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preamp for aksa 55

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My B1 (symmetrical supply / no cap version) didn't match my AKSA 55N+ but worked extremely well with the NXV200 and a LM4780. I've found the AKSA tends to thrive with a pre with a low output impedance (<75R) and my B1 is a bit highish at 330R.

Personal experience only so cannot generalise.

I am a newbie with regards pre-amps.

AKSA doesn't have a particularly difficult input stage to drive from the perspective of the source. Even at 330R output impedance from a B1, that's well within the comfort zone from a technical point of view ?????
 
I would like to say that I am not very satisfied with the various problems I am having with this particular amp (AKSA). First of all there is the issue of hum and buzzing. It is more prone to the problem than my previous amp. It hums with some but not all things connected to it. Now when I approached Hugh about this, he said there was nothing wrong with the amp. My response is that the amplifier does not play music on its own. It has to be connected to something else therefore its all very well blaming the source, but that does not resolve the problem. Furthermore, I dont think its true to say that theres nothing wrong with the amp. It is partly to blame for the humming.

I have tried 2 commercial preamps now. Both brand new products both of which buzzed terribly and had to be returned at my expense. I just want to sort this out once for all.
 
Hello Kenji

Please, don't blame the Aksa amp, I know this amp and never it would do any hum and buzzing.

You just have a ground problem, maby cause by your wires connection, have you check all wires and the 10 ohm ground lift resistor ?

Be sure that your Aksa amp input wires ground are connect at one end only to the amp ground, if you connect both end of the input wire ground you will have a ground loop.

Those ground problems will bring hum and buzzing wen you connect your amp to most brand of preamps.

Bye

Gaetan
 

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My B1 (symmetrical supply / no cap version) didn't match my AKSA 55N+ but worked extremely well with the NXV200 and a LM4780. I've found the AKSA tends to thrive with a pre with a low output impedance (<75R) and my B1 is a bit highish at 330R.

Personal experience only so cannot generalise.

That's an interesting observation. I recall a number of preamps being tested on AKSAs at local DIY gatherings, and the pre that has done consistently well is a buffered attenuator, with output impedance around 3R.
 
Preamp for AKSA 55

I have heard both a Krell preamp (output impedance unknown) and a friend's home brew Solid State Class A preamp with an output impedance of <75 ohms driving an AKSA55, and there were absolutely no problems,
and only a small difference in performance, with the Krell preamp sounding slightly warmer.
Any problems are almost certainly due to the existing setup. Perhaps guidance should be sought from an experienced constructor who lives in the same area ?
SandyK
 
Hi Kenji,

Gaetan obligingly supplied a nice diagram which you might check out in a search for earth loops.

Please follow this through carefully.

I remember well when we originally chatted via email. I quickly formed the conclusion that you would not be happy with any amp supplied, and told you as nicely as I could. Your expectations were too high, and I was not confident you had the skills to assemble a project of intermediate complexity.

But you insisted, and I sold you a traded AKSA55 at lower cost which I'd rebuilt to a high standard.

Then the trouble began. You had a lot of trouble getting it going, and caused a lot of angst, not just for me, but for many others. All this had marked effect on the reputation of my product. Eventually, you found that it performed well, and you even complimented the sound quality at one point. Until then, you cast aspersions on the design, on my help, and demurred again and again on the good advice given you by others.

Now it is happening again.

I exhort you to find someone skillful in hifi, and ask them to have a good look at your system, and the documentation. Have a third party go over it, check everything you have done with your system, and make sure that there are no ground loops or poor placements. This will go a long way to fixing all your problems.

The AKSA is a pretty good amp, and inexpensive for the sound quality it offers. There is definitely a magic to it, which has been exceptionally difficult in my later designs to improve upon. Try to listen to people here, instead of finding fault and agonising in public about it. Nothing worth doing is that straightforward, hum and compatibility issues can take some perserverance.

Have a good look at Gaetan's diagram. It's very good, and identifies the critical factors in earthing.

Cheers,

Hugh
 
Alright AKSA, thankyou for your reply. I have a few further questions to you and Gaetan.

The AKSA is a pretty good amp, and inexpensive for the sound quality it offers.
What sort of price range are you comparing to?

There is definitely a magic to it, which has been exceptionally difficult in my later designs to improve upon
What is this magic you refer to that I can hope to eventually gain? Can you try to explain a bit more?

To Gaetan:

Can you tell me what the dfference is between the way the inputs are hooked up to the amps in your diagram and just taking a pair of wires from each input to each amp?
I'd like to know how such a minor difference and a short distance could make any difference.
In any case, that is not what the instructions say and that confuses me more.

cheers
 
Alright AKSA, thankyou for your reply. I have a few further questions to you and Gaetan.

What sort of price range are you comparing to?

What is this magic you refer to that I can hope to eventually gain? Can you try to explain a bit more?

To Gaetan:

Can you tell me what the dfference is between the way the inputs are hooked up to the amps in your diagram and just taking a pair of wires from each input to each amp?
I'd like to know how such a minor difference and a short distance could make any difference.
In any case, that is not what the instructions say and that confuses me more.

cheers

Hello Kenji,

I have lot of amps in my life, my best was a Crimson and a Radford, but the Aksa amp was sounding much better than those two amps.

A years ago, in the Montreal Audio Show, I did listen to many many high prices amps, only few very costly amps, like a VTL tube amp costing $15,000, was sounding as good as the Aksa.

Wen the Aksa are properly assemble and connected it sound with a 3D and life-like sound that we can really call magic.

Did you look a my second diagram ?

Even a very short ground loop wil do hum and buzzing.

Don't forget to show us the photo I've ask you.

Bye

Gaetan
 
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Ex-Moderator R.I.P.
Joined 2005
With all those crappy amps out there I can imagine you think a better amp is like magic
Its probably just a good amp
No better nor worse than other good amps
With a good amp the signal passes through with minimal change
What comes in comes out
Well, we may still have to wait fore the perfect amp that leaves the signal untouched

Your speakers and signal defines whether you hear magic or not
How you can promise all people that an ordinary good amp will give you unbelieveable magic is far out
Surely it takes a bit more than that
 
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Member
Joined 2002
Paid Member
Can you tell me what the dfference is between the way the inputs are hooked up to the amps in your diagram and just taking a pair of wires from each input to each amp?
I'd like to know how such a minor difference and a short distance could make any difference.

In any case, that is not what the instructions say and that confuses me more.

cheers

The standard way of connecting, as per instructions, work fine with my AKSAs. A single star earth with lift resistors on each PCB, but on your system could be different to normal.

When I have my AKSA connected directly to my source (no preamp) it is very quite. Conecting a tube preamp introduces a very small amount of hum that is not usually noticeable. I have tried a couple of cheap DVDs (double insulated) as sources and these caused servere hum when not playing music. Luckily my CD player and Transporter are very quite.

When looking for ground loops you need to look at your entire system not only each piece of equipment. Remember the safety earths are usually connecting all your eqipment's earths together back at the GPO. Look for any equipment that is connected to a different earth potential.

You need to consider if DIY is for you. If you are losing lots of sleep, it might be better to cut your losses and move on.

A good picture of the inside of your amp would be extremely useful.
 
Last edited:
Member
Joined 2002
Paid Member
With all those crappy amps out there I can imagine you think a better amp is like magic
Its probably just a good amp
No better nor worse than other good amps
With a good amp the signal passes through with minimal change
What comes in comes out
Well, we may still have to wait fore the perfect amp that leaves the signal untouched

Your speakers and signal defines whether you hear magic or not
How you can promise all people that an ordinary good amp will give you unbelieveable magic is far out
Surely it takes a bit more than that

It's all relative and personal taste. You can use whatever terms you like to describe a subjective experience. :eek:
 
Ex-Moderator R.I.P.
Joined 2005
Well, I suppose at first it really is magic
After a while you get used to it, and it just sounds as usually

What can I say
I have heard a very expencive setup with expencive ATC SMC150 Aniversary, top of the line NAIM electronics, expencive cables
No complains, it really did sound good, and I admit I actually expected worse
But it didnt impress me none either
But if you are used to very good sound, whats there to expect
But magic? Please dont call it that
MUSIC is magic
Life would be pointless without music
Electronics i just a tool

I would say too many people expect the electronics to deliver this special feeling of magic
Point is maybe too many people just doesnt understand how to listen, how to feel the music
Maybe we should learn to listen first, learn how to feel the music vibrate in the blood
Thats where the magic of music is
 
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Preamp for AKSA55

"When looking for ground loops you need to look at your entire system not only each piece of equipment. Remember the safety earths are usually connecting all your eqipment's earths together back at the GPO. Look for any equipment that is connected to a different earth potential.

You need to consider if DIY is for you. If you are losing lots of sleep, it might be better to cut your losses and move on.

A good picture of the inside of your amp would be extremely useful.- Greg Erskine"

I agreee 100% with everything that Greg has said here.
As not all connected equipment has a hum, it is possible , although unlikely, that the dwelling itself has a faulty mains earth. I had a problem like that many years ago, and the main electrical earth at the premises was corroded. All kinds of hum and interference came through the amplifiers used at the time, until I corrected the fault. This would need to be checked by an electrician,and NOT as I did back then !

SandyK
 
Member
Joined 2002
Paid Member
Well, I suppose at first it really is magic
After a while you get used to it, and it just sounds as usually

Hi tinitus.

Maybe you should do what I have done, kept every amp that I have built or purchased. This way you can swap between your amps and get the magic over and over. :D

Yes there are amps out there as good or better, but you have to draw a line somewhere on costs and effort.

I understand your objection to the term "magic" but hey...:)

regards
 
Ex-Moderator R.I.P.
Joined 2005
I understand your objection to the term "magic" but hey...:)

Yeah, a nice magical word
I also object to the use of "science"
Any kind of magical component could lead to forgetting the importance of

Solid engineering
Good craftmanship
Good practice
Hard work
Knowledge by study
And not to forget the use good common sense

Those are the "magical" words

Its like violin building
Most people think its all very delicate work
I can tell you, some of it is also heavy work
And to learn it is hard work

None of it comes easy
Maybe thats the point
That you cannot BUY good sound
It takes hard and serious work
 
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Hello Kenji,

I have lot of amps in my life, my best was a Crimson and a Radford, but the Aksa amp was sounding much better than those two amps.

A years ago, in the Montreal Audio Show, I did listen to many many high prices amps, only few very costly amps, like a VTL tube amp costing $15,000, was sounding as good as the Aksa.

Wen the Aksa are properly assemble and connected it sound with a 3D and life-like sound that we can really call magic.

Did you look a my second diagram ?

Even a very short ground loop wil do hum and buzzing.

Don't forget to show us the photo I've ask you.

Bye

Gaetan


Hello Gaetan,

here is a video I made which shows the inside:
Download Video.mp4 from Sendspace.com - send big files the easy way
 
Hello Gaetan,

here is a video I made which shows the inside:
Download Video.mp4 from Sendspace.com - send big files the easy way

Hello

Your video of your Aksa amp are interesting, you go a bit fast but I still can see few things. A photo showing all the inside of the amp in one close shoot would be usefull.

All your wires routing are not very good. Power supply wires should be keep short and you should twist them and put them away from input wires and input section of the pbc.

You have a ground loop wen you connect your Aksa amp to a preamp.

I have extract two frames of your video, and circle the problems.

You use insulator on your RCA, that is ok, but you connected the input wires ground at both end, wen you will connect most preamps you will have a ground loop.

Look at the photos of your amps input wire and look a the two diagrams.

You can see in the first diagram that there is a ground loop wen a preamp are connect to your amp.

You should do as the second diagram.

Bye

Gaetan
 

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Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.