Author Topic: GECO AUDIO - kidNAP (naim/avondale derivative)  (Read 173728 times)

Offline GECO

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GECO AUDIO - kidNAP (naim/avondale derivative)
« on: October 23, 2011, 03:49:45 PM »
a while ago I started with a series of DIY kits that offer very good performance and easy to build.
maybe one of the more difficult ones to build is a NAIM NAP140 / avondale NCC200 derivative.

i have build 30 variants of this amp and this one is quietest of all of them. it is also the basic unit that I based my current amps on but I use more and bigger power supplies, servos and all over a more refined product.

seeing that I hold no IP on this except for the layout artwork. I will make it publicly available for anyone to build. the sound quality of this unit is way better than a lot of the commercial products that one might have access to. So be prepared that this will annihilate your beloved Rotel   ;) not to mention any AVR that you think might be any good.

one channel shown. Amp board. PSU with incorporated speaker protect.



« Last Edit: October 23, 2011, 04:08:41 PM by Rudi »

Offline GECO

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Re: GECO AUDIO - kidNAP (naim derivative)
« Reply #1 on: October 23, 2011, 03:50:40 PM »
the actual boards




Offline GECO

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Re: GECO AUDIO - kidNAP (naim derivative)
« Reply #2 on: October 23, 2011, 03:52:29 PM »
build into a box, one channel




Offline GECO

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Re: GECO AUDIO - kidNAP (naim derivative)
« Reply #3 on: October 23, 2011, 03:53:15 PM »



Offline undefined.za

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #4 on: October 23, 2011, 05:38:10 PM »
Simply beautiful.

I can't wait to start this build!

Rudi: Thank you so much for all of the commitment and knowledge you give to this forum. I am positive that I am not the only one that is extremely grateful for all of your hard work!

Offline johnc

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #5 on: October 23, 2011, 06:16:48 PM »
Shweet!

Could you post some basic specs such as output voltage swing etc?
Do you have any boards for sale?
Go to the centre of the gravity's pull, and find your planet you will.

Offline GECO

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #6 on: October 23, 2011, 06:38:10 PM »
you should get about 90W into 8 ohm.
rail voltages 45V

but to get a idea of what this thing is all about, just google NCC200
I can claim that it is better than the NCC200 in so far that I had a module and this one is definitely quieter, and that is all layout related, although that claim has already been made  ;D.
I also made changes from the original circuit and setup but essentially it is all the same thing.

I will sell the boards. you will need 4 boards in total and they will go for R400 to complete a stereo amp. you will get a full BOM and preferred devices list.
If somebody feels adventurous to make up complete kits they are welcome to do so.

BOARD SIZES 95mm x 125mm
« Last Edit: October 23, 2011, 07:04:48 PM by Rudi »

Offline GECO

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #7 on: October 23, 2011, 07:22:31 PM »
output devices that works very well with this amp.

MJ15003 - very good mids - tough as nails.
BDY58 - obsolete but sounds incredible. (pops if you breathe on it)
BUX10 - BDY58 replacement
MJ802 - very good all-rounder- jack hammer, almost indestructible and sounds good to.
BUV20 - very pricey but very good.
BUX98a - BUV20 replacement - cheap. needs some tuning but details can be provided.

Offline GECO

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #8 on: October 23, 2011, 07:31:34 PM »
preferred signal caps.
I have used hundred of various caps over the years in different applications. the one caps that I have found to be the most neutral without affecting the sound to much

both input and feedback
Hitano - low ESR, available from Communica and Electrocomp.


the tantalum on the input is a leftover from the Julian Vereker days. works surprisingly well.

Offline GECO

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #9 on: October 23, 2011, 07:37:52 PM »
setting up.

the best biasing current to use on this amp, ignore what is suggested for the NCC200

+/-35 V     20mA
+/-40 V     53mA
+/-45 V     78mA

Offline GECO

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #10 on: October 23, 2011, 07:40:14 PM »
output inductor and resistor values.

inductor - 1mm 10 turns.
resistor - 3R3 - 4R7 5W depending on transistor used.

Offline xumbug

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #11 on: October 23, 2011, 08:59:08 PM »
Nice one Rudi,

My caps are here ;D see you later in the week ;)

Stu
SDA Acoustics loudspeakers, Audio Research Ref 3 Pre amp and Ref 210 power amps, Bel Canto VB3.5 Dac, Pathos Endorphin cd player, squeeze box touch.

Offline GECO

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #12 on: October 23, 2011, 09:09:02 PM »
great stuff Stuart. I am looking forward to demo you the system as it is now and show you what the combination is capable of.

nice little amp this one  ;) very economical version of the one we've got. one can get some solid performance from it.

Offline GECO

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #13 on: October 24, 2011, 08:46:30 AM »
several people have shown interest in building this amp. please indicate if you are interested so I can order some boards. this should be a easier build than the F5 and setting it up is very easy. I will always be available to assist anybody that needs help. the heat dissipation in negligible and you can bolt it to the case without a heat-sink if you wish. (heavy load is then not recommended)

required for stereo
2 amp boards
2 PSU and speaker protect boards

R400 for all four

you still have to buy all components but to populate the boards and associated hardware to complete boards should be less than R600
cost of case and transformers is entirely up to you and how you spec them.

required. 225 -300va per side but it will be very happy with one 300va if you want to economise.

it is very possible to build a very high end amp for less than R2000

Offline Heinrich

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Re: GECO AUDIO - kidNAP (naim/avondale derivative)
« Reply #14 on: October 24, 2011, 08:58:06 AM »
DAMMIT Rudi.

i think a rule should me made of how long you should wait before you are allowed to post anything about another desireable project.
someone told me that i can make ice cubes with left over wine.
i am confused, what is left over wine?