Writing the book....

[Structo]

I agree, a lot of it is experience.

Talbany was kind enough to help me tune my first D amp with a lot of my questions and his answers, that I will always be grateful for.

I think one of the obstacles of providing tweaking information is, how much do you tell somebody that maybe over their head when dealing with lethal voltage.

A couple years ago I helped a guy on another forum to tune his amp to what he wanted to hear out of it.
About a month after we started corresponding, he stopped responding.

I still have no idea what happened to him, God forbid he killed himself working on his tube amp.

So disclaimers are very necessary when helping someone that you have no idea about their capabilities in electronics.

[gui_tarzan]

Coming from the perspective of the musician, not an engineer, would help.

Here's where I'm going to lose a bunch of people... Would I buy a book today? Probably not because the resources are everywhere on the 'net. Not only do I get theory from guys here and other sites (which I hate because of the math involved) but I get other sources for why this resistor or that capacitor works better for X sound.

The truth is we could all do the same thing Leo Fender probably did and break out the RCA tube book and build the same thing he did. Having the experience of others so widely available makes it far easier to learn and actually be productive in this hobby as we have seen by so many, including yourself, Bruce.

Trade secrets aside, knowledge belongs to the people (stealing the quote from a famous movie) and it should be shared to improve everyone involved. Granted, some people learn better from books and I'm sure there would be a market for it, but the last book I bought was my bible about twenty years ago. I'm also a cheap bastard, I won't pay for information if I can get it free but I will share my knowledge with others as I can so it's beneficial to everyone and pays back what I was given by others.

"But I went to school and invested thousands of hours that are valuable and spent a bazillion dollars on equipment blah blah blah"

Yeah, so what? I'm doing the same thing and so are many others, and when I actually work on someone's amp I will charge them a fair price. But sharing information as far as I'm concerned is free unless I decide to put it into a medium that is permanent and beneficial to someone else that's willing to pay for it.

I'm not trying to discourage you Bruce, I'm just giving you my perspective. If you can encourage someone to continue this hobby and even make a legitimate business out of it, great! It's not easy to find someone that actually knows a 6550 from a 12AX7 or for that matter, what a tube is to begin with.

So to answer your question:

Clear, concise information starting from the ground up with REAL world experience as to what, where, when and why along with the how.

Organization - keep their focus and make it easy to find stuff

[Phil_S]

Ahem....cough, cough...
http://www.amazon.com/Designing-Power-S ... 0956154514

Amazon says it's out of print and they have no copies to sell....

That's never the place to get one of Merlin's books. It is just a convenient reference. The place to buy it is lulu.com. I believe, lulu prints them to order. I think they have some way of doing it one book at a time. Don't hold me to this. I'm not 100% sure.

[talbany]

Trade secrets aside, knowledge belongs to the people (stealing the quote from a famous movie) and it should be shared to improve everyone involved. Granted, some people learn better from books and I'm sure there would be a market for it, but the last book I bought was my bible about twenty years ago. I'm also a cheap bastard, I won't pay for information if I can get it free but I will share my knowledge with others as I can so it's beneficial to everyone and pays back what I was given by others.

As far as sharing info for free.. We should never expect someone who actually worked and perfected his craft through years of hard work to just be handed to you on the net..Accept and be grateful for those experienced that do share for free and try not to blame/critize them for not sharing all of their years of experience for nothing from you in return..That's just being plain arrogant !!...IMO

Preach Mode....OFF

Tony

[Tubetastic]

Trade secrets aside, knowledge belongs to the people (stealing the quote from a famous movie) and it should be shared to improve everyone involved. Granted, some people learn better from books and I'm sure there would be a market for it, but the last book I bought was my bible about twenty years ago. I'm also a cheap bastard, I won't pay for information if I can get it free but I will share my knowledge with others as I can so it's beneficial to everyone and pays back what I was given by others.

As far as sharing info for free.. We should never expect someone who actually worked and perfected his craft through years of hard work to just be handed to you on the net..Accept and be grateful for those experienced that do share for free and try not to blame/critize them for not sharing all of their years of experience for nothing from you in return..That's just being plain arrogant !!...IMO

Preach Mode....OFF

Tony

This - nobody owns anyone anything. Why some think others should give-up whats theres is beyond me - give me your wages too while your at it...

I had aspirations of working with a well known builder who worked repairs for a company when not building his own. I worked my ass off at college to get the electronic qualifications the company said I didn't have and looked forward to learning from him. I passed the exams and within the first 10 minutes of starting there he told me he wasn't going to teach me anything. I was gutted.

He was in his rights though, he owned me nothing. That left me to get on with it - which I did through trial and error. I despised him for it because I was info hungry but, we got on later-on.



Apart from a Book - I love books, there aren't enough books in the world and once the electric goes down you can't read the web!

I'd also consider/suggest downloadable modules or chapters of a book or possibly special areas of interest, Bruce. Where people can buy pieces of info at their own pace.

What to write. Only you can decide that on what you feel is missing or can add too.

[sepulchre]

I love books too. And it's hard to beat Merlin's. I think he's working on a Power Amp book but said it would take awhile. It's an expensive venture to cover all the bases and he certainly does his research.

I have both editions of his preamp books. They're great to reread, I always get ideas from them; "What if you used that this way?", etc. The Power Supply book is also good, very thorough.

So if you want to write one, Power Amps would be an excellent subject IMHO.

[ToneMerc]

As far as sharing info for free.. We should never expect someone who actually worked and perfected his craft through years of hard work to just be handed to you on the net..Accept and be grateful for those experienced that do share for free and try not to blame/critize them for not sharing all of their years of experience for nothing from you in return..That's just being plain arrogant !!...IMO

Tony

I agree 100%.

I remember this quote from a rather sucessful NHRA engine builder/driver regarding his crew chief leaving, " I taught you everything I showed you, not everything I know"

TM

[gui_tarzan]

[edited]

After reading my previous comment I realize that it could have been taken in a very negative way the way I stated it.

If someone is willing to put the information out there for anyone to access, why not take advantage of it AND CONTRIBUTE BACK to the community when you have something new to share. That's the important part of the equation - giving back. It's not a gimme gimme gimme, it's a give and take, mutual experience.

I didn't say someone like Bruce should give away his decades of experience, I simply said in one form or another, most of it is out there now, freely accessible, if one is willing to look for it. For others it may be very valuable in book form.

I apologize if my previous statement came across as everyone should be a leach, that was not my intent.

[John_P_WI]

Being that it is a culmination of Bruce's work, I think a great title would be "Tone of Life".... hehe, of course a chapter of the same name and content would be cool too...

[Tubetastic]

re guiz: I didn't think that at all - the interweb and words don't always come across as they look.

[teemuk]

What sort of information is difficult to find in other books? What subjects are most useful?

I dunno, especially concerning tube amps there's so much written that NOT finding information usually falls down to nothing but lazyness to research properly. The generic theory in all regards, IMO, has been addressed pretty well in all kind of material: books, articles, websites, forums... Problem might be that people fail to use that information in practice. Like "voicing" amps... no one can surely claim that topics like RC filters, either within gain stages or as separate circuit blocks, haven't been discussed ad nausem. Heck, even a generic analog electronics theory book discusses the topic. But still folks tackle with utilising that theory in practice in "voicing" amps so that they actually sound and work usefully in the application they are designed for.

Anyway, I was going to answer that perhaps you should write stuff you haven't yet seen addressed in other books.


I would love to see some "valve myths" debunked too. Like that trife about harmonics of distortion that has been parroted erroneuosly since early 1970's, the stupid misconception that tubes have a "frequency response", that tubes are synonymous to soft clipping, et cetera. Everyone in the know knows the truth about these myths but still they are rarely addressed. I'm sick of theory books showing difference of solid-state and tube clipping with DRAWN images where tube alweays clips nicely and roundly and the solid-state always hard clips. Everyone who has looked at oscilloscope screen showing various tube gain stages clipping vs. various solid-state distortion circuits clipping knows there's only very slight truth behind such stuff. Usually it's just very misleading. I'm sick of the fact that many people are either balatantly unaware of real-life circuit behaviour or have deeper motives for publishing such information than actually educating and teaching people.

[talbany]

It's actually pretty simple really!
Guitar amps are tone generators!!...Sound is a very subjective thing,everyone hears differently..Everyone plays differently..Everyone has different gear..Every amp circuit is different..Every tube sounds different etc.etc.etc...
Something might sound good to 1 person and not sound so good to another...This makes it virtually impossible to make a statement like this circuit or that part sounds good (or better) than another one..Some guitar players (mostly Jazz guy's) like the sound of solid state..There is just no accounting for it..This is why I said it's virtually impossible to put an accurate term that everyone on the planet can relate to a certain sound, it's impossible.. This is why you have to form your own style and opinion and even then hope others agree..This is why you have to do things empirically to actually hear the differences and form your own opinion as to how to relate that to a particular sound put it into practice so if someone approaches you and describes a sound to you, you have to translate that interpretation and figure out which circuits and components you need to achieve that sound..You have really nowhere to turn but your experience, not someone else's..

the stupid misconception that tubes have a "frequency response"

Tony

Tubes do have a frequency response!.. here is why..
The internal impedance of the tube actually sets the damping factor of the circuit, which, in turn, controls how the amp reacts to the speaker, which has a widely-varying impedance. A tube with a high internal impedance will effectively exhibit more lows and highs, or a more "scooped" midrange, (like a EL-34)because it will react more to the low resonant peak and the rising impedance peak at high frequencies which all speakers have. Power ratings can also effect headroom and determine the onset of clipping This is why different output tubes sound different, and why different output transformer primary impedances can change the tone. There are also other factors..So you need to take this info and hear for yourself the differences the internal plate impedance's and power ratings have in every tube used in a guitar amp and store it in you mind and call upon it when someone says..I want a scooped sound or I like plenty of low end or I want a clean amp etc,etc..

This is just tubes!

Tony

[teemuk]

Tubes do have a frequency response!.. here is why..

So you meant to say that CIRCUITS have a frequency response? ...Because a tube surely will amplify from DC to megahertz's and it's the surrounding circuitry that defines the response.

So, why keep on repeating that tubes have a frequency response when in fact they don't? Yes, I know the underlying principles where the electrical characteristics of the transformer, tube and everything else in the circuit interact and create certain frequency response but this is not the same as tubes themselves having it. BIG DIFFERENCE.

There's not "more mids" in any tube or anything on that manner. There may be differences in characteristic curves, internal impedances and capacitances, which then react with certain ways in the circuit but there's really no way to predict any of that without being familiar with the rest of that circuit too. Saying that tubes have a frequency response is akin to saying a resistor has a frequency response and trying to prove that by saying that different value resistors in a RC filter circuit provide a different response.

This is a great example of those myths and misconceptions concerning tube amps that I see addressed way too rarely and more often shortcutted with "sexy" descriptions of tone you get when switching, say, from EL34 to 6V6. Problem is, when someone states something like that people tend to take it as a gosbel and they never even learn about the true phenomonenons behind certain type of "response" from the circuit. No pun intented. When I read a scientifical theory book, like that concerning electronics, I don't benefit as much from knowing that something will happen when I change x instead of knowing why that something happens. There's thatr important line between painting and painting by numbers, or giving a hungry man a fish vs. teaching him to fish, and so on...

[talbany]

Tubes do have a frequency response!.. here is why..

So you meant to say that CIRCUITS have a frequency response? ...Because a tube surely will amplify from DC to megahertz's and it's the surrounding circuitry that defines the response.

So, why keep on repeating that tubes have a frequency response when in fact they don't? Yes, I know the underlying principles where the electrical characteristics of the transformer, tube and everything else in the circuit interact and create certain frequency response but this is not the same as tubes themselves having it. BIG DIFFERENCE.

There's not "more mids" in any tube or anything on that manner. There may be differences in characteristic curves, internal impedances and capacitances, which then react with certain ways in the circuit but there's really no way to predict any of that without being familiar with the rest of that circuit too. Saying that tubes have a frequency response is akin to saying a resistor has a frequency response and trying to prove that by saying that different value resistors in a RC filter circuit provide a different response.

This is a great example of those myths and misconceptions concerning tube amps that I see addressed way too rarely and more often shortcutted with "sexy" descriptions of tone you get when switching, say, from EL34 to 6V6. Problem is, when someone states something like that people tend to take it as a gosbel and they never even learn about the true phenomonenons behind certain type of "response" from the circuit. No pun intented. When I read a scientifical theory book, like that concerning electronics, I don't benefit as much from knowing that something will happen when I change x instead of knowing why that something happens. There's thatr important line between painting and painting by numbers, or giving a hungry man a fish vs. teaching him to fish, and so on...

So.. In your opinion plate impedance's and power ratings on a given tube doesn't effect the sound of a guitar amp..
You took my statement way out of context..Of coarse there are other things that effect the sound!..Tubes are just a part of the sum of the amp ...Do I really have to tell you that.

Saying that tubes have a frequency response is akin to saying a resistor has a frequency response and trying to prove that by saying that different value resistors in a RC filter circuit provide a different response.

Perhaps you should read up on RC Filter circuits..

I'll revisit my post and also add..
I also see what you are trying to say..Perhaps some of it is a bit extreme. Impedance's Capacitance really mean nothing by themselves it''s not until you apply them in a given circuit or circuits that they react and effect sound(first day of electronics 101).. We can do circuit analysis and tone stack calculations and run curves all day long and even then in a harmonically complex system it can all change,because everything effects everything else all the way to the speaker..There are way too many tolerances involved here to determine the exact frequency response (consistently) of a complex system like a guitar amp,as well as how someone perceives that sound..The load lines, circuit analysis, tone stack calculations, frequency response of a given speaker, all that and more exists just be used as a guideline in designing as well as reliability and performance..The rest is simply your perception (what components sound good to you in that circuit) and how you perceive the sound is where the art form exists!..Some more sensitive can actually hear the differences resistors capacitors,tubes make.. Who am I or anyone else can say otherwise..
BTW..Most good engineers already know all of this and it doesn't really have to be explained in every post they do when referencing the characteristic's of a given component,again taken out of context..Keep this in mind

I would like to hear Bruce's take on some of this discussion!

Tony

[bluefireamps]

What is lacking is information on how to tweak circuits and how they will then sound.

This is a VERY subjective topic and very hard to analyze as well as document and display the data.. Most of this is done through empirical testing and trial and error and years of building all kinds of different type amps.. It's also a big part of the art and interpenetration of amp building and many other things..Much of it takes years to obtain and most are very protective of this info..It's like you can follow your grandmothers recipes but it's never quite the same when she makes it in her kitchen..
IMO..after you do it long enough and find your own unique style of building and tweaking amps you can make anything sound good using any number of different parts and combination of parts,and know exactly how it will sound while your building it..Some things you just cannot get out of the books,experience is the only teacher

As far as general amp theory goes my advice there is SO much great info in the RCA Radio Design Handbook (RDH4) written by the founders of tube amps.. It's The Bible!..read it.... Read it again!

Tony

I agree with all of what you've written but that doesn't mean you can't try to cover that. I did already state that it was empirical and I agree that every designer has his own style just as each guitarist does. Bruce was looking for input. I still feel the areas I mentioned have not been covered well previously, despite the fact they may be more amp or circuit specific. Hey, who wouldn't want to read a book by Dumble or Fischer if that were possible?

Dave