doing - by making circuits - not scribbling practice problems on paper. For simulation software they like CircuitMaker which I guess is OK though I don't much like the Windows version I just installed.

Why do I say it might be better for a beginner than "Art"? In fact I have an older but quite serviceable edition of "Art," but am going to switch to this book. The biggest problem I have with Horowitz and Hill is that they frequently rush through subjects, especially when a bit of math is involved; perhaps that's because they they intended their text to be used at university where the teacher could fill in any gaps. Scher and Monk, on the other hand, are explicitly writing for non-students & seem more willing to slow down & provide as much info as needed for understanding a tricky bit.

Some info on the authors from the Amazon page:

Paul Scherz is a physicist/mechanical engineer who received his B.S. in physics from the University of Wisconsin. He is an inventor/hobbyist in electronics, an area he grew to appreciate through his experience at the University's Department of Nuclear Engineering and Engineering Physics and the Department of Plasma Physics.

Dr. Simon Monk has a degree in Cybernetics and Computer Science and a PhD in Software Engineering. Monk spent several years as an academic before he returned to industry, co-founding the mobile software company Momote Ltd. He has been an active electronics hobbyist since his early teens and is a full time writer on hobby electronics and open source hardware. Dr. Monk is the author of numerous electronics books, including 30 Arduino Projects for the Evil Genius and Arduino + Android Projects for the Evil Genius.

I solder prototypes on perfboard  including SMD0805/0603, Mini-Melf and SOT-23.

Yes, I've got the aging eyes. One of the first things I bought a couple of years ago when deciding to do my own guitar setups was that binocular magnifying visor that Dan Erlewine wears in all his videos - he probably wears it to bed for all I know. Well that's cruel. Anyway I use it for anything close up.

I am curious when you say you solder SOT-23 right onto perfboard - is there a trick you're using to avoid an intermediary attachment board? There are all sorts of DIY I read about, some might be doable, others seem insane.

With the copper-bottomed perfboard, for example, I wonder if it's possible to attach SM to the underside - that is, right to the copper - if the copper is cut and/or added to as need be. A sharp hobby blade (Xacto, etc.) can cut it & there are all sorts of things that could be added - e.g. maybe very small snippets of copper foil tape; once a circuit tests out as working, the tape could be epoxied over, so as not to rely on the adhesive only. Or get good w/ working very fine wire such as for the size for winding - but that's getting kind of crazy maybe.

J201, 2N5254 and other classic, audio grade types are no longer made so prices skyrocket, only "switching" types are really being made today, and some RF types, so we must use whatever's available.

Well, I am going to take Enzo's advice (& yours) and do some research & look around for myself - it's one way to force myself to slow down a bit & learn a little bit.

However regarding above, ON at least, and probably others, seems to be telling customers it is still making fabulous audio types - only just SM like the ones voltwide shows in his schematic. If through-hole quality goes down another notch would you not think of occasionally using SM audio types? Or is circuit design still more important & can compensate enough?

Grumble . . . well, I have been looking. In his quick-and-dirty guide to substitutions, RG Keen says the following - and I assume this was before through-holes started dying off quite so fast:

JFETs present a bigger problem. N-channel JFETs vary all over the map, and by an almost intractably large amount. The big problem is that the variation of Vgs and gm values is huge for these parts. This is one place that you may have real problems. However, almost all JFET circuits are set up with trimmer resistors to adjust the operating conditions for the JFET because of the large variation in the JFET. I personally stock 2N5485 and 2N5457 JFETs. BF244C is almost exactly the same as the 2N5485.

But I know it's good for me to start thinking about the part this way, so I'll see what I can find.

The Newcomer's Forum / Adapter boards for SM?
« on: February 03, 2016, 11:34:50 AM »
Some of the new parts that get designed are never made in through hole versions. There are little adapter boards that you can solder surface mount IC's to for prototyping.

So okay then . . . I may need to get some of these little adapter boards.

The active preamp schematic by voltwide, over in the active guitar thread he started, calls for a couple of transistors of this sort, which DigiKey and Mouser have only as SM.

I am guessing I should match up the stated style or type of surface mount to an appropriate adapter. For example
the data sheet for the 2sk3557 transistors has this cryptic line under "product info":  "EITA, JEDEC : SC-59, TO-236, SOT-23, TO-236AB." So when I go DigiKey, they have only one adapter in stock for SOT-23 to DIP . . .  but they do have it, albeit it costs nearly $3.

A couple of questions -

1) Any best place to get these boards? Or just wherever I am getting whatever else I am getting?

2) There's really no way for me to do this other than adapter boards, right? As a DIY'er I only have perfboard to mount to. There are DIY methods  - Cheap/Easy homemade SMD-to-DIP adapters - but they seem like a real PIA.

Preamps and Effects / Re: active guitar
« on: February 03, 2016, 10:11:42 AM »
Thanks for the asy file - works.

As for the taper of the 2 pots - I figured the simulation would use linear - no point in getting fancy. I was actually asking, which type of taper you are using in your Strat?

Most players w/traditional tone controls prefer audio taper, but a few prefer linear for one or the other pot; and in this case I don't know your own preference, nor whether this circuit rewards linear taper in a way not usual w/a purely passive circuit.

Preamps and Effects / Re: active guitar
« on: February 03, 2016, 07:32:29 AM »
Voltwide, when I open the file in LTSpice, it complains "Couldn't find symbol(s) 'potentiometer 2" - both pots are therefore missing.

Is this 'potentiometer.sub'? And is that a model you built, or something I can find online in a library?

Googling I found this . . .

. . . and copied it as a text file into both the same directory as gitpre.asc and also the "sub" folder inside my installation of LTSpce on Windows - however I still get the same complaint.

Also for these 2 pots, would they be audio taper, as with a traditional passive system?

Preamps and Effects / Re: active guitar
« on: February 03, 2016, 05:28:45 AM »

I got tired of LTSpice for Mac, poor interface, so yesterday installed it for Windows, much better.

Preamps and Effects / Re: active guitar
« on: February 03, 2016, 04:35:42 AM »
Quick question - looking at the schematic you show two grounds coming off R4. Am I correct in assuming this is only a convention to indicate how battery negative is tied in as 0V/ground to existing ground in the wiring harness, e.g. sleeve of guitar jack, strings, etc.?

Preamps and Effects / Re: active guitar
« on: February 03, 2016, 04:20:10 AM »
Thanks, very helpful. This may be my next little project!

Preamps and Effects / Re: active guitar
« on: February 03, 2016, 02:20:47 AM »
Actually a prototype breadboard is working in my strat. The sound varies between very clear strat sound and something close to a humbucker sound . . .
Although only tested with my Fender Strat, this circuit should work in any electrical guitar with passive magnetic pick-ups.

This interests me for a very particular reason: I like to walk around a bit while playing; since I can't afford a wifi connector right now, a long cord is the only way - but then capacitance typically becomes an issue. In my innocence, I had thought I could get away with using a buffer close to the amp & the long cord in front of it, and only lately learned that putting the buffer by the amp is "too late" (though may have other benefits sound-wise). So now instead of being chained to my amp by a short cord I'm chained to my pedals!

I was advised that active pickups might solve this problem & give me back my long-cord freedom; but a preamp might do the same w/out having to switch out my present set of pickups. So I might want to try it at some point.

HOWEVER -  my guitar has humbuckers. You mention it should work w/pretty much any passive pickup. Does that mean the increased signal strength typical of humbuckers should not be an issue? Also are there particular components in the circuit that can be tweaked? I know very little of circuit analysis so my only way way of "analyzing" this would probably be to mock it up in something like LTSpice, though I am not that good at that either.

The Newcomer's Forum / Drawers or boxes for coin envelopes?
« on: February 02, 2016, 06:50:39 AM »
Enzo, I like the coin envelopes idea for parts, but what I'm stuck on is drawers or boxes to put them in. What do you use? I've Googled a lot but most boxes come in odd sizes, too shallow or too big. In the threads on MEF you mention drawers but nothing specific. And there is one person who uses smaller size envelopes & is able to stick them in boxes meant for baseball cards; but I'd prefer the larger size envelope that you suggest.

The big plastic 60-drawer units all seem to have drawers that are too small or shallow (top to bottom) - esp. since I'd rather have the envelopes upright so small parts don't fall out since they will be unsealed.

For now I will just use whatever boxes I have at hand & not get too picky.

These are those threads over on MEF -

Schematics and Layouts / Anyone using the latest CircuitMaker on Windows?
« on: February 02, 2016, 02:26:55 AM »
[NOTE: I thought I could answer this question for myself by searching the forum for "CircuitMaker" - but the search mechanism gave me zero hits, so either I did it wrong or it's balking for some reason. So I'm posting this question instead.]

I saw CircuitMaker recommended by many folks as an alternative to LTSpice or other programs. A link was given to an old, XP version, but I'm running Windows 7 (via Parallels on a Mac) and the program installer is 16-bit and refuses to work.

So I Googled and they are still around - web site at which has a "community" aspect of course - and still offering a free version - there may be paid options as well, I don't know. I've installed and the exe is DXP.EXE, version 11 something-or-other, for Windows 7.

So far it seems very slow - which is not my usual experience with Windows 7 via Parallels - and not brilliantly designed. From the look of it they are running it on a browser platform of some sort and those can often be rather clunky.

Is anyone using this? Thumbs up or down?

My alternatives are:
- iCircuit, Mac only - very pretty & works well for simple analog circuits, but the component library is way too small for anything more than that
- LTSpice on Mac - terrible interface!
- Fritzing, which is a neat newish layout program, also browser-based but better built it seems. You can lay out a schematic, then "breadboard" it, then do a PCB, both manual and autorouting available. However I can't see that it runs simulations. It seems strictly layout.

iCircuit works very well but is too limited. What I just realized I ought to do is download LTSpice for Windows, which looks to have a much better interface than the Mac version (e.g. a toolbar, amazing!).

The Newcomer's Forum / Re: Disappointed by Ruby chip amp from RunOffGroove
« on: February 02, 2016, 01:56:47 AM »
Thanks for the organization tips. I know there was a thread on where similar stuff got discussed, but now I am going to have to get real - so instead of boxes, envelopes (or maybe envelopes in boxes) sounds good to me. As you say if I don't know what I have or where it is, it makes things harder.

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