I try to be "charming" at Tinder, and with members of the opposite sex.
Here I try to be technically correct.
Often ignore tons of inaccurate or plain ignorant comments, I´m not Tech Police by any means, just another Forum Member and in principle ignore noob errors as done in good faith, nobody is born knowing, and within possibilities try to help.
Dissing/ignoring importance of transformer Inductance is gross.
Would have said nothing if a Noob said so, and as I mentioned above, would try to explain him instead.
When the wrong statement issuer is *supposed* to know Transformer theory very well, and is beyond explanations, what can I do?
At most, mention it, which I did.
OCD? ..... maybe ....... sometimes I guess OCD is a *requisite* to be a DIY Forum Member.
Any specialty, not only Audio/Electronics.
Not giving names, this is not personal, at all, and sadly seen many times all over the Forum. 🙁
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I have to agree with JMFahey. There is no problem with ignorance, noob or otherwise. None of us are omniscient.
The problem arises when someone makes statements with a tone of authority and self-assuredness, and the statements are incorrect. That is counterproductive to the learning and sharing process here.
The problem arises when someone makes statements with a tone of authority and self-assuredness, and the statements are incorrect. That is counterproductive to the learning and sharing process here.
Some Info On Load Testing
Hope this helps to understand the simple method I referred to for load line testing. The test resister is simply in parallel with an unloaded OPT. The resulting current and/or the voltage in the sample resister can be measure to obtain the information required. No load resister should be attached to the secondary.
From the test data in this simulation the audio power dissipated in the 3K resister is ~1.54 Watts. Power in the 4K resister is ~1.28 Watts. And rp of the 2A3 calcs out to 723R.🙂
Driving the stage to clipping will give the max audio power available.
For a PP pentode stage driven to clipping there will be a maximum. The audio power will decrease on both sides of that load condition.
Hope this helps to understand the simple method I referred to for load line testing. The test resister is simply in parallel with an unloaded OPT. The resulting current and/or the voltage in the sample resister can be measure to obtain the information required. No load resister should be attached to the secondary.
From the test data in this simulation the audio power dissipated in the 3K resister is ~1.54 Watts. Power in the 4K resister is ~1.28 Watts. And rp of the 2A3 calcs out to 723R.🙂
Driving the stage to clipping will give the max audio power available.
For a PP pentode stage driven to clipping there will be a maximum. The audio power will decrease on both sides of that load condition.
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Yes! No, no, no! Try to stay on the road, folks.
The TUBE factory needs to specify the TUBE, without transformer flaws and losses. Assume a transformer can lever "any" final load impedance. THE way to test the TUBE is a large choke (to pass DC) shunted by a variable resistor. Measured mid-band so choke parasitics are "small".
Say the optimum load for the tube is about 5k. And the application load is nominal 8 Ohms. Then over-wind the choke for a 25:1 turns ratio.
The context of my statement was that you don't want to put said resistor into an amplifier, not a test jig.
If you're designing a guitar amp, this could be a way to generate extra THD at lower levels. That could have some merit.
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A guitar amp final has the same problems & limitations as a HIFI amp. The design approach required for success is essentially the same.🙂
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A guitar amp final has the same problems & limitations as a HIFI amp. The design approach required for success is essentially the same.🙂
My information is every "how to design your amp" tutorial I have saw so far. Maybe I didn't read the proper ones. I feel quite confident about my understanding of the resistive loaded tube, but I struggle to understand the dynamics of the inductive ones. I feel I miss some theoretical tools to be able to grasp it. I am gonna try to just write down the equation and try to understand for myself the importance of those parameters.
In post # 11 you wrote "I can´t believe some of the comments I read here, by supposedly knowledgeable Members.. So in the context of this thread, and you using 'some of the comments' (plural), it must mean that according to you at least two of the forum members in the 10 posts before yours, are "supposedly knowledgeable members".
You only quoted nigelwright7557 (btw: How is that for not giving names and not being personal). So at least one more.
When I look at the comments in post # 1 till # 10, I don't see that or those other comment(s) that deserve(s) to be ridiculed by you.
rock guitar amps tend to be none feedback to get some coloration.
hi fi usually has feedback to improve fidelity.
hi fi usually has feedback to improve fidelity.
Do you want "crunch" from your Hifi amp? Would you like to get that clipped THD at lower power levels in your Hifi amp?
How about bandwidth that is mostly non existent below about 60Hz?
If I understand properly, the primary is more or less equivalent to a resistor and an inductance in series. Both form high pass filter that need to be tuned very low in order to have low frequencies ? (the output is at the poles of the inductance) ?
I didn't quite got those leakage inductance thing. Transformer seems to be way more complex that I naively though. Do you have some good ressources online about transformer and tube amps ?
I didn't quite got those leakage inductance thing. Transformer seems to be way more complex that I naively though. Do you have some good ressources online about transformer and tube amps ?
All Too True!! But looking thru my copy of Aspen Pittman's 'The Tube Amp Book, 4th Edition' as I have many times I see little difference in a cross section of instrument amp final section from a common HIFI amp. With two exceptions, the OPT is physically smaller & doesn't have the LF response of the OPT in a HIFI amp. Hammond & others have filled that need with a whole line of suitable product.🙂 The other is application of Tremolo, a simple added mod.
The instrument amp front end is different to fill the needs of the sources used & any FX the user would like.
I worked on my Grandson's Peavey JSX in 2012. The build & performance are top notch. Results attached.
In 1965 I built a PP 6L6GC amp for a friend to use with his guitar. And another circa 1956, PP 25L6s for use as a practice amp. The front ends were not HIFI but the rest of those amps was.🙂 Hammond had no replacement OPTs in those days & I didn't go looking. What was available worked OK.🙂
The instrument amp front end is different to fill the needs of the sources used & any FX the user would like.
I worked on my Grandson's Peavey JSX in 2012. The build & performance are top notch. Results attached.
In 1965 I built a PP 6L6GC amp for a friend to use with his guitar. And another circa 1956, PP 25L6s for use as a practice amp. The front ends were not HIFI but the rest of those amps was.🙂 Hammond had no replacement OPTs in those days & I didn't go looking. What was available worked OK.🙂
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