I am not sure, maybe a damn hacker...but i am trying to have a safe inform... if he let me do it... i will do it gladly.
But some secrets he will keep, those ones, really, nobody could imagine!... a simple Aksa, very good unit, without 4 secrets.... but the one will beat so many amplifiers that you will be very surprised.
Carlos
But some secrets he will keep, those ones, really, nobody could imagine!... a simple Aksa, very good unit, without 4 secrets.... but the one will beat so many amplifiers that you will be very surprised.
Carlos
AKSA Schematic
Carlos,
Go for it, as discussed. Many thanks for your enthusiasm; I'm proud to have met you, and thank you profusely for your passionate interest! Gee, life's interesting in your fifties, isn't it?
This schematic will be representative only. It will not be complete, although it will work very well and best many popular amplifiers. Most DIYers here will be astonished at the simplicity, and the appearance of conventional design. But remember, there is more to it than you see, and there is component choice, and then there is layout. ALL these issues are very important - EVERYTHING affects the sound, and I've never met anyone smart enough to tell me how something will sound by merely looking at the schematic.
It will not be as good as the genuine kitset AKSA, but gee, at least we should allow the beautiful lady to model in her evening dress!!
This approach is also something NP suggested, and for this, I thank him.
I have designed many amplifiers, almost all hybrid, with tubes, BJTs, and mosfets. Most don't go beyond the workshop, because for a variety of market-related reasons, they are not commercial. Some of these amps are very special, too, but I won't be showing them just yet!!
The AKSA remains my most commercial design.
Cheers,
Hugh
Carlos,
Go for it, as discussed. Many thanks for your enthusiasm; I'm proud to have met you, and thank you profusely for your passionate interest! Gee, life's interesting in your fifties, isn't it?
This schematic will be representative only. It will not be complete, although it will work very well and best many popular amplifiers. Most DIYers here will be astonished at the simplicity, and the appearance of conventional design. But remember, there is more to it than you see, and there is component choice, and then there is layout. ALL these issues are very important - EVERYTHING affects the sound, and I've never met anyone smart enough to tell me how something will sound by merely looking at the schematic.
It will not be as good as the genuine kitset AKSA, but gee, at least we should allow the beautiful lady to model in her evening dress!!
This approach is also something NP suggested, and for this, I thank him.
I have designed many amplifiers, almost all hybrid, with tubes, BJTs, and mosfets. Most don't go beyond the workshop, because for a variety of market-related reasons, they are not commercial. Some of these amps are very special, too, but I won't be showing them just yet!!
The AKSA remains my most commercial design.
Cheers,
Hugh
As the anticipation grows, I'm getting excited. It's like talking a half drunk girl out of her clothes at a party.
I hoped you would come to this decision. Your amp is one I've considered building. I know that you can't tell how an amp will sound from only it's scematic, and actual component choice, bias levels, and pc board layout are very critical for the outcome, but some things can be assumed from a rough scematic. I would want some Idea of topology and level of complexity before I laid my money out. If it was too complex for me to understand how it worked, I'de be at a great disatvantage trying to debug a component misplacement and unable to repair it if I fried it farting around with something (likely occurance).
There may be a few hacks out here that would try to copy your work, but they aren't likely to be paying customers anyway. Most people who would build your amp (me included) would be willing to pay a resonable cost for boards and parts plus a profit to have you do the R&D plus the parts sourceing and packaging.
For my first big project, I chose an Aleph 2. It was simple enough for me to understand and had a very high audioplile pedigree. Harvardians group buy also simplified the decision, but If Nelson had offered boards at 10 times the price, I would have bought them. And I would have also bought a kit if it was offered. At the time of commitment, the only Info I could get about your amp was gobs of glowing DIY reviews, and you have to take such claims with a grain of salt.
I hoped you would come to this decision. Your amp is one I've considered building. I know that you can't tell how an amp will sound from only it's scematic, and actual component choice, bias levels, and pc board layout are very critical for the outcome, but some things can be assumed from a rough scematic. I would want some Idea of topology and level of complexity before I laid my money out. If it was too complex for me to understand how it worked, I'de be at a great disatvantage trying to debug a component misplacement and unable to repair it if I fried it farting around with something (likely occurance).
There may be a few hacks out here that would try to copy your work, but they aren't likely to be paying customers anyway. Most people who would build your amp (me included) would be willing to pay a resonable cost for boards and parts plus a profit to have you do the R&D plus the parts sourceing and packaging.
For my first big project, I chose an Aleph 2. It was simple enough for me to understand and had a very high audioplile pedigree. Harvardians group buy also simplified the decision, but If Nelson had offered boards at 10 times the price, I would have bought them. And I would have also bought a kit if it was offered. At the time of commitment, the only Info I could get about your amp was gobs of glowing DIY reviews, and you have to take such claims with a grain of salt.
What a pair
Thanks DX for having the ever optimistic view of life. It helps me through the day.
Thanks also to Hugh (who I see is also touched by DX's zeal) for allowing him to release a bit of the pie. If Nelson Pass had input which encouraged this as well, thanks to him too.
Maybe forum days ain't so bad after all.
In all seriousness, thanks to all that contribute and make this a place where I can learn, even at my slow pace.
Sandy (enjoying the music as we speak).
Thanks DX for having the ever optimistic view of life. It helps me through the day.
Thanks also to Hugh (who I see is also touched by DX's zeal) for allowing him to release a bit of the pie. If Nelson Pass had input which encouraged this as well, thanks to him too.
Maybe forum days ain't so bad after all.
In all seriousness, thanks to all that contribute and make this a place where I can learn, even at my slow pace.
Sandy (enjoying the music as we speak).
Thank you all friends, have your seat belts attached?
Hello Grim..... like you (Grrrrrrrr!)...not dislike, we are brothers...now!, not yesterday!
The amplifier is the most basic form that can make good sound, there are around 7 modifications that increase a lot the sound, and not only parts, but also the material used to build the mentioned part.
This way will work good, i tested few hours ago...I could perceive differences.
Diferential transistors are matched 2N5401
Bias multiplier can use BD139
Voltage amplifier cannot inform, a lot of them works there
Drivers are 2SC4793 and 2SA1837
Output are 2SC5200 and 2SA1943
VBE multiplier transistor can be mounted over 2SC5200
Bias is 50 mA, and re-adjust again some minutes after first adjustment
100 Ohms resistor connected to Voltage Amplifier transistor is a trimpot, small variable potentiometer.
If you do not reach the bias current, change R12 value
Voltage is plus and minus 36 Volts and power will be 55 Watts RMS over 8 ohms with 0.65 Volts RMS input
My thanks to Hugh that decided to show this amplifier to us, try it first, and them can here to tell us some evaluation.
regards,
Carlos
Hello Grim..... like you (Grrrrrrrr!)...not dislike, we are brothers...now!, not yesterday!
The amplifier is the most basic form that can make good sound, there are around 7 modifications that increase a lot the sound, and not only parts, but also the material used to build the mentioned part.
This way will work good, i tested few hours ago...I could perceive differences.
Diferential transistors are matched 2N5401
Bias multiplier can use BD139
Voltage amplifier cannot inform, a lot of them works there
Drivers are 2SC4793 and 2SA1837
Output are 2SC5200 and 2SA1943
VBE multiplier transistor can be mounted over 2SC5200
Bias is 50 mA, and re-adjust again some minutes after first adjustment
100 Ohms resistor connected to Voltage Amplifier transistor is a trimpot, small variable potentiometer.
If you do not reach the bias current, change R12 value
Voltage is plus and minus 36 Volts and power will be 55 Watts RMS over 8 ohms with 0.65 Volts RMS input
My thanks to Hugh that decided to show this amplifier to us, try it first, and them can here to tell us some evaluation.
regards,
Carlos
Attachments
Re: Good idea, i think i have one of them here.
Your reply is strongly reminiscent of Groman(swe) alias Halojoy. No offence meant!
I even had the strong feeling he was back!. But of course this is all too simple and not good. You are living in Brazil and Carl Groman is up in the north of Sweden.
Hi Carlos,destroyer X said:
Your reply is strongly reminiscent of Groman(swe) alias Halojoy. No offence meant!
I even had the strong feeling he was back!. But of course this is all too simple and not good. You are living in Brazil and Carl Groman is up in the north of Sweden.
Folks,
My thanks to Carlos, who posted this indicative AKSA circuit with my full support.
I decided to publish an indicative AKSA circuit for the interest of members of this forum. I make it clear, however, that this is NOT the full AKSA circuit, which is quite a bit different. This is similar to the AKSA, and in fact very like Rod Elliott's P3A, for those of you who might know that circuit.
There are numerous detail changes, and a pcb layout, and some pretty careful component choice, which distinguish Carlos' circuit from the real thing.
Pavel's criticism is entirely correct. The 10R ground lift resistor is very important. A couple of power diodes across this resistor solves the problem, however.
Now, a few words about the AKSA approach/topology.
This is a conventional Bailey-inspired PP Class AB fully complementary SS power amplifier. This topology is widely used because it works, and incidentally has low parts count. With great care in operating point, layout and parts selection it can be made to sound very good indeed, but it has taken years to figure out all the details. For those who want to retrace the steps in the journey, here is the start point. For those interested in the destination, the choice is more commercial, but the work is now complete at affordable cost for the kit builder.
A word about chip amps. I have heard a few in recent times, and some of them are very, very good, entirely satisfying. However, there is still a place in the Sun for the discrete amplifier circuit, because side by side comparison reveals they do different things. For starters, the discretes have more power. And one should never forget that in terms of bang for the buck, nothing is superior to a chip amplifier.
Cheers,
Hugh
My thanks to Carlos, who posted this indicative AKSA circuit with my full support.
I decided to publish an indicative AKSA circuit for the interest of members of this forum. I make it clear, however, that this is NOT the full AKSA circuit, which is quite a bit different. This is similar to the AKSA, and in fact very like Rod Elliott's P3A, for those of you who might know that circuit.
There are numerous detail changes, and a pcb layout, and some pretty careful component choice, which distinguish Carlos' circuit from the real thing.
Pavel's criticism is entirely correct. The 10R ground lift resistor is very important. A couple of power diodes across this resistor solves the problem, however.
Now, a few words about the AKSA approach/topology.
This is a conventional Bailey-inspired PP Class AB fully complementary SS power amplifier. This topology is widely used because it works, and incidentally has low parts count. With great care in operating point, layout and parts selection it can be made to sound very good indeed, but it has taken years to figure out all the details. For those who want to retrace the steps in the journey, here is the start point. For those interested in the destination, the choice is more commercial, but the work is now complete at affordable cost for the kit builder.
A word about chip amps. I have heard a few in recent times, and some of them are very, very good, entirely satisfying. However, there is still a place in the Sun for the discrete amplifier circuit, because side by side comparison reveals they do different things. For starters, the discretes have more power. And one should never forget that in terms of bang for the buck, nothing is superior to a chip amplifier.
Cheers,
Hugh
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