NAP-140 Clone Amp Kit on eBay

[huggygood]

if you want low thd,build this : Album Archive - Matti Otala amplifier
if you want a listen to musique,build a naim amp and listen to musique ...
the simulation is good to get an idea but the best way to know how to sound an amp is to listen to it.

 

[mjf]

Well, I think I will give up.

The THD results I get, even at 1W, are much higher than those in that site.

If someone has simulated the Naim with better results, now it's a good time to show them.

Same thing for the NAP 200 circuit above.

......yes, the bc input transistors are c-type........have you tried out bc550c or so what?

 

[carlmart]

Just did, a 45v type by NXP. The usual ones are for 30v.

Nothing changed.

 

[Bigun]

If someone has simulated the Naim

There are plenty of simulation files in this thread:TGM10 - based on NAIM by Julian Vereker

I used Spice to design a proper thermal management for the amplifier, it doesn't rely on the ad-hoc method Naim used in the early models that catches people unawares. The as-built results were excellent. And the simulations also illustrated why the special networks on the base of the driver transistors were used and are needed.

 

[penmarker]

I used to be in the camp of "If you use the same parts that measure ok then the sound will be the same as the original," but a few months ago my friend came over and brought his NAC52 pre clone and LJM MX50 power amp built from a kit. The MX50 sounds marginally better than my NAP200 clone, the mids were sweeter and music had a sense of presence in the room. Female vocals appear in the living room and all in all it was a better amp.

So it made me think, the NAP200 is somewhat a legendary amp, it couldn't be surpassed by some kit from China? Plus I've replaced all the sands and caps with similar parts following Algar Emi's and Acoustica.org. But same parts are not the same as carefully tuned and tested parts with stringent standard checking like Naim's.

I changed my mind that day, it was truly a humbling experience.

Either that or the MX50 is really better than NAP200 lol. Those who knows should chime in because I certainly don't.

 

[huggygood]

no better I think but different.
the mx50 is much easier to implement, the naim requires a real research work on the components and their assembly.
I try not to trust the simulation results of an amp for years,
I listen and with several different speakers because depending on the speakers it does not sound the same.
and then, it must be said, in some amp we can just throw the components in and it works already very well, and others, we must sort, select, adjust to get the best.

 

[gaborbela]

I can not agree more with this statement! I spent countless hours on my Naim Clone until I arrived at the NCC200 Clone and even with that. In the end, I messed up I used some hookup wire like Cardas has no signal way and the whole amp sounded muddy and I got so displeased I turn away for a while. Now I need new PC boards because of the 100X PC boards can take it any more. Meanwhile, I found the Greg Ball modification so I want that option to be available on the new PC boards (homebrew)
I got ill, some PTSD so not much progress the last couple of years. What I want to say anything can and very likely will affect the sound of the amp. Plus when you use new parts there is a burn in time on it so slow progress. One can ask why I do not buy the NCC200 clone and I would be almost there. I am a DIY-er plus when you live on disability and other projects on the table (including my own amp) and only use DALE or better resistors or boutique parts it cost a lot. DIY experimenting is not cheap.

By the way, did you test any mx50 eBay clone (if yes can you share it with us) and you found it better or this statement based on a simulation only?

 

[huggygood]

@ gaborela.
I will answer you on the last subject because there I eat and I go back to work, I will answer you more completely tonight.
I had both, the AX50 MF originals and the clones.
What I can tell you is that I preferred the originals but I did not like them.
they are not bad but tiring to listen.
when clones, it's the same signature but more messy and noisy.
tested on JMlab speakers, elispson 1303, jbl 4312 and L200.
now, I do not have these speakers, maybe I would have to try again, I still have the clones.
for naims, I always found what I was looking for.
black curtain
Zen
music and happiness of every day

 

[huggygood]

go, it's gone for a ride.
I bought a pair of pcb amp, a pcb of power suppy, I selected all the transistors
and the capacitors, I am now looking for a not too ugly aluminum case
and a toroidal transformer has two secondary and two middle point

 

[Dave S]

I used to be in the camp of "If you use the same parts that measure ok then the sound will be the same as the original," but a few months ago my friend came over and brought his NAC52 pre clone and LJM MX50 power amp built from a kit. The MX50 sounds marginally better than my NAP200 clone, the mids were sweeter and music had a sense of presence in the room. Female vocals appear in the living room and all in all it was a better amp.

So it made me think, the NAP200 is somewhat a legendary amp, it couldn't be surpassed by some kit from China? Plus I've replaced all the sands and caps with similar parts following Algar Emi's and Acoustica.org. But same parts are not the same as carefully tuned and tested parts with stringent standard checking like Naim's.

I changed my mind that day, it was truly a humbling experience.

Either that or the MX50 is really better than NAP200 lol. Those who knows should chime in because I certainly don't.

Did you use the same PS (transformer, rectifier and caps) for both amps? This makes a big difference to the sound and is one reason why a clone may sound rather different to an original.

The older Naim topology is voiced for a particular sound. IMO it sounds good at low listening levels and somehow makes unfamiliar music sound "right" e.g. I can listen to Radio Paradise at background listening levels on my NAP200 clone all day. OTOH I much prefer my Leach amp for serious listening. The MSG effect of the Naim is just too much when the volume is higher.

BTW, if you want to make the Naim sound like most other amps... short out the collector resistor of TR2 and replace the output resistor with the usual coil//resistor.

 

[traderbam]

Well, I think I will give up.

The THD results I get, even at 1W, are much higher than those in that site.

If someone has simulated the Naim with better results, now it's a good time to show them.

Same thing for the NAP 200 circuit above.

You may want to try transistor models from the manufacturers' websites. Your .asc file doesn't include the models you have chosen. Best to set the output transistor bias current to 20mA to 30mA.

 

[rensli]

Hi guys,

2SC2705 and A1145 did not come in time from ebay due to problems in china post office :S

This time i ordered them trought turkey post office... NCC200 is physically finished but,

does NOT work without VAS transistors ...


in Mean-time i build a dirty LM1875T, a pair into this awsome case Chips came new and as a gift.

I followed SC 20W LM1875 schematic, REMOVED 10R resistor from circuit to ground on both channels..

This 10R resistors ruin the sound when LM1875 being listened as STEREO from 1 PSU.

Avondale VBE in action, dropping to +/-25V from +/- 51V Regulatior radiators are hot and dangerous to touch... its MJ15003/15004 series... unkillable, especially with 20W amps on the output.

LM1875 is better in stereo, easier to the ear when compared to a naim clone. In overall.. hassle free ready to enjoy in 10-20m3 rooms.

On the other hand, LM1875 does not have soft "hits-hats", rhythm, valve like tone and ofcourse

The most i like about naim is the instrument like sound...most realistic.

 

[huggygood]

it working,you are enjoy,it's perfect

 

[rensli]

NAP 140 Clone on the left +/- 34.9V DC
H-140 Clone(NCC200) on the right +/- 37.8V DC

Both sound differenent.
In short:

NAP 140 very big sound, very rhythmic
H-140 clone dry, clear sound

I still prefer LM1875 @ home usage any time over everything Very good with all kind of speakers.


Will do few major mods to NAP 140 clones:

1. Replace aluminum case for wood and steel combination, result smaller heatsinks = a bit warmer outputs.
2. Replace all resistors with vishay MBB series 0.11€ cent per unit.

 

[savvas]

I can't see no NCC200 (i.e. original Avondale boards), most probably a fleabay clone which is far from both Naim and Avondale ones. Everything based on original RCA schematic, to my experience, relies pretty much in parts selection so any changes must be stated.

 

[Ian Finch]

Parts selection has to play a big part in any design that employs tweaked component values and specific semis to increase certain harmonics for enhanced details, perception of soundstage etc. I think that we need to have a clear idea of which parts do that before assuming that all parts could have an effect because most are not critical at all and some have been changed several times over the years in production.

Naim sound is really a system sound and there are also some issues with noise immunity in the simple design of the preamps which make a lesser but still significant difference to sound quality. The expensive SNAPS and HICAP outboard power supplies for preamps is a hint that there was a weakness there in a basic design that was just too simple .

FWIW, I've listened to around 50 Ebay clone builds by different people, myself included and never once heard anything like an original model. It doesn't take much effort to get them to around 75% there however, provided the major cost obstacles to low noise and good sound have already been met in good quality power supplies, matching preamp, shielding and using high quality speakers and source.

 

[rensli]

I can't see no NCC200

I have listened 5 different layouts of the same amp topology in the past 4 years.

Layout and cable tieng does not influence the "soundstage" or whatever in there. Good layout contributes more in "amp overall stability so it does not blow up in a long run" and cable tieng removes noise from the amp output.

Yes, i have listened to NCC200, from a +/- 30V regulated PSU, 1 channel.
MJE15031/32 drivers, MJL21194 outputs. It was ok, but maybe un-natural.

So i still remember how agressive, clear, dry sound could be made out of chinese H-140 clone without using any exotic tantalum or resistors.

H-140 is more natural then NCC200 also... its just 330+220uF cap and 2SA1145 combination sounds better to me.

IMO chinese ppl did a good job with a H-140.

NAP140 original clone is a different beast... its big sound.

Parts selection has to play a big part in any design that employs tweaked component values and specific semis to increase certain harmonics for enhanced details

Its true and i hate this part (

 

[Ian Finch]

Hi rensli - that's some more fine experimenting you are doing and it's great that you take the time to share it.

.. its just 330+220uF cap and 2SA1145 combination sounds better to me.

Unfortunately, there is no published schematic for H140, so we would need a kit to trace the schematic and follow your comments. Do you have any specific H140 schematic or parts description for it that you follow?

 

[savvas]

The expensive SNAPS and HICAP outboard power supplies for preamps is a hint that there was a weakness there in a basic design that was just too simple .

Yep, low PSRR of the design led to improved power supplies by Naim (that do make a difference) and empty pockets of customers.

There are key elements that gave Naim implementations their unique sound, namely one the usage of tantalum cap in signal and feedback path.
As for the tweaked versions, chinese or not, there are plenty of suggestions here or at PFM forum. IME the feedback cap can make you love it or hate it.

IMHO, I don't think ever the sound would lean on the neutral side of things, it has rich harmonics and it's strength is the PRAT making it such a joy to listen it to.

I haven't followed all the changes in the chinese clone but Les (Avondale) has new versions in which bigger power supply voltage and bias can be used. For those who came to love this particular sound, this could be the next step. Personally I much prefer to endeavor in this path than buy another chinese clone (although much cheaper and so more experiment-friendly)

 

[rensli]

Unfortunately, there is no published schematic for H140, so we would need a kit to trace the schematic and follow your comments. Do you have any specific H140 schematic or parts description for it that you follow?

Black PCB are same as these blue one's:

h-140 audio schematic - Google Search

Schematic is at home computer... i will get there tommorow.

On next month(may) i will start building new housing for both clones.
The only components i will re-solder are outputs and mica capacitors.

Rene