Home » Audio » Thermionic Emissions » Can Someone suggest a good book on S.E.T.'s.
Can Someone suggest a good book on S.E.T.'s. [message #11299] Wed, 01 March 2006 20:45 Go to next message
Peter Swartz is currently offline  Peter Swartz
Messages: 56
Registered: May 2009
Baron
I want to learn better how my amp works to better understand why I'm having a hum problem, etc...I've got a pair Consonance M500's and want to do some upgrades and would like to gain more technical info on the detailed working of my S.E.T. Or maybe a good web
site that has the info. Hell,I'm probably going to post this message and then realize that the AudioRoundTable has a link to the resources I'm looking for, Let's see, here goes

Re: Can Someone suggest a good book on S.E.T.'s. [message #11300 is a reply to message #11299] Thu, 02 March 2006 06:23 Go to previous messageGo to next message
Damir is currently offline  Damir
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Registered: May 2009
Illuminati (2nd Degree)
I don`t have any book "specialized" only for SET amplifiers, but there`re many old electronics/tube books, now on-line with valuable informations. See for example, "Pete MIllett`s Tube DIY Audio pages" (www.pmillett.com) with many "classical" books, for example, "RDH3", "Basic Theory and application of electron tubes", etc.
In "new books department", reccomendable are "Valve Amplifiers - 3rd Edition" and "Building Valve Amplifiers", both from Morgan Jones.

Re: Can Someone suggest a good book on S.E.T.'s. [message #11302 is a reply to message #11300] Thu, 02 March 2006 13:44 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
If I may suggest you download Damirs tutorials on his SET 300b amp. They should offer a good starting point for understanding how these circuits are designed and what they do. It helped me.
You can find them in the Group Build section on this site.

and then... [message #11306 is a reply to message #11302] Mon, 13 March 2006 17:58 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
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Registered: May 2009
Illuminati (2nd Degree)
pick the first thing you don't understand, and ask a question. When you get it answered, move on to the next...

Don't worry, we won't get tired...and it'll teach us something while we're at it.
cheers,
Douglas


Re: and then... [message #11307 is a reply to message #11306] Thu, 16 March 2006 06:51 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
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Registered: May 2009
Illuminati (13th Degree)
The hardest thing in teaching something as complex as electronics to newbies through a forum like this is to find the fundamental connections between what they understand and what they are looking to find out.
Example; OPT primary winding resistance. You look at catalogues of transformers and mostly you se a few standard values; 5k/3.5k/8k/10k/ and rarely 12or 14k. Once in a while 7.5k. Now if those are the standard values and each one is somehow most applicable to one set of RP values then a begginner says hey whats the fuss, you already know what value you need as soon as you pick your tube for the output.
Then loadlines; all that seems to have been done for you by many charts and experiments; just follow the yellow brick road and voila'.
But I know it's not that simple when you are struggling to come up with a better set of values to co-respond with a goal you have regarding a rarely used tube or a different and not so common circuit.

Re: and then... [message #11308 is a reply to message #11307] Thu, 16 March 2006 12:55 Go to previous messageGo to next message
Damir is currently offline  Damir
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Well, the operating point you choose (Uak/Ia/Ugk) for a given tube determined your primary load impedance. (The term "primary winding resistance" is better used for the "static" DC resistance of the wire).
But, practice teach us that it`s only the beginning, a reccomendation.
Yes, we have the "standard" SE impedances, mostly - for 300B it is about 2k5, 3k, 3k5, 5k, or so. In principle, with higher values (with the same OP) we`d have a little larger damping factor, lower distortion, but lower power.
But, the main difference, IMO, is the quality of concrete device, and not (for example) 3k/3k5 difference. It is complex subject, really - there are books written about OPTs and tube/OPT interactions.
The best, (IMO, again) what "average DIY-er" can do is to buy quality OPT with various taps and trying for yourself various connections / OPs. (For example, "Lundahl" LL1620 or 1623.)


Re: and then... [message #11309 is a reply to message #11308] Thu, 16 March 2006 13:46 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
Exactly my point. As in all things to do with physics and electromagnetic behaviour there are reams and libraries full of work done on those fundemental laws. But as an audio experimentor all we really need to know are; hey...can this output tube work with this primary winding?

How do I set the load resistor?

Fixed or Floating bias?

How to get the three basic voltages to my output tube from the power supply?

How to find Cap vs Inductor input filter values?

What is global feedback and how is that done in the amplifier?

When to best use these various scheme's for maximum sound quality and whether to look at doing things like running tubes hotter for more power or cooler for less distortion. Why use a 6l6 or an el 34 instead of a KT 88 in a particular circuit?

Many times I see articles written about things like say this, "What To Do With Those Old Transformers and How To Use Them In Circuits If You Don't Have The Right Transformer For The Job." Thanks But let me learn the right thing to do first before offering me choices I will never make. It just confuses things while simple explanations of why a transformer is chosen to do a particular job is really the most helpfull type of information.
Statements like this:
I choose the 5k primary transformer because with a 300B output tube I get this amount of power;..This amount of distortion,.. and this output impedance.
How do I know this? Here's how;...
Like what Damir is doing with his description of the maths involved; the changes he makes and the effect those changes have on the sound.

And Douglas does when he describes the different iterations of the circuit and how those iterations can be adjusted to get another value that co-responds with a different set of results.

These are the things I think about as a novice. And also the proper way to run signal and ground wireing to and from the circuits to the connectors. As well as proper safety practice.

One of the most illuminating moments for me so far is the simple recognition that you actually could wire up a simple SE schematic by running the wiring exactly as it looks on the schematic. It may not be the best option and you may get some hum but it can be done.

Re: and then... [message #11310 is a reply to message #11309] Thu, 16 March 2006 15:15 Go to previous messageGo to next message
Damir is currently offline  Damir
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Well, it seems to me that this hobby is half electronics, half "musical instrument" building... ../emoticons/smiley.gif
Re: and then... [message #11311 is a reply to message #11310] Thu, 16 March 2006 16:43 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
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Registered: May 2009
Illuminati (13th Degree)
I'd say thats a fair assesment. You guys that take the time to tutor people and explain the how and why of what you do are a huge help. It's; at least to me; the real positive effect of these forums and I for one appreciate it.

that's about it... [message #11323 is a reply to message #11310] Mon, 29 May 2006 07:24 Go to previous messageGo to previous message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
as there are more parallels to that conclusion than one could draw to say, a laboratory equipment. While it may not seem so, both schools of thought are useful.

There is a general sort of things to do to every cicruit, good grounding scheme for instance that can be carried from project to project. The details of what constitutes a good grounding scheme are easier to quantify as a whole...the amp is quiet. Just like any other part of the circuit design, there are a lot of ways to get there.
cheers,
Douglas


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