On Line Tube Learning for newbies....

[rotaspec]

Originally Posted by tympani1d

Now here is a question, teaser, idea for some of those among us here who presently make kits, or sell parts:
How about a beginners course with packaged hands on lab work kits?

Now I have grandchildren full of wonder at that mysterious amber blue glow.... damn they've got good ears!!

It is a good idea, but it would have to be low voltage for safety, or the seller would be risking legal liability in the event of an accident. Most of the kits available now are not aimed at nor attractive to beginners, so they have little to fear, but it's a different story when a 7 year old tries to put together a 250v PSU.

Grandchildren not only have great ears, but great eyes as well. Drop a tiny component on the carpet and you will spend ages looking for it. They will spot it in seconds

Gary

[tympani1d]

Originally Posted by rotaspec

It is a good idea, but it would have to be low voltage for safety, or the seller would be risking legal liability in the event of an accident. Most of the kits available now are not aimed at nor attractive to beginners, so they have little to fear, but it's a different story when a 7 year old tries to put together a 250v PSU.

Grandchildren not only have great ears, but great eyes as well. Drop a tiny component on the carpet and you will spend ages looking for it. They will spot it in seconds

Gary

Well.............heck I still think a learning lab "breadboard" type device would appeal to all ages? I kinda think that we'd never have learnt anything years ago if the fear of getting hurt kept us from playing with old radios and other such junk as kids...
Now of course life needs to guaranteed safe to be be lived

[tympani1d]

Originally Posted by tympani1d

Well.............heck I still think a learning lab "breadboard" type device would appeal to all ages?

Maybe a modular power supply, some breadboard panels and plug in tube socket pcb's. One could develop something from these pcb's:
Classic Valve Design - Original and Legacy Design PCB's


Which is where I got the idea that a really nice tube electronics learning lab would/could be nice to have available.

By the way, does anyone have a copy of "The Laboratory Manual" or "Instructor's Manual" for: "Fundamentals of Semiconductor and Tube Electronics" author: H. Alex Romanowitz 1962? I like to find a copy as mine long ago drifted away.

[lone star]

If any one in the Austin, Texas area is or knows an absolute beginner to the bottle head culture, please pass this on. Lone Star School of Music is offering a Stereo Tube Amp Class. The class is scheduled to begin Saturday Jan 23rd and will for four weeks.
Music Lessons, Guitar, Bass, Drums, Mandolin, Accordian, Piano, Electric, Voice, Vocals, Lone Star School Of Muisc - Stereo Build - 1
Everyone will build a 12 watt S5 Electronics kit.
Feel free to pass this info on to anyone you know in the Austin area. It will be a lot of fun!
Thanks

[Sithlord2007]

Just wondering if someone can give an equivilant in terms of power output of a 40-watt tube amp as compared to a solid state amplifier? If so, how is it generally figured?

For instance, I came across a litle tube amp claiming 7 watts equivilant to 30 watts Solid State.

Thanks!

Ed

[coffeedj]

Originally Posted by Sithlord2007

Just wondering if someone can give an equivilant in terms of power output of a 40-watt tube amp as compared to a solid state amplifier? If so, how is it generally figured?

For instance, I came across a litle tube amp claiming 7 watts equivilant to 30 watts Solid State.
Ed

This is a very grey area, but I generally use a 5 to 1 ratio for SE designs and ~4 to 1 for Push pull designs. SE amps distort in the even harmonics, and thus a minor overload is pleasant. PP have higher odd harmonic distortion and will start to become unpleasant earlier. Transistors have only odd harmonics and will become harsh with any overload.

I have put my 7W SE guitar amp design against a Fender Transistor 50W stack and it whomps it all over the place in attack, volume, and quality. Part of the reason is I use a lot of iron in my design, so there is a lot of stored inductive energy for attacks. Transistors hit a brick wall in overload--tubes fail gracefully after the stored energy is used up. If the tube design has a lot of negative feedback, then it generally will not perform as well in overload and you will need to derate my figures.

[Jen-B]

Originally Posted by Sithlord2007

Just wondering if someone can give an equivilant in terms of power output of a 40-watt tube amp as compared to a solid state amplifier? If so, how is it generally figured?

He, he... if the load is the same then 40W is 40W is 40W, and it's not going to matter whether it's from a tube or a transistor. The equations for power be the same for all technologies!

If it 'sounds different' then look to other aspects, but not the power rating!

Originally Posted by Sithlord2007

For instance, I came across a litle tube amp claiming 7 watts equivilant to 30 watts Solid State.

The marketing men should be thrown in prison!

[coffeedj]

True if you are just measuring steady state load--but the question referred to equivalence in what I assume is real listening use. Of course I do have to admit that more and more mastering compresses performances into a tighter and tighter band. Pretty soon we will have only .1 db of dymanic range in a recording--and then you are absolutely correct--it makes no difference at all.

However, for most performances there is significant dynamic and harmonic difference. In that case you have to consider transients, distortion relationships, harmonics, slew rates, stored energy, and so on. Specs never tell the whole story or else we would never need to listen to an amplifier before buying.

[leadbelly]

Originally Posted by pmillett

Hey everybody -

I have been doing some work on the web site, and have split off the technical books and tube data into a different domain. I did this partly in an effort to manage traffic, so I can split this info onto a different server more easily should I need to.

Pete Millett's DIY Audio pages still has the projects and misc. DIY audio stuff on it.

A new site, tubebooks.org - Vintage info from the age of vacuum tubes (also tubebooks.org - Vintage info from the age of vacuum tubes) now has the tube data and technical books.

There is a link to the new site from the old one. Also, if you go to one of the old pages you should get re-directed to the new one (for example, visiting redirect will bump you to Tube Data).

You may need to refresh your browser to get the updated pages, and re-adjust any bookmarks or links you may have.

Pete

[kach22i]

Help

There are many links in these pages, I have clicked on a dozen of them and did a bunch of Google searches to re-find a favorite article which I failed to bookmark or just can't find. I had always meant to read it more than once so it could sink into my thick skull, but since I cannot find it I'm asking for you help.

This is the closest article to what I am looking for:
Milbert Amplifiers, Most Musical Amplifiers

I'm an architect, not an electrical engineer, so please forgive me if/when I mess up the terminology.

The article I'm looking for describes certain conditions where tubes can provide the "juice" transistors cannot. I think it says something to the affect that power circulating on the tube plates is available and drawn upon to amp up the blips in the signal which last only microseconds. Furthermore, transistors have no such reserve and those tiny flux spikes or blips get lost going back into a maze of supporting capacitors and transformers in a request for more energy.

I've made up some of my own jargon in layman's terms to avoid misuse of terms like signal transients , sorry about that.

I'd rather not use a word than to misuse a word.

Or as a president once said don't misunderestimate me.

Now help me find that silly article, please.

Cheers, George/kach22i