Output impedance
Hi all Guys!
Just to know if someone measured the output impedance of the AlephX as Grey posted originally.
In my simulation it's pretty high, but I don't know if it's real or not...
I know that you can say me: "Hey, build it and measure it by your own from real" but I'm still on the way to build an AlephX so...
TIA
Fabrizio
Hi all Guys!
Just to know if someone measured the output impedance of the AlephX as Grey posted originally.
In my simulation it's pretty high, but I don't know if it's real or not...
I know that you can say me: "Hey, build it and measure it by your own from real" but I'm still on the way to build an AlephX so...
TIA
Fabrizio
A suggestion...
With the Aleph-X boards about to be let loose onto
the world, many of us will be wondering about
voltages, bias, heat dissipation and whatnot.
Perhaps those lucky enough to have built the Aleph-X
can consider putting brief entries in the Aleph-X wiki describing
their setup (voltage rails, bias level/resistor values, etc).
As more and more people complete their projects, we
will have a repository of designs people can reference.
Cheers,
Dennis
With the Aleph-X boards about to be let loose onto
the world, many of us will be wondering about
voltages, bias, heat dissipation and whatnot.
Perhaps those lucky enough to have built the Aleph-X
can consider putting brief entries in the Aleph-X wiki describing
their setup (voltage rails, bias level/resistor values, etc).
As more and more people complete their projects, we
will have a repository of designs people can reference.
Cheers,
Dennis
Carpenter,
you have clearly been "assimilated", or, to put it another way, you simply need someone to hold your hand and comfort you in the time of need, whether it's Grey or Fred or whoever. You did jump ship quickly! Good for you!
Since you stated you can 'grow' very quicly under Fred 'brand of genius' I will be looking forward for you posting the working circuit Grey was going to freely and generously distribute.
Dennis, should you ever need it, you are welcome to email me with all the questions you have on the AX. You got my number.
I think I can pretty much guide you to successful completion.
Let me clearly state that my knowledge is entirely anecdotal and based on experience with this circuit. I know where everything should be and how to get there.
If you want the expert EE opinon write to Fred or one of his protege'.
you have clearly been "assimilated", or, to put it another way, you simply need someone to hold your hand and comfort you in the time of need, whether it's Grey or Fred or whoever. You did jump ship quickly! Good for you!
Since you stated you can 'grow' very quicly under Fred 'brand of genius' I will be looking forward for you posting the working circuit Grey was going to freely and generously distribute.
Dennis, should you ever need it, you are welcome to email me with all the questions you have on the AX. You got my number.
I think I can pretty much guide you to successful completion.
Let me clearly state that my knowledge is entirely anecdotal and based on experience with this circuit. I know where everything should be and how to get there.
If you want the expert EE opinon write to Fred or one of his protege'.
sorry for your disappointment, grataku.....
But, we need all the "brains" we can get on this forum.
I only recently began receiving emails from Fred. He's no monster, though I once perceived him as such.
I'm not interested in taking "sides". If Grey wants to hang with us and mentor us, I'm thrilled. If Grey wants to move on, that's his business. I will miss him.
John
But, we need all the "brains" we can get on this forum.
I only recently began receiving emails from Fred. He's no monster, though I once perceived him as such.
I'm not interested in taking "sides". If Grey wants to hang with us and mentor us, I'm thrilled. If Grey wants to move on, that's his business. I will miss him.
John
Re: Re: Output impedance
Hi Nelson!
I got 0,75 ohm with 2 couples of out devices
Obviuosly if I add devices the impedance goes down to almost 0,25 with 6 couples of devices.
It seems strange to te, as I measured the out impedance of another Amp I built (but with bjt) and with 3 couples of devices the impedance was almost not measurable.
I don't know if this is a problem with the simulation with mosfets instead of BJT, that's why I asked the forum.
Bye! Fabrizio
Nelson Pass said:
Hi Nelson!
I got 0,75 ohm with 2 couples of out devices
Obviuosly if I add devices the impedance goes down to almost 0,25 with 6 couples of devices.
It seems strange to te, as I measured the out impedance of another Amp I built (but with bjt) and with 3 couples of devices the impedance was almost not measurable.
I don't know if this is a problem with the simulation with mosfets instead of BJT, that's why I asked the forum.
Bye! Fabrizio
Theres a Jamming strategy at work in this Thread.
What are you lot going to do about it??
Knock Knock,
I'm not sure wait's gone on here, I tried to get on very early this morning but could not, obviously people were busy with the white out. I've been waiting the hear from Grey about an earlier post.
Down Under here we have had very bad bush fires and young men going off to war, I must have missed something sorry.........
Ah yes had a peek at Texas, lots of black holes in there.
In terms of big picture I've pulléd a few pranks on and off... just jocking here and there... but to find all this a little as you folks say is rather WEIRD.
The Timing is bad, Mr Pass has just awarded a prize for the X Aleph Lottery and we've got all this rubbish.
I mean Hello, is anyone home..THE LIGHTS ARE ON but..........
From a leadership perspective, the issue for the forum is a strategic one at this point, what drives it forward from hear on? Better get out your paddles out fast, not much unless someone excluding Mr Pass jumps in the saddle.
Grey, for all his strengths and weaknesses is clearly gifted, as an innovator, a mentor, a leader and a man with a Passion for Passdiy.
He is thankless giver of enjoyment, knowledge and wisdom. He was simply gifted....with a touch of genius for your forum.
Technical skills are one thing, but its the behavourial side that make a person the winner in my experience as illustrated by the recent threads below which are a sober reminder at this time.
When your that good, you've got choices, I'm sure he'll be back.
Ian
The stranger had ridden just past the last building on the street and the desert opened before him like a vista of infinite possibilities. Behind him, he could hear other voices joining the argument about.
Just to clarify some things, Fred has been posting under a number of names recently (and these are just the ones I can remember off the top of my head):
loren girsley
NE Thagard (this one shows an unusual...
JH,
A valid strategy. If you use two current sources, you will gain a little more control over the two sides of the differential, but at the expense of having to use balanced inputs, since the two sides...
Set the plate 6 dB crossover for as low as it will go and add a 12 or 18 dB lowpass filter at whatever frequency you choose. You'll be fine.
Grey
Higher resistor values to bias...hmmm, without seeing a schematic, I'm going to guess that you're talking about a simple grounded Source FET with a comparatively large (I dunno, what, 2.2-10k?) resistor...
All right, I've got a spare moment, let's tilt at windmills and break this thing down into functional units. Hell, I should have done this eons ago.
Taking it from the front end:
What are you lot going to do about it??
Knock Knock,
I'm not sure wait's gone on here, I tried to get on very early this morning but could not, obviously people were busy with the white out. I've been waiting the hear from Grey about an earlier post.
Down Under here we have had very bad bush fires and young men going off to war, I must have missed something sorry.........
Ah yes had a peek at Texas, lots of black holes in there.
In terms of big picture I've pulléd a few pranks on and off... just jocking here and there... but to find all this a little as you folks say is rather WEIRD.
The Timing is bad, Mr Pass has just awarded a prize for the X Aleph Lottery and we've got all this rubbish.
I mean Hello, is anyone home..THE LIGHTS ARE ON but..........
From a leadership perspective, the issue for the forum is a strategic one at this point, what drives it forward from hear on? Better get out your paddles out fast, not much unless someone excluding Mr Pass jumps in the saddle.
Grey, for all his strengths and weaknesses is clearly gifted, as an innovator, a mentor, a leader and a man with a Passion for Passdiy.
He is thankless giver of enjoyment, knowledge and wisdom. He was simply gifted....with a touch of genius for your forum.
Technical skills are one thing, but its the behavourial side that make a person the winner in my experience as illustrated by the recent threads below which are a sober reminder at this time.
When your that good, you've got choices, I'm sure he'll be back.
Ian
The stranger had ridden just past the last building on the street and the desert opened before him like a vista of infinite possibilities. Behind him, he could hear other voices joining the argument about.
Just to clarify some things, Fred has been posting under a number of names recently (and these are just the ones I can remember off the top of my head):
loren girsley
NE Thagard (this one shows an unusual...
JH,
A valid strategy. If you use two current sources, you will gain a little more control over the two sides of the differential, but at the expense of having to use balanced inputs, since the two sides...
Set the plate 6 dB crossover for as low as it will go and add a 12 or 18 dB lowpass filter at whatever frequency you choose. You'll be fine.
Grey
Higher resistor values to bias...hmmm, without seeing a schematic, I'm going to guess that you're talking about a simple grounded Source FET with a comparatively large (I dunno, what, 2.2-10k?) resistor...
All right, I've got a spare moment, let's tilt at windmills and break this thing down into functional units. Hell, I should have done this eons ago.
Taking it from the front end:
"Grey, for all his strengths and weaknesses is clearly gifted, as an innovator, a mentor, a leader and a man with a Passion for Passdiy.
He is thankless giver of enjoyment, knowledge and wisdom. He was simply gifted....with a touch of genius for your forum."
Nice obituary Macka.
By the way, you really got to update your list of Fred's aliases.
He is thankless giver of enjoyment, knowledge and wisdom. He was simply gifted....with a touch of genius for your forum."
Nice obituary Macka.
By the way, you really got to update your list of Fred's aliases.
grataku said:
Hey guys, both Grey & Fred are watching. I am sure they will both be back. Fred when his SinBin is done (he is trying real hard to behave) and Grey when he feels like it. Complaining that they are not here will only keep them away longer (i am privy to information you do not have).
dave
(in official capacity)
I recall the output impediance of the amp can in fact be measured electronically. It sort of like seeing if the amp is a perfect voltage source.
I did this with my 1st class a amp the JLH , the damping factor for 8 ohms was 30, I then used this to calculate T/L tuning of the speakers, then I found the Aleph...the rest is history.
My memory is a bit scratchy, but I think you measure the ac output with a sine wave accurately, then add the load and re measure and take note of the incrumental voltage drop across the load.
From here with simple formula you can calculate the Xdcr of the amp, like the voltage drop across a normal resister.
You may need to take a reasonable sample of measaurements then average them to get a reliable reading.
macka
I did this with my 1st class a amp the JLH , the damping factor for 8 ohms was 30, I then used this to calculate T/L tuning of the speakers, then I found the Aleph...the rest is history.
My memory is a bit scratchy, but I think you measure the ac output with a sine wave accurately, then add the load and re measure and take note of the incrumental voltage drop across the load.
From here with simple formula you can calculate the Xdcr of the amp, like the voltage drop across a normal resister.
You may need to take a reasonable sample of measaurements then average them to get a reliable reading.
macka
Of a more practical matter regarding listening tests and to followup on my post 1817 my puppies (JBL L100 Century) arrived last night:
I figure this has some relevance as I propose to trial the X Aleph if it behaves it self on theses monitors
"On opening the tea chests I was greeted to a pair for JBL Century L100's in mint condition, the cabinets have hardly a mark on them, the drivers absolutely mint, and the seller included a spare tweeter as one tweeter was poked a little at one point, but sound is not affected apparently!"
Okay, the exciting part........all I can say is audio bliss, these babes are a perfect match for the Mr Pass's heritage and work of art, the Aleph 2. I can't wait to play the X A.........
For a speaker design now over 25 years old the sound makes the jaw drop. How could this be!!!! I mean Hello...... . . . .
There is a clarity, a snap and life a like character to the sound which suggests these are not just a great loudspeaker but a very good monitoring transducer period............
So clean, accurate, and a snappy imaging with precision and a bite that makes you think Mark Knoppler is in front of you here ...now..
In reference to the Rushmore, Mr Pass really has something here:
My hypothesis is that hi end engineering of drivers and system has been around us or a long time, and true to his credit as Mr Pass suggests in the Rushmore literature this came and when with a surge before marketing took over in the 80's and 90's.
I think its also true to say they did not know how a good a speaker(s) they had at the time with amp technology as it was, particularly solid state amps back then. If only Mr Pass was around 15 years earlier...... .
By the way, on the technical side the woofers in the Century run full range, no low pass network , they must have mechanical rolloff in breakup mode, but well damped, on the mid only a 1st order high pass cap, no low pass either, and the tweeter only a cap again.
Can we conclude 1st order crossover adds to impoved sound?
I'll have to drag the fan out before I fire up the Aleph again, its 30 deg c now @8.15 am and we expect 40deg c today.
That stinking hot mate!!!! (Muhahhahahahah)
Anyways that's me for now.
Ian
I figure this has some relevance as I propose to trial the X Aleph if it behaves it self on theses monitors
"On opening the tea chests I was greeted to a pair for JBL Century L100's in mint condition, the cabinets have hardly a mark on them, the drivers absolutely mint, and the seller included a spare tweeter as one tweeter was poked a little at one point, but sound is not affected apparently!"
Okay, the exciting part........all I can say is audio bliss, these babes are a perfect match for the Mr Pass's heritage and work of art, the Aleph 2. I can't wait to play the X A.........
For a speaker design now over 25 years old the sound makes the jaw drop. How could this be!!!! I mean Hello...... . . . .
There is a clarity, a snap and life a like character to the sound which suggests these are not just a great loudspeaker but a very good monitoring transducer period............
So clean, accurate, and a snappy imaging with precision and a bite that makes you think Mark Knoppler is in front of you here ...now..
In reference to the Rushmore, Mr Pass really has something here:
My hypothesis is that hi end engineering of drivers and system has been around us or a long time, and true to his credit as Mr Pass suggests in the Rushmore literature this came and when with a surge before marketing took over in the 80's and 90's.
I think its also true to say they did not know how a good a speaker(s) they had at the time with amp technology as it was, particularly solid state amps back then. If only Mr Pass was around 15 years earlier...... .
By the way, on the technical side the woofers in the Century run full range, no low pass network , they must have mechanical rolloff in breakup mode, but well damped, on the mid only a 1st order high pass cap, no low pass either, and the tweeter only a cap again.
Can we conclude 1st order crossover adds to impoved sound?
I'll have to drag the fan out before I fire up the Aleph again, its 30 deg c now @8.15 am and we expect 40deg c today.
That stinking hot mate!!!! (Muhahhahahahah)
Anyways that's me for now.
Ian
