NAP-140 Clone Amp Kit on Ebay

[gaborbela]

The problem when you use smaller capacitor than the required value you get less bass !
The amplifier sound will be total different .
I tested before ,after my experience you need the 10uF there .
Greets

[Bengali]

Now you know it is very difficult to answer your question, right ?

Lou

Hi Lou,

Thanks for the taking the time to answer and sharing. Yes, understood
sound quality is hard to say good or bad.

In the past, I built the my ref C type gainclone. I used it with the maggie
MMG's I had at the time which are 86dB. It did not sound good at all, just
harsh and bright. tried removing the coupling caps, different types,etc...
I sold it and the buyer said it sounded just wonderful with his speakers.

My simple logic is with speakers around 86dB, maybe it is not wise
to build class AB amps unless they can put out quite some power.

Maybe the NAP140's 70w output might suffice. I really don't know until
I try as you mentioned

I do like the sound of the aleph amp I built and currently use but the
idle power is just a killer.

[crispycircuit]

I bought the 140 boards from Jim's Audio and received the schematic but no parts list. Does anybody have a parts list with resistor wattage and cap voltage? My power supply will be 40V or less. I'd like to order from Mouser in case you already have Mouser part numbers. Thx.

[2Bak]

This kit comes with 100uf/16v caps at C3 and C5.



However the supplied printed circuit shows 47uf/50v caps at those positions.



Looks like they shipped it with 47uf at an earlier stage, but didn't update the printout.
I've also seen other circuits having 68uf there.

I guess you would be OK with 47uf, but I wonder what the consequences of using lower values would be for this amp...?

Thanks.

[marcel5996]

Hi, I built a pair of these NCC200 style clones (140-H) after building the other version (140-C). I only replaced the BC550 small transistors with BC546, the rest is as supplied with the kit (output is toshiba 2sc5200) . Dual mono psu with 30 volt secondaries (43v after rectification, too high?) They sound very nice but I measure 66-70 mv offset on both boards, exactly the same. Isn't this too high? Had 25-30 mv from the other kit (different components and output transistors). Any thoughts?

[gaborbela]

Hello
Please change the LTP (TR1 hFE) about 10% less than TR2 !
You can read about these on the NCC200 schematic .
These about to reduce the offset .

Greets

[kclusa@yahoo.co]

Hi,

The 47uF next to 1K will affect the gain of the amplifier.

In short, at higher frequency, the gain is (27+1)/1 = 28.
at lower frequency, the gain will be (27+1+x)/(1+x) < 28 where "x" is the impedance due to 47uF or 100uF.

In theory, higher capacitance value results in better frequency response. However, more bass does not necessary means better bass unless you have a perfect huge decoupling capacitor and perfect woofer. It is up to you to choose the right value. I believe Naim was using 47uF.

Why don't you just use whatever come with the kits then adjust the value later on as part of the tuning procedure ?

Lou

Originally Posted by 2Bak

This kit comes with 100uf/16v caps at C3 and C5.



However the supplied printed circuit shows 47uf/50v caps at those positions.



Looks like they shipped it with 47uf at an earlier stage, but didn't update the printout.
I've also seen other circuits having 68uf there.

I guess you would be OK with 47uf, but I wonder what the consequences of using lower values would be for this amp...?

Thanks.

[gaborbela]

Hello

The 100uF 16V is the input capacitor ?
If yes it is already way to high.
I agree with kclusa@yahoo.co , test your amplifier with the parts you got it .
If you think there is a room for improvement try it do after .
Usually I com pare one side to another .
Always leave one side the orig. set up ! When you are satisfied after you can adjust the another side to !

Greets

[2Bak]

Thanks both of you.
I'll start out with the 100uf values that came with the kit.

This kit comes with Nichicon Muse FW 220uf/50V and Nichicon Muse FX 100uf/16v. However, I will most likely replace those with either Nichicon's fineste (KZ) or Elma Silmic II.
Not that I've ever heard 'superior' types, but since I prefer to keep replacements after launch to a minimum I will probably drop those KZ or Silmics in to begin with...

Also I've ordered Styroflex to replace all the ceramics, and I will order some Yageo or Holco resistors to replace a few resistors in the signal path, as per Avondale's recommendation for NC220.

My present amp is a LM3875 Gainclone with fairly good parts, and this NAP clone is supposed to replace the GC. Hope it'll be worth it, otherwise I'll consider HPA-nxV200se modules from Holton Precision Audio.

Jan

[kclusa@yahoo.co]

Hello,

Just want to comment on these two capacitors.

Particular for Silmic II, it requires very long period of run-in time. Need 2-3 weeks of running before any conclusion. The sound will transition during that period.

Lou

Originally Posted by 2Bak

Thanks both of you.
I'll start out with the 100uf values that came with the kit.

This kit comes with Nichicon Muse FW 220uf/50V and Nichicon Muse FX 100uf/16v. However, I will most likely replace those with either Nichicon's fineste (KZ) or Elma Silmic II.
Not that I've ever heard 'superior' types, but since I prefer to keep replacements after launch to a minimum I will probably drop those KZ or Silmics in to begin with...

Also I've ordered Styroflex to replace all the ceramics, and I will order some Yageo or Holco resistors to replace a few resistors in the signal path, as per Avondale's recommendation for NC220.

My present amp is a LM3875 Gainclone with fairly good parts, and this NAP clone is supposed to replace the GC. Hope it'll be worth it, otherwise I'll consider HPA-nxV200se modules from Holton Precision Audio.

Jan