Speaker ohms dropping?

[wolfeman28]

Haha I think if we start drawing out load lines and plate characteristic curves, people will start having aneurisms.

But if you are really interested, the book that finally made me 'understand' power sections and all the math that goes along with them was- 'Vacuum Tube Circuit Design: Guitar Amplifier Power Amps' by Richard Kuehnel.

Tis a great piece of literature to have laying around.

 

[Rogue]

But if you are really interested, the book that finally made me 'understand' power sections and all the math that goes along with them was- 'Vacuum Tube Circuit Design: Guitar Amplifier Power Amps' by Richard Kuehnel.

How much background do you have to have to get the most from this book? I don't have an electronics background, except for a fundamental level and what I'm currently working on, but I do have considerable theory and math background (that I've mostly forgotten ).

 

[wolfeman28]

But if you are really interested, the book that finally made me 'understand' power sections and all the math that goes along with them was- 'Vacuum Tube Circuit Design: Guitar Amplifier Power Amps' by Richard Kuehnel.

How much background do you have to have to get the most from this book? I don't have an electronics background, except for a fundamental level and what I'm currently working on, but I do have considerable theory and math background (that I've mostly forgotten ).

He explains everything, but you do need to have a firm understanding of general tube theory to get the most from it. For instance, he assumes you know what the parts of the tube are, what the tube does, etc.

 

[glpg80]

This is incorrect. This would apply to a solid state power amp only. A lower speaker load on a tube amp is actually better than a higher speaker load. In either case the correct load of course is optimal.

i beg to differ my friend! let me clarify because i think you thought i had it backasswards!

if you have an 8 ohm speaker, and your amp is set on 4 ohms, being a tube amp, you can most CERTAINLY put this into the speaker. its not optimal, but it WILL work without risk to hurting anything.
not the case if it's reversed: if you have a 4 ohm speaker, and the amp is set to 8 ohms, you CANNOT put the amp into this, or you'll most likely damage the amp.

or, if you have a 16 ohm speaker, you'd want to put the amp on 16 ohms for optimal sound, BUT you can run the head on 4 or 8ohms SAFELY.


with 2 16 ohm cabs, (16x16 = 256) then 256/32 = 8 ohm setting on your head.

or, if you're running an 8 ohm cab and 16 ohm cab, (8x16 = 128) 128/24 = 5.333 meaning a 4 ohm setting on your head. it runs safely.

either way, go by what is stamped on the speakers and you should be fine!

yeah yeti is correct, a lower reactance load than what the secondary of the output transformer is selected for will cause permanent damage to the OT due to eddy currents causing heat because of the resistance of the internal wire used to wind the secondary.

the rule of thumb is assuring the amplifier see's a higher load than what is expected, meaning an amplifier set to 4 ohms running into a 16 ohm cabinet will indeed work and work fine. you will not have max power transfer therefore the higher reactance load could or could not cause an OT to heat up depending on build quality and wire diameter/DC/AC current ratings and other properties of the transformer, but it will work indeed without any other problems.

as has been said before, match impedances if you dont understand for safe measure. transformers are expensive to replace

I will keep this brief, because the last thing I want to do is get involved in any potential flame war, and this is my first post, but.......

Gruppe, This is incorrect, and there are many determinates that need to be accounted for, and becomes obvious when you consider both closed load (grounded load), and open load (infinite load) Scenarios when discussing class ab1 push pull valve output stages, and then plotting some theoretical loadlines both extremes of the spectrum, on the curves of the valves you are using,and also taking into consideration both the plate, and screen voltages that are used in guitar amps. (most valve datasheets do not show curves for screen voltages near what are used in typical guitar amps, you will have to use the transfer characteristics listed to redraw them).

A higher reflected primary impedance is potentially more dangerous (ie running a 16ohm load into the 4ohm tap) than a lower load into a higher tap, for the reasons that article James posted states, and will be the scenario to do potential harm to the OT

a lower than desirable reflected a-a load is only dangerous because the odds of the load line passing above the maximum dissipation curve over much of the tubes operation is increased, which will lead to "Red Plating" under signal conditions. Depending on how bad the situation is, This can be remedied by biasing colder, lowering the screen voltage, and also depends on how efficient the power supply is. this stress is mostly hard on the output valves however. The article posted sort of says this.

Now how much in either direction does it take to have these adverse effects?, and how much leeway do we have? the general rule of thumb is that there is quite a bit of leeway, because there is no such thing as an ideal perfect a-a load, theres an ideal one for power transfer, and an ideal one for linearity, (the datasheets often provide one for power transfer) and a mismatch by one step in either direction is generally acceptable, but again this will depend on how close to edge you already are in either scenario as is, and the only way that I know of at least to figure that out is draw loadlines.

Cool place guys!

-Black Cat

load lines of power tubes will help, but it will do nothing if you know nothing about output factor and how to calculate it properly. to say the transformer you are using or its windings and current ratings do not matter in this regard is very ignorant.

the reason we have a good bit of leeway because of a non-ideal load is the same reason i mentioned one way is fine, and the other is not. the purpose of running a correct load is for maximum power transfer. we can get technical and start throwing some math at this if you would like. i have been running my OT under controlled environments on many settings as stated above and not once has it left the temperature of cold to the touch. one of the most important aspects is lowering the screen voltage, but this has more to do with calculating output factor. the bias of the tubes also has to deal with output factor. the primary impedance of the tubes you are using and the primary impedance ratio of the output transformer, once again, has to do with output factor. it is as important here as the voltage amplification of the signal being sent to the grids from the phase inverter.

and welcome to the forum

 

[Black Cat]

load lines of power tubes will help, but it will do nothing if you know nothing about output factor and how to calculate it properly. to say the transformer you are using or its windings and current ratings do not matter in this regard is very ignorant.

Honestly Gruppe I think you are convoluting two separate issues, over thinking it a bit, and I don't quite see the point you are trying to make with this statement above, or how you are relating it to the discussion, at hand which to me is "which direction of Mis-match is safer", but I'll humor it a bit though. Output power cannot be calculated using just an equation. It must be measured. There are too many unknown variables in the form of various losses including but not limited to the OT (both Core losses which includes eddy current loss within the core, and copper losses), The output Valves (loss across them), and loss due to the power supply, - too many hidden unknown factors/or ones that are hard to impossible to calculate for you to be able to use an equation to do so, so it is kind of a moot point. I also have no clue where this accusation of ignorance, and all this business about dismissing transformer ratings came from either to be honest.

the reason we have a good bit of leeway because of a non-ideal load is the same reason i mentioned one way is fine, and the other is not. the purpose of running a correct load is for maximum power transfer.

see thats the thing, This "maximum power transfer is the purpose" is not necessarily true, and is a supposition that really is more grounded in designing for audio reproduction, or text book application, not necessarily a guitar amp, again there is no such thing as an perfect a-a load in practice, especially for a guitar amp, and this is on the broad assumption that the poweramp in question in was designed with the goal of maximum power transfer.

There's also no rule that the a primary load for maximum power transfer needs to be used, and in fact Most guitar amps DONT! , so assuming that using a 16ohm cabinet and selecting the 16ohm tap is going to result in the best power transfer scenario in practice is a bit misguided. This is what James Peters was trying to say above.

It still stands however that when in doubt, a lower reflected primary Z, is always going to be the safer option, over a higher one which can potentially cause the most damage between the two, too high is the scenario where you will encounter flash over, and insulation fatigue/puncture due to extreme flyback voltages. Both scenarios may happen in very extreme cases, which leads to quite a bit of freedom when designing, but however if the core argument is over which is "safer" it is always lower. The article posted gives an excellent review of these reasons, so I need not repeat them. Think about it this way: when you are designing a PP output stage and drawing loadlines around an a-a load you want to use, what are you really doing?, you are assuming a static nominal secondary load. an OT doesn't have an impdedance it only reflects what it sees at the secondary back to the primary. say you have a case where you ideally want to reflect 4.4K to the valves with an 8ohm secondary load which happens to be reactive... well every +-1ohm diferential in the secondary load is going to reflect a +- 550ohm difference in the primary, depending on the speaker, you might expect that 8 ohms to deviate more towards 6 ohms at it's lowest and upwards to 20-30ohms at it's high points! particularly in the very upper registers, and lower registers near it's resonance peak of which will change from speaker to speaker now you see the reason? There is no environment that you have control over unless you are using an ungodly 20 - 30db amount of -FB. most guitar amps use maybe 3 to 10db, and also remove this feedback with resonance and presence controls which so happen to remove feedback in the frequency ranges where the speaker impedance dramatically increases.

-Black Cat

 

[JakeAC5253]

Welcome to the forum Black Cat!

 

[glpg80]

Honestly Gruppe I think you are convoluting two separate issues, over thinking it a bit, and I don't quite see the point you are trying to make with this statement above, or how you are relating it to the discussion, at hand which to me is "which direction of Mis-match is safer", but I'll humor it a bit though. Output power cannot be calculated using just an equation. It must be measured. There are too many unknown variables in the form of various losses including but not limited to the OT (both Core losses which includes eddy current loss within the core, and copper losses), The output Valves (loss across them), and loss due to the power supply, - too many hidden unknown factors/or ones that are hard to impossible to calculate for you to be able to use an equation to do so, so it is kind of a moot point. I also have no clue where this accusation of ignorance, and all this business about dismissing transformer ratings came from either to be honest.

before we go any further, dont reference me as "gruppe" - my screen name is glpg80 - type it out or dont reference it at all

and yes, you can calculate every known factor in an amplifier, there are datasheets for everything. i should mention i do have two engineering degrees and work on embedded MCU programming/PCB board prototyping and circuit troubleshooting as a day job. i am not BS'ing anything in this topic. i suggest you research output factor, not output power. there is a large difference, and you would need to know the output factor in order to calculate the output power. i wrote an article in another forum which shows how to do this should you be interested. to say you cannot calculate the power section of a circuit is entirely pure speculation or lazyness on your part and should not be assumed impossible. there are plenty of writeups that exist all over the internet that explain how and why you should do so to begin with. i would be glad to PM you a few links if you would like. it is recommended you do so when engineering a new circuit design for safety and transformer spec requirements regardless, you cant eyeball a design without applying the math otherwise you are asking for trouble.

there are alot of real-life instances like the resistance of copper and build tolerances, but when you get to this level you are splitting hairs, because the datasheet's for tubes and the load lines you draw are only as good as your ability to see them or your printer. YMMV.

see thats the thing, This "maximum power transfer is the purpose" is not necessarily true, and is a supposition that really is more grounded in designing for audio reproduction, or text book application, not necessarily a guitar amp, again there is no such thing as an perfect a-a load in practice, especially for a guitar amp, and this is on the broad assumption that the poweramp in question in was designed with the goal of maximum power transfer.

so you are saying transformers which are the most perfect component utilized inside a guitar amplifier do not inhibit perfect loading in practice? do you not know that transformers store energy in the form of an electric field and involve the simple movement of electrons and protons? how much more basic can you get? there are no moving parts.

do you even know what anode to anode plate loading and the purpose of the output transformer serves in electrical sense? please explain it to me in detail, because i think you are talking in an area of which you know nothing.

There's also no rule that the a primary load for maximum power transfer needs to be used, and in fact Most guitar amps DONT! , so assuming that using a 16ohm cabinet and selecting the 16ohm tap is going to result in the best power transfer scenario in practice is a bit misguided. This is what James Peters was trying to say above.

a primary load is given based on the tubes used, the number of tubes, the datasheet speculations for required impedance of a pair, the biasing of those tubes for the intended class of operation, and the deviated voltage/current ratings over time for each of of the topics i just mentioned. the transformer can be any value based on the caculation of output factor in regards to the power supply you intend to run the tubes with, their class of bias, etc.

It still stands however that when in doubt, a lower reflected primary Z, is always going to be the safer option, over a higher one which can potentially cause the most damage between the two, too high is the scenario where you will encounter flash over, and insulation fatigue/puncture due to extreme flyback voltages. Both scenarios may happen in very extreme cases, which leads to quite a bit of freedom when designing, but however if the core argument is over which is "safer" it is always lower.

what you speak of here is called output factor - you know of it, but not the term for it! there is a method to calculate the primary impedance the tubes see in regards to the power supply design for the plates in which the anode-anode primary Z should never have more than a maximum potential voltage drop of you B+, and normally a 10% rule at maximum should be instated for previous build tolerance reasons.

Think about it this way: when you are designing a PP output stage and drawing loadlines around an a-a load you want to use, what are you really doing?, you are assuming a static nominal secondary load. an OT doesn't have an impdedance it only reflects what it sees at the secondary back to the primary. say you have a case where you ideally want to reflect 4.4K to the valves with an 8ohm secondary load which happens to be reactive... well every +-1ohm diferential in the secondary load is going to reflect a +- 550ohm difference in the primary, depending on the speaker, you might expect that 8 ohms to deviate more towards 6 ohms at it's lowest and upwards to 20-30ohms at it's high points! particularly in the very upper registers, and lower registers near it's resonance peak of which will change from speaker to speaker now you see the reason?

resistance tolerances are not reflected anywhere. that is not how reactance works. reactance is a vector, just as electromagnetic fields are a vector. you will get current spikes which are stepped up when referencing the secondary as a primary causing a large voltage spike on the plates which is called flyback on a massive scale - the reason you do not assume a secondary plug is grounded when nothing is plugged in to one of them. you also mentioned internal arc-over, another common result of current spikes resulting in over-voltages on the primary and damaging tubes. it is worth mentioning you run AC on a transformer, not DC. this AC current is a phase based vector changing in direction and amplitude which is what is ultimately transferred by electrons flowing in isolated plates of a conductive core - usually iron.

here is an example for you - look at it this way, if the secondary plugs were open by design, not grounded when nothing is plugged in, flyback could kill one of your tubes before you even had time to reach for the off switch - should a load be unplugged while the transformer is in the operating condition and a magnetic field is stored. impedances in general are based on resistance with the vector amplitude direction of AC current reflection, based on the voltage of the primary of the tubes and lastly the impedance load the secondary sees. the secondary does not have to be reactive, and by the book many people hate oscilloscope based biasing using using a resistor of 8 ohms as a secondary load rated to 250W and putting a fan on it. very primative but it does work - the reason it is not taught is due to keeping time and heat to a minimum because resistance decreases log-rhythmically with the increase in heat - the transformer will "meet" the resistor's value along the way until the transformers ultimate death due to a shorting of the secondary if you allow current run away.

you seem to forget energy is stored in the form of a magnetic field which fluctuates in regards to maxwell's laws and vector calculus. neither of us have the ability to run through these calculations, but energy is not 100% transferred through copper wire to copper wire. although transformers are extremely perfect, they WILL meet loads or come close to them based on the winding ratio and the insulation properties of the plates that make up the transformer as well as the heat characteristics. this is why it is said transformers are the worlds most expensive fuse savers.

There is no environment that you have control over unless you are using an ungodly 20 - 30db amount of -FB. most guitar amps use maybe 3 to 10db, and also remove this feedback with resonance and presence controls which so happen to remove feedback in the frequency ranges where the speaker impedance dramatically increases.
-Black Cat

when encasing the output transformer in a negative feedback loop you are 100% correct, i agree with you here and have nothing to add.

let me know if you want those links

 

[srinivassa]

Man, I almost hate to bump this.

16 Ohm speakers always measure about 13 Ohm with a voltage meter. I think 8 Ohm ones measure about 7.2 Ohm.

Have you ever reversed your terminals and measured? I can't remember what the difference is, but they definitely do not measure the same forward and backward.

Either way, what your amp will see is 16 Ohms and 8 Ohms. The meter puts off a signal that is DC, so it doesn't have a frequency component at all. That's what people mean by reactance, it is a resistance measured in Ohms that corresponds to a signal with a certain frequency. Capacitors are famous for this behavior (passing higher freq signals (low reactance) and blocking low freq (high reactance)).

Sorry I did not read everything. I know I am just dumbing it down at the point.

 

[kaseri]

I've bought four EV12L Classic 16ohm speakers this year and they have all measured between 10.5 - 11.5 ohms.

 

[Black Cat]

somebody said I should check up here, and I suppose playing nice was too much to ask so I'm not going to either

and yes, you can calculate every known factor in an amplifier,
there are datasheets for everything.

so you are saying every datasheet is 100% correct as it correlates to the physical component, regardless of how horribly nonlinear they are? to me a datasheet is horribly idealistic and speaking of non linear components you so reference in your text below, you are also saying you have datasheets for transformers that list all of the following in their data sheet?:
inter-winding capacitance
primary resistance
equivalent primary leakage inductance
primary capacitance
secondary leakage inductance
secondary resistance
core loss resistance, which includes lamination thickness
primary inductance
secondary capacitance
frequency response
If you have datasheets for output, and power transformers that acurately list all of these please post a link to where these datasheets live, I would love to see them

i should mention i do have two engineering degrees and work on embedded MCU programming/PCB board prototyping and circuit troubleshooting as a day job.

okay... so? I don't see how either have much to do with thermionics, which hasnt been taught as part of normal curriculum in nearly 30 years, nor do bistable conditions have to do with the discussion at hand. if any of this was truly pertinent it would have been brought up earlier. right now it just comes across as defensive "straw grasping" for credibility

i am not BS'ing anything in this topic. i suggest you research output factor, not output power. there is a large difference, and you would need to know the output factor in order to calculate the output power. i wrote an article in another forum which shows how to do this should you be interested.

please tell me it's this link, where you flat out say you don't fully understand the principals of what you advocate:
http://slocloneforums.com/viewtopic.php?f=4&t=3513
for those who are not members of that bbs let me quote:

I can get you started, but i have alot to learn myself. i dont have enough information to solve this question, but i know enough to point you in the right direction.

the impedance of the OT primary is for the plate load impedances of the tubes used purely for speaker function as well as OT function. the number of tubes that you run and the recommended plate impedances are a product of efficiency - tubes are only about 60% efficient anyway but this value cannot differ too much otherwise you will be stressing both tubes and transformer windings by not having enough current to drive the OT therefore putting the tubes (or transformer) into breakdown - as speakers will not be the first to go.

power output calculations are as follows (what i have in my notes

Po = (( Zo' ) * (gm*Vg)^2)

Zo prime = Zo * (rp/(rp+Zo))^2

in the above equation, it deals with the load factor we have touched base on. google will not yield much about load factors. maybe someone can break this down further and explain it better than i can, but it deals with the 3.4K primary impedance value plate to plate at 4ohms across the OT. that is all i know, and cannot further explain the equation for you.

gm = voltage measured at the output of the phase inverter * .707 to get rms value for the formula, as peak values will yield the wrong answer.

Vg = average transconductance = see datasheets

thats all i know and all i can tell you from my own research and notes. hope this helps some.

to say you cannot calculate the power section of a circuit is entirely pure speculation or lazyness on your part and should not be assumed impossible.

Whether or not you accept it, It's pretty well accepted by virtually every audio engineer the only way to know how much you are truly outputing is to measure it, for the reasons I have stated earlier, the losses are far too great, and devices far too imperfect. which again has nothing to do with the original post.

so you are saying transformers which are the most perfect component utilized inside a guitar amplifier do not inhibit perfect loading in practice?

this one made me chuckle a bit. Transformers, especially the OT is the WORST component in the amplifier, not only are the highly non-linear, but they exhibit a huge number of unwanted parasitic qualities see above, and exhibit the most compromise in design, doesn't sound like a perfect part to me, does it to you?

do you even know what anode to anode plate loading and the purpose of the output transformer serves in electrical sense? please explain it to me in detail, because i think you are talking in an area of which you know nothing.

Do you? It seems to me that you just paraphrase others work, and throw out technical jargon in the hopes of impressing some that don't know any better. This one made me laugh even harder! talk about trying to save face, for such a self proclaimed expert you seem to ask a lot of remedial questions on other DIY based forums I have seen you post in, and yet you are very quick to try and discredit other very knowledgeable people here, which really just comes across as hyper defensive on your part.

Tell me exactly what you want to know. Chances are I, or some others here may have already helped you in other forums.

a primary load is given based on the tubes used, the number of tubes, the datasheet speculations for required impedance of a pair, the biasing of those tubes for the intended class of operation, and the deviated voltage/current ratings over time for each of of the topics i just mentioned. the transformer can be any value based on the caculation of output factor in regards to the power supply you intend to run the tubes with, their class of bias, etc.

again you have made no point, or backed up your claims, you are just reciting something you have read. If you do not fully understand what your are trying to paraphrase you need to cite your sources! I'm quite aware of the term "power factor" and what it is, and you will rarely appropriately ever see it side by side in any text book chapter dealing with vacuum tube output stages, mainly because it is of no great relevance as a term. You will typically more traditionally see it mentioned in linear power supply design. "output factor" seems a bit self derived, (not necessarily by you) please list a credible source.

resistance tolerances are not reflected anywhere.

Who said anything about resistance tolerances LOL! being that it is a reactive speaker load, it is pretty general knowledge that the impedance of said load will rise dramatically with increasing and decreasing frequency, which yes get reflected back to the primary, but it seems you missed that part

you will get current spikes which are stepped up when referencing the secondary as a primary causing a large voltage spike on the plates which is called flyback on a massive scale - the reason you do not assume a secondary plug is grounded when nothing is plugged in to one of them. you also mentioned internal arc-over, another common result of current spikes resulting in over-voltages on the primary and damaging tubes. it is worth mentioning you run AC on a transformer, not DC. this AC current is a phase based vector changing in direction and amplitude which is what is ultimately transferred by electrons flowing in isolated plates of a conductive core - usually iron.

here is an example for you - look at it this way, if the secondary plugs were open by design, not grounded when nothing is plugged in, flyback could kill one of your tubes before you even had time to reach for the off switch - should a load be unplugged while the transformer is in the operating condition and a magnetic field is stored. impedances in general are based on resistance with the vector amplitude direction of AC current reflection, based on the voltage of the primary of the tubes and lastly the impedance load the secondary sees. the secondary does not have to be reactive, and by the book many people hate oscilloscope based biasing using using a resistor of 8 ohms as a secondary load rated to 250W and putting a fan on it. very primative but it does work - the reason it is not taught is due to keeping time and heat to a minimum because resistance decreases log-rhythmically with the increase in heat - the transformer will "meet" the resistor's value along the way until the transformers ultimate death due to a shorting of the secondary if you allow current run away.

you seem to forget energy is stored in the form of a magnetic field which fluctuates in regards to maxwell's laws and vector calculus. neither of us have the ability to run through these calculations, but energy is not 100% transferred through copper wire to copper wire. although transformers are extremely perfect, they WILL meet loads or come close to them based on the winding ratio and the insulation properties of the plates that make up the transformer as well as the heat characteristics. this is why it is said transformers are the worlds most expensive fuse savers.

again very paraphrased. and no I haven't forgotten anything

 

[Anonymous]

https://en.wikipedia.org/wiki/Ohm

 

[glassjaw7]

So James and Dave have this right as far as I can tell. LOVE having all these builders around here!

* Lower impedance will _generally_ stress the power tubes gradually more and more as the volume goes up.

* Higher impedance will _generally_ stress the power tubes less as the volume goes up until the powertubes cut off at high volume levels. This will create voltage spikes on the plates of the power tubes called flyback.

 

[glpg80]

i cant even believe you would think referencing a 1 year old topic is worth anything on this forum, that bbs post is quite out-dated. to say in 1 year i still know nothing about it is pretty gay.

heres a recent post i made in a PM describing the rest of the required math, since you seem to get your jollies off on trying to prove points of which you cannot make.

this deals specifically with an EL84 amplifier and calculating the needed output factor for the output transformer:

for class A we want to bias at 12W - the full expected output of the tube. you cant go any higher = 14W for example, unless under a load line the amount of time the valve stays under the max power is greater than above. so we set the max target to what the datasheet recommends = 12W.

the datasheet says 250V, I = 48mA, we need to solve for P

P=I*V = (.048)*(250V) = 12W

like i said though, we dont have 250, we have 300.

so solve for I => (12W)/(300V) = 40mA

it is recommended that 250V be Pa.

7k primary impedance chosen.

40mA was the maximum current we calculated that we want the grid to be able to swing before clipping based on the plate voltage we are using of 300V DC. with a primary plate impedance of 7k, we need to find the output voltage swing across this impedance.

V = I*R, where R = OT impedance

V = (.040)*(7k) = 280V, which is within the 300V capability of your amplifier.

the 40mA is the peak maximum we want your EL84 to see, not the RMS value which is what the AC guitar signal is existing of that is modulating the current that produces a voltage across the OT primary impedance.

so we need to convert 40mA into RMS. 40mA * (1/√(2)) = 28.3mA

to check our designed power output, which you said you wanted around 6W, we now use this AC modulated wave that will be amplified.

P = I^2 * R, where R is the primary impedance.

(.0283)^2 * 7k ohms = 5.6W

there are the rest of your calculations. put it all together now:

 

[glpg80]

so you are saying every datasheet is 100% correct as it correlates to the physical component, regardless of how horribly nonlinear they are?

datasheets are the analytical representations of an electrical object in a controlled environment for a given time period needed to produce characteristics beneficial to the designer wanting to use that product. and reworded i am basically applying common knowledge that if it has not been tested, said datasheet or analysis results do not exist.

to me a datasheet is horribly idealistic and speaking of non linear components you so reference in your text below, you are also saying you have datasheets for transformers that list all of the following in their data sheet?:
inter-winding capacitance
primary resistance
equivalent primary leakage inductance
primary capacitance
secondary leakage inductance
secondary resistance
core loss resistance, which includes lamination thickness
primary inductance
secondary capacitance
frequency response
If you have datasheets for output, and power transformers that acurately list all of these please post a link to where these datasheets live, I would love to see them

someone would need to begin working around transformers in order to understand frequency response characteristics and how to design around them for 3dB rolloffs above 60hz to remove hum from heaters in the output stages of speakers. to say datasheets are impossible to make is wrong which is exactly the point you are trying to make. as i said before, everything is possible, it all depends on lazyness on your part or someone elses - or it could be a knowledge basis requirement. maxwell's equations with lorentz corrections as well as faraday's work is in PDF form at the royal societies of london. if you want some dry material to answer your questions, then by all means go right ahead.

please tell me it's this link, where you flat out say you don't fully understand the principals of what you advocate:

yes i did post that to help someone else understand power output calculations - and i have not visted or gone to that forum in a very long time. the post mentioned is over a year old. knowledge earned is knowledge gained - see my above post for more information and calculation characteristics of how to apply output factor calculations in which this post is not referenced, but i did mention here on this BBS. as i have said before, i have nothing to hide. i would not claim to know something i didnt

Whether or not you accept it, It's pretty well accepted by virtually every audio engineer the only way to know how much you are truly outputing is to measure it, for the reasons I have stated earlier, the losses are far too great, and devices far too imperfect. which again has nothing to do with the original post.

who said anything about just audio engineering? they dont teach audio engineering in classes, they teach you the basics and take the training wheels off as you go. you calculate and design anything in electronics before building. im sure you understand alpha and beta test stages. without datasheet's or the mathematical expertise to create your own analysis which i have said once before neither of us possess, you are shooting in the blind because of all of the variables that are un-controlled. the closer you can get within calculations, the better off you are in applications and beta stages.

this one made me chuckle a bit. Transformers, especially the OT is the WORST component in the amplifier, not only are the highly non-linear, but they exhibit a huge number of unwanted parasitic qualities see above, and exhibit the most compromise in design, doesn't sound like a perfect part to me, does it to you?

typical design spec's and insulation characteristics have allowed transformers to be designed at and above 100,000+ hours of operation. you tell me a single component today in a circuit that lasts under load with those characteristics and tell me otherwise. the best capacitors are at 30 years. transformers you can build today will outlast either one of us. if thats not damn near perfect, then you tell me what is?

Do you? It seems to me that you just paraphrase others work, and throw out technical jargon in the hopes of impressing some that don't know any better. This one made me laugh even harder! talk about trying to save face, for such a self proclaimed expert you seem to ask a lot of remedial questions on other DIY based forums I have seen you post in, and yet you are very quick to try and discredit other very knowledgeable people here, which really just comes across as hyper defensive on your part.

you post questions to further gain knowledge or to help others in their quest. in the end believe what you would like. DIY forums are exactly that, DIY forums. most of the posts you are referencing off of other BBS's are not recent and are very old. discrediting other very knowledgeable people here? you ask a question, i give an answer. i dont beat around the bush. i have helped hundred's of people on this forum and others - the fact you feel like you can come here and bewilder me with no proof and all drama posts is pretty daunting on your part. if you feel otherwise, then explain yourself. because i know i have done nothing wrong!

Tell me exactly what you want to know. Chances are I, or some others here may have already helped you in other forums.

without knowing your other alias's its hard to pull off the e-cred statuses isnt it? i dont hide behind multiple monikers - the fact i use the same one across all forums means im not doing this for the sake of argument. im doing it because you're talking in an area of passion of which i live and breathe it day in and day out with my life depending on it - quite literally.

again you have made no point, or backed up your claims, you are just reciting something you have read.

i am citing nothing. obviously you peg me as an idiot that is not capable of knowing anything about electronics. this is not a who has the bigger balls contest. if you cant talk about electronics for the sake of electronics then say so. i am always for learning something new, what i am not here for is for the sake of an e-cred statement for you or anyone else. anyone who has received help on this forum knows this just as much as i do.

If you do not fully understand what your are trying to paraphrase you need to cite your sources! I'm quite aware of the term "power factor" and what it is, and you will rarely appropriately ever see it side by side in any text book chapter dealing with vacuum tube output stages, mainly because it is of no great relevance as a term. You will typically more traditionally see it mentioned in linear power supply design. "output factor" seems a bit self derived, (not necessarily by you) please list a credible source.

if you would read the post stated on the slo clone BBS, you will read that a year ago, i specifically stated there is not alot of information in regards to output factor calculations and derivations. the math i originally posted above this post is the rest of the needed information and is what i have calculated based on my own knowledge. there is no text book in modern technology referencing vacuum tubes today - it is all remedial knowledge.

Who said anything about resistance tolerances LOL!

you specifically said resistances are reflected back onto primaries, and this is incorrect. i was simply correcting you and explaining the math as to why

being that it is a reactive speaker load, it is pretty general knowledge that the impedance of said load will rise dramatically with increasing and decreasing frequency, which yes get reflected back to the primary, but it seems you missed that part

the voltage drop across the impedances will rise and fall sharply, the impedance outputs of the tubes that the tubes expect to see in relation to load/hardwired impedance of the transformer will not change its physical properties. they will change in relation to frequency response designed by specifications of the transformers, the tubes being used, and other countless variables. AC modulation of a DC current from a power supply seen across the primary is what is going on here - as tubes are current driven. but im sure you know this.

again very paraphrased. and no I haven't forgotten anything

if you think i need the internet to carry an electronics conversation you are quite wrong

 

[JakeAC5253]

I REALLY doubt if anyone here gives a flying turd if you know what you are talking about glpg80, but you come off as an arrogant and clueless person who likes to hear himself talk. In too many threads have I seen your argument take a full 180 degree flip once somebody makes a counterpoint. Its clear you may have some formal schooling on the topic, I dont know whether you actually have engineering degrees or not, I could really care less. Its also clear that you are a bit pretentious and really dont have a very deep (deeper than formula relstionships) understanding of the material, and are too full of yourself to admit it. You also get too personal in your arguments, its embarassing and childish.

 

[glpg80]

I REALLY doubt if anyone here gives a flying turd if you know what you are talking about glpg80, but you come off as an arrogant and clueless person who likes to hear himself talk.

for someone that thinks they know alot about electronics, you sure are quick to peg someone which you know nothing about. speaking of which i have helped you more than once in PM's. funny how you turn on a dime dude.

In too many threads have I seen your argument take a full 180 degree flip once somebody makes a counterpoint.

arguement? who said anything about arguing? you cant talk about electronics without arguing?

Its clear you may have some formal schooling on the topic, I dont know whether you actually have engineering degrees or not, I could really care less. Its also clear that you are a bit pretentious and really dont have a very deep (deeper than formula relstionships) understanding of the material, and are too full of yourself to admit it. You also get too personal in your arguments, its embarassing and childish.

here is another question, who said you had to have a degree to love electronics? you dont have any room to talk at all as far as relationships of understanding material. you were mentioning blocking distortion in a topic where its merely preamp tube related or part of the solid state design of muting circuitry. as i have said before i am all for learning something new - to say i know everything is idiotic and limiting. you nor i will get far with that attitude especially in any fields. but when i aim to help someone else who asks a question i do my best to provide accurate information with the least amount of jargon as possible - referencing only what i have to in order to answer correctly and fully.

last time i checked we are all here to learn something. it is what a forum is for, and what is supposed to happen to begin with. it seems you have me confused with the wrong e-cred attitude.

 

[JakeAC5253]

I REALLY doubt if anyone here gives a flying turd if you know what you are talking about glpg80, but you come off as an arrogant and clueless person who likes to hear himself talk.

for someone that thinks they know alot about electronics, you sure are quick to peg someone which you know nothing about. speaking of which i have helped you more than once in PM's. funny how you turn on a dime dude.

In too many threads have I seen your argument take a full 180 degree flip once somebody makes a counterpoint.

arguement? who said anything about arguing? you cant talk about electronics without arguing?

Its clear you may have some formal schooling on the topic, I dont know whether you actually have engineering degrees or not, I could really care less. Its also clear that you are a bit pretentious and really dont have a very deep (deeper than formula relstionships) understanding of the material, and are too full of yourself to admit it. You also get too personal in your arguments, its embarassing and childish.

here is another question, who said you had to have a degree to love electronics? you dont have any room to talk at all as far as relationships of understanding material. you were mentioning blocking distortion in a topic where its merely preamp tube related or part of the solid state design of muting circuitry. as i have said before i am all for learning something new - to say i know everything is idiotic and limiting. you nor i will get far with that attitude especially in any fields. but when i aim to help someone else who asks a question i do my best to provide accurate information with the least amount of jargon as possible - referencing only what i have to in order to answer correctly and fully.

last time i checked we are all here to learn something. it is what a forum is for, and what is supposed to happen to begin with. it seems you have me confused with the wrong e-cred attitude here.

Thanks for proving my point. Personal attacks, entitlement issues, and arrogance. When did I ever claim to be an authority on electronics? A conversation is lost to you.

 

[glpg80]

Thanks for proving my point. Personal attacks, entitlement issues, and arrogance. When did I ever claim to be an authority on electronics? A conversation is lost to you.

you cannot help those who do not want to be helped, only help those who cannot help themselves. my mistake for trying.

this is my last word in this topic. not another word is coming out of my mouth on this forum as far as electronics are concerned. the next time someone posts a bias question ill make sure its noted to be only responded by fortin, james, or dave.

 

[srinivassa]

V=IR FTW!

 

[BadgerEE]

There was some great technical information in all this discussion. I have a background in EE, but my "job" is design work for exo-atmospheric kill vehicles, so guitar amp electronics and theory is a different book to me. Good reading I'll try to put to some use.