Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: tubeswell on December 16, 2012, 05:58:15 pm
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http://www.valvewizard.co.uk/Book1.html (http://www.valvewizard.co.uk/Book1.html)
Hiya Merlin - is there a coupon code for Lulu?
TIA
Pete
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6% off - QUICKSIX
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I must wait few days hoping it will appear also at my online book seller shop (as the previous)
Many thanks for the news :thumbsup:
K
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:BangHead: :cussing: :BangHead: :cussing: :sad: :embarrassed: :cry:
I JUST BOUGHT THE FIRST EDITION 3 WEEKS AGO!! :sad2:
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Don't worry also the first edition is a very good book
EDIT: From a post at Ampgarage
There is some description of what's new here:
http://valvewizard.co.uk/Book1.html (http://valvewizard.co.uk/Book1.html)
You will also find the contents, chapter 1 and chapter 15, which you can read for free. I suggest you look them over for an idea of how it differs from the first edition.
There is a lot of new material, including some complete preamp designs in chapter 14. There is much more emphasis on practical design in this edition; a lot of the dull math and esoteric circuits have been stripped out, leaving only the the most popular/interesting stuff. This allowed me to fit in new stuff without adding to the page count/cost. There is a lot more discussion of blocking and how to avoid it, and how to minimise noise in high gain designs. Plus there's stuff on signal switching using relays, SSRs and FETs, which is bound to interest some folks!
Hope this helps,
Merlin
So you can see that the first book is still useful, also you would like to have the second edition (like me)
K
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:BangHead: :cussing: :BangHead: :cussing: :sad: :embarrassed: :cry:
I JUST BOUGHT THE FIRST EDITION 3 WEEKS AGO!! :sad2:
I like the first edition *because* it's got a lot of math in it which forced me to learn some new stuff. Imma get the 2nd edition too though!!
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> it's got a lot of math in it
Math? Or just arithmetic?
If you really dig math, you may like Kuehnel. The Fender Bassman 5F6-A (http://www.ampbooks.com/home/books/bassman/) takes no shortcuts or approximations, sets up the matrix and crunches it with Cramer's Rule.
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I gotta be honest...it's probably the math that kept me away from this hobby for so long.
I do not enjoy doing things "the wrong way",,,and always felt that if I didn't understand ALL of the math involved, then I would be just faking it and basically building fancy toasters that I wouldn't be able to repair....
I think I understand now, that there is room here for guys who don't understand all of the math, but can interpret a schematic and build something that makes them want to learn more of "the right way".......I'm sure I'll never "get" ALL of the math (unless I get struck by lightning),,,,,but his book definitely reminds me that a lot of the answers to the tube universe ARE mostly mathematical........I will buy the 2nd edition
PRR, thanks for beng here to share your knowledge,,,,and prompt me to Google things like "Cramer's rule" :icon_biggrin: :notworthy:
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I think I understand now, that there is room here for guys who don't understand all of the math, but can interpret a schematic and build something that makes them want to learn more of "the right way".......I'm sure I'll never "get" ALL of the math (unless I get struck by lightning),,,,,but his book definitely reminds me that a lot of the answers to the tube universe ARE mostly mathematical........I will buy the 2nd edition
PRR, thanks for beng here to share your knowledge,,,,and prompt me to Google things like "Cramer's rule" :icon_biggrin: :notworthy:
SG, im with ya, couldn't have said it better myself.
I just downloaded the pre amp and power amp books on I books for 12.00 each. Not sure what version they are most likely 1st.
For me it is a good starting place because as far as theroy goes i am a green horn. Like SG I can build a known good design from a layout and schematic I just have no practical electrical experience. Hoping that Santa brings me the TUT books on my list (suggested by several members) also because now that working out of town is over 2013 is going to be continuing education in amp building for me.
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I'm thinking of getting Merlin's second edition of the preamp book when it gets on Amazon in a few weeks. I emailed him and asked a few questions about it and he's been very helpful with me in replying and giving advice. Sounds an all round good guy.
For me i just do't know if the book might be a bit beyond my abilities just now. I'm fairly new at amp repair and i can do a few things; i've replaced filter caps, coupling caps, done all my biasing etc. you know, the basics. But the maths kinda scares me off as i know nothing about it. I'm prepared to study hard though and learn it if it can help in this further down the line. For amp repair and maintenance do you need the math though? I thought the maths and the equations were more for someone who is designing their own amp from scratch and need to work out stage gain and all that stuff.
So i don't know if i'd be wasting my time getting the book if i know nothing about maths?
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For amp repair and maintenance do you need the math though?
Yes, you still need some depending on what your doing.
For me i just don't know if the book might be a bit beyond my abilities just now. I'm prepared to study hard though and learn it if it can help in this further down the line.
So i don't know if i'd be wasting my time getting the book if i know nothing about maths?
IIRC, PRR once said here "read everything you can, just don't believe all of it." Got to start somewhere. You might not get it yet but will someday.
I still say TUT1 (Kevin O'Connor) is a great book to start with for tube amps, theory, (some) math, diagrams. TUT3 also is very good, focus on builds and layouts.
Brad :icon_biggrin:
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IIRC, PRR once said here "read everything you can, just don't believe all of it." Got to start somewhere. You might not get it yet but will someday.
I still say TUT1 (Kevin O'Connor) is a great book to start with for tube amps, theory, (some) math, diagrams. TUT3 also is very good, focus on builds and layouts.
Yeah that's more or less the way i feel about it as well; try to absorb as much info as possible. I'll definitely get the book in the coming few weeks when i see it released on Amazon again.
The Kevin O'Connor books look very interesting as well.
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If you really dig math
Only math I really like is making change! It was sort of neat using the equations to figure the frequency rolloff and stuff (which took me a looonnggg time to get) but in the end, a couple decade boxes hooked up work easier and are more fun.
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> felt that if I didn't understand ALL of the math
W.W.J.D?
This usually means the guy we are celebrating a birthday for next week. I would not presume to know what He would do. Anyway he didn't preach about amps.
No, I mean What Would Joseph Do? Joe the carpenter, dad to Christ.
We do not know a lot about Joe. He may have built temples or carved door-latches or pig-troughs.
We do know he did not have detailed Building Codes, span-tables, graded lumber. Math was right out: Roman numerals are way too awkward to multiply, He may have known other numbers, but he had no adding machine or calculator and his notepad was a stick in the dust. So no heavy computations.
BUT carpenters from before Joe to the present day do a LOT of their work by rule-of-thumb.
You want to put up a second floor or a roof. If you lay logs side by side, it may be strong, but that's a LOT of log. (And the mideast has been logged-out a very long time.)
A few large logs one way, then short logs or board crossways, is more economic. But how big?
The length of a beam (joist, rafter) can be about 15 times the vertical depth.
Today: my garage spans 12 feet, 144 inches. 144/15= 9.6 inches. Indeed we used "2x10"s which today are a shade over 9.0 inches. (We can run a bit shy because we buy graded lumber; Joe would be splitting trees and using knotty parts.)
The width of a beam, in residential work, about 1/10th of the spacing between beams. Today: 1.5 inch joists on 16 inch centers.
In heavy work (grain storage) you'd keep the depth about the same but double or triple the width. 9 or 10 inch deep by 3" or 4.5" wide joists on 16" centers.
A deeper joist is stronger and much stiffer BUT imagine a joist 18 inches deep and a half-inch wide. It wants to flop sideways. When you load it, it crumples. Showing that taking a good thing too far is bad. Basic carpenter thinking. (And not immediately obvious to a math-head.)
You can't walk on just beams, you need a solid floor. This is equivalent to "beams" as wide as the space between them. When beams are "over-wide" they can run about 20 or 30 times the depth. I have 0.5" flakeboard spanning 16", 32:1. If I used tree-wide boards (instead of 4x8 sheets) I'd use 3/4" boards, 21:1.
A short column's area can be 1/300 of the floor it supports. However NO stick in a frame can be more than 50 times its thin side, it will buckle under light load. (We propped a 100 inch rise with a 2x4, it buckled when Dana went upstairs.) If it has a heavy load, 1/20 is necessary. (Joe would use a 5x5; we have steel 16X stronger than wood so a 3" tube is ample despite 33:1 slenderness.)
And EVERYthing is approximate. If math-head calculates a 9.6"x 1.2" beam, buy a 2x12 (10.2"x1.5"). If you need at least a 2x3, but have lots of 2x6, use 2x6. A 26'x20' roof needs more than 520 square feet of cover (even if it were flat; mine is steep and took 22 4x8 sheets).
So... WWJD if he did tubes?
When you have a significant plate resistor, the cathode bias resistor is *about* Mu times less. 12AX7 with 100K in the plate, try a 1K cathode resistor. 12AU7 with 47K in plate, try 2.2K.
0.01uFd into 1Meg is 17Hz. From this you can estimate any RC filter just by pushing the decimal point around and then 2X or 5X shifts for 0.22 and 0.47 standard-values.
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Hi PRR
This sounds like the difference between a very very good Artisan and an Artist
An artist don't care about exact measures and do things only following his intuition
what results is a Work of Art
K
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Thanks AGAIN PRR....I can't say enough about how great it is to find a resource like this forum, with guys like you here to help guys like me figure this stuff out......somedays I just sit and read, and other days I find the courage to open my mouth and expose the inner idiot....
I can own all of the books on the topic, but none of them are as convenient as being able to pose a question and have it answered by people with true experience....I feel like the caveman who has been shown fire, and now all I have to do is figure out how to make it work for me.
Here's a link I found recently for some free older reading material,,,,I'm sure it's not new here, but it is new to me:
http://www.tubebooks.org/technical_books_online.htm#Vacuum (http://www.tubebooks.org/technical_books_online.htm#Vacuum) Tube theory & circuit design
The gentleman who scanned these books for US deseves a medal of the highest honor.......
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Ordered.
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Merlin just posted this on AX84: use 20DEC to get 30% discount, today only.
Just ordered mine.
Jaz
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Merlin just posted this on AX84: use 20DEC to get 30% discount, today only.
Just ordered mine.
Jaz
Dang! just in time for it to be the 21st Dec on this side of The international Date Line!
(Edit: And the world hasn't ended yet BTW)
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Merlin just posted this on AX84: use 20DEC to get 30% discount, today only.
Just ordered mine.
Jaz
Same here :icon_biggrin: I was gonna wait until it was up on Amazon but i logged onto valve wizard today and saw the deal so ordered.
Anyone that's thinking of getting it and you're still on the 20 DEC wherever you are; get in quick and enter 20DEC in the coupon code thingy for 30% off!
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Dang! just in time for it to be the 21st Dec on this side of The international Date Line!
I don't think that matters. It only matters what time it is in Western America, so you should have another 12 hours before the code expires.
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Dang! just in time for it to be the 21st Dec on this side of The international Date Line!
I don't think that matters. It only matters what time it is in Western America, so you should have another 12 hours before the code expires.
I'd already ordered it from Lulu and got 6% off with their code thingy.
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PRR,
Rules of thumbs, The problems with thumbs is they get smashed by heavy hammers. What would Joe do? If I know my Joe's the guy would likely know a few applications in Greek, While not a math genius, he would know a squared plus b squared equals c squared. My belief is the guy geometry would match most current High Schoolers.
From a quick perusal of Greek numerals, multiplying, adding and subtracting is a lot simpler than using Numerals.
I would like to para-quote an old professor from the University of New Mexico. If it is engineered it would look flimsy.
Some engineering is done so the product has a limited life. (Most common item is airplanes)
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Ordered mine as well.
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Ordered :icon_biggrin:
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If I know my Joe's the guy would likely know a few applications in Greek, While not a math genius, he would know a squared plus b squared equals c squared.
Maybe.
My grandfather was a brick mason. While he could undoubtedly do a math calculation, he wouldn't do A2+B2=C2. What's the point?
He'd use 3-4-5 to make a right angle. He had a different rule for laying out a hexagon in brick, another for octagons, other for more elaborate shapes. Maybe the architect used the formulas...
The guys who actually DO stuff don't calculate; they use the results found by mathematicians who DO calculate to develop shortcuts that give the desired result.
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Came from a family of blue collar workers, including masons, carpenters, and an occasional electrician, It was these guys that supported my endeavors into engineering. Got my push to do well in Algebra, from a gentleman who didn't get into 9th grade, but knew algebraic concepts. I can make claims to being a third generation miner, if not a fourth or fifth generation miner.
I agree you can only design so far using theory, then it is time to put up or shut up. When it comes to valve amps, the theory is tried and true, we are not on the vanguard of amplifier design, so to me it makes sense to be able to use the old charts, wind an occasional nichrome resistor.
As I follow the forum, I see the envelope being pushed.
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Get 30% off at Lulu today, enter 25DEC at checkout. :mail1:
Merry Christmas!
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Just found out they are giving 40% off today the 26th with coupon code 26DEC (case sensitive). I am phasing out of the amp building hobby but could not pass up at that price.
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My book shipped yesterday (28th). :icon_biggrin:
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It arrived in the mail last Saturday, awesome as usual !