how do you deal with opposite advice?

[nateflanigan]

News flash!  There's a lot of conflicting information on the internet!

There's not really one issue I'm trying to sort out or anything, really just wondering how does anybody deal with abyss of information out there.  It's really not uncommon to read one very authoritative, scientific, seemingly learned, some what biased, view on a given topic only to find an opposite treatise that is equally authoritative, scientific, seemingly learned and some what biased.  My brain wants this stuff to be math, with one correct answer but it feels more like string theory or pottery class or at least debate club.  To me it's all words on a computer screen, I don't have any reason to give more credence to one source or another.  Deep in my heart I know the answer come down to personal hands on experience, but I just wanted to wonder out loud for a minute.

[EL34]

I run into this all the time.

I am usually at odds with with the poindexter types that try and calculate results and then post them as facts.
They post graphs, charts and spread sheets.

Scientist always calculate things, but then they do actual experiments to test those calculations.
More times than not, the real world results are quite different than expected.
That's why they do the experiments, to see whow things work in the real world.

I like real world results.
My theory is that the time spent making pie charts could be spent actually figuring out how something works in real life.
It's just a theory 

[jjasilli]

There's a lot of conflicting information on the internet. . . one very authoritative, scientific, seemingly learned, some what biased, view on a given topic only to find an opposite treatise. . .

You're really saying different things here, mixing apples and oranges.  A view is not a treatise.  I would consider a treatise to be a well-regarded reference book or website, like the RCA Tube Manuals; KOC's TUT series of books; Aiken's or Merlin's (Valve Wizard) websites; Dougs Library of Information.  A view is subjective opinion.  Some of what we do is pure science/technology.  One example is tube bias.  There are objectively true, technological outside parameters:  too hot and the tube is damaged; too cold and the tube is turned off.  There is a wide range in-between in which the tube will function; but linearity will vary, so tone will be different.  Here, there is a lot of room for subjective preference.  The shape of the waveform is scientific fact; whether or not someone likes the tone is opinion.  Also there are several different technological approaches to bias a tube (cathode, fixed, cap input, etc.).  They all enable a tube to function, but they sound different.

IMHO the foundation is to have good reference sources.  From the buzz on the internet, it is up to you to tease-out what is science, and what is opinion.

[Fresh_Start]

[long winded version of JJ's post]

In my limited experience, there are two keys to unravelling this Gordian Knot and they are inter-related:
A) Figure out which individuals and/or resources usually are reliable sources of information (as opposed to unsupported opinion), and
B) Test things yourself

It's really an iterative process where you develop reasonable filters, apply advice or "facts" to a real amp, revise your filters, ad naseum.  After a couple of builds and a couple of years, you'll identify certain information sources that you can trust implicitly.  Others may be mostly fact, but sprinkle opinions in which frequently are presented exactly the same way as "facts".  For me, Randall Aiken, R.G. Keen and our peerless host Doug Hoffman fall into the first group.  Merlin and the Tone Lizard fall into the second group.  Kevin O'Connor straddles the two - mostly really solid facts but there's a sprinkling of opinions stated as facts which are hard for the novice to identify as opinions.  Of course, there's also a third group you have to identify and largely ignore.  Harmony Central???

Another thing to keep in mind is that even well intentioned folks who are reasonably knowledgeable may not be able to answer your question accurately.  They don't know all of the things you've already tried, and they don't have your amp on the bench to look at, test, tweak, etc.

Also, "great tone" to my ears may be like fingernails on a chalkboard to your ears.  "Anemic" reverb for one guy might be "swampy" to another.  Neither one is wrong, just different perspectives.  I was all set to build the "Single Ended Lead" design on AX84 based on all of the positive comments on its great tone.  Even bought the transformers (yes, I am a moron at least some of the time).  Then I finally found some sound clips.  Modern high-gain metal or whatever you call it is not my cup of tea.  Back to the drawing board to figure out what to do with the transformers...

Going to original source documents helped me a lot.  Examples are Jack Darr's book, The Radio Designer's Handbook, tube data sheets (search function on Pete Millet's site), etc.  Actually, Pete Millet provides a great collection of original material:
 http://www.tubebooks.org/technical_books_online.htm

Doug's Library and Schematic Heaven are invaluable resources IMHO.  Sure, you can pull up 100 variations of the "18 Watt" Marshall, but why not start by looking at the original?  PRR keeps reminding me that there's no substitute for "known good" schematics and layouts.  Of course, I keep ignoring that concept to a greater or lesser extent.

I've tried to put together a fairly comprehensive set of links in the "References" sticky.  I add references as I stumble on new ones, but frankly I wish other people would give me more input.  There's no way I have read half, let alone all, of the stuff in those links.  Plus, sometimes links go dead and I won't know it unless I try to go there myself.  That's a bit off-topic, but a plea for help anyway

One last thought:  there's no substitute for building the same amp twice.  Seriously.  I built, and then re-built a 5F2-A derivative.  Learned more from the two re-builds than I did from the first try.  I built two Princeton Reverb clones and learned at least as much from the second one as I did from the first.  Following up with a Super Reverb clone helped even more.  Now I know how to build a moderate gain amp with reverb and bias vary tremolo.  IMHO that's a reasonably solid foundation.

Good luck!

Chip

[LooseChange]

Form your own opinion and screw everybody else! 

Some things are "math". The other stuff is opinion.

[nateflanigan]

Thanks for taking the time to say all that guys, especially the always awesome fresh_start.  It's probably obvious I haven't built many guitar amps, but I got here via PRR and prodigy-pro so I'm not totally inexperienced.  After building the MILA mic pre (an original design from a forum member) on a turret board I never wanted to touch another circuit board or transistor again.  Not that PCB's sound bad or anything ridiculous like that, it's just not fun from a fabrication stand point.  I like (very reluctantly) the re-build idea, I know I would learn a lot from that. 

[Ritchie200]

In a past life when fighting with company bean counters over capital, justification, and return, I used to piss them off with this quote:

Everything that can be counted does not necessarily count; everything that counts cannot necessarily be counted.
Albert Einstein

I've applied this to many things in my life.  I am also from Missouri.  We have a saying here, "Show Me".  I am also of German descent which means you can always tell a German, but you can't tell 'em much.  I've also come to the conclusion that many of the people I used to put a lot of trust in are about as smart as a bag of hair.  In other words, I like to form my own opinion based on 25% research, 25% life experience, and 50% plain old sweat.  

So other than me being crabbier than everyone else, it looks like we are all pretty much saying the same thing!
Jim

[EL34]

So other than me being crabbier than everyone else

Oh, so you think you are crabbier than everyopne else?
I might be able to out crab you on some days.

I'll have to do some calculations and some charts first.

[simonallaway]

B) Test things yourself

+1 on this. I'm a programmer by trade, and in the financial industry performance is *everything*. So there's plenty of hearsay and "asserted opinion" going around about what actions are considered slow. You'll hear people say things like "don't convert text to uppercase, it's too slow" when they don't actually know themselves, they just heard it somewhere. Luckily in programming it's easy to write a piece of code to prove/disprove their hypothesis quantitatively. So I'll write something that converts random text to uppercase 10 million times, measure how long each one took, average it. Then you get to say "well, doing that only adds 10 microseconds to the process, so you're an idiot" 

[EL34]

Yeah, it seems there are a lot of sheep out there that just follow and are not able to think for themselves.

[Shrapnel]

LOL...

I just gotta say I see this a lot with the health industry. "This is bad for you that is bad for you and here's the proof," from one source, and from another showing the opposite, with their own proof. Remember the deal on eggs being bad for you, then later, the "we were wrong" story. Too many so-called experts preaching their theories as facts when all the facts are still out (or worse, ignored, because they don't fit the agenda.)

Live Life, Love Life, Use moderation, and get your own opinion.

[EL34]

yeah, eggs and butter were bad. 

Instead, we would like you to eat these chemical substitutes we made in our lab.
They are way better for you.

I never fell for any of that crap.
I love real eggs and real butter

common sense rules

[Bassmanster]

There's nothing wrong with instinct and intuition when straightforward experiments and/or laws of physics don't apply.

[simonallaway]

Remember the grocery bag fights?

Use paper! No, wait, you're killing trees!
Use plastic! No, wait! they're not biodegradable.
Use paper! No, they're made by 4 year old slaves in Bangladesh!
Use plastic! Noooo, seagulls eat them.