Amp wiring and layout question.

[Zippy]

There are plenty of PHDs in AIP reviewing this, going through a lot of Q&A. This is American Institute of Physics.

Yes, I know AIP. I published my first paper in physics almost 20 years ago.

This is not the only paper I published, I own two patents under my name.

That's a good start.

Now, what does this have to do with guitar amplifiers?

[Alan0354]

Calculate a 6" run with one inch separation. You will find the capacitance is very low. But a magnetic loop can emit field quite far, like your radio totally get interrupted within 50' of the power line. Those are EM loop couple, not capacitor coupling.

Do you really work in this field? The EM coupling is dependent on current, frequency, angle between conductors, and distance. You're blowing smoke and waving your arms at the same time.

The leads of OT can have current over 100mA at large signal, that's likely be the problem in the other thread that the loop from the plate through OT to the other plate through cathode...ground to the cathode of the original tube.

In the amp, most of the loop are parallel to the chassis, so you don't have to worry about the angle between the two loops.

Also, when you hit 0 grid, current do flow. The gain of an OD amp is very high, you don't need much coupling.




Anyway. Sounds like you consider capacitor coupling. I gave you the formula already, do the calculation, find the capacitance and see how much it couple.

[Alan0354]

There are plenty of PHDs in AIP reviewing this, going through a lot of Q&A. This is American Institute of Physics.

Yes, I know AIP. I published my first paper in physics almost 20 years ago.

This is not the only paper I published, I own two patents under my name.

That's a good start.

Now, what does this have to do with guitar amplifiers?

Nothing, you and Vibratoking are the two that non stop challenge me every step. I did not offend anyone of you as everyone can see. You two are questioning my credential. I am just be happy asking some question, learn something here instead of constant being challenge.

Why can't we just get along, everyone has their opinion and I don't think I ever insist I am right, you bring out the proof and I listen.

[Zippy]

Now, what does this have to do with guitar amplifiers?

Nothing, you and Vibratoking are the two that non stop challenge me every step. I did not offend anyone of you as everyone can see. You two are questioning my credential. I am just be happy asking some question, learn something here instead of constant being challenge.

Why can't we just get along, everyone has their opinion and I don't think I ever insist I am right, you bring out the proof and I listen.

I don't hear you asking questions. It's more like you're blowing smoke and trying to get people to jump on some bandwagon. You're trying to apply scenarios that just not appropriate to guitar amplifiers. It's not high frequency electronics nor high power radio frequency emissions. Certainly, as a functioning electronics professional, you have learned the domains of power and frequency where various effects do or do not apply.

When you start puffing yourself up with credentials, then you lay that open to criticism. If you weren't hiding behind some credential and making it the basis of your arguments, I'd say nothing about it. There are a lot of good people here that get along well without the puffing and preening. Check your ego at the door, and you'll get along a lot better.

Cheers.

[matt h]

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[Alan0354]

Now, what does this have to do with guitar amplifiers?

Nothing, you and Vibratoking are the two that non stop challenge me every step. I did not offend anyone of you as everyone can see. You two are questioning my credential. I am just be happy asking some question, learn something here instead of constant being challenge.

Why can't we just get along, everyone has their opinion and I don't think I ever insist I am right, you bring out the proof and I listen.

I don't hear you asking questions. It's more like you're blowing smoke and trying to get people to jump on some bandwagon. You're trying to apply scenarios that just not appropriate to guitar amplifiers. It's not high frequency electronics nor high power radio frequency emissions. Certainly, as a functioning electronics professional, you have learned the domains of power and frequency where various effects do or do not apply.

When you start puffing yourself up with credentials, then you lay that open to criticism. If you weren't hiding behind some credential and making it the basis of your arguments, I'd say nothing about it. There are a lot of good people here that get along well without the puffing and preening. Check your ego at the door, and you'll get along a lot better.

Cheers.

You say plenty. You keep saying I don't know anything. If I don't say anything, you say I don't know anything, if I say what I did, I am egotistic.

As I said, EM is frequency independent, look at the first chapter in EM regarding to static magnetic loop, the field radiates out at DC. Read small loop antenna, it does not have to be RF or anything close to wave length. It might not be efficient, but it radiate. In a guitar amp, things are on top or each other or few inches apart, it does not take a lot of radiation to couple.

You sure puff a lot of smoke so far and you did not back up with theory other than saying I am puffing smoke. Isn't if about time you back up what you say? We are going nowhere keep saying puffing smoke. I gave you the Wiki link in calculating capacitance between parallel wires. So it's time for you to proof your point.

This is getting old, I tried very hard to make peace.

[Alan0354]

Alan, is English your first language?

No.

[Zippy]

You say plenty. You keep saying I don't know anything. If I don't say anything, you say I don't know anything, if I say what I did, I am egotistic.

Having a credential doesn't make you correct. Parading a credential in the face of being wrong is ill-posed when you've already shown that you are talking outside your field of expertise.

As I said, EM is frequency independent, look at the first chapter in EM regarding to static magnetic loop, the field radiates out at DC.

To induce a voltage in an adjacent conductor, the EM field has to vary. The field from a DC current-carrying conductor does not induce voltage.

I gave you the Wiki link in calculating capacitance between parallel wires.

Where would we be without Wiki?

Equations mean nothing if you don't know how or where to apply them.

I'll see your Wiki and raise you one (that matters).

http://en.wikipedia.org/wiki/Inductance

[Alan0354]

You say plenty. You keep saying I don't know anything. If I don't say anything, you say I don't know anything, if I say what I did, I am egotistic.

Having a credential doesn't make you correct. Parading a credential in the face of being wrong is ill-posed when you've already shown that you are talking outside your field of expertise.

As I said, EM is frequency independent, look at the first chapter in EM regarding to static magnetic loop, the field radiates out at DC.

To induce a voltage in an adjacent conductor, the EM field has to vary. The field from a DC current-carrying conductor does not induce voltage.

I gave you the Wiki link in calculating capacitance between parallel wires.

Where would we be without Wiki?

Equations mean nothing if you don't know how or where to apply them.

I'll see your Wiki and raise you one (that matters).

http://en.wikipedia.org/wiki/Inductance

You audio frequency is AC, it generates EM field. I gave you the example even DC radiate magnetic field.

What is inductance have to do with this? Don't pull out any link, I describe small loop radiation due to currrent in the loop and I did say from calculation, two wire over 1" apart can hardly have enough capacitance to couple. It's time for you to pull something out.


Another obvious point, if it is only capacitor coupling, you can build a shield and tame everything. I did have experience, putting metal barrier does not fix my old amp oscillating. EM field at audio frequency penetrate deep into metal, the chassis likely not able to shield the magnetic field.


Did I offend you somewhere, you are very insistence in getting after me. Is this how this forum works? I can do that. I am new and I am trying to be very polite so far.

[Zippy]

What is inductance have to do with this? Don't pull out any link, I describe small loop radiation due to currrent in the loop and I did say from calculation, two wire over 1" apart can hardly have enough capacitance to couple. It's time for you to pull something out.

I never argued that capacitance was an effect at a distance of 1" between wires. There is, however, a non-zero capacitance between leads and ground plane - and at some places in the circuit, it may matter.

I DID cite that some leads in Dumble preamps use parallel runs. Inductance is at play here because the wires are AC and physically closely coupled.

WTF? (What's the field?)

I'm outta here, Alan. You're arguing in circles and have no sense of what goes on in an amp. I'm nuts for sustaining you.

[matt h]

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[Alan0354]

Alan, thanks for clarifying that English isn't your first language. I asked not because I wanted to belittle you or imply that you were stupid, but I was wondering if there was another explanation. You've stated that you haven't offended anyone and are of the impression that people are "challenging" you for no reason. There are two issues at work here.

The first is one of language-barrier issues: the TONE of your writing is actually very inflammatory and condescending. Without a proper introduction and some awareness of your personal background (I do not mean your academic qualifications) there's no way to judge you but as inflammatory and condescending-- very "troll" like behavior (the internet slang for "troll", not the mythical being of folklore.)

The second issue is the approach you've been taking to posting on this board with content... which is to ask a question about some topic which may or may not actually correspond to the subject you wish to lecture us on and then cite your credentials as a reason we should believe you. This presents, very much, as a twisted and misunderstood application of the Socratic method of teaching. This isn't a classroom, we're not your students, we're not looking for a lecture, and in some cases, we know much more than you do about a topic, or certain aspects of a topic. Stating, after the fact, that you were posting information as a public service lest others encounter problems is not helpful.

Please understand this board is, or can be, a very welcoming place for discussion. However, the way you are going about this, by lingual and cultural bias, is not going to be received warmly and it is not going to be productive for you, the members here, or the lurkers reading in silence.

I Don't even know how I am being condescending. I truly asking a question because I always think the layout and wiring is for a special effect. I read another post and I was actually surprised that people want to avoid crosstalk. That's the reason I post this post all together and truly ask the question why put a board in between.

I just put in my opinion about the loop effect. I did not even mention about this until zippy kept challenge cross thread from the other one. I truly don't mean to come out this way. I wish you actually quote where I do that so I can see it and understand better.

This question is actually very important to me as I am about to build my new amp, if I see a good reason to do it the tradition way, it's going to be very different than what I have it planned because I have to drill the holes for the tubes.


If I offend anyone by my tone, I really don't mean that. That's the last thing I want to do. I have a lot to learn about guitar amps. I thought I am just talking theory, speak my opinion and let people give reason to either agree or disagree.

[Phil_S]

I'm going ask folks to play nicer on this one and give Alan here a little slack. I think the premise of the initial post was not so far out but the dialog devolved from there. I agree with Matt that there seems to be a cultural barrier here. Let's dial it back a little and see if the conversation dies of it's own weight or goes somewhere. If nothing else, help him to understand many of the "rules" simply don't apply to a relatively low frequency, low gain amplifier, so we can ignore a lot of stuff that may be important in the electronics discipline. Basically, this is why an amateur like me can build a perfectly good guitar amp of no particular pedigree and barely understand something like corner frequency.

[matt h]

(deleted)

[Alan0354]

Ok

Anyway, so I can drill the preamp tube holes closer without planning the board in between?