The break is closed!... if you want to go ahead, related the main thread
I thank you by the break..could not find a Sinclair Z30 thread to place those images.
I think that thread was archived...in the files...not used, so, if not too much wrong, i expect not to have disturb you too much.
regards,
Carlos
I thank you by the break..could not find a Sinclair Z30 thread to place those images.
I think that thread was archived...in the files...not used, so, if not too much wrong, i expect not to have disturb you too much.
regards,
Carlos
Carlos,
this originally Sinclair project 60 amp (Z-30) works and is easy to build, but it is IMHO rather a harmonic synthesizer than an amp, look here:
http://web.telecom.cz/macura/sinclair.jpg
and here is the historical document:
http://web.telecom.cz/macura/z30.jpg
The original Sinclair 60 project is dated 1969. I had been operating the re-designed amp for some 15 years without problems.
But please do not expect more than possible.
Cheers, Pavel
this originally Sinclair project 60 amp (Z-30) works and is easy to build, but it is IMHO rather a harmonic synthesizer than an amp, look here:
http://web.telecom.cz/macura/sinclair.jpg
and here is the historical document:
http://web.telecom.cz/macura/z30.jpg
The original Sinclair 60 project is dated 1969. I had been operating the re-designed amp for some 15 years without problems.
But please do not expect more than possible.
Cheers, Pavel
Hi, PMA,
What do you think about op-amp based power amps (like your NP-PMA) and gainclones (like Peter Daniel's Patek amp, it seems to have great review on 6moons).
Some are skeptical about those chip based power amps, and still said that discretes are still better.
What is your personal opinion, is discretes still better? Since you have experience with both approaches.
What do you think about op-amp based power amps (like your NP-PMA) and gainclones (like Peter Daniel's Patek amp, it seems to have great review on 6moons).
Some are skeptical about those chip based power amps, and still said that discretes are still better.
What is your personal opinion, is discretes still better? Since you have experience with both approaches.
Lumanauw,
IMHO it depends on the circuit design rather than discrete/opamp/chipamp labeling.
In case your target is high-power amplifier, I would suggest discrete solution.
Upupa Epops and me have performed many comparison tests of chipamps vs. discrete or opamp front end based amps. We do not prefer chipamps like 3886 or 4780 (or any other available nowadays), though it is possible to build good amps with them. Probably it is an output stage solution (quasi-complementary class AB) and thermal feedback from output stage to input circuits that do not enable them to reach absolute top.
This is my experience and I am not about to start any flame wars between those who prefer chipamps and those who do not
.
IMHO it depends on the circuit design rather than discrete/opamp/chipamp labeling.
In case your target is high-power amplifier, I would suggest discrete solution.
Upupa Epops and me have performed many comparison tests of chipamps vs. discrete or opamp front end based amps. We do not prefer chipamps like 3886 or 4780 (or any other available nowadays), though it is possible to build good amps with them. Probably it is an output stage solution (quasi-complementary class AB) and thermal feedback from output stage to input circuits that do not enable them to reach absolute top.
This is my experience and I am not about to start any flame wars between those who prefer chipamps and those who do not
.
Hi, PMA,
You have built opamp based power amp, what do you think if the front end is OPA627? Is it good for front end? You use current feedback opamp in your power amp, do you think for front end it is better current feedback type?
I've got funny sound from OPA134 forced biased (by output CCS of 7mA), it sounds becomes very dirty. Better TL081 forced this way, sounds better (to me).
Is BB opamps (including OPA627) all becomes dirty sound when forced by CCS (to work in classA)? Maybe you have experience with this?
You have built opamp based power amp, what do you think if the front end is OPA627? Is it good for front end? You use current feedback opamp in your power amp, do you think for front end it is better current feedback type?
I've got funny sound from OPA134 forced biased (by output CCS of 7mA), it sounds becomes very dirty. Better TL081 forced this way, sounds better (to me).
Is BB opamps (including OPA627) all becomes dirty sound when forced by CCS (to work in classA)? Maybe you have experience with this?
PMA said:
Don't blame it too much, Pavel. Lot of THD lines are from power supply (notably 100Hz) and their intermodulation product.
What about the same amplifier but with better supply and high class AB bias?
I Know, I known thare is better amply around. But I love the simplicity and cheapness of this one.
I believe that everyone even moderately qualified can distinguish between PSU spectral lines and distortion products.
Sure, it can be slightly improved by increasing (optimizing) bias current. Then thermal behavior becomes an issue.
It can be improved, but never it will be perfect. Personally I do not like class B or class AB traditional output stages, for the reason of switching residuals that are audible. So I prefer class A or class AB with error correction and MOSFET output devices (wider transition area).
Sure, it can be slightly improved by increasing (optimizing) bias current. Then thermal behavior becomes an issue.
It can be improved, but never it will be perfect. Personally I do not like class B or class AB traditional output stages, for the reason of switching residuals that are audible. So I prefer class A or class AB with error correction and MOSFET output devices (wider transition area).
Hi PMA,
"Personally I do not like class B or class AB traditional output stages, for the reason of switching residuals that are audible. So I prefer class A or class AB with error correction and MOSFET output devices (wider transition area)."
It is simply ignorant or poor design that underlies such statements! Competent design addresses such problems.
Cheers,
Greg
"Personally I do not like class B or class AB traditional output stages, for the reason of switching residuals that are audible. So I prefer class A or class AB with error correction and MOSFET output devices (wider transition area)."
It is simply ignorant or poor design that underlies such statements! Competent design addresses such problems.
Cheers,
Greg
Hi Greg,
Take some advice from someone who knows - Pavel is an exceptional engineer with strong creativity and manifold experience. To cap it all he is an avid listener, with more classical repertoire than most engineers I've seen.
It is not possible to agree with everything an expert says, but he is much more expert than most. I certainly would not come out with categoric statements like yours; somebody always proves you wrong. And in any event, the notion of competent design is probably lost on 80% of audio designers out there.....
Unless, of course, you mean to start a traditional Oz bushfire??
Yours in humour and mild curiousity.......
Hugh
Take some advice from someone who knows - Pavel is an exceptional engineer with strong creativity and manifold experience. To cap it all he is an avid listener, with more classical repertoire than most engineers I've seen.
It is not possible to agree with everything an expert says, but he is much more expert than most. I certainly would not come out with categoric statements like yours; somebody always proves you wrong. And in any event, the notion of competent design is probably lost on 80% of audio designers out there.....
Unless, of course, you mean to start a traditional Oz bushfire??
Yours in humour and mild curiousity.......
Hugh
PMA said:
Pavel,
I read you, but please observe. The low level take-over region, where Gm doubling occurs and/or xover non-linearity, isn't that the same for class A, class AB and maybe, partly, for class B (depending on exactly how it is implemented)? In other words, the difference between A and AB cannot lie in the difference in the lowlevel xover, because there they are the same.
Jan Didden
My dear PMA, with your permission, i will open my big mouth
But, first of all, i want to express my respect to you, as i am following the threads, and i really apreciate your competence and qualities...also Janeman is someone that have his own ligth, this one understand Psychologie too.
Well, Hugh is the King!.... the day before yesterday i was constructing an old Sony once again.... sounded awfull as the first time, and i tried to modify.... result the same trash.....then i made it alike Hugh amplifier...result sligthly better.... well, i had to put Hugh parts to have it sounding well...so....he optimized that bootstraped design, and i must confess i tried twice to make it better and i failled...have to respect this guy.....AKSA chairman.
But, i have to start some conversation with you, in special to you, made to you PMA...thinking exactly in your person, to have a message adressed to you.
I was, last week, observing a band plenty of musicians.... they were Marching and playing many metals and drums.
I felt strong emotions.... an my desire was following them marching...i did not, too much old to do the things i done, inside the Coast Artillery when i was young, following my Grandfather screaming order, "Turn rigth!".... MARCH!.... my emotions where inside my brain (inside brain 1).
I was remembering old days PMA, i had a Jeep...an army jeep, with pedals...pushing and pulling i made it move fast behing the trop of young man marching...giants they are for me... i always felt good hearing the drums.... my memories made me cry (inside brain 2)
And i was there..... again.... around 49 years passed since i was apreciating the soldiers marching, sinchronized, with flashing polished belts and boots...perfectly syncronized...all them 180 centimeters tall.... the Artilhery General Guards.....and i was remenbering i was one of them, in the sixties i was commanding the Platton marching that same place...my voice was the scream.... 184 centimeters tall and strong as i could never be again....MARCH!!!..... again some tear fell down...i did it! (inside brain 3)
Now, very distant my home town.... something distant alike Sweden to North Italy distance...i was observing soldiers again... and the drums where producing enormous echo in the near buidings and surrounding constructions... a distorted sound, caused by those delayed repetition signals... a children was crying, producing terrible screams saying that want to go home... creating noises in my ears.... some cars and motorcicles producing their noises...people talking also....but i fast "erased" all those sounds...i just stop to perceive them (inside brain 4)
The metals played a beautifull sequences, and sound reflections and some guys out of tone..could produce a nice harmony... some echos of my own soul are there, once again.... i was feeling vibration of boots hitting the pavement...vibrations inside my body are producing to me a very stimulating feeling (inside brain 5)
And the people was going more and more beeing compressed in the space they could be, as soldiers hold people distant from the troop marching.... enormous hairs, some hats because sun and people stand over chairs and children over daddy shoulders are mufling all the sound...but i was hearing perfectly, because that was my music, my young years was inside Artilhery...i had a home inside the fortification...the soldier are my daily vision and my toy was a German enourmous rifle, damages and full or rust.... besides i am not agressive, and i hate war, flags, limits, countries and all that bull ship that only create problems, i loved those guys that marching are informing everybody.... do not start a figth!...as we are ready to go...so...keep the peace!, because we are strong enougth to send anyone to hell...... Power to Peace...something clever...exibition of power, to avoid losses of respect.
The sound was awfull dear PMA, there are distortions, reflections, metals out of tone, vibrations....i was happy (inside brain 6)
I will stop, as i am tired to type.... music after enter our mechanical ears produce sensitive feelings, and those are connected to our memories... brain can correct failures, brain can delete children noises, brain can focus..... so..... those distortions, really PMA....really, really, really.... are not so big problem...considering Hystorical value of this amplifier...considering the beautifull music i will hear, with the seventies distortion, remembering my first love... my first kiss...her perfum.
I have to take into account that the circuit was adjusted by Pavel Macura..... that this circuit is apreciated, as hystorical by Greg Erskine, my friend, and that i need some references to perceive something good or bad..... this one, playing alone..without A/B instantaneous comparison may sound good..... 3 minutes hearing and my system adjust all things...including deleting the wind noises i have in my appartment, very near the clouds i leave...so.... this papper of distortion dear PMA...well, this paper, if very soft, with a tender touch or perfumed, my dear friend...can have better use...yeahhh!
I am not spetrum analiser, nor scope, or waveform monitor, i am not an intermodulation meter, and i am not a distortion analiser...i am a man!
No!...do not be offended, as i love you PMA!.... i am just showing you that people are very different, and that i am more connected to feelings than connected to meters.... and all my life i was surrounded by those instruments...as i could not evaluate Radio Frequency with my ears and feelings...but audio... we can.
regards,
Carlos
But, first of all, i want to express my respect to you, as i am following the threads, and i really apreciate your competence and qualities...also Janeman is someone that have his own ligth, this one understand Psychologie too.
Well, Hugh is the King!.... the day before yesterday i was constructing an old Sony once again.... sounded awfull as the first time, and i tried to modify.... result the same trash.....then i made it alike Hugh amplifier...result sligthly better.... well, i had to put Hugh parts to have it sounding well...so....he optimized that bootstraped design, and i must confess i tried twice to make it better and i failled...have to respect this guy.....AKSA chairman.
But, i have to start some conversation with you, in special to you, made to you PMA...thinking exactly in your person, to have a message adressed to you.
I was, last week, observing a band plenty of musicians.... they were Marching and playing many metals and drums.
I felt strong emotions.... an my desire was following them marching...i did not, too much old to do the things i done, inside the Coast Artillery when i was young, following my Grandfather screaming order, "Turn rigth!".... MARCH!.... my emotions where inside my brain (inside brain 1).
I was remembering old days PMA, i had a Jeep...an army jeep, with pedals...pushing and pulling i made it move fast behing the trop of young man marching...giants they are for me... i always felt good hearing the drums.... my memories made me cry (inside brain 2)
And i was there..... again.... around 49 years passed since i was apreciating the soldiers marching, sinchronized, with flashing polished belts and boots...perfectly syncronized...all them 180 centimeters tall.... the Artilhery General Guards.....and i was remenbering i was one of them, in the sixties i was commanding the Platton marching that same place...my voice was the scream.... 184 centimeters tall and strong as i could never be again....MARCH!!!..... again some tear fell down...i did it! (inside brain 3)
Now, very distant my home town.... something distant alike Sweden to North Italy distance...i was observing soldiers again... and the drums where producing enormous echo in the near buidings and surrounding constructions... a distorted sound, caused by those delayed repetition signals... a children was crying, producing terrible screams saying that want to go home... creating noises in my ears.... some cars and motorcicles producing their noises...people talking also....but i fast "erased" all those sounds...i just stop to perceive them (inside brain 4)
The metals played a beautifull sequences, and sound reflections and some guys out of tone..could produce a nice harmony... some echos of my own soul are there, once again.... i was feeling vibration of boots hitting the pavement...vibrations inside my body are producing to me a very stimulating feeling (inside brain 5)
And the people was going more and more beeing compressed in the space they could be, as soldiers hold people distant from the troop marching.... enormous hairs, some hats because sun and people stand over chairs and children over daddy shoulders are mufling all the sound...but i was hearing perfectly, because that was my music, my young years was inside Artilhery...i had a home inside the fortification...the soldier are my daily vision and my toy was a German enourmous rifle, damages and full or rust.... besides i am not agressive, and i hate war, flags, limits, countries and all that bull ship that only create problems, i loved those guys that marching are informing everybody.... do not start a figth!...as we are ready to go...so...keep the peace!, because we are strong enougth to send anyone to hell...... Power to Peace...something clever...exibition of power, to avoid losses of respect.
The sound was awfull dear PMA, there are distortions, reflections, metals out of tone, vibrations....i was happy (inside brain 6)
I will stop, as i am tired to type.... music after enter our mechanical ears produce sensitive feelings, and those are connected to our memories... brain can correct failures, brain can delete children noises, brain can focus..... so..... those distortions, really PMA....really, really, really.... are not so big problem...considering Hystorical value of this amplifier...considering the beautifull music i will hear, with the seventies distortion, remembering my first love... my first kiss...her perfum.
I have to take into account that the circuit was adjusted by Pavel Macura..... that this circuit is apreciated, as hystorical by Greg Erskine, my friend, and that i need some references to perceive something good or bad..... this one, playing alone..without A/B instantaneous comparison may sound good..... 3 minutes hearing and my system adjust all things...including deleting the wind noises i have in my appartment, very near the clouds i leave...so.... this papper of distortion dear PMA...well, this paper, if very soft, with a tender touch or perfumed, my dear friend...can have better use...yeahhh!
I am not spetrum analiser, nor scope, or waveform monitor, i am not an intermodulation meter, and i am not a distortion analiser...i am a man!
No!...do not be offended, as i love you PMA!.... i am just showing you that people are very different, and that i am more connected to feelings than connected to meters.... and all my life i was surrounded by those instruments...as i could not evaluate Radio Frequency with my ears and feelings...but audio... we can.
regards,
Carlos
Hi, PMA,
Right now I feel that my feedback amp (not someone else's) is better than my non-global feedback amp (again, mine, not someone else's. Maybe other people can make non-feedback amp better than my feedback amp). Maybe in the future this will change again, I don't know
I learn that EVERY stages (every transistor) has to be "to think about" how to get the best performance for their function.
The term "make everything as linear as possible before applying feedback" seems very wise here (Although DougSelf doesn't agree with this phrase)
Right now I feel that my feedback amp (not someone else's) is better than my non-global feedback amp (again, mine, not someone else's. Maybe other people can make non-feedback amp better than my feedback amp
). Maybe in the future this will change again, I don't know I learn that EVERY stages (every transistor) has to be "to think about" how to get the best performance for their function.
The term "make everything as linear as possible before applying feedback" seems very wise here (Although DougSelf doesn't agree with this phrase)
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