Testing out some tone caps...

[Mike Sulzer]

Mustard caps?
Personally, I prefer Ginseng caps but I'll admit that pure cocaine is a lot faster.
Anyone here ever smoked a resistor?

I have smoked a lot of resistors (mostly designing and building amplifiers), but I did not inhale.

[Steve A.]

... No one is trying to start an argument with you, but as I said before, I don't agree that Marshall picked a particular capacitor for the tone of it. I'm sure you wont find any reference to them doing that either. They did pick a good quality part, but that's about it.

Well, in doing R&D on their amps I think that they liked the sound of the components that they were using in their circuits. Assuming that they were buying parts from a supplier (and not just running over to the nearest Radio Shack ) they probably continued to get the same brand of parts from them, at least for awhile. My reasoning behind that is inertia: it is easier to continue to do things as they were- to place a reorder for parts rather than institute an entirely new order. Hence the consistency in many parts in Fender amps.

However, back then there was the common opinion that "parts is parts" and when a particular item was no longer available, the supplier might switch over to another part without even telling the customer. Hence the inconsistency of many parts in Fender amps...

Another example would be the magnets that Gibson used in their pickups in the 50's: they usually just specified "magnets" and not specific varieties of Alnico. So one batch of PAF's might have had, say, Alnico 5 while others might have had Alnico 2 (names have been changed to protect the innocent!)

But I agree that Marshall was not like a wine connoiseur, sniffing each brand and vintage of capacitor...

Steve Ahola

P.S. So was Marshall using Grey Poupon Mustard caps or just plain old Guldens?

[Joe Gwinn]

There was a similar double blind test done to see if there is a difference in two buffer circuits, one using an op amp, and the other a JFET:

Lutherie Myth/Science: A Listening Evaluation of Discrete vs Integrated Circuit Audio Preamplifiers in Stringed Musical Instruments

They had a switch on the bass labeled "A" and "B". In the end, some thought one sounded better than the other, and others had no preference.

The study was correctly designed, although in retrospect one thing was omitted, the "null hypothesis".

Null Hypothesis? This is a term from the Design of Experiments, a branch of Statistics, and originated from agricultural research in Britian around 1900.

You have two "treatments", say two kinds of fertilizer for growing tomatoes, and the question is which fertilizer is better.

The Null Hypothesis is that there is no difference (in other words the fertilizers are equally good), so your first task is to "reject the null hypothesis" (that is, to show that one fertilizer is clearly better than the other). Seems simple enough, but there is a catch. When you grow things, you never get the same yield twice, so there is a danger that normal random variation in yield will lead you to falsely conclude that one is better than the other when there is in fact no difference.

What to do? Run the experiment many times swapping garden plots (to cancel out differences in soil) with seed from many sources (as not all seeds are alike) and so on. This leads to the question of how many tests one must make to be sure of seeing a true difference. It's a long story, but the basic rule is that the smaller the expected effect and/or the larger the random variation the more tests it takes to be sure.

Coming back to preamplifiers, the result was that the assessments were evenly balanced between the two kinds of preamp, and if they had done the computations (not difficult, but more than just computing some means), it's pretty clear that they would have been unable to prove that there was any significant audible difference.

In fancy Design of Experiments words, they were unable to reject the null hypothesis. They would probably be stunned and insulted if you told them that - it sounds like a serious personal failing. But it's just statistics jargon.

[Steve A.]

Mustard caps?
Personally, I prefer Ginseng caps but I'll admit that pure cocaine is a lot faster.
Anyone here ever smoked a resistor?

As a matter of fact I do have a wood smoker on my property and I always smoke my resistors for several days before using them in my projects. For the best results I've been using the wood from oak barrels originally used for aging bourbon.

So what are the other people here using to smoke their resistors? I have heard good things about using wood from apple and almond trees but have not tried that myself.

Steve Ahola

[Joe Gwinn]

As a matter of fact I do have a wood smoker on my property and I always smoke my resistors for several days before using them in my projects. For the best results I've been using the wood from oak barrels originally used for aging bourbon.

So what are other people here using to smoke their resistors?

Well, in Electronics there is a widely-held theory that electronic components require highly compressed magic smoke to operate, and that anything that allows this magic smoke to escape will cause the component to stop working.

In this theory, there is no role for external smoke at atmospheric pressure, regardless of the kind of smoke.

[Possum]

....

I noticed that stepper motors have some kind of "magic" smoke in them, what IS that stuff anyway, how can smoke remain smoke, you would think it would condense on something? What does it actually DO?

[SteveJ]

I've made some good money over the years from putting the smoke back in.

[GlennW]

I just drop my resistors in the bong...a few months later they have the sound.

[Steve A.]

...You have two "treatments", say two kinds of fertilizer for growing tomatoes, and the question is which fertilizer is better...

In view of the recent posts on this forum, I think that fertilizer is a very appropriate subject...

Steve Ahola

[David Schwab]

I have smoked a lot of resistors (mostly designing and building amplifiers), but I did not inhale.

And God that awful smell.

I remember building a compressor when I was younger, and my girlfriend at the time looked at the circuit board after I plugged in the battery for the first time and said;

"Ooh, is that part supposed to light up?"

No. And it's not supposed to smoke either!

[David King]

Wow, we just answered a lot of important but un-asked questions.

Every try plugging a good sized electrolytic cap with the spade connectors directly into a wall outlet?
I did it once when I was about ten, I can still remember the fuzzy sound in my ears for the next day or two. It actually didn't smell that bad but it sure made a mess of the wall plate. I'd recommend using a switched outlet with the switch a good 10 feet away from the outlet.

[Joe Gwinn]

Joe, that is a good point about matching the cap values. But there is something to be considered first before one can proceed with the kind of careful tests you have described, because they involve a lot of care and effort: what is the best setting for the tone pot to give the most sensitivity to the capacitor characteristics? This is not so obvious. On 0, the upper midrange frequencies that the ear/brain is so sensitive to are much attenuated. On 10, the capacitor has a large resistor in series. Although most people are not convinced that the degree of isolation is as large as I think, no one seems to be denying that there is such an effect. I suspect that the best position is somewhere in between. Any ideas on a test to determine what that position is?

There are many different tone control circuits used in guitars, so I don't know that there is a single best approach. If we are trying to tell if capacitor construction and/or dielectric type matters, I would use the switch to select the candidate capacitor, and then fool with the tone control while playing. Do this for all candidate caps. Then, I would set the tone capacitor to midrange, and play a piece over and over as one tries out the candidate caps one after another.

I think this approach will quickly tell us what does and does not matter.

[David Schwab]

Every try plugging a good sized electrolytic cap with the spade connectors directly into a wall outlet?

I had an engineer friend who was the sound man in an old band of mine back in the 70's (when he was still in school) and he said at NJIT they used to take electrolytic caps and plug them into the wall socket, and then throw them into a bucket of water (from a safe distance) and watch them explode! Now he designs oscilloscopes for Tektronix.

[nbtone]

I read a book once where Sandy Nelson was quoted as saying that in 1960 he went into the recording studio to record a record and couldn't get the sound he was used to. Hollywood had bought all the new equipment that came out that year, and the sound was too tinny!!
Anyone remember Sandy Nelson??