Dartzeel amp schematic - build this?

[marigno]

No, I didn't.
I used the bare 108's PCB you find on eBay, Aliexpress, very simple to modify, look at the pictures.

I had to use two cable bridges (orange ones in the pic) because I cut, for a mistake, both tracks going to the diamond. You only need to cut one.

 

[desertstorm]

E2 EDITION

So you want to build the "Cu Edition", not the "E2 Edition".
The "E2 E" has a more conventional design and is easier to build than the "Cu E"
The "Cu E" is now detached from the HiFi set. It has some issues to be corrected, I'm waiting for some hardware to be delivered so I can tear it down, and modify it to upgrade it to the "E2 E".
However, the "Cu E" worked until a week ago, then I replaced it with the "E2 E".
You better start the "WHA-217 E2 Edition", using at least 6 final pairs. Read my post #2094 to see which transistors you can use.
Using a 50+50Vac transformer you are a bit under 200Wrms, it actually provides a 135Vdc (less than 140V peak value) with 180Wrms/8Ohm. If your purpose is to have a really high power you can use a couple of 600VA transformers with 55+55Vac secondary, resulting in 148Vdc, 220Wrms. With a 60+60Vac transformer, you will have 162Vdc with 260Wrms. Keep in mind that I tested the amplifier up to 156V but not over.

thank you so much sir i will try to Build your E2 Edition

 

[andrewlebon]

1 Paar Stereo Dual Channel Referentie Zwitserland Dartzeel NHB 108 Eindversterker Pcb|Operational Amplifier Chips| - AliExpress
Hello marigno
greetings is this pcb ok .
warm regards
Andrew

 

[marigno]

Yes!!!

 

[andrewlebon]

Hello marigno
greetings can a single sided pcb be used for servo feedback
warm regards
Andrew

 

[marigno]

What you need is a non-inverting servo made according to its schematic. A single servo is needed for this amp.
On eBay, you find a double servo so you can buy this one and have it work as a single one.
If you want to make the PCB yourself, choose a single OpAmp like OPA277, no matter if the PCB is single/double-sided. All film capacitors must be high-quality polypropylene 5%.

For the next referrals, please use the email address of mine you have, we don't want to bother other people in the thread.

 

[marigno]

WOTS WHA-217 E2

I corrected some errors in schematics, here are the good ones.

On Amp: Common points
emitter T1/R5 and
emitter T2/R6
must be not connected to the mass 0V

On servo: I forgot to colorize blue the 10MOhm resistors.

I also added a more friendly schematic for the Amp, easier to be read.

 

[Erlend Sæterdal]

Super Marigmo 👌

 

[xman2005]

Great man. Marigno

 

[levinson mark]

complementary stage

 

[desertstorm]

I corrected some errors in schematics, here are the good ones.

On Amp: Common points
emitter T1/R5 and
emitter T2/R6
must be not connected to the mass 0V

On servo: I forgot to colorize blue the 10MOhm resistors.

I also added a more friendly schematic for the Amp, easier to be read.

sir can i use this schimatic for 12 pairs final opt sir?

 

[paul_peraic]

Are there any ChiFi assembled amps that are for sale with this circuit ?

 

[marigno]

sir can i use this schimatic for 12 pairs final opt sir?

Sure you can. But you better refer to the docs I sent you last time.
For the next referrals, please, use my email address, we do not want to bother other people in the thread.
Ciao!

 

[marigno]

Are there any ChiFi assembled amps that are for sale with this circuit ?

Yes, you can find on eBay and Aliexpress the "original clone" of NHB-108 which you have to modify in order to add the final pairs, the xVbe, and the output filter. But I would prefer to buy a bare board and choose the components I like. The assembled board uses the MJE1503x transistors, which have a very different hFE among NPN/PNP. If you want to substitute them you have to be very careful in order not to damage the PCB; you better use a desoldering tool. Moreover, the assembled board does not have the four 2N5xx1 transistors thermally coupled and you cannot couple them, you have to buy new ones and do the operation by yourself, then replace the originals. You can avoid updating the two CCSs, but must substitute the 39Ohm resistor with a 360Ohm one, that will dissipate 0.061mW.

 

[desertstorm]

Good day once again sir Fabrizio sir regarding E2 amp sir with attach picture sirl just want to know with your guidance where i connect that feedback sir thank you sir

 

[desertstorm]

Sir this is my initial layout for WOTS WHA E2 i want to fix it using 3RU heatsnk sir

 

[analog_sa]

where i connect that feedback

Relax. The feedback is already right where it should be. Unless you want to dramatically re-engineer the concept.

 

[marigno]

Sir this is my initial layout for WOTS WHA E2 i want to fix it using 3RU heatsnk sir

You are a nice and very kind fellow, but you must put a better effort into this project.
The feedback... did you read carefully the text file I sent you?
Did you study all the schematics that belong to the project?
Did you realize how the layout is designed?
Do you know the main key point of this project is to have no feedback coming from its output? If you don't know this, why do you want to put your effort into building a so complex amplifier? There are lots of simpler solutions with feedback!
So, my suggestion is:
1) read, or better, study the txt file that introduces the project. It is the one I sent you, not the one in my initial post; understand well all the key points of this project;
2) look yourself in the mirror and understand if you feel ready to carry on the building of such an amplifier, it is not suitable at all for newbies;
3) do not change the layout, or use a layout similar to mine, remember some transistors must sense the heat from the final pairs.

Do not expect I can understand your pdf file, the only things I can see:
1) you didn't respect the constraint of placing the transistors in order to sense the heat of the final pairs;
2) the small transistors 2Nxxxx are not placed in a way that can be thermally coupled.
I had to stop, it is hard to look at your layout.

Last, but not least: in a forum, every member is supposed to know what is the concept of the ancient word "Netiquette": it underlies a group of rules, one of which is never to reveal any name of any member. Use my email address, you have it, we do not want to bother people in the forum with personal questions, and, please, do not send me any PM, it is nonsense since you have my email. You do not have to bother yourself to enclose documents here, everything is simpler with the mail, I can check my mail anywhere I am.

This is not meant to be a reproach, you just have to understand if you are able to carry out this project. You must be sincere with yourself! If you feel like it, and decide to continue, you can send me all the emails you want and I will be happy to guide you. There are lots of things to discuss in order to increase our knowledge. In this case, accept another suggestion: buy the bare PCB of the clone of NHB-108 from eBay or Aliexpress.

We, in this thread, expect your next post here not before one month (if you are super-fast), saying you did hear the sound!

For your convenience, you can find the text file explaining the project here enclosed as a PDF, it can be useful for some other members too.

 

[marigno]

Let's go further

The NHB-108 has been a very interesting experience and a good school. Now it is time to go a step further. So let's pick the good and leave the bad.
The DBT "Paragon Follower" sounds really great! And the Aikido is a state of the art.
I stop here, I am already way off-topic.
Just look at the schematic. A zero feedback main amplifier, to say no feedback loop, only local feedback.
WOTS WHA-337. Maybe someday it will have three dimensions.

 

[analog_sa]

And the Aikido is a state of the art.

In disagreement here, perhaps for the first time.