I repaired the set and a fisher amp. I have not built anything but I have used a soldier iron on many things including many car audio installs. The AKSA and JLH class A both sound intresting to me. I have thought about a chip amp but if I am going to spend my money (not much being a student) I want to end up with a high end peice.
I do have to say it is amazing how many tube kits are out there but there are so few comleate SS kits. It seems that it might be easier to go with a tube kit.
I do have to say it is amazing how many tube kits are out there but there are so few comleate SS kits. It seems that it might be easier to go with a tube kit.
When i made first AKSA, i had the post sale Hugh contact.
And he love to talk about his product:
Carlos, that capacitor is important, if you have time, remove it and put a ceramic unit, you will hear difference, and also bias, do not reduce or increase..... 54 miliamps...keep it exactly, as i tested many variations and.....because.....and this.....guarantee......make the best....... if you change.......not a good result...
- What a hell!....this man is brainwashing me!
But why?.... i already paid....what this man wants?
hummmmm, this strongly effort to make this amplifier constructed exactly the way he said....that the board was studied deeply....even the parts positioning....that he found the best combination...hummmmm.....i concluded he was trying to avoid some modification....maybe modifications will make the same result....yeaaah!......that's rigth!.... yeahhh..... brainwasher.....yeahhh.... i will make it better...yeeeeeehh!
Then i start to change all...this resistor here, this floating one,...why not soldered in output line....Yeaaaah!, this is a bulf Sheet (good not to speak good english...hehe), everyone use two driver emitter resistors.... that hell invention.... suspended, not well referenced...floating...this is wrong!...he knows nothing...Yeeeeeaaaah!, a mith creator...lyer!...will not use that....and i go changed.
And a remember:
Carlos!
This transistor have to be this one.....the gain have to be that low, the -3dB roll of have to be 150 MHz.....do not put higher frequency unit, and do not put lower frequency unit, this other one have to be this one...the gain have to be 185....do not change, the kit has matched parts, a hard work to separate and find adequated parts...i checked moving operational point of the "transverse reverse subcrossed exponential second destruction point under the Epson unballanced voltagecurrent multiplier"....i said!... a hell to that Australian!...he is inventing stories!
And i start to make the ASKA, the inverted AKSA name amplifier....and i said with myself....yeaaaaah!
I will make it better....yeaaaah!...the fact that this guy is upside down, related Brasil, he is opposite world face, so..... may be very strange to walk with glue or magnets attached his foot, not to fall down...as he is upside down..... his mind may be strange too.....Yeeeeaaaaah!..... he may received a Kangaroo punch and turn mad!
So, i start changing, having 2 units, will be easy to see that mine is better....Yeaaaaaah!....mine is better....he research years, and mine will result better?.... despite non sense to myself, i insist with that alike a teenager (alike an idiot one, because this is more stupid thatn average teenager can do!), he said locked himself inside the laboratory, and stayed there till start to have health problems because of circulation and others not nice to talk about....that family turns nervous against him to dedicate so much time to that kind of research...and spending money.... substituting parts, hearing and making wave form monitor pictures, and printing, a hell expensive printer Ink....but i go doing.
I was thinking that i was better, because he lost some time of his life beeing a Military...and i was constructing amplifier, he is same age as i am...so...i am more experienced, had more time burning fingers....YeeeeeeaaaaH!....will make it better...hehe (sadic) will show him my design!
This is bulf sheet, i will change, that capacitor is too big, enormous protude thing....will show him!.....will show him!..... what to make with that enormous Capacitor....Yeaaaaaaaaah!...he is trying to hypnotyse me!... this is not science...capacitor changing quality...this is stories to make children sleep!
Will use BD139.... will use BC transistor here.... that driver is black plastic.....and cheap..... this is a trick..... the idea was to reduce price..... it is cheap!..... reduce price.....Yeaaaaah!
Everybody use another coil, why that long coil...this is other full sheet!...will change too.
Well, the result was wonderfull...of course!....my brain decide that my amplifier is better!...because i made it!....because i am experienced!..... and already decided that Hugh was a magic....made not sense that story to use this part.....foolish!...Yeaaaaah!...foolish!....transistor is transistor and not more than transistor...have gain, have frequency and have this, that and those!
I send Hugh schematic, i made audio recording, with microphone to show him.... and ask him to make it..... that kicked 55!
But see how our own pride create traps to ourselves, the first law i ever follow is to compare things, using other people, in a fair blind comparison testing....but i did not!.... why!..... differences so clear!...do not need!..... why?
And Hugh returned to me with the same old high level education:
Carlos, this modification is "interesting", but i am not sure will turn amp better, as i tested it before and ....and......and.
A Hell to that Kangaroo!...i will call my friends....Yeaaaah!...will make a blind testing!...... they hate Hugh because he dennied to show them the schematic.... How deer him do that? (my friends jellows about that....i was respecting Hugh intelectual and registered property, beeing better to a foreigner related them...old friends...they felt that unfair!)
They tried to discover the one was Hugh amplifier....the AKSA and the ASKA....same supply, same speaker...hehe..... Mr. Kangarôo will see!...yeaaahhhh!.... they are hardly intended to fu....hehe...explode!, intended to send shame on 55 amplifier...i told not, i show not....a fair comparison...and this is detailed somewere in our forum.
Was a shame to ASKA, my glorious amplifier was kicked.....and friends happy, because i was controling my face reactions and did not look to them directly in the eyes...so....they could not see what i was feeling.....
Latter, i return to Hugh, a lot of humble questions in mails to me....all them from Hugh, asking about results, and saying thanks to try to develop his amplifier (he may be kidding!...what a hell i was trying to huck him, cooperating only with my SELF!)
He said that will make one as mine to compare, and i was crazy to say...NO!...NO!...NO!..do not waste time with that.... wass a full sheet!...had not courage.
He returned:
Carlos, i think something strange, i could not find better results with your ASKA (hehe....had a name!?)
Then i told him what really happened, and also put some informations in our forum.
Waiting he turn nervous with me...... he asked me if my board was too much distructed, as i remove and replaced a lot of components and that board i received had a fail, a lower quality one....he replaced the board supplier, because of that fail...asking if i want him to send another board i may be destructed because of the research made... i felt ashamed!... really ashamed!
Not only the amplifier impressed me...he also impressed me!.... and 2 weeks after i received a picture of his family.....so, he was not nervous with me..... and i found something even better that AKSA 55...... Hugh daugther....Oh! my God!.... what a pretty lady!
regards,
Carlos
And he love to talk about his product:
Carlos, that capacitor is important, if you have time, remove it and put a ceramic unit, you will hear difference, and also bias, do not reduce or increase..... 54 miliamps...keep it exactly, as i tested many variations and.....because.....and this.....guarantee......make the best....... if you change.......not a good result...
- What a hell!....this man is brainwashing me!
But why?.... i already paid....what this man wants?
hummmmm, this strongly effort to make this amplifier constructed exactly the way he said....that the board was studied deeply....even the parts positioning....that he found the best combination...hummmmm.....i concluded he was trying to avoid some modification....maybe modifications will make the same result....yeaaah!......that's rigth!.... yeahhh..... brainwasher.....yeahhh.... i will make it better...yeeeeeehh!
Then i start to change all...this resistor here, this floating one,...why not soldered in output line....Yeaaaah!, this is a bulf Sheet (good not to speak good english...hehe), everyone use two driver emitter resistors.... that hell invention.... suspended, not well referenced...floating...this is wrong!...he knows nothing...Yeeeeeaaaah!, a mith creator...lyer!...will not use that....and i go changed.
And a remember:
Carlos!
This transistor have to be this one.....the gain have to be that low, the -3dB roll of have to be 150 MHz.....do not put higher frequency unit, and do not put lower frequency unit, this other one have to be this one...the gain have to be 185....do not change, the kit has matched parts, a hard work to separate and find adequated parts...i checked moving operational point of the "transverse reverse subcrossed exponential second destruction point under the Epson unballanced voltagecurrent multiplier"....i said!... a hell to that Australian!...he is inventing stories!
And i start to make the ASKA, the inverted AKSA name amplifier....and i said with myself....yeaaaaah!
I will make it better....yeaaaah!...the fact that this guy is upside down, related Brasil, he is opposite world face, so..... may be very strange to walk with glue or magnets attached his foot, not to fall down...as he is upside down..... his mind may be strange too.....Yeeeeaaaaah!..... he may received a Kangaroo punch and turn mad!
So, i start changing, having 2 units, will be easy to see that mine is better....Yeaaaaaah!....mine is better....he research years, and mine will result better?.... despite non sense to myself, i insist with that alike a teenager (alike an idiot one, because this is more stupid thatn average teenager can do!), he said locked himself inside the laboratory, and stayed there till start to have health problems because of circulation and others not nice to talk about....that family turns nervous against him to dedicate so much time to that kind of research...and spending money.... substituting parts, hearing and making wave form monitor pictures, and printing, a hell expensive printer Ink....but i go doing.
I was thinking that i was better, because he lost some time of his life beeing a Military...and i was constructing amplifier, he is same age as i am...so...i am more experienced, had more time burning fingers....YeeeeeeaaaaH!....will make it better...hehe (sadic) will show him my design!
This is bulf sheet, i will change, that capacitor is too big, enormous protude thing....will show him!.....will show him!..... what to make with that enormous Capacitor....Yeaaaaaaaaah!...he is trying to hypnotyse me!... this is not science...capacitor changing quality...this is stories to make children sleep!
Will use BD139.... will use BC transistor here.... that driver is black plastic.....and cheap..... this is a trick..... the idea was to reduce price..... it is cheap!..... reduce price.....Yeaaaaah!
Everybody use another coil, why that long coil...this is other full sheet!...will change too.
Well, the result was wonderfull...of course!....my brain decide that my amplifier is better!...because i made it!....because i am experienced!..... and already decided that Hugh was a magic....made not sense that story to use this part.....foolish!...Yeaaaaah!...foolish!....transistor is transistor and not more than transistor...have gain, have frequency and have this, that and those!
I send Hugh schematic, i made audio recording, with microphone to show him.... and ask him to make it..... that kicked 55!
But see how our own pride create traps to ourselves, the first law i ever follow is to compare things, using other people, in a fair blind comparison testing....but i did not!.... why!..... differences so clear!...do not need!..... why?
And Hugh returned to me with the same old high level education:
Carlos, this modification is "interesting", but i am not sure will turn amp better, as i tested it before and ....and......and.
A Hell to that Kangaroo!...i will call my friends....Yeaaaah!...will make a blind testing!...... they hate Hugh because he dennied to show them the schematic.... How deer him do that? (my friends jellows about that....i was respecting Hugh intelectual and registered property, beeing better to a foreigner related them...old friends...they felt that unfair!)
They tried to discover the one was Hugh amplifier....the AKSA and the ASKA....same supply, same speaker...hehe..... Mr. Kangarôo will see!...yeaaahhhh!.... they are hardly intended to fu....hehe...explode!, intended to send shame on 55 amplifier...i told not, i show not....a fair comparison...and this is detailed somewere in our forum.
Was a shame to ASKA, my glorious amplifier was kicked.....and friends happy, because i was controling my face reactions and did not look to them directly in the eyes...so....they could not see what i was feeling.....
Latter, i return to Hugh, a lot of humble questions in mails to me....all them from Hugh, asking about results, and saying thanks to try to develop his amplifier (he may be kidding!...what a hell i was trying to huck him, cooperating only with my SELF!)
He said that will make one as mine to compare, and i was crazy to say...NO!...NO!...NO!..do not waste time with that.... wass a full sheet!...had not courage.
He returned:
Carlos, i think something strange, i could not find better results with your ASKA (hehe....had a name!?)
Then i told him what really happened, and also put some informations in our forum.
Waiting he turn nervous with me...... he asked me if my board was too much distructed, as i remove and replaced a lot of components and that board i received had a fail, a lower quality one....he replaced the board supplier, because of that fail...asking if i want him to send another board i may be destructed because of the research made... i felt ashamed!... really ashamed!
Not only the amplifier impressed me...he also impressed me!.... and 2 weeks after i received a picture of his family.....so, he was not nervous with me..... and i found something even better that AKSA 55...... Hugh daugther....Oh! my God!.... what a pretty lady!
regards,
Carlos
Carlos,
Thank you, thank you........ I feel like I've just been given an Oscar..... beware the cult of personality, I'm not sure I can live up to all of this!!
I have to say reading through this thread that I can't really disagree with any of it. I'm not about to persuade anyone to buy the AKSA; the reputation and the product speaks for itself, and if audiophilia nervosa takes hold as it does with most then it all becomes a journey, with confusing signposts.......
All the other amps mentioned in despatches here are good. It just depends on your taste, and your aspirations, and your budget. Trust is also a big part of this - there is a leap of faith to buy an AKSA. The AKSA is not cheap, but nothing of any substance is cheap, try building the Zen or Aleph series!! A large portion of my business is repeat, but no-one has taken me to court yet, so the AKSA is probably filling a niche market.
Jacco, just today I saw two HSV Gen III V8s on the road with the magic '300' badge on the back (That's kilowatts, not horsepower!!). Their performance is certainly blistering and effortless, and on the open road their fuel economy is excellent. A number of auto reviewers have canned them for less than expected bottom end torque, however. But I wanted to offer you a few thoughts if you are considering a purchase.
The Gen III GM 5.7 (now available as a 6 litre in the Monaro and maybe also in the HSV) is all alloy. The block is almost identical to the existing cast iron 5.7 - the old 350 CID small block. A number of racers here have tried the all alloy block - it's almost 100 Kg lighter, wonderful for racing - but suffered all sorts of nasty problems with rapid ring and piston wear, and soon went back to the thin wall cast iron block. A significant number of the early Gen III road cars reported heavy oil use at only 20,000 kms, and were rebuilt under warranty with new pistons and rings. I predict that these new variants, particularly the 6 litre version which has greater rod angularity, will maybe trash their rings and pistons early in their life, and I would urge caution. The older cast block is fine; but the aluminium remake is not sufficiently robust for the job.
Thank you for your comments on the bridged Glass Harmony. I will certainly give you the run-down when it's done and send you a few photos. Who knows, I might even build to order!!
Cheers,
Hugh
Thank you, thank you........ I feel like I've just been given an Oscar..... beware the cult of personality, I'm not sure I can live up to all of this!!
I have to say reading through this thread that I can't really disagree with any of it. I'm not about to persuade anyone to buy the AKSA; the reputation and the product speaks for itself, and if audiophilia nervosa takes hold as it does with most then it all becomes a journey, with confusing signposts.......
All the other amps mentioned in despatches here are good. It just depends on your taste, and your aspirations, and your budget. Trust is also a big part of this - there is a leap of faith to buy an AKSA. The AKSA is not cheap, but nothing of any substance is cheap, try building the Zen or Aleph series!! A large portion of my business is repeat, but no-one has taken me to court yet, so the AKSA is probably filling a niche market.
Jacco, just today I saw two HSV Gen III V8s on the road with the magic '300' badge on the back (That's kilowatts, not horsepower!!). Their performance is certainly blistering and effortless, and on the open road their fuel economy is excellent. A number of auto reviewers have canned them for less than expected bottom end torque, however. But I wanted to offer you a few thoughts if you are considering a purchase.
The Gen III GM 5.7 (now available as a 6 litre in the Monaro and maybe also in the HSV) is all alloy. The block is almost identical to the existing cast iron 5.7 - the old 350 CID small block. A number of racers here have tried the all alloy block - it's almost 100 Kg lighter, wonderful for racing - but suffered all sorts of nasty problems with rapid ring and piston wear, and soon went back to the thin wall cast iron block. A significant number of the early Gen III road cars reported heavy oil use at only 20,000 kms, and were rebuilt under warranty with new pistons and rings. I predict that these new variants, particularly the 6 litre version which has greater rod angularity, will maybe trash their rings and pistons early in their life, and I would urge caution. The older cast block is fine; but the aluminium remake is not sufficiently robust for the job.
Thank you for your comments on the bridged Glass Harmony. I will certainly give you the run-down when it's done and send you a few photos. Who knows, I might even build to order!!
Cheers,
Hugh
DJNUBS,
I suggest you have AKSA kit. You won't be dissapointed with the sound, the man behind it will assist you kindly until you finished the amp.
You can go directly from Chicago to NewYork, or you can go to Europe first, then to Africa, then to Asia, and ended in in the same NewYork, but with alot-lot difference in your expense.
I think DestroyerX has travel through the complicated path, I never understand his post by reading it 1 time.
(Hehehe.. joke, Carlos.....)
I suggest you have AKSA kit. You won't be dissapointed with the sound, the man behind it will assist you kindly until you finished the amp.
You can go directly from Chicago to NewYork, or you can go to Europe first, then to Africa, then to Asia, and ended in in the same NewYork, but with alot-lot difference in your expense.
I think DestroyerX has travel through the complicated path, I never understand his post by reading it 1 time.
(Hehehe.. joke, Carlos.....)
I was Military too, and i think they are great, when not figthing!
The meaning, as you could perceive, despite my Eingrish, is that beeing busy doing his Military obligations, could not focus on electronics.
And while i was already assembling things, he was using his time to his Military profession, or service, or obligation, or option...do not know how you call....we call Military Service, as it is a Nation Service, we all have to serve the Army and be trained when complete 18 years old.
And alike all places, the US Military format is used:
"You all are sub extract of anything!.... you will turn a man here, now you are only small children...something that have the value of the fly that is over the Sh-- of some animal!"
No problem with them....not figthing i like them all...inside their places training and watching TV...when they move, for Democracy, i dislike them.
Carlos
The meaning, as you could perceive, despite my Eingrish, is that beeing busy doing his Military obligations, could not focus on electronics.
And while i was already assembling things, he was using his time to his Military profession, or service, or obligation, or option...do not know how you call....we call Military Service, as it is a Nation Service, we all have to serve the Army and be trained when complete 18 years old.
And alike all places, the US Military format is used:
"You all are sub extract of anything!.... you will turn a man here, now you are only small children...something that have the value of the fly that is over the Sh-- of some animal!"
No problem with them....not figthing i like them all...inside their places training and watching TV...when they move, for Democracy, i dislike them.
Carlos
Sorry, i am impeached to inform too much details
As, there are details, some parts and connections that make enormous difference, and turn that simple circuit something unbeliavable when compared to the published basic schematic, and compared to my modifications.
I took care, when making my own ASKA, to remove special parts, my idea was to check if those parts make a real difference or not.
They make!
So, not only the Version to be published, some chance to our forum guys develop the schematic, as Hugh did, but also this one i am showing now, that i prepared minutes ago, trying to remenber exactly what i done.....not sure if this is the one i made to compare....cannot remember exactly, and as could not face the factory unit, even with factory board, i dismounted as i use to do...having parts to do others units.
Hugh defend his intelectual property, as gave him a lot of job, as i tried without method, i did not remember the modifications iwas doing, increasing, removing....nothing recorded....he made scope pictures and study whole thing...had some organized work method.....i did not made comparison.....i heard mine and conclude that was better....and it was not!....in blind testing it loose.
Also, i did not use the factory transistors....and the differential unit and the voltage amplifier make enormous difference in sound quality result.
My unit loose focus, loose highs, had a little bit more bass, but this cost me a lot of noise generated...... junk!
I do not suggest my ASKA to nobody, as the factory unit is many miles ahead this one, in audio quality.
This is the maximum i can talk....and i think i talked too much.
Carlos
As, there are details, some parts and connections that make enormous difference, and turn that simple circuit something unbeliavable when compared to the published basic schematic, and compared to my modifications.
I took care, when making my own ASKA, to remove special parts, my idea was to check if those parts make a real difference or not.
They make!
So, not only the Version to be published, some chance to our forum guys develop the schematic, as Hugh did, but also this one i am showing now, that i prepared minutes ago, trying to remenber exactly what i done.....not sure if this is the one i made to compare....cannot remember exactly, and as could not face the factory unit, even with factory board, i dismounted as i use to do...having parts to do others units.
Hugh defend his intelectual property, as gave him a lot of job, as i tried without method, i did not remember the modifications iwas doing, increasing, removing....nothing recorded....he made scope pictures and study whole thing...had some organized work method.....i did not made comparison.....i heard mine and conclude that was better....and it was not!....in blind testing it loose.
Also, i did not use the factory transistors....and the differential unit and the voltage amplifier make enormous difference in sound quality result.
My unit loose focus, loose highs, had a little bit more bass, but this cost me a lot of noise generated...... junk!
I do not suggest my ASKA to nobody, as the factory unit is many miles ahead this one, in audio quality.
This is the maximum i can talk....and i think i talked too much.
Carlos
Attachments
The more I think about it the more I like the idea of a JLH class a amp. The ASKA looks good but at 330 a channel it is a bit more then I want to spend. I also have found that I love the sound of class A amps.
I guess now I need to find a parts list. Is there a list of all the parts needed for this amp somewhere online or do I need to look at the wiring diagram and make a list myself?
I guess now I need to find a parts list. Is there a list of all the parts needed for this amp somewhere online or do I need to look at the wiring diagram and make a list myself?
I am not seeing a parts list on that site (I have been looking at it since yesterday). Am I just missing it?
I am looking at building the 1969 version due to the fact that the amp section looks like something I could build and not be intimadated. I plan on building it with a simple PS rather then a regulated one. This is to lower cost and complexity. I figgure that I can always change it later.
I am looking at building the 1969 version due to the fact that the amp section looks like something I could build and not be intimadated. I plan on building it with a simple PS rather then a regulated one. This is to lower cost and complexity. I figgure that I can always change it later.
I was sure you will find someway to have fun, you are great.
By the way.... having some audio of V8 running motors, alike the Magnificent Pontiac GTO, please, send me.
nanabrother@yahoo.com
regards,
Carlos
By the way.... having some audio of V8 running motors, alike the Magnificent Pontiac GTO, please, send me.
nanabrother@yahoo.com
regards,
Carlos
I feel very small differences related the 1969 JLH design.
They sound nice, both!
I do not think they are perfect...nothing is perfect in this world, and, related music, having that "air pumps"..... the speakers, we cannot reproduce perfect sound... as speaker cannot follow audio waves perfectly.
But also that Rodd design sounds interesting, and using simple parts...i tried to put sophisticated transistors...bad result i had.
Graham Maynard designs are other level of class A products, more serious, but also more complicated.
As the man is talking in class A, talking JLH, thinking simple....this is a simple offer to him.
regards,
Carlos
They sound nice, both!
I do not think they are perfect...nothing is perfect in this world, and, related music, having that "air pumps"..... the speakers, we cannot reproduce perfect sound... as speaker cannot follow audio waves perfectly.
But also that Rodd design sounds interesting, and using simple parts...i tried to put sophisticated transistors...bad result i had.
Graham Maynard designs are other level of class A products, more serious, but also more complicated.
As the man is talking in class A, talking JLH, thinking simple....this is a simple offer to him.
regards,
Carlos
Carlos, can you tell me, what do you imagine as " complicated " ? Both amps, simply and complicated, have 95 % parts the same. Last 5 % ( in most of cases ) is only hanful of cheap transistors. If you know good solder cca 40 - 50 devices, quite the same you can solder 70 - 80 devices and you get ( in most cases ) much better parametres. Why are you afraid ? Sure, you aren't only one, who " adopt in brain " theory, that only simply is best, but it is nonsens.
Hi Eupopa Pops (Pavel),
In response to your question: it is similar. The AKSA is based on an old AR Bailey design from the sixties, with mods to the feedback stage, the voltage amp/LTP stages, and the driver stage. All these mods are in the public domain, but I have re-engineered it with very high quality components, great care in dimensioning, and a good layout. While I used a CRO and DMMs throughout the design process, I spent much of the time in listening tests, and developed a careful routine for sonic assessments.
I have avoided stepping into the lions den with you and your 'brother' because most of the time you answer your own questions and you are both - ahem - pungent personalities, very sure of your own experience and correctness. You have built hundreds of amps, you are both clever engineers, and you know every aspect of amp design. I could certainly not convince you otherwise, particularly with something outrageously simple! Goodness, it's a scandal!!
I believe that it is a mistake to design an amplifier for lowest possible distortion. It is an engineering challenge, yes, but it won't sound good. I believe distortion is almost inevitable, and that it should be harnessed to improve the sound. This is, after all, what tubes do.......... The issue revolves more around psychoacoustics and how we perceive music than around the engineering aspects of low distortion design.
However, Pavel, simplicity is not bad, it's good, because it increases reliability and lowers cost. In many cases it even improves performance - not always, but often. A Chev V8 is a very simple design still being made today, but every single design decision taken by Ed Cole and his panel at GM back in the early fifties was agonized over for weeks and months, making it one of the greatest V8s ever developed. It's getting a bit long in the tooth today, and in my view is now bested in performance terms by the Benz and Toyota V8s, but the essential design was extremely simple and very durable.
The other issue is technological convergence. Why do so many amps gravitate towards Class AB PP with a LTP input stage? The philosophy behind these questions is very important; technology is full of fad and fashion - just like medicine - and every six months there is a new 'topology du jour'. I can remember when the mu follower was the big rave, and before that, the SRPP, and in SS amp design at present it's fully complementary with a star studded cast of current sources and mirrors! Have you seen a LTP driving a SE Rush cascode? I did once - I built one, it was very novel and incredibly exciting, but it sounded terrible!! For the HT people, the latest fad is Class D (which is quite good, I might add) - complexity, fads and fashion are NOT the answer to the very best sound, and keeping component count down is GOOD. I believe this is what makes high end an art as well as a science.
Cheers,
Hugh
In response to your question: it is similar. The AKSA is based on an old AR Bailey design from the sixties, with mods to the feedback stage, the voltage amp/LTP stages, and the driver stage. All these mods are in the public domain, but I have re-engineered it with very high quality components, great care in dimensioning, and a good layout. While I used a CRO and DMMs throughout the design process, I spent much of the time in listening tests, and developed a careful routine for sonic assessments.
I have avoided stepping into the lions den with you and your 'brother' because most of the time you answer your own questions and you are both - ahem - pungent personalities, very sure of your own experience and correctness. You have built hundreds of amps, you are both clever engineers, and you know every aspect of amp design. I could certainly not convince you otherwise, particularly with something outrageously simple! Goodness, it's a scandal!!
I believe that it is a mistake to design an amplifier for lowest possible distortion. It is an engineering challenge, yes, but it won't sound good. I believe distortion is almost inevitable, and that it should be harnessed to improve the sound. This is, after all, what tubes do.......... The issue revolves more around psychoacoustics and how we perceive music than around the engineering aspects of low distortion design.
However, Pavel, simplicity is not bad, it's good, because it increases reliability and lowers cost. In many cases it even improves performance - not always, but often. A Chev V8 is a very simple design still being made today, but every single design decision taken by Ed Cole and his panel at GM back in the early fifties was agonized over for weeks and months, making it one of the greatest V8s ever developed. It's getting a bit long in the tooth today, and in my view is now bested in performance terms by the Benz and Toyota V8s, but the essential design was extremely simple and very durable.
The other issue is technological convergence. Why do so many amps gravitate towards Class AB PP with a LTP input stage? The philosophy behind these questions is very important; technology is full of fad and fashion - just like medicine - and every six months there is a new 'topology du jour'. I can remember when the mu follower was the big rave, and before that, the SRPP, and in SS amp design at present it's fully complementary with a star studded cast of current sources and mirrors! Have you seen a LTP driving a SE Rush cascode? I did once - I built one, it was very novel and incredibly exciting, but it sounded terrible!! For the HT people, the latest fad is Class D (which is quite good, I might add) - complexity, fads and fashion are NOT the answer to the very best sound, and keeping component count down is GOOD. I believe this is what makes high end an art as well as a science.
Cheers,
Hugh
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