Where's my voltage gain?!

[R.G.]

That's too bad. All hat and no cattle.

[Merlinb]

It's a very generous offer. But, anything I write, has to be submitted to Corporate Legal, and has to go through them.

Translation: There is no paper, no job at the space centre, no EE degree, no nothing.

[raiken]

Translation: There is no paper, no job at the space centre, no EE degree, no nothing.

In other words, an internet armchair engineer?

[R.G.]

It's sad really. The explosion of easy communication, pseudo-anonymity, and free advertising has caused the second explosion of "I'm an amplifier and/or effects genius!" web sites, and my-words-are-pearls statements. I guess it's irresistible if one is trying to sell stuff.

I don't understand the kind of pride that leads people to blather on, knowing they'll get caught out. A simple "Oh. I didn't know that." prevents a lot of public humiliation.

It's a simple application of the First Rule of Holes:

When you find you're standing in a hole, stop digging.

[Enzo]

And that's the hole truth.

[mooreamps]

Translation: There is no paper, no job at the space centre, no EE degree, no nothing.

I don't suppose you'd post this to my corporate e-mail. Can't fake this one, unless you're only intention is phishing me for info :

gary.m.moore@lmco.com


-g

[R.G.]

I don't suppose you'd post this to my corporate e-mail. Can't fake this one, unless you're only intention is phishing me for info

It is sad, really, that someone could think that having an email address is some kind of credentials.

Worse yet, it's silly to offer an email address as backup for a technical statement. Where
you might be from is of no consequence if you can't both say things that are technically sound and support them with good reasoning and references to check the reasoning.

Refusal to address technical questions, lack of any reasoning behind the assertions, and offering of answers to different questions are all signs that the original technical assertions have no basis.

You're standing in an intellectual hole. It would be wise to climb out by supporting your statements or to stop digging.

[mooreamps]

All I did was answer the man's question ; and you people jump me for it. I am real, the job is real, and I don't see see any of you jumping any of the others when they talk about the projects they are working on. You've picked just the wrong guy to start an arguement with. So, I am just an "armchair engineer" ? I'll show my lasted 18 watt project. It is real, and it will be a nice amplifier when completed, and yes it will use fixed bias just like the man who started this thread ; In The First Place !!!


-g

[Alex R]

All I did was answer the man's question ; and you people jump me for it.

No you didn't just answer the man's question, you jumped on Merlin aggressively, out of nowhere, in your first post, like this:

What he fails to mention... ...Also, if you should find any of this published in his books later on, you will now know where it came from.

You were implying that Merlin is the kind of guy who might steal your ideas and put them in a book. Out of nowhere. Looks like you were winding him up to me. Well, is Merlin a plagiarist? Do you have some previous with him? Or were you just looking for a fight in a random kind of way? Can you back up the implication of intellectual dishonesty you slung so casually at Merlin? If not, all of this looks more like a wearisome and pointless wind-up than a serious attempt to get your theory across. I won't say, to test your theory, because at no point have you looked like someone who might be interested in potential flaws in your thinking, but rather like someone who is quite sure no such flaws are possible due to the imagined omnipotence of his intellect.

You've picked just the wrong guy to start an arguement with.

Who started the argument? Seems to me like it was started when you made your implications about Merlin in the post I quoted. And it continued when you chose not to enter into a discussion about your theories when they were criticised. Am I wrong?

[R.G.]

All I did was answer the man's question ; and you people jump me for it.

Jump you for it? What "jump you for it"?

From rereading the thread, Merlin answered a technical question. You disagreed with Merlin's comment and threw in a dig at Merlin, as in:

Also, if you should find any of this published in his books later on, you will now know where it came from.

In addition, the technical part of your disagreement with Merlin's comment did not on the face of it make sense. Merlin asked for clarification and your response was, essentially "parametric amplifiers", which further mystified some technically literate readers. After a couple of plies, this wound up with you stating some things which directly contradict the literature on tube electronics.

It's fine to do that - not everything is known about tubes, even today. But if you're going to toss the accepted science overboard, you are reasonably going to have to defend your assertions with analysis and data. Problem is, you flatly refused to provide any backup for what you said. It got worse from there.

I am real, the job is real,

That's very nice. I'm happy for you.

and I don't see see any of you jumping any of the others when they talk about the projects they are working on.

What projects you're working on?? That's not the issue at all. Remember the link to "non sequitur"? Literally "it does not follow"? The guy was trying to figure out why his gain wasn't as expected. How does that relate to whatever project you're working on?

You've picked just the wrong guy to start an arguement with. So, I am just an "armchair engineer" ? I'll show my lasted 18 watt project. It is real, and it will be a nice amplifier when completed, and yes it will use fixed bias just like the man who started this thread ; In The First Place !!!

That's nice. Good job. Great work.

The issue is not whether you can build an amp. It's whether you have any insight into design. You may, may not. Can't tell from what you post.

Wouldn't it be simpler to post some backup than to keep digg... er, feeling put upon?

[Enzo]

My sister works for Lockheed-Martin, but she's no engineer, as far as I know.

[jimboyogi]

OK. Vox AC10 is Vox AC10.
But what is with raiken amp designing / building schematics.

about EL84
pair EL84 in PP have Raa = 8 kOhms.
one EL84 in SE have RA = 5.3kOhms
http://www.drtube.com/datasheets/el84-philips1969.pdf

Maybe in designing or building some error. Your schematics please.

I thought all of the relevant values and specs are contained within my first post here -

Valve specs are:
u = 40, ra = ~ 5.3K ohms

Circuit specs:
B+ = ~250V, input grid leak = 1M, Ra = 100K, following stage Rg = 1M, bias is a blue LED giving a bias voltage of 2.8V.

and my updated trial values here -

OK, I've tried a few of all of your suggestions, and here is what I found -

Vk = 2.8V(blue LED), Ra = 100k, Rg = 1M, Gain = 24

Vk = 1.9V(red LED), Ra = 100k, Rg = 1M, Gain = 28

Vk = 1.9V(red LED), Ra = 47k, Rg = 1M, Gain = 26

Vk = 1.1V(2*1n4007), Ra = 47k, Rg = 1M, Gain = 26 (with the beginnings of grid current limiting @ 1Vpp input)

So I got the most gain, and the most appropriate input sensitivity with this setup-
Vk = 1.9V(red LED), Ra = 100k, Rg = 1M, Gain = 28


I have only been addressing this first gain stage, no EL84's yet!

BTW - this thread has not turned out quite as I expected!

[Alex R]

Sorry about your thread jimbo! It is an interesting topic.

So Ra down from 100k to 47k gives slightly lower gain. Is that because, despite higher current, there's less voltage to swing around at the plate? Is that an appropriate way of looking at an LED-biased triode stage? (Excuse the no-hard-sums approach, my MA is in Victorian Literature.)

[vintagekiki]

Load resistance for EL84 Class AB two tubes in PP is Raa = 8 kOhm, not 5.3 kOhm. OT with Raa = 5.3 kOhm is probably for 6V6. EL84 and 6V6 has diferent load resistance. Perhaps it is less total amplification for it.
EL84 Data
http://www.drtube.com/datasheets/el84-philips1969.pdf

[Robert M. Martinelli]

I don't understand the kind of pride that leads people to blather on, knowing they'll get caught out. A simple "Oh. I didn't know that." prevents a lot of public humiliation.

That's very true, R.G.!

Time ago I answered a guy who was looking for help, but I did it in a hurry and, worse yet, while I was doing something else at the same time.... A "brain fart" was the immediate and obvious result (wrong calculation) and this resulted in a misleading post. I was "caught up" almost immediately by a "fellow solder fume breather" (Credits:Enzo). Not only I apologized immediately for my mistake, but I was so mad and angry against myself for my stupidity that I was willing to quit the forum and throw myself away in a scrapyard (Enzo "saved" me, or I should better say salvaged ).

When you're wrong, the right things to do are:

1-Understand it (hard for someone) 2-Admit it (even harder for someone) 3-Learn the lesson 4-Feel richer thanks to that experience 5-Get along the best you can.

They call this process "growing up" - unfortunately some people don't grow up, they just grow old (like someone said, growing old is mandatory, growing up is not).

Cheers

Bob

P.S. Edit - I forgot step 1a-Swallow your pride (in this case essential for a good outcome of the above process)