No problem at all: Take your time-machine and leap back about twenty years. They were quite common back then. Hundreds of thousands of those must have been produced (and been thrown away in the meantime).
😉
Sorry for being sarcastic but sometimes I can't resist! Maybe you will find these from suppliers that are specialised in HAM radio stuff.
Regards
Charles
While the idea to have a switch is a good one, I don't see any reason to implement the switch on a PCB (there is no space for it anyway). But anybody can use a switch (and place it where it's convenient) and connect it to the board lifting the leads of resistor or the cap. One can also install Zobel at the binding posts and mount the switch in there, to simplify connections.Jamh said:
If you want to to have short connections and Zobel part still on the PCB, why not use a small relay somwhere close to the board and do switching in this way?
I would still like to hear why there is no Zobel in Aleph amps?
Whether 'tis zobler in the mind to suffer
RC or not RC that is the question........
"BTW, I didn't notice Zobel in any of Aleph amps, why is it?"
Because it is a common source output stage and not a follower. The open loop output impedance is that of the load impedance. John Curl described the effect of capacitive cable loads on common source or common emitter amps on the forum somewhere. Also don't forget that a lot of the Passlabs stuff (for those who actually include the high frequency compensation that Mr. Pass designed in the circuit, when rollin their own) have pretty conservative amounts of negative feedback and bandwidth. Some of the X amps that do have source followers don't even have negative feedback around the output stage. You can compare apples, oranges and sour grapes if you want to, but it is not going to help your case or teach you about Zoble networks. Maybe you should look at the schematics of the hundreds of amps that do use them. I thought one the virtues of the chip amp was that you didn't to know anything (or much, anyway) about amplifier design. So much for that theory...........
Are you asking because you really want to know, or this an attempt maintain you persona as a high end audio guru? I sure hope it is the former........ Just where exactly are you going with all this? I am not the only one who is curious. 😕
"... and Mr. D is building gainclones"
I don't think so (no clock board either!)....... in fact I may stop even reading about them if this is a typical thread. I may just leave it to the the GC Il Duce to insure that the gains run on time. I guess when there is so little to something you have to create enough controversy to compensate for falling interest.
RC or not RC that is the question........
"BTW, I didn't notice Zobel in any of Aleph amps, why is it?"
Because it is a common source output stage and not a follower. The open loop output impedance is that of the load impedance. John Curl described the effect of capacitive cable loads on common source or common emitter amps on the forum somewhere. Also don't forget that a lot of the Passlabs stuff (for those who actually include the high frequency compensation that Mr. Pass designed in the circuit, when rollin their own) have pretty conservative amounts of negative feedback and bandwidth. Some of the X amps that do have source followers don't even have negative feedback around the output stage. You can compare apples, oranges and sour grapes if you want to, but it is not going to help your case or teach you about Zoble networks. Maybe you should look at the schematics of the hundreds of amps that do use them. I thought one the virtues of the chip amp was that you didn't to know anything (or much, anyway) about amplifier design. So much for that theory...........
Are you asking because you really want to know, or this an attempt maintain you persona as a high end audio guru? I sure hope it is the former........
Just where exactly are you going with all this? I am not the only one who is curious. 😕"... and Mr. D is building gainclones"
I don't think so (no clock board either!)....... in fact I may stop even reading about them if this is a typical thread. I may just leave it to the the GC Il Duce to insure that the gains run on time. I guess when there is so little to something you have to create enough controversy to compensate for falling interest.
Does this mean that the TDA7294, as it's written in the datasheet that there's no need for a zobel, is using a common source output?
Perhaps I'm missing the point, but isn't the question related to the nature of the speaker as much as the amp? Unless the chip amp includes the equivalent (whatever that may be) to a zobel circuit and is expected to be used with the ordinary variety of speakers, it would seem to me a zobel is as useful there as with a discrete amp.
Re: Whether 'tis zobler in the mind to suffer
I'm asking because I'm not an amp designer and I would really like to know. What is wrong with that?
People should be able to ask any questions on this forum, without being subject to questionable comments, like yours above.
I wasn't aware that my persona worries you so much. I promise I'll try to improve.
Fred Dieckmann said:
Are you asking because you really want to know, or this an attempt maintain you persona as a high end audio guru? I sure hope it is the former........
I'm asking because I'm not an amp designer and I would really like to know. What is wrong with that?
People should be able to ask any questions on this forum, without being subject to questionable comments, like yours above.
I wasn't aware that my persona worries you so much. I promise I'll try to improve.
Indeed, that is the case. It's a combination of factors but your are safe if you always have the filter but you may not if you omit it.sam9 said:
Shouldn't input coupling caps be added to the layout since we are on the safety is the way to go thread? Personally I would just leave out the zobel network.. but then I'm not a big fan of safety.. it's boring!
Naz
Naz
There are also fuse for the primary, fuse for the secondary. Should they be considered on the PCB as well. The warning and suggestion of the Zobel with chip amps are very welcome and let us the newbies aware and might start look into or research about Zobel network functionalities..but I didn't like the way it was shoved and pushed into the group project design which it would not even be considered to build one by the persons who suggested the change for the lowly so call chip amp.
Remember projects by the fanatics, for the fanatics...
Regards,
Chris
Remember projects by the fanatics, for the fanatics...
Regards,
Chris
Gather around folks... We have a winner!
ABSOLUTEMENT !!!
Gather around folks... We have a winner!
You guys can argue subjective cr@p till the cows come home, but EE's put rovers on Mars! You try doing that next time you feel your pride swelling up.
No DYI can claim ANY form of success without riding on the backs of other's HARD WORK.
When you can take sand and make your own semis, then I suggest that before you let your ego pass gas, you need to try making your own sand!
"But I have never (fill in the blank).... !!!"
(F-a-m-o-u-s l-a-s-t w-o-r-d-s.)
ABSOLUTEMENT !!!
Gather around folks... We have a winner!
You guys can argue subjective cr@p till the cows come home, but EE's put rovers on Mars! You try doing that next time you feel your pride swelling up.
No DYI can claim ANY form of success without riding on the backs of other's HARD WORK.
When you can take sand and make your own semis, then I suggest that before you let your ego pass gas, you need to try making your own sand!
"But I have never (fill in the blank).... !!!"
(F-a-m-o-u-s l-a-s-t w-o-r-d-s.)
This thread is an embarrassment.
Rather than quibble and get all defensive about things not well understood, WHY not simply ask Fred D to EXPLAIN what a zobel network is, how it works, and THEN learn the boundaries and parameters to know HOW to tweak the sumbytch.
If you hate Fred so much, Go to Rod Elliott's site and look around in his archives.
My hat really goes off to Fred D who endures far more abuse than he dishes out... who is WILLING to offer his EXPERTISE to a bunch of knuckleheaded parts changing wannabe's.
You may not like his presentation, but Thou Shalt Not Kill the Messenger.
The man is brilliant, and he's passionate.
He stresses his points dogmatically only because the hardheads won't listen. He's trying to help you dingbats, so think twice before you run him off.
"There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves." -- Will Rogers
I must also tip my hat to BrianGT who is demonstrating an open mind and is working hard to IMPROVE his product, by LEARNING and applying that newly gained knowledge, rather than spew more BS than a used car salesman to protect some macho pseudo image of expertise. We must always remember that actors are immitators. Salesmen are salesmen, but engineers make the product that you're buying. Do you buy a car because of what the salesman tells you? Or do you buy because of what you get under the hood?
Lastly... in the late 70's, when I worked for Altec Lansing in Anaheim Calif, I built a Heil 400 watt Class A amp for myself. It served me very well for many years, and I THOUGHT it was well built.
Then, according to the fire inspector, (see where I'm going with this?) the amp started to oscillate (aged caps?)... and then guess what? IT BURNED DOWN MY HOUSE on June 24 of 1984.
The insurance company was rather pist when they could not find the UL label. I wonder why?
Rather than quibble and get all defensive about things not well understood, WHY not simply ask Fred D to EXPLAIN what a zobel network is, how it works, and THEN learn the boundaries and parameters to know HOW to tweak the sumbytch.
If you hate Fred so much, Go to Rod Elliott's site and look around in his archives.
My hat really goes off to Fred D who endures far more abuse than he dishes out... who is WILLING to offer his EXPERTISE to a bunch of knuckleheaded parts changing wannabe's.
You may not like his presentation, but Thou Shalt Not Kill the Messenger.
The man is brilliant, and he's passionate.
He stresses his points dogmatically only because the hardheads won't listen. He's trying to help you dingbats, so think twice before you run him off.
"There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves." -- Will Rogers
I must also tip my hat to BrianGT who is demonstrating an open mind and is working hard to IMPROVE his product, by LEARNING and applying that newly gained knowledge, rather than spew more BS than a used car salesman to protect some macho pseudo image of expertise. We must always remember that actors are immitators. Salesmen are salesmen, but engineers make the product that you're buying. Do you buy a car because of what the salesman tells you? Or do you buy because of what you get under the hood?
Lastly... in the late 70's, when I worked for Altec Lansing in Anaheim Calif, I built a Heil 400 watt Class A amp for myself. It served me very well for many years, and I THOUGHT it was well built.
Then, according to the fire inspector, (see where I'm going with this?) the amp started to oscillate (aged caps?)... and then guess what? IT BURNED DOWN MY HOUSE on June 24 of 1984.
The insurance company was rather pist when they could not find the UL label. I wonder why?
Sorry to hear about the house.
Aged cap caused the equipment to burn, but Zobel need cap for it to work, how can we prevent the cap become aged, or can Zobel still effective with aged cap ? What I do not want is to have my house get burnt so to make sure no aged cap... to disable the Zobel... to prevent the amp from oscillation.. to start over heating.. to start a fire..
Where can I buy the UL sticker for all my diy thingies so that the insurance company will feel better if needed?
Thanks in advance,
Chris
Aged cap caused the equipment to burn, but Zobel need cap for it to work, how can we prevent the cap become aged, or can Zobel still effective with aged cap ? What I do not want is to have my house get burnt so to make sure no aged cap... to disable the Zobel... to prevent the amp from oscillation.. to start over heating.. to start a fire..
Where can I buy the UL sticker for all my diy thingies so that the insurance company will feel better if needed?
Thanks in advance,
Chris
Re: This thread is an embarrassment.
Amen! I admire Fred's persistence - I ducked out of this conversation ages ago, having been ungraciously and unthinkingly dismissed for suggesting some trivially easy layout improvements. I've never been treated like that ever - least of all in a public forum. And I didn't even suggest Zobels and input caps 😉
Still, I'm over that now, and bigger things have happened since then. I still like Peter
I agree totally - I emailed him last week to express similar sentiments...
For what it's worth (probably not much), I believe that in audio engineering, you do need a degree of intuition and an open, inquiring mind. But, you really need a good grounding in the basics - this is absolutely essential in my opinion. I speak from experience because I started out with plenty of the former, but things only started to really make sense when I forced myself to learn electronics theory in my mid-late teens. Learning the theory is also essential ground work if you want to design your own circuits rather than "cloning" published work.
Not every EE is closed-minded about audio - just look at NP and JC. Certainly on this site I've learned lots from these people, but I've also learnt from non-EE members like Peter D. But this shouldn't mean I can't teach Peter D in return. None of us know it all 😉
So, when people try to talk about technical issues, it normally means that they're trying to help others learn - that's certainly the case when I post. The least someone can do to repay this effort is to try and listen, rather than getting all defensive because of deep routed insecurities about basic fundamental electronics. The people on this site form a fantastic resource, and we really should be encouraging each other rather than bickering about no-brainer decisions.
I'm also sorry to hear about the fire. Personally, I'm quite big on safety - I'm sure most of us are. Kind of puts me off class A power 😉
Cheers,
Mark
head_spaz said:
Amen! I admire Fred's persistence - I ducked out of this conversation ages ago, having been ungraciously and unthinkingly dismissed for suggesting some trivially easy layout improvements. I've never been treated like that ever - least of all in a public forum. And I didn't even suggest Zobels and input caps 😉
Still, I'm over that now, and bigger things have happened since then. I still like Peter
head_spaz said:
I agree totally - I emailed him last week to express similar sentiments...
For what it's worth (probably not much), I believe that in audio engineering, you do need a degree of intuition and an open, inquiring mind. But, you really need a good grounding in the basics - this is absolutely essential in my opinion. I speak from experience because I started out with plenty of the former, but things only started to really make sense when I forced myself to learn electronics theory in my mid-late teens. Learning the theory is also essential ground work if you want to design your own circuits rather than "cloning" published work.
Not every EE is closed-minded about audio - just look at NP and JC. Certainly on this site I've learned lots from these people, but I've also learnt from non-EE members like Peter D. But this shouldn't mean I can't teach Peter D in return. None of us know it all 😉
So, when people try to talk about technical issues, it normally means that they're trying to help others learn - that's certainly the case when I post. The least someone can do to repay this effort is to try and listen, rather than getting all defensive because of deep routed insecurities about basic fundamental electronics. The people on this site form a fantastic resource, and we really should be encouraging each other rather than bickering about no-brainer decisions.
I'm also sorry to hear about the fire. Personally, I'm quite big on safety - I'm sure most of us are. Kind of puts me off class A power 😉
Cheers,
Mark
three-hundred-sixty-five-degrees...
... i hope those Rovers don't burn Mars down!!!
(do they have UL labels?)
((what would be the Mars equivalent of the UL?))
... i hope those Rovers don't burn Mars down!!!
(do they have UL labels?)
((what would be the Mars equivalent of the UL?))
Does any body know the reason why Zobel (C and R) is not inside the IC in the first place? Or may be because there is no need to have the Zobel if the IC is not used as an audio amprefier?
It has to be a reason why the Zobel is not part of the IC I think.
Regards,
Chris
PS: So Class AB equipment are safe and it will not set the house on fire?
It has to be a reason why the Zobel is not part of the IC I think.
Regards,
Chris
PS: So Class AB equipment are safe and it will not set the house on fire?
chris ma said:
Because you can't fabricate components of the required value (capacitor) and power rating (resistor*) on an IC die...
Cheers,
Mark 😉
* OK, you might be able to do the resistor, but I bet it would add significantly to the cost of the chip, certainly compared to the price of an external resistor. It would also require another pin (for connection to the capacitor and ground - ideally, the ground of a Zobel goes back to the power star ground point)
I still maintain that Zobel is not required in this circuit.
Ask anybody who built an amp using Brian's board if any problems were ecountered, because Zobel was not there.
I don't know why some of you still make an issue about it. Is it because it's a good opportunity to get at the "parts swappers"? After all, nobody mentioned it when I posted schematics of my version of the amp first, or when Brian posted layout of his first board, months ago.
For some reason it only came up when Fred mentioned that subject. He may be brilliant, or he may be persistant, but I'm talking from my personal experience of having amps in variety of different systems and never, ever, I experienced a problem.
IIRC, Fred also claimed (and was very persistant) that Aleph X posted by Grey will not work and would oscillate. Yet number of amps have been built and no problems experienced either. So how good is his experise?
Ask anybody who built an amp using Brian's board if any problems were ecountered, because Zobel was not there.
I don't know why some of you still make an issue about it. Is it because it's a good opportunity to get at the "parts swappers"? After all, nobody mentioned it when I posted schematics of my version of the amp first, or when Brian posted layout of his first board, months ago.
For some reason it only came up when Fred mentioned that subject. He may be brilliant, or he may be persistant, but I'm talking from my personal experience of having amps in variety of different systems and never, ever, I experienced a problem.
IIRC, Fred also claimed (and was very persistant) that Aleph X posted by Grey will not work and would oscillate. Yet number of amps have been built and no problems experienced either. So how good is his experise?
- Status
- Not open for further replies.