Hi Eric,
Wow, you went above and beyond on this review, Sir! Thank you, you've really given me a shot in the arm this morning!!
Your long, careful journey with the mains phase issue still fascinates me. I have decided to suggest to all constructors that the mains connections should be tried to assess which is the better wiring. It's not terribly difficult to do during assembly, but clearly it is VERY important. I believe this comes back to the interwinding capacitance in the transformer.
The NAKSA 80 had been designed, but not productionised, when I suffered my illness last year, in July. On discharge from hospital in November 2012, I was very uncertain if my brain was OK. I determined to go through the production process, so I could have the N80 professionally in an electronics factory, and with help from Paul my engineer friend, we got through it. It's a bit step from a schematic to a repeatable, easily made implementation. I did find a few damaged areas in my brain, but not in spatial and conceptual areas - only speaking and writing. When I started selling the N80 in May 2013 we took a deep breath - but there have been no issues and the performance has impressed most people that have heard it.
You mention that everything affects the sound of this amp. I thought this is 100% true, as we are working at the highest areas of analog sound quality. Even wire and cable will influence things markedly. I see this as inevitable, this is a race car, not a runabout, and speakers, cables, mains leads and positioning are critical for those seeking the best sound quality.
Thanks Eric, you'd made my day......
Groetjes,
Hugh
Wow, you went above and beyond on this review, Sir! Thank you, you've really given me a shot in the arm this morning!!
Your long, careful journey with the mains phase issue still fascinates me. I have decided to suggest to all constructors that the mains connections should be tried to assess which is the better wiring. It's not terribly difficult to do during assembly, but clearly it is VERY important. I believe this comes back to the interwinding capacitance in the transformer.
The NAKSA 80 had been designed, but not productionised, when I suffered my illness last year, in July. On discharge from hospital in November 2012, I was very uncertain if my brain was OK. I determined to go through the production process, so I could have the N80 professionally in an electronics factory, and with help from Paul my engineer friend, we got through it. It's a bit step from a schematic to a repeatable, easily made implementation. I did find a few damaged areas in my brain, but not in spatial and conceptual areas - only speaking and writing. When I started selling the N80 in May 2013 we took a deep breath - but there have been no issues and the performance has impressed most people that have heard it.
You mention that everything affects the sound of this amp. I thought this is 100% true, as we are working at the highest areas of analog sound quality. Even wire and cable will influence things markedly. I see this as inevitable, this is a race car, not a runabout, and speakers, cables, mains leads and positioning are critical for those seeking the best sound quality.
Thanks Eric, you'd made my day......
Groetjes,
Hugh
Let all us AKSA customers agree to give Hugh a shot in the arm every day!
Yes that's what I understand it to be, Hugh - and it is v. important!!
I have used an article from "Bound for Sound" as my bible, wrt mains transformer orientation, ever since I built my first AKSAs - what, 15 years ago? (I will look for the article when I get home tonight and hopefully edit my post to give the URL.)
Regards,
Andy
Hi Hugh,
Nice one Hugh!
That's a great review and well justified in my humble opinion!
One thought.. do you use a mains input filter on the Naksa 80? I had some experience years ago where changing the mains phase and earthing arrangements were subtlety changing the PSU RF rejection and as these days we all live in a wideband 'sea' of RF , maybe it is this that produces the audible differences. In one of my designs the removal of the Y caps from the input filter was credited by the customer with 'better bass.'
Unfortunately I could never prove or disprove this comment because I did not hear the amp in the setup where this effect was supposed to occur!
Nice one Hugh!
That's a great review and well justified in my humble opinion!
One thought.. do you use a mains input filter on the Naksa 80? I had some experience years ago where changing the mains phase and earthing arrangements were subtlety changing the PSU RF rejection and as these days we all live in a wideband 'sea' of RF , maybe it is this that produces the audible differences. In one of my designs the removal of the Y caps from the input filter was credited by the customer with 'better bass.'
Unfortunately I could never prove or disprove this comment because I did not hear the amp in the setup where this effect was supposed to occur!
Unfortunately, the original Bound for Sound article seems no longer to be available as the website is gone ... but at the below link, it's summarised:
Ultimate Setup Guide - Jul-Aug01 AUDIOPHILE AUDITION
Regards,
Andy
Mmmm, read the article carefully, Hugh. If you to do that, with the reversed power cord, you change the fuse from being on the Active to being on the Passive lead. Not a good idea, AIUI.
What you should do is:
* remove the earth plug from a double adaptor and then use this to plug the amp into a wall socket.
* then clip the power transformer primary wires to the input mains one way ... and measure the voltage on the case (relative to wall-socket earth)
* then reverse the connection of the power trannie primary ... and measure again.
Choose the connection which delivers the lower AC voltage and solder the power trannie primary. Then plug the amp directly into the wall (without the double adaptor).
Regards,
Andy
Yes, Andy, I can see this. However, if I find that the reverse lead sounds better, I can then reverse the primary transformer leads inside the box. Even if the reverse connection externally, the ground lead is not affected and the case is still grounded. I really need to do this quickly for testing purposes, and a reversed A/N power lead is a quick method so long as the ground is OK. Of course, you would start with the normal lead to see that the fuse does not blow!
Actually, there are many sockets in Australia which are incorrectly fitted. You can buy a neon test gadget that tests for this here; in many European sockets (Eric tells me!) that can be connected correct or reversed with the same two pin plugs!
Cheers,
Hugh
Actually, there are many sockets in Australia which are incorrectly fitted. You can buy a neon test gadget that tests for this here; in many European sockets (Eric tells me!) that can be connected correct or reversed with the same two pin plugs!
Cheers,
Hugh
Hi Hugh,
You are right. In almost all countries in Europe, except Great Brittain I think, we can turn the mains plug. Earth connection is on both sides of the plug (see picture). It doesn't make any difference. Your computer will work, the coffee machine will make coffee and the lights will burn. The only thing where it makes difference is audio. The right polarity sounds better. When you tell this to an electrician he will look at you in a strange way and think you are nuts. The only way to know if your polarity is oke is to meassure it. It has to be a routine. In the future it is the first thing I will do if I buy a new audio device.
You are right. In almost all countries in Europe, except Great Brittain I think, we can turn the mains plug. Earth connection is on both sides of the plug (see picture). It doesn't make any difference. Your computer will work, the coffee machine will make coffee and the lights will burn. The only thing where it makes difference is audio. The right polarity sounds better. When you tell this to an electrician he will look at you in a strange way and think you are nuts. The only way to know if your polarity is oke is to meassure it. It has to be a routine. In the future it is the first thing I will do if I buy a new audio device.
Attachments
Thank you Eric,
I will immediately build a 'reverse' lead, and then use it with a normal lead to compare and get the correct phase for fully built N80s that go out. And I will amend the instructions to reflect the issue too!
Thanks for your useful tip, it's very important to get it right.
Cheers,
Hugh
I will immediately build a 'reverse' lead, and then use it with a normal lead to compare and get the correct phase for fully built N80s that go out. And I will amend the instructions to reflect the issue too!
Thanks for your useful tip, it's very important to get it right.
Cheers,
Hugh
Hi Hugh,
You could always fit a changeover switch with instructions 'tune for minimum hum'
Hi Hugh,
You could always fit a changeover switch with instructions 'tune for minimum hum'
You're not actually "tuning for minimum hum", audiopip - you are deciding which way round gives you the better sound.
But, yes, I generally use a DPDT mains switch and reverse the wires on one side so 'down' is normal mains and 'up' is A-N reversed. But because I do the measurement test described in the article I linked to, beforehand, and then do the power transformer primary connections, I always use 'down' to turn on the component ... the 'up' uption is simply there to be able to demonstrate the sonic difference between the two modes.
Regards,
Andy
Which is why the Universe has given us the dpdt switch....
which I use (with center off) on my Lifeforce
Yes, the diagram should come in very useful for people, Paul.
My own wiring is exactly that. (Except I think the real world is in fact the reverse of what is written on the diagram! IME, when you have the toggle switch in a DPDT switch down, W is connected to Y and X is connected to Z! Whereas the diagram says this happens when the switch is up! )Regards,
Andy
Okay, I read this article. There is absolutely no explanation about how using the lowest voltage reading makes the sound better. It is stated that it does, and everyone accepts that without any explanation. BTW, what kind of voltage readings are we talking about here, a millivolt or something?
Thus, can anyone explain how the sound get better? Using a listening observation isn't really proof of anything as a lot of things can influence a listening observation.
What is really important is proper wiring in the wall and the little tester can tell you that. Furthermore, with proper safety precautions, one can easily correct any errors at the power point/wall outlet.
Sorry, Steven, you don't seem to "geddit" - although I agree that the article is not as extensive (in the explanation) as the original article, which unfortunately seems to have gone.
Yes, the wiring in the wall needs to be correct - as you say, you can buy a little testing device to check this.
As Hugh explained, this issue is to do with power trannie inter-winding capacitance ... connect the power trannie primaries to the (correctly wired!
) mains one way ... then connect them in reverse (no change to the mains wiring arrangement).One way will sound better.
If you know what factor you need to measure, to "measure" how well leading edge transients are produced ... you will be able to measure the difference. If you don't know what to measure ... then you won't. And voltages? - with one lead of the AC volt meter plugged into the wall-socket's earth hole and the other touching a screw-hole on the case - ie. the bare metal - you can read about 100v AC one way and 30v AC the other way (but remember, the component itself should only be connected to A & N - not mains earth). These figures are for Oz 240v mains.
If you're confused about why there should be a sonic difference, I recommend you get hold of a small book called "The Wood Effect" by Clark Johnsen.
Regards,
Andy
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Sorry, Steven, you don't seem to "geddit" - although I agree that the article is not as extensive (in the explanation) as the original article, which unfortunately seems to have gone.
Yes, the wiring in the wall needs to be correct - as you say, you can buy a little testing device to check this.
As Hugh explained, this issue is to do with power trannie inter-winding capacitance ... connect the power trannie primaries to the (correctly wired!
One way will sound better.
And voltages? - with one lead of the AC volt meter plugged into the wall-socket's earth hole and the other touching a screw-hole on the case - ie. the bare metal - you can read about 100v AC one way and 30v AC the other way (but remember, the component itself should only be connected to A & N - not mains earth). These figures are for Oz 240v mains.
If you're confused about why there should be a sonic difference, I recommend you get hold of a small book called "The Wood Effect" by Clark Johnsen.
Regards,
Andy
Hi Andy,
Of course I don't get it because that's why I questioned things.
Much of all this if based on the assumptions that power points/wall outlets and power transformer primary windings are improperly connected. It's not hard to do either, frankly.
Hm, when I get some time I might have to do your voltage check. Something just doesn't sound right with 30vac on a neutral leg. That, to me, is an electrical problem that needs correction. Neutral is supposed to be pretty close to 0vac, unless I just don't get that one either.
Steve
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