If you are a technician you know what is going on in a circuit without that.
You find that in Japanes schematics. It is to show untrained technicians where to put the scope probe or the signal injector.
You find that in Japanes schematics. It is to show untrained technicians where to put the scope probe or the signal injector.
Guys, I just got my latest issue of Audio Xpress magazine (or whatever it is called now). Inside was an interview of a very well known audio DIYer conducted by another well known audio DIYer.
THIS FORUM was mentioned, and not in a very positive light because of this stuff. The interviewee does not wish to participate in this forum because of a few people with bad attitudes.
A well respected DIYer decides to share a preamp circuit, and 94 posts later people are arguing about what is and what isn't the signal path. No one talks about the preamp. Instead it starts to sound like AA. My Kung Fu is better than your Kung Fu.
Do we really care about the red line? Whether or not the cathode cap is in the signal path, most will agree that it affects the sound. Don't like caps, use LED's (or batteries, or whatever) thats what DIY is all about. I can cook up my own designs from scratch, but most readers of this forum can't. Schematics posted by knowledgable DIYers are often the starting point for others. If you didn't know any better, would you want to start here after all that has been said?
I, for one am looking to build a phono pre that works better than the simple IC based design that I have now (copied right off of the National APP note). I looked at this circuit, and decided that it wasn't for me (I am too cheap to buy good transformers), but I welcome the opportunity to see it. Maybe next time we won't get the opportunity.
There are some posters here who may be "wizards of the simulator" and don't build much. Their ideas are still cool and have sparked my interest to build more than one of those ideas. They present their ideas with out insulting others.
Does this circuit suck? I don't know because I have never heard it. If I was curious (and could afford to) I would build one and find out. I have seen a few designs that I would never thought sound good, but do. Maybe I'm stupid, but I haven't figured out how to look at a circuit yet and know how it sounds. Yes, I can find strengths and weaknesses based engineering principles, but as stated, EVERY design is always a compromize, and every designer sees them differently. If not, there would only be one amplifier design, and it would likely be silicon based.
THIS FORUM was mentioned, and not in a very positive light because of this stuff. The interviewee does not wish to participate in this forum because of a few people with bad attitudes.
A well respected DIYer decides to share a preamp circuit, and 94 posts later people are arguing about what is and what isn't the signal path. No one talks about the preamp. Instead it starts to sound like AA. My Kung Fu is better than your Kung Fu.
Do we really care about the red line? Whether or not the cathode cap is in the signal path, most will agree that it affects the sound. Don't like caps, use LED's (or batteries, or whatever) thats what DIY is all about. I can cook up my own designs from scratch, but most readers of this forum can't. Schematics posted by knowledgable DIYers are often the starting point for others. If you didn't know any better, would you want to start here after all that has been said?
I, for one am looking to build a phono pre that works better than the simple IC based design that I have now (copied right off of the National APP note). I looked at this circuit, and decided that it wasn't for me (I am too cheap to buy good transformers), but I welcome the opportunity to see it. Maybe next time we won't get the opportunity.
There are some posters here who may be "wizards of the simulator" and don't build much. Their ideas are still cool and have sparked my interest to build more than one of those ideas. They present their ideas with out insulting others.
Does this circuit suck? I don't know because I have never heard it. If I was curious (and could afford to) I would build one and find out. I have seen a few designs that I would never thought sound good, but do. Maybe I'm stupid, but I haven't figured out how to look at a circuit yet and know how it sounds. Yes, I can find strengths and weaknesses based engineering principles, but as stated, EVERY design is always a compromize, and every designer sees them differently. If not, there would only be one amplifier design, and it would likely be silicon based.
tubelab.com said:
Well, this is certainly not AA - but thanks for sharing. Nobody picked on Andrea about the DCR of his Kung Fu. Or maybe they did, and I just didn't get it. Or, maybe Andrea didn't want to talk about low DCR Kung Fu because he never tried it and didn't want to be called on it. Or, the DCR of his Kung Fu was low enough, but he didn't understand it was the ONLY reason his rig sounded so good.
This thread got off to a bad start. Andrea is a prolific builder AND documents his work for everyone to see. Cool beans. He knows a lot more than I do, and I am sure he gives much more to this list than he gets in return. More respect is due than was delivered.
But, by my reconin', most that participated in the big "red line" debate should have known better. All zoos have signs "don't feed the animals" for good reason. And, I observe that Andrea did not take the bait...
As for the AudioXpress interviewee, so what. One bad thread here in an ocean of good ones. Does tubelab sacrifice tubes for the respect of random guys on the Internet? Does tubelab sacrifice tubes to impress the ladies? Does tubelab sacrifice tubes in the hopes of a lucrative publishing contract with some dying print journal? Or does tubelab sacrifice tubes because some tubes were born to die in the name of science?
Don't assume that the quiet folks can't tell who is all socket and no tube.
Oops, gotta run! Andrea is putting GM70s in his two stage 845.
Tubelab, just saying hi !
You have the best diy tube site with the craziest amp with good pictures. I enjoyed your website. I bet you have a hell of a sound with these house tube amps. Nothing beats out tube amps with regard to electric guitar sound. Please continue to inspire lot of diy'er.
You have the best diy tube site with the craziest amp with good pictures. I enjoyed your website. I bet you have a hell of a sound with these house tube amps. Nothing beats out tube amps with regard to electric guitar sound. Please continue to inspire lot of diy'er.
tubelab.com said:
Yes unfortunately. The forum appeals to all levels of experience. A new user seeing that a component isn't on 'the signal path' will draw incorrect conclusions about its importance and how the circuit works. It's a view based on voltages, no doubt because they're easier to measure. Had electronics favoured ammeters over voltmeters the 'red line' would be different.
And I suggested fixed bias for the front end tube only because grid leak might be too contentious. 🙂
As usual, rdf, a reasonable response. The roadmap is not the road, ceci n'est pas une pipe, and it's not nice to put incorrect notions in the heads of those who are doing their best to grasp a pretty difficult and arcane technology.
Personally, I think that anyone not willing to subject his ideas to the normal give and take of technical debate (and I think we do a pretty good job of keeping things in that realm) misses a great opportunity. But George, Andrea, Jan, Iain, Ian, Jack, Nelson, Bill W., Sheldon and numerous other well-known and well-regarded published DIYers do step up to the plate and make use of this medium for teaching and communication. And their egos don't seem to be too fragile- they've survived the experience.
Personally, I think that anyone not willing to subject his ideas to the normal give and take of technical debate (and I think we do a pretty good job of keeping things in that realm) misses a great opportunity. But George, Andrea, Jan, Iain, Ian, Jack, Nelson, Bill W., Sheldon and numerous other well-known and well-regarded published DIYers do step up to the plate and make use of this medium for teaching and communication. And their egos don't seem to be too fragile- they've survived the experience.
In short: a signal path is any path through which a signal currents flow, including parasitic capacitances between cathodes and filaments, between wires and a chassis, etc...
Sheldon said:
The original question asked for suggestions on improving the sound. What's the relevance of pursuing formalisms instead? What further makes Thevenin more formal than Norton? These are technical questions, not personal challenges.
I like this guy's idea of a "signal path":
"HERESY No 1. SIGNAL PATH
I read about signal path so many times I am almost ready to believe it. Short signal paths, pure s.p., elegant s.p. silver wire in s.p. you name it. I am sure everybody knows what I am talking about.
The bitter truth is IT IS NOTHING LIKE what people think it is. The so called "signal" does not flow along some PATH. Lets take a pre amp for an example. The signal (current) enters via RCA jack, and the first thing it sees is usually a parallel resistor or some kind of parallel pot. The signal sinks to the ground through this resistor and that's all. Yes. The journey is over. It is like the movie hero who dies in the first scene. Hard to believe?
Having said that - lets agree once and for all - the CURRENT flows, and the VOLTAGE IS. The voltage does not flow.
The Waves PROPAGATE in circuits but they happen everywhere at the same time and involve all circuits.
The minuscule current flowing from your CD source to the ground via this parallel impedance of a mentioned pot produces small voltage resulting from the impedance of the pot (Ohm's law) This voltage is then being "read" by the grid electrode of the tube, or in non-hifi units - the base of transistor, and this signal in turn regulates the series impedance of the active element. The electricity from power supply then copies the original signal in what we call "amplification stage". So this is a copy, not the original. Signal path is a myth. The VOLTAGE - does not flow by definition. The voltage IS. The current flows. But it does not flow from source to the load (receiver). The current flows from power supply to the ground via active elements. In every STAGE of amplification the current flows in VERTICAL manner, not "horizontal". If an amp has 3 stages, there will be 3 cases of current flowing from PSU to ground by the active part. So path is from PS to ground, not from CD to speakers. Once we understand it - it is easier to talk further.
Another thing is timing of signal - it does not go from one place to another. The WHOLE CIRCUIT responds to signals instantly, the whole event HAPPENS. It does not flow. The circuit response is everywhere at the same time, all elements at the same time. No flow. Input receives - output responds. At the same moment."
http://www.lampizator.eu/HERESY/heresy.html
"HERESY No 1. SIGNAL PATH
I read about signal path so many times I am almost ready to believe it. Short signal paths, pure s.p., elegant s.p. silver wire in s.p. you name it. I am sure everybody knows what I am talking about.
The bitter truth is IT IS NOTHING LIKE what people think it is. The so called "signal" does not flow along some PATH. Lets take a pre amp for an example. The signal (current) enters via RCA jack, and the first thing it sees is usually a parallel resistor or some kind of parallel pot. The signal sinks to the ground through this resistor and that's all. Yes. The journey is over. It is like the movie hero who dies in the first scene. Hard to believe?
Having said that - lets agree once and for all - the CURRENT flows, and the VOLTAGE IS. The voltage does not flow.
The Waves PROPAGATE in circuits but they happen everywhere at the same time and involve all circuits.
The minuscule current flowing from your CD source to the ground via this parallel impedance of a mentioned pot produces small voltage resulting from the impedance of the pot (Ohm's law) This voltage is then being "read" by the grid electrode of the tube, or in non-hifi units - the base of transistor, and this signal in turn regulates the series impedance of the active element. The electricity from power supply then copies the original signal in what we call "amplification stage". So this is a copy, not the original. Signal path is a myth. The VOLTAGE - does not flow by definition. The voltage IS. The current flows. But it does not flow from source to the load (receiver). The current flows from power supply to the ground via active elements. In every STAGE of amplification the current flows in VERTICAL manner, not "horizontal". If an amp has 3 stages, there will be 3 cases of current flowing from PSU to ground by the active part. So path is from PS to ground, not from CD to speakers. Once we understand it - it is easier to talk further.
Another thing is timing of signal - it does not go from one place to another. The WHOLE CIRCUIT responds to signals instantly, the whole event HAPPENS. It does not flow. The circuit response is everywhere at the same time, all elements at the same time. No flow. Input receives - output responds. At the same moment."
http://www.lampizator.eu/HERESY/heresy.html
Were this true, it would violate general relativity's speed of light limit -- though maybe we can design quantum amps that utilize spooky action at a distance.
Indeed, in most USA graphs current flow follows the way of the electrons. In the 1970s we were taught current flows from high potential to low. It's only a matter of defenition but it's distracting from time to time 🙂Jaap said:Does "it" flow up or down ?
Maybe if I wire my amp with red wire I shall obtain The perfect amp?!😀
Anyway, after reading - quickly, I must admit - these threads I have a better understanding of bias.😀 😀
Enjoy your design AND the music.
Serge
Anyway, after reading - quickly, I must admit - these threads I have a better understanding of bias.😀 😀
Enjoy your design AND the music.
Serge
@ SY ... headline
Hello SY,
in the headline you asked:
What is the signal path—the red line?
In this forum of course not because most of the users here have a commercial interest.
Those who want to sell some Voodoo components tell you something like:
The signal is manifested in almost every part of the circuit .
Suggests signal path is in every part of the circuit. e.g.
#70
Therefore you have to paint the circuit red, hi hi. This is a technical forum rule and users have to accept it!
I don't like this Voodoo and it looks like this forum is more by-audio than diy-audio , isn't it? 😉 fan club forum
Darius
PS: I know that you want to 'rescue' your friends but this is not a good thing to split and edit a thread the way you did it.
Hello SY,
in the headline you asked:
What is the signal path—the red line?
In this forum of course not because most of the users here have a commercial interest.
Those who want to sell some Voodoo components tell you something like:
The signal is manifested in almost every part of the circuit .
Suggests signal path is in every part of the circuit. e.g.
#70
Therefore you have to paint the circuit red, hi hi. This is a technical forum rule and users have to accept it!
I don't like this Voodoo and it looks like this forum is more by-audio than diy-audio , isn't it? 😉 fan club forum
Darius
PS: I know that you want to 'rescue' your friends but this is not a good thing to split and edit a thread the way you did it.
This is indeed a technical forum, which is why we are all calling your posts into question. Its not voodoo, its current loops. You've still not explained your position why you think that its the "signal path" that matters when there is no technical support for such a thing other than convenience.
I think if you were to explain why you think your "signal path" is what matters in terms of sonics and not the AC current loops then we can have a discussion. All I see is hand waving and then cries and accusations that we are all being sheep. We would be sheep if we just bought into your claims without explaination on why it is so.
I think if you were to explain why you think your "signal path" is what matters in terms of sonics and not the AC current loops then we can have a discussion. All I see is hand waving and then cries and accusations that we are all being sheep. We would be sheep if we just bought into your claims without explaination on why it is so.
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