DreadPirate said:
Sorry to revive a rather old thread - but I bought this same kit about a year ago (maybe 18 months!) and have just got around to looking at building it.
I wasn't supplied with a schematic, and I was happy to find the copy you had posted. Mine differs slightly ffrom yours, in that it has two additional components in the feedback loop.
My board also has all component values on the silk screen layer.
I preapred the attached schematic, based on your poseted schematic, and comparing that with my PCB.
Tony.
EDIT: I can't seem to get the schematic clear here..
EDIT: Embed image.
Attachments
I've also noticed some people have been having problems with the transistor orientation.
I scanned the silk screen side of the board, and marked out (in orange text) the Base / Emitter and Collector pins.
This hopefully will help others who might be constructing this kit.
All the transistors supplied with my kit appear to be exact matches for the layout.
I scanned the silk screen side of the board, and marked out (in orange text) the Base / Emitter and Collector pins.
This hopefully will help others who might be constructing this kit.
All the transistors supplied with my kit appear to be exact matches for the layout.
Hi marcel5996
I may be a little late, I don't read the forum very often, but the first thing to check is where you attach your speaker. Of what you're saying it looks to me that you have connected the speaker between the negative power rail of your board and the ground (or from negative power rail and the speaker output). This way you're shorting through the speaker the negative rail.
If your amp is stable without load then your load is the problem. Check where are your terminals attached on board.
I may be a little late, I don't read the forum very often, but the first thing to check is where you attach your speaker. Of what you're saying it looks to me that you have connected the speaker between the negative power rail of your board and the ground (or from negative power rail and the speaker output). This way you're shorting through the speaker the negative rail.
If your amp is stable without load then your load is the problem. Check where are your terminals attached on board.
807 said:
Hans, Indeed there is an error with my schematic!
Well spotted - the upper network should be the same as the lower of course.
The PCB as supplied is correct - that was just my mistake.
I will correct it and repost the correct schematic.
Thanks,
Tony.
EDIT: The correct schematic is now displayed in the post above. The attached schematic is still wrong however - I could not edit that.
I built both boards today - my next steps are to construct a suitable chassis - and then test...
Taking stock of the various NAP 140 clones
I’m trying to understand the merits of the various NAP 140 clone kits and pcbs. From what I can determine there are at least four or 5 of these:
• Gigaworks kit (NAP 140/Avondale) design
• Tubeshunter kit -NAP140c
• Diyhifi.net (NAP 140-same board as tubeshunter?)
• Jim’s Audio Red NAP pcb
• Avondale NCC200
Forum members have posted their experiences on their technical and musical success or otherwise in building NAP 140 clones but it is often not clear which specific “variant” they are referring to. Also there a references to errors on pcb overlay and the need to change the quality of various components.
I was wondering if, as a result of this collective experience, there was some general consensus on which particular kit variant (after tweaking components and correcting errors in kits) was the best way forward-both technically and musically- and how well the best of these variants compares with the real thing?
I’m trying to understand the merits of the various NAP 140 clone kits and pcbs. From what I can determine there are at least four or 5 of these:
• Gigaworks kit (NAP 140/Avondale) design
• Tubeshunter kit -NAP140c
• Diyhifi.net (NAP 140-same board as tubeshunter?)
• Jim’s Audio Red NAP pcb
• Avondale NCC200
Forum members have posted their experiences on their technical and musical success or otherwise in building NAP 140 clones but it is often not clear which specific “variant” they are referring to. Also there a references to errors on pcb overlay and the need to change the quality of various components.
I was wondering if, as a result of this collective experience, there was some general consensus on which particular kit variant (after tweaking components and correcting errors in kits) was the best way forward-both technically and musically- and how well the best of these variants compares with the real thing?
Hi
I have built the tubeshunter nap140c kit and it works perfectly with no changes to the circuit, such as orientation problems etc.
the only problem I had was i could not seem to measure the voltage across the emitter resistors when setting up the quiescent current.
Other than that I would recommend without hesitation - I will probably buy another pair in the near future.
I am also really pleased with the sound, easily as good as my old Roksan Kandy (probably better actually !)
Graham
I have built the tubeshunter nap140c kit and it works perfectly with no changes to the circuit, such as orientation problems etc.
the only problem I had was i could not seem to measure the voltage across the emitter resistors when setting up the quiescent current.
Other than that I would recommend without hesitation - I will probably buy another pair in the near future.
I am also really pleased with the sound, easily as good as my old Roksan Kandy (probably better actually !)
Graham
http://209.85.227.132/translate_c?hl=en&sl=zh-CN&u=http://www.hifidiy.net/jhwz/200707/t20070720_1194.htm&prev=/search%3Fq%3Dhifidiy.net%2Bnap%2B140%26hl%3Den%26sa%3DG&rurl=translate.google.co.uk&usg=ALkJrhie4mENawCEpBkgvBBR67uErQylHg
Might be of some use? I got the diyhifi version, Havent started it yet, but it looks OK quality wise.
Might be of some use? I got the diyhifi version, Havent started it yet, but it looks OK quality wise.
Re: Taking stock of the various NAP 140 clones
I bought my kit from Tubeshunter - and the boards I received are marked Diyhifi.net - so I'm guessing it's safe to say they are from the same source.
I've also noticed that snow48_6 and gigawork seem to be selling **very** similar DAC boards on eBay (are these possibly from the same source too?)
Tony.
pattox said:
I bought my kit from Tubeshunter - and the boards I received are marked Diyhifi.net - so I'm guessing it's safe to say they are from the same source.
I've also noticed that snow48_6 and gigawork seem to be selling **very** similar DAC boards on eBay (are these possibly from the same source too?)
Tony.
There certainly appear to be two main variants of the Chinese supplied boards, referred to by some as the "long and thin" and the "short and fat". It appears from my ploughing through the threads that MOST of the board labelling errors seem to apply to the "long and thin" versions; most of the "short and fat" boards, like the gigaworks ones, do not seem to be incorrect in this respect.
I note that most of these boards appear at various times on www.taobao.com, which is worth a look, as is diydiy.net for one of the suppliers selling on taobao.
The "short and fat" boards are discussed at length in the following thread, which also provides PCB overlay files and layouts (and clearly shows how the boards are copies of the avondale circuit):
http://bbs.hifidiy.net/viewthread.php?tid=48492&extra=&page=1
in particular:
http://bbs.hifidiy.net/viewthread.php?tid=48492&extra=&page=2
You will note that the pdf file links on page 2 of the thread cause added confusion in that ALL all the capacitor and transistor numbers are different from the gigaworks ones, yet clearly the boards are derived from the same master layout which is attached in one of the posts...
My own boards (yet to be built) were bought in China from taobao before I knew about the above, and these are clearly similar to the gigaworks kit [but at a fraction of the price
]. However instead of 2 off 2705 transistors there's a 2705 and a 2240, so it is an interesting challenge to find which should be fitted where.......
Just my tuppence worth....
I note that most of these boards appear at various times on www.taobao.com, which is worth a look, as is diydiy.net for one of the suppliers selling on taobao.
The "short and fat" boards are discussed at length in the following thread, which also provides PCB overlay files and layouts (and clearly shows how the boards are copies of the avondale circuit):
http://bbs.hifidiy.net/viewthread.php?tid=48492&extra=&page=1
in particular:
http://bbs.hifidiy.net/viewthread.php?tid=48492&extra=&page=2
You will note that the pdf file links on page 2 of the thread cause added confusion in that ALL all the capacitor and transistor numbers are different from the gigaworks ones, yet clearly the boards are derived from the same master layout which is attached in one of the posts...
My own boards (yet to be built) were bought in China from taobao before I knew about the above, and these are clearly similar to the gigaworks kit [but at a fraction of the price
]. However instead of 2 off 2705 transistors there's a 2705 and a 2240, so it is an interesting challenge to find which should be fitted where.......Just my tuppence worth....
Re: Speaker Protection
There are several on Ebay.
Speaker Protection Modules on Ebay
Vellerman do a kit as well.
The world is your oyster, when you explore the "search" button!
DreadPirate said:
There are several on Ebay.
Speaker Protection Modules on Ebay
Vellerman do a kit as well.
The world is your oyster, when you explore the "search" button!