Let's ask Hugh what he thinks about it. The schematics was displayed on Rod Elliot's pages few years ago, later erased.
From what I know Hugh wishes not to make the schematics public and I suggest you all respect that, until Hugh says otherwise.
Ahem,
Paul, thank you for pointing out this thread to me. Appreciated.
Pavel, clever man that you are, please take down this schematic. 😡 It permits anyone so inclined to have a stab at an 'AKSA' with no compensation for the years I put into refining it. The result of this schematic, and certainly Upopa has his own 'kits' and would like to use them, is an inferior amp with ordinary sonics, not like the AKSA at all. This would be bad for reputation as well.
The ESP label indicates it is copyright anyway, please see his website. I've seen Rod pretty angry on this score.
In fact the schematic is is missing several fundamental components, something I requested of Rod almost three years ago to protect my ideas. We had quite a discussion over whether it should be public domain, and in the finish he agreed to take it down after a couple of weeks.
Actually, a good amp is equal parts topology, layout and component choice, so there is actually much more to it than a schematic.
I must, by necessity, take a very different approach to NP. I'm new on the block, sell only kitsets, and he's famous, sells a lot of retail amplifiers. We've been spoiled by this approach!! I'd like to share all my ideas around, but they are all I have, patent protection is illusory and expensive, particularly for electronics, and until I too can build retail I have no choice.
Accordingly, please remove the post, or if you cannot, take steps to ensure it is. I will thank you for it. 🙂
Cheers,
Hugh
Paul, thank you for pointing out this thread to me. Appreciated.
Pavel, clever man that you are, please take down this schematic. 😡 It permits anyone so inclined to have a stab at an 'AKSA' with no compensation for the years I put into refining it. The result of this schematic, and certainly Upopa has his own 'kits' and would like to use them, is an inferior amp with ordinary sonics, not like the AKSA at all. This would be bad for reputation as well.
The ESP label indicates it is copyright anyway, please see his website. I've seen Rod pretty angry on this score.
In fact the schematic is is missing several fundamental components, something I requested of Rod almost three years ago to protect my ideas. We had quite a discussion over whether it should be public domain, and in the finish he agreed to take it down after a couple of weeks.
Actually, a good amp is equal parts topology, layout and component choice, so there is actually much more to it than a schematic.
I must, by necessity, take a very different approach to NP. I'm new on the block, sell only kitsets, and he's famous, sells a lot of retail amplifiers. We've been spoiled by this approach!! I'd like to share all my ideas around, but they are all I have, patent protection is illusory and expensive, particularly for electronics, and until I too can build retail I have no choice.
Accordingly, please remove the post, or if you cannot, take steps to ensure it is. I will thank you for it. 🙂
Cheers,
Hugh
Hugh, I respect your desire to keep it non-public. I am just curious, however, what rights a person has if a schematic has been made "public domain".
It is like if I explained something to you here in the forum, I would not be able to patent it, according to my IP lawyer. Wouldn't that apply to schematic?
Plus, someone else, once saw the schematic, would be free to publish it, wouldn't he? I mean I wouldn't be too happy if someone goes after my "citation12" because it looks like P61, not that I would ever commercialize it, 🙂.
It is like if I explained something to you here in the forum, I would not be able to patent it, according to my IP lawyer. Wouldn't that apply to schematic?
Plus, someone else, once saw the schematic, would be free to publish it, wouldn't he? I mean I wouldn't be too happy if someone goes after my "citation12" because it looks like P61, not that I would ever commercialize it, 🙂.
AKSA said:
Hugh,
this is a great misunderstanding. Upupa does have his own circuits and kits, but they have nothing to do with "AKSA" topology, not in the least.
Pavel
Millwood,
You are quite right. There are no rights. I request the circuit to be removed as a favor to me and to my company; there is no legal compulsion to do so and certainly nothing can be patented in that circuit as published anyway. But one of the joys of this forum is that the denizens are not only intelligent hobbyists, but they are also decent, rational human beings. From what I've seen that doesn't apply in most forums. What was that said once about academic spats? 'And the fighting was relentless, and protracted and very nasty, because the stakes were so low'.
However, set aside the legal issues, which conspire against most original thinking anyway since the mindsets are so totally at odds. Consider that the more is known about the circuit, the more sales will suffer as people try to build their own to make what they imagine is a precise copy of an AKSA. It will sound ordinary, I lose sales, and the reputation is slowly eroded. You can easily get hold of schemats for the seminal amps of our time, but where they are still made, there are impediments, and often you need to pay for the service manual, or even prove you are a service technician to get them. This has no legal basis either, but it serves as a useful barrier to entry, and this prevents public domain exploitation. Barriers to entry are fundamental to the marketing cycle, obvious in the case of a complex, expensive commercial product, but trival for a kitset amplifier which can be assembled on the kitchen table.
Pavel, thank you for your cooperation. I posted to the administrator of the site as well. Much appreciated, and no bad feelings at all.
Now, where were we? Mosfets versus bipolars?
I choose bipolars every time.........
Cheers,
Hugh
You are quite right. There are no rights. I request the circuit to be removed as a favor to me and to my company; there is no legal compulsion to do so and certainly nothing can be patented in that circuit as published anyway. But one of the joys of this forum is that the denizens are not only intelligent hobbyists, but they are also decent, rational human beings. From what I've seen that doesn't apply in most forums. What was that said once about academic spats? 'And the fighting was relentless, and protracted and very nasty, because the stakes were so low'.
However, set aside the legal issues, which conspire against most original thinking anyway since the mindsets are so totally at odds. Consider that the more is known about the circuit, the more sales will suffer as people try to build their own to make what they imagine is a precise copy of an AKSA. It will sound ordinary, I lose sales, and the reputation is slowly eroded. You can easily get hold of schemats for the seminal amps of our time, but where they are still made, there are impediments, and often you need to pay for the service manual, or even prove you are a service technician to get them. This has no legal basis either, but it serves as a useful barrier to entry, and this prevents public domain exploitation. Barriers to entry are fundamental to the marketing cycle, obvious in the case of a complex, expensive commercial product, but trival for a kitset amplifier which can be assembled on the kitchen table.
Pavel, thank you for your cooperation. I posted to the administrator of the site as well. Much appreciated, and no bad feelings at all.
Now, where were we? Mosfets versus bipolars?
I choose bipolars every time.........
Cheers,
Hugh
Hugh, I don't disagree with your point of view. and appreciate your participation and helping out us arm-chair designers, 🙂
I would love to get your perspective on this. I would always go with a mosfet because I like them. I have blown many a set of bjts and not yet one set of mosfet (in a class B amp - I have gone through a couple recent on the JLH1969 MOSFET experiment). Plus, they are quite inexpensive for the kind of current they can take.
they may not have the linearity and gains of bjts but they sound every bit as good (to my ears anyway).
AKSA said:
I would love to get your perspective on this. I would always go with a mosfet because I like them. I have blown many a set of bjts and not yet one set of mosfet (in a class B amp - I have gone through a couple recent on the JLH1969 MOSFET experiment). Plus, they are quite inexpensive for the kind of current they can take.
they may not have the linearity and gains of bjts but they sound every bit as good (to my ears anyway).
Hi Pavel,
Many thanks, appreciated. I can see your point about your designs, too, often wondered about that. They are bloody good, I might add. I respect the original mind behind them, and would say in passing that your power follower ideas are something I too worked on almost ten years ago and in fact built a very good amp, a SE hybrid design using a tube/bipolar/mostet, which remains my standard reference. It produces 28W rms with 150W of heat - per channel.
Now, NP is encouraging me to publish the schematic of my hybrid preamp, the GK-1! Don't know what to think about this, it has some original circuitry in it I'm a bit diffident about sharing around...
Cheers,
Hugh
Many thanks, appreciated. I can see your point about your designs, too, often wondered about that. They are bloody good, I might add. I respect the original mind behind them, and would say in passing that your power follower ideas are something I too worked on almost ten years ago and in fact built a very good amp, a SE hybrid design using a tube/bipolar/mostet, which remains my standard reference. It produces 28W rms with 150W of heat - per channel.
Now, NP is encouraging me to publish the schematic of my hybrid preamp, the GK-1! Don't know what to think about this, it has some original circuitry in it I'm a bit diffident about sharing around...
Cheers,
Hugh
As we discussed privately, it is my thesis that you will sell
more kits if the schematic is widely discussed. I might be
wrong, and it's not my money.
more kits if the schematic is widely discussed. I might be
wrong, and it's not my money.
millwood said:
Partially correct. You wouldn't be able to patent internationally (e.g., PCT) after public disclosure, but you'd have one year in the US to file for a US patent.
Shouldn't that be in the Everything Else section
"Hugh, I don't disagree with your point of view. and appreciate your participation and helping out us arm-chair designers,"
You design arm-chairs? 😕
"Hugh, I don't disagree with your point of view. and appreciate your participation and helping out us arm-chair designers,"
You design arm-chairs? 😕
Fred,
How dreadfully naive of you!! A defacto Australian too (of course, Texas is MUCH smaller than Australia, but I digress).
Of course we design arm chairs here; didn't you know? We are presently discussing the perennial choice between mosfets and bipolars; these are heady matters in arm chair design, and knowing your expertise in this matter I am appalled you've not even considered this....
What precisely are your thoughts on parasitic oscillation of arm chairs? Dominant poles? Hidden zeroes? Have you pondered on the issues of open loop gain where children are concerned?
Doubtless some smart-**** will suggest the use of a swinging choke to control the recliner function. For once in my life, words fail me.....
Cheers,
Hugh
How dreadfully naive of you!! A defacto Australian too (of course, Texas is MUCH smaller than Australia, but I digress).
Of course we design arm chairs here; didn't you know? We are presently discussing the perennial choice between mosfets and bipolars; these are heady matters in arm chair design, and knowing your expertise in this matter I am appalled you've not even considered this....
What precisely are your thoughts on parasitic oscillation of arm chairs? Dominant poles? Hidden zeroes? Have you pondered on the issues of open loop gain where children are concerned?
Doubtless some smart-**** will suggest the use of a swinging choke to control the recliner function. For once in my life, words fail me.....
Cheers,
Hugh
Re: Shouldn't that be in the Everything Else section
no, Fred. We tell experienced, successful designers like John Curl how they don't understand the circuits that they designed and that have worked well in the real world, 🙂, without a single success of our own to show for.
Fred Dieckmann said:
no, Fred. We tell experienced, successful designers like John Curl how they don't understand the circuits that they designed and that have worked well in the real world, 🙂, without a single success of our own to show for.
Re: Re: Shouldn't that be in the Everything Else section
Hi!
😀 😀 😀 😀 😀 Nothing beats irony! LOL
Well, to the topic: I was wondering why Rod uses such "high end"-mosfets (at least they are comparatively expensive), as opposed to for example NP often using "standard" IRFP240, which are about 20 % of the price of the mosfets for the new ESP amp...? Are they really that superior, or does the design of the amp simply require such devices?
Bye,
Arndt
Hi!
millwood said:
😀 😀 😀 😀 😀 Nothing beats irony! LOL
Well, to the topic: I was wondering why Rod uses such "high end"-mosfets (at least they are comparatively expensive), as opposed to for example NP often using "standard" IRFP240, which are about 20 % of the price of the mosfets for the new ESP amp...? Are they really that superior, or does the design of the amp simply require such devices?
Bye,
Arndt
Re: Re: Re: Shouldn't that be in the Everything Else section
They are a little more expensive, not exorbitantly so, if you look hard enough!
The lateral mosfets "start" earlier -- Vgs(t) is about 0.8 to 0.9 volts, at 100 ma and ~ 2.4 volts at 1 amp.
they also have much preferable thermal characteristics.
Cradle22 said:
They are a little more expensive, not exorbitantly so, if you look hard enough!
The lateral mosfets "start" earlier -- Vgs(t) is about 0.8 to 0.9 volts, at 100 ma and ~ 2.4 volts at 1 amp.
they also have much preferable thermal characteristics.
Re: Re: Re: Re: Shouldn't that be in the Everything Else section
Hi!
Well, the cheapest source for semiconductors in Germany (if they carry the needed device) is Reichelt (www.reichelt.de).
If I compare IRFP240 (1.35 € / piece) to 2SK1058 (5.10 € / piece), there is a huge difference, especially if you consider buying large quantities for matching.
I am interested in building the "new" ESP 100 project (the high power version with four mosfets per channel), but I simply can't afford buying something like 20 - 40 devices for matching...
Bye,
Arndt
Hi!
jackinnj said:
Well, the cheapest source for semiconductors in Germany (if they carry the needed device) is Reichelt (www.reichelt.de).
If I compare IRFP240 (1.35 € / piece) to 2SK1058 (5.10 € / piece), there is a huge difference, especially if you consider buying large quantities for matching.
I am interested in building the "new" ESP 100 project (the high power version with four mosfets per channel), but I simply can't afford buying something like 20 - 40 devices for matching...
Bye,
Arndt
Re: Re: Re: Shouldn't that be in the Everything Else section
those "lateral" type mosfets are more thermally stable than vertical type mosfets (the irfs for example).
Cradle22 said:
those "lateral" type mosfets are more thermally stable than vertical type mosfets (the irfs for example).
I think the lateral type MOSFETs don't have as much Vgs variation as vertical types. Certainly, Rod would never put out a project that required that MOSFETs be matched.
As an aside, I used to work for a pro audio company that made large (1kW) power amps using paralleled vertical MOSFETs. They never matched any devices and I never saw or heard of any failures. They just used 0.33 ohm source resistors and source-follower configuration.
About Reichelt - their prices are excellent for what I looked at. Do you know if they ship to the UK in small (<10) quantities?
As an aside, I used to work for a pro audio company that made large (1kW) power amps using paralleled vertical MOSFETs. They never matched any devices and I never saw or heard of any failures. They just used 0.33 ohm source resistors and source-follower configuration.
About Reichelt - their prices are excellent for what I looked at. Do you know if they ship to the UK in small (<10) quantities?
Hi!
I always thought I always had to match the devices, at least in order to achieve "high end" status... Therefore I never tried anything like P68, P100 or AlephX before... And certainly the Pass DIY people always match the transistors...
Well, as for Reichelt, take a look at this thread
Reichelt UK group buy
Bye,
Arndt
richie00boy said:
I always thought I always had to match the devices, at least in order to achieve "high end" status... Therefore I never tried anything like P68, P100 or AlephX before... And certainly the Pass DIY people always match the transistors...
Well, as for Reichelt, take a look at this thread
Reichelt UK group buy
Bye,
Arndt
Cradle22 said:
Quite contrary to often heard claims, paralleling unmatched devices, as long as reasonable load sharing is achieved, would lower distortion figures compared to matched devices (but not by much, so don't bet the next breakthrough in high end audio on it).
Operating at slightly different operating points, the distortion wouldn't match, whereas the signal does match, between devices. By elementary arithmetics, S/N would improve.
O.K. this is only an objectivist's idea of the picture.
Best Regards,
Peter Jacobi
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