This talk about Q meters got me thinking. What's the most useful test equipment?

[SK66]

For me it's a signal generator and basic voltmeter. If it's a known design I just count turns and make sure there's no shorts (expected dcr, etc). For new designs and occasional "checks" it's the signal generator. With it hooked up to a driver coil I measure the AC output of the pickup throughout the entire range of signal output. This gives me a very "visual" description of the pickups character. Harsh or smooth, focused response or flatter curve, full or harsh, bright or dark, etc etc.
I've never found a bad pickup measuring inductance/Q/etc that didn't also show an anomaly in one of those two pieces of equipment. i.e. odd dcr, continuity between pole/coil, weird signal "notch/spike" or completely unexpected response curve.
I have a lot of test equipment, mostly expensive stuff, Tenma digital 2 channel scope, Wandel Golterman digital signal generator/line tester (pretty cool), fluke rackmount multimeter, genrad rlc digibridge, another wavetek signal generator (never used any more), Bell gauss/tesla meter, ferrofluid, ferro film, etc.
The Wandel Golterman is used mainly as a signal generator, but has the ability to also compare the signal the pickup is generating to the signal it's exposed to and any noise level the pickup adds. Cool idea, just wish I had the damn manual.
Still the most useful is the handheld ohmmeter/voltmeter (also fluke, sits next to the winder) and the signal generator. All the other tests are kinda just numbers compared to other numbers, and I have hundreds of pages of "specs"...but the ac output curve is "descriptive" and quite "telling".

Don't get me wrong, if you're inquisitive and have the money, buy all the equipment (I did). The information gained can only help...but in the end I found it all to be basicly "relative", Inductance being the most useful "spec" of all the other measurements, but still "relative".
I did full "bench tests" of all specs for the second/third/maybe forth hundred pickups (the first hundred or so I didn't have all the equipment) and I also played them all...Gave me a good understanding of how things interact (maybe "feel for" how they interact is better because I can't define it in absolute terms even today).
Now I only test for shorts and maybe inductance (usually first couple with a new spool of wire). Occasionally I make "spot checks" for output curve/install in the test guitar when working with known designs. The rest of it is just there for testing a rare/special pickup and new designs.

[Possum]

So you just run the signal generator to drive the coil and measure the AC voltage generated through the spectrum? You said "visual" of the output, are you charting the numbers from the voltmeter?

[R.G.]

Originally Posted by Possum

So you just run the signal generator to drive the coil and measure the AC voltage generated through the spectrum? You said "visual" of the output, are you charting the numbers from the voltmeter?

Hey... isn't that kind of what I was suggesting with measuring pickup response curves a ways back?

Hmmmm...

[NightWinder]

Thanks for sharing that SK- Looking forward to learning some new methods and such-

[SK66]

Originally Posted by Possum

So you just run the signal generator to drive the coil and measure the AC voltage generated through the spectrum? You said "visual" of the output, are you charting the numbers from the voltmeter?

Yes, that's how it's done and yes I will chart the numbers. If you use a simple graphing program it makes things very obvious.
I don't worry that the testing may not be "standardized" with other manufacturers....there is no such thing as "standardized testing" in this industry.

[Yves]

Actually, there is a brief describing some process, which I believe is the same approach that the one you use SK, along with some picture of the coil used for that purpose, here:

http://www.buildyourguitar.com/resou...emme/index.htm

Yves.

[Possum]

no this is different method, AC resistance, AC voltage, the other method is to use a spectrum analyzer, charting software, I don't think it operates the same way. Joe Gwinn had a similar method of hooking the frequency generator directly to a pickup and a resistor and reading voltage across the resistor to find peak resonance, trouble is it didn't work very well with hand wound pickups that can have very smooth peaks so you kinda got lost trying to find it. I kinda like SK's method because it deal in numbers not lines on paper. Simple. Yes there's no standard way to measure any of this, if it works for your needs that all that I care about...

[SK66]

Actually, the Lemme analyzer is the same in principle. I originally considered buying his analyzer, but the cost was prohibitive and for about the same money (or less) I bought 2 very nice pieces of equipment(used) which can also be used for other things. If I want to check with resistors (pots), caps, cables I just connect them in series with the pickup.
It doesn't look like he's selling it anymore, but I think the cost was around $700.00 back then.

[Béla]

Computer sound card output running into a coil stripped from a 2$ earphone, the coil above the pickup, output going into a HighZ input, back into the PC.
Software used is a registerware(don't worry, wont send spam) called RoomEQWizard.
Makes nice graphs like this:


Oh, and in case you need an integrator, just use this calibration file: http://www.mediafire.com/?k3zjuzbyzh9

[Steve Conner]

Ooh, that's awesome Bela! I've used that FFT analysis method for designing tone controls, but never tried it on pickups. Also, I didn't know about RoomEQWizard, I was using other software, but it doesn't work on my new PC. Thanks for the tip!

[Joe Gwinn]

Originally Posted by Possum

Joe Gwinn had a similar method of hooking the frequency generator directly to a pickup and a resistor and reading voltage across the resistor to find peak resonance, trouble is it didn't work very well with hand wound pickups that can have very smooth peaks so you kinda got lost trying to find it. I kinda like SK's method because it deal in numbers not lines on paper. Simple. Yes there's no standard way to measure any of this, if it works for your needs that all that I care about...

The problem is inherent -- low Q pickups will have very broad peaks. For this, one must instead use the phase method (the one with the Lissajous figures http://en.wikipedia.org/wiki/Lissajous_curve). Although if the peaks are that broad, the exact resonance frequency isn't much use unless one is trying to pick values of R, L, and C that approximate the actual pickup's curve.

Plotting the response spectrum and looking at it will certainly tell if one is in the ballpark, and will also (as mentioned by SK) easily detect shorted coils. The spectrum as a table of numbers also works, although I prefer to look at plots.

[David Schwab]

Originally Posted by Béla

Computer sound card output running into a coil stripped from a 2$ earphone, the coil above the pickup, output going into a HighZ input, back into the PC.
Software used is a registerware(don't worry, wont send spam) called RoomEQWizard.

Ooh! Runs on Mac OS X too! OK I have to check this out.

[Possum]

Let me know if it works on your Mac, looks like you may have to mess with Java stuff to make it work, if your Mac doesn't blow up I may try it here :-)

[David Schwab]

Originally Posted by Possum

Let me know if it works on your Mac, looks like you may have to mess with Java stuff to make it work, if your Mac doesn't blow up I may try it here :-)

I haven't tried it yet, but I checked out the Java thing... I'm running Leopard (OS X 10.5.2 for the non-Mac heads) and it uses Java 5.0 as standard. It has a preference app that let's you switch between that and some old version like 1.6 or something.

Apparently Tiger (10.4.x) might not be using the newer version as the default and you have to tell it to do so.

I'll give it a launch right now...

OK.. doesn't blow anything up. It also seems to be having an issue finding my M-Audio sound card.

I have Tiger installed on my second hard drive for running Pro Tools, so I'll try it there this weekend.

[Possum]

I downloaded the program and running 10.4.10 I have Java 5, something isn't working right the generator frequencies sound screwed up and weird....

[soundmasterg]

something isn't working right the generator frequencies sound screwed up and weird....

Its your ears Dave.

[Possum]

It looks like you may have to upgrade your system to be able to use Java 6, but in googling around the newest upgrade has problems, stay away from it for now.

My ears don't sound like THAT. My ears have that sweet PAF, vocal kinda juicy, squirmy, squishy, gooey, squirting, dry, wet, crackling, compressed, FAT, vintage 1950, grey haired, kick your young ass.......tone.

[David Schwab]

Originally Posted by Possum

It looks like you may have to upgrade your system to be able to use Java 6, but in googling around the newest upgrade has problems, stay away from it for now.

Which update, 10.4.11, or 10.5.x? 10.4.11 is fine. There's even a Java update from Apple.

10.5 had some issues, which were improved with the 10.5.2 update, but they really rewrote a lot of the underlying system code, so expect some applications to not be compatible.

I wanted to update to Leopard, and was real careful about it... I installed it on my second hard drive along with all the important stuff my wife and I need... MS Office, the Adobe Creative Suite, and my music apps like Cubase SX. Everything seemed fine.. I had read about Acrobat 8 not being compatable, but it was just the printer.. which I hardly ever use.. Distiller still worked as well as the built in PDF tools.

So after weeks of testing I figured it was good to go, and upgraded my 10.4.11 install.

Then my sound card stopped working because it needed new drivers... then apps were crashing and some files had their access permissions screwed up because of a ACL (access control list) bug.

Things are much better now, but Cubase doesnt want to run without crashing (it is an old version) and my new copy of Pro Tools doesn't work in 10.5... so now I have 10.4.9 on my second drive.

Still better than updating to Windows Vista though! I really love Leopard... it has some very cool new features, like QuickView.

Originally Posted by Possum

My ears don't sound like THAT. My ears have that sweet PAF, vocal kinda juicy, squirmy, squishy, gooey, squirting, dry, wet, crackling, compressed, FAT, vintage 1950, grey haired, kick your young ass.......tone.

Heh... I hear music fine... conversations are another thing.. and then I have this annoying tinnitus that never goes away.

[Possum]

I googled 10.4.11 update and there are alot of problems people are having with it and Safari 3, I make my living on this machine and don't jump on new updates until I hear its safe. I"m running the earlier version and its super stable so why take a risk and it probably wouldn't make the program run right anyway, there are other programs out there too. Fuzz Measure works fine on this machine, doesn't do quite as much but its not that important anyway.

[David Schwab]

I didn't have any problems with 10.4.11, and nothing specific to Safari that Safari doesn't already have.

There is a new version of Safari out anyway (3.1) for both 10.4 and 10.5.

I'm running 10.4.9 on my other drive because that's the version that ProTools is certified with, but they said there isn't any issues with 10.4.11.

[Possum]

Do roomEq work properly on that machine? I don't have a sound board installed the machine is just stock; I was told that recording boards and Protools won't work on this particular G5, I didn't care at the time, it was an open box sale and a good deal. Maybe I ought to read the user's guide, I could be doing something wrong, some of the frequencies sound right from the generator but some of them sound like buzz saws :-) Anyway, I'm not upgrading, I'll wait til they iron some of this stuff out, the last upgrade was a good one and I didn't see any issues being posted, this new one is too new and too many people having problems, like I said this is a work machine, if it goes down or gets messed up my work stops. These OSX machines are way more difficult to maintain than the OS9 machines are. I still do all my print production work on OS 9.2 on a G4, OSX is still horrible in dealing with print fonts for prepress work and none of the font management systems work as good as ATM did.....

[David Schwab]

I haven't tried it on the 10.4 side.. it might work there. On Leopard it's giving that sound card error.

This G4, which ironically is named the "Digital Audio" model, has no built in audio line in jacks! So the only way to record with it is to use a sound card.

The G5's used PCI-X slots, so when they came out a lot of cards didn't fit. But they do now. M-Audio even has a trade in where you can get an updated card.

Pro Tools either works with their hardware, or with the M-Audio cards if you get the M-Power version.

I use Suitcase Fusion for font control. That works as well as ATM Deluxe did. I have heard many good reviews of the free Linotype Font Explorer, which is also very similar to the old ATMD. Apple's Font Book is a joke.

I had to reinstall Adobe CS 3 on this machine, so now everything works well in 10.5.2. We have 10.4.11 on all the Macs at work. Most of them are new Mac Pros, but there's a few G5's and G4's as well. Seems to be working fine.

I've been on OS X for print production for a while now. Most of the bugs have been worked out, but of course you need OS X native software... but we did run PageMaker in classic (9.2) at my last job.. the little that we ever needed to use it.

[Possum]

I get the same sound card error on this machine. I looked at Suitcase Fusion on version tracker and it only gets 3 stars. Font Agent which I use gets four stars, none of them get five stars :-) The programs for prepress on OSX are so bloated and heavy they don't run real well, InDesign I tried and couldn't believe how clunky and slow it was on a G5, I'm still using Quark 4.1 on the old G4 and it screams in comparison. InDesign sets better type but I was real unimpressed by it in OSX. I'm pretty much moving into full time pickup making and sick of the design world anyway, 35 years of designing stuff that goes into the garbage can and no one remembers, what a life. My agency portfolio is molding away in the garage. I won all the awards I ever wanted and national exposure in design annuals and it never amounted to increased income :-) Its not a field I would recommend to anyone these days, the level of professionalism fell out the bottom when people who's only qualification is that they owned a Mac started calling themselves "designers." Do a marker comp thats believable and spec type by hand and list the names of ad agencies one has worked at or design school, no one can these days :-) Typography is a dead art, I don't think they even have typography annuals anymore, people think kerning is some variety of corn....

[David Schwab]

Originally Posted by Possum

I get the same sound card error on this machine.

OK, so it's not my sound card...

Originally Posted by Possum

I looked at Suitcase Fusion on version tracker and it only gets 3 stars. Font Agent which I use gets four stars, none of them get five stars :-)

If you look through the comments on VT, you'll find me tell all those idiots why they are using font managers incorrectly. They also all swear by that Linotype program, which I thought was a real joke. These are the same people who don't know what a spot color is, and insist on placing native layered Photoshop files in their InDesign document and wonder why it doesn't print right...

We use Font Agent at work. At my last job we used Suitcase. I like Suitcase better. I liked ATM Deluxe best of all, and the latest versions of Suitcase remind me of it. The biggest complaint these people have about Suitcase seems to be with auto activation of fonts, and that's the first thing I turn off! Might be OK when you are using your own font library, but not in a work situation.

Suitcase is nice because you can override the system fonts.

Originally Posted by Possum

The programs for prepress on OSX are so bloated and heavy they don't run real well, InDesign I tried and couldn't believe how clunky and slow it was on a G5, I'm still using Quark 4.1 on the old G4 and it screams in comparison.

Well OS X is slower than OS 9, but if you are dealing with Quark 7 files, and ID CS3 files, you have no choice! Everything runs fine on my aging 1 GHz G4. The G5's are fast, but the new Intel Macs are a lot faster. Photoshop launches in 6 seconds on the Mac Pro I use at work!

Originally Posted by Possum

InDesign sets better type but I was real unimpressed by it in OSX. I'm pretty much moving into full time pickup making and sick of the design world anyway, 35 years of designing stuff that goes into the garbage can and no one remembers, what a life. My agency portfolio is molding away in the garage. I won all the awards I ever wanted and national exposure in design annuals and it never amounted to increased income :-) Its not a field I would recommend to anyone these days, the level of professionalism fell out the bottom when people who's only qualification is that they owned a Mac started calling themselves "designers." Do a marker comp thats believable and spec type by hand and list the names of ad agencies one has worked at or design school, no one can these days :-) Typography is a dead art, I don't think they even have typography annuals anymore, people think kerning is some variety of corn....

I was out of the work the last 8 months... I saw an add in the paper looking for a "Mac graphics guru"... they insisted you had a BA, and "at least 6 months experience"! Yeah, that person will know it all... and they wont have to pay him much.

[Possum]

Six months experience, well that takes the cake, thats funny! I have an AS in graphic design from '74, the first design class I took in the course the instructor walked to the front of the class and lit his big cigar, took a puff, and said "if any of you have any brains you'll quit school right now and go get an apprentice job at a design studio or ad agency." "You'll learn more in a month there than you will here in two years." You coulda heard a pin drop after that one. I didn't feel so bad because I was freelancing as an apprentice and learning to do marker comps doing Yellow Pages ad layouts and getting paid by the piece :-) I think I was the only one in the graduating class that actually got into the field right out of school. My first job was baptism by fire. A small design studio/ad agency, after about 6 months pretty much the entire staff quit at the same time after being forced to work long weekend nights without extra pay, I walked out with them and took my skills freelance with a little help from friends, only had two jobs after that, one that nearly killed me in L.A. from stress, rest of it I've always had my own clients, Shrapnel Records and EMG Pickups were my biggest, I'm slowly letting go of Shrapnel now but they want me to do album design for their better artists like Leslie West and other star players. Once I get rolling I know I can beat the income I make doing label work, it doesn't pay well since Macs came along, down hill ever since. What a life, definitely time to change and sell my own products instead of lining other people's pockets with my help.

[David Schwab]

I hear ya brother! I've been doing this since about 1980.. was a plate maker and offset stripper then. I was a stripper, eh, lithographer, until the big Mac take over in the mid 90's, and then while I was out of work I taught myself Quark, the Adobe apps, etc, running on my PowerMac 6100 pizzabox (8 MB RAM, 500 MB Hard drive, and 60 MHz CPU! Yeah Baby!)

Now I'm working as a production artist on the graveyard shift for a big printer in Brooklyn... tough to get used to the hours (10PM to 6AM), but the pay is good. I like being a production artist.. it's less of a headache than dealing with the clients directly. Once I start selling at least 4 sets of pickups a week I can retire from this field ...

Funny what you said, because I always tell people I decorate trash when they ask what I do for a living!

I take on an occasional design job, but I was never trained as a designer... I'm just a former surrealist/cubist that hasn't painted in many moons...

[Possum]

Heee, now all the forum guys are visualizing you taking your clothes off in a strip bar for old ladies. We had a class in stripping and camera work when I went to school, jeez they even had us set some sample type in real LEAD and printed it on a small letter press, man, thats ancient :-) Those hands on classes were super valuable, way more than the "design" part of the curriculum. The stuff I learned there let me do things on cheap stat cameras that no one else could do, ha. My first Mac was a Plus and I actually typeset alot of jobs on it back when typesetters switched over to Macs. Now they are all gone, no more typesetters, sad. Another industry that was lost was album cover design, eventually all the big record companies hired kids off the streets pretty much and staffed up, replacing all the amazing album artists and photoretouchers we all knew and loved. In a way I'm lucky to be doing album art now since no one hires for that anymore. I just wish it paid better, Shrapnel is a small indy label and hanging on by their teeth.....

[David Schwab]

Boy, we really highjacked this thread..

[Béla]

Haha, yeah. Any luck running that REW thing? I'm no expert, but I'm sure you don't need the latest Java or OSX to run it. You can always lurk around in the REW forums if something doesn't work out right, there might already be an answer.



boy, and I thought that having a mac is about having less problems running stuff...

[Possum]

the problem is that this is a PC program in the beginning, some of those guys don't write stuff for macs very well....obviously there are some issues with this program if two of us are getting the same error message on completely different machines.

[David Schwab]

Originally Posted by Béla

boy, and I thought that having a mac is about having less problems running stuff...

It is, and Macs have less problems when running Mac software. I know from being everyone's computer tech (in-laws, friends, etc.) how often the PC users I know have issues just getting printers and scanners to work! Good thing I know more Mac users, including my father-in-law after my wife got tired of him complaining about his Dell! He has two Macs now.

A properly written Java application will run anywhere equally well. LimeWire is a good example. Runs fine on a Mac. If this program isn't working right, it's because of the way it was coded.

OS X even runs Linix and BSD Unix apps because it's based on BSD Unix and has X 11 (the windowing system) installed.

If I had one of the newer Intel based Macs, I would also be able to boot into Windows. I can try running the Windows version in VirtualPC, but I think that will have sound issues because it has to go through a hardware abstraction layer (HAL).

[Possum]

I dug around their forums at Home Theater, it looks like REW just plain doesnt work on a Mac, how stupid is that? Others get the buzz saw signal generator and the weird alert when booting up, there is no support for it on Mac that I can see there either. It looks like it may work on Windows on an Intel Mac though...

[Possum]

Bela, your frequency response chart looks suspisciously like the sound card calibration test I did, What pickup did you use? Are you using a laptop? My wife was going to give away a laptop PC that got dropped once and sometimes shuts itself off so messing with that. Haven't tried a pickup yet but the sound card measure test looks real close to your pickup chart? This is a cool program too bad they don't know how to do Mac programming, it sure doesn't work on one...

[Béla]

The measurement was taken from a damaged humbucker that's in a guitar that has an onboard buffer (I don't know the input impedance of the circuit - Vref is on one end of the pickup and the other end is going into the non-inverting input of the TL082, and there are no tone or volume pots directly on the pickup).

A sound card calibration should not look like that at all. It should be mostly flat (within 0.5 dB), with a roll-off at the extremes, at around 5Hz on the bass side and 18kHz-20k on the treble. I'm using the built-in AC'97 sound card output on my desktop PC, and it's going into the input of a Boss GT-8 (going back into the computer via SPDIF).

[Possum]

the sound card test on my laptop looks alot like your chart :-) if you look at the help files in the program they have an example thats pretty close to what I got. You have to save that as a calc file then it compensates for the cards' flaws.
How did you hoook up the driver coil? It has to be set vertically between the two coils, not flat over one of the coils, that Lemme article shows how to do that....I"ve never measured humbuckers before, just single coils with a driver coil. will be interesting to do this with buckers if I have time to mess with this.....