Dx Precision, finally released... now debugged and better than HRII

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In the reality Nico, i do not like the name BOM...bill of material

This is the way Greg made the part list.... i do prefer part list then "bom".... but...bom really sounds good to brazilians...we have percursive minds and hearts... percursive ears...our tradition is this way.... we have African blood inside our vains, rithm is strong inside our souls.... we love drums, also bass sounds... we love rithm!

Related description of components in a list... i do prefer Part list, but when we work in a group, say, not alone, we cannot force all thing to be done the way we like...i do not like, even rectangular boards, and this is the way we have made Precision I...because needed to be done this way, because the number of transistors...also i would prefer they assembled all around the board..but this is bad to the layout...well... we do not do whatever we want..we have to obbey what is rigth and wrong and share to everybody the rigth to include their own ideas into the baby amplifier that will born.

Greg have taken to himself whole responsability to prepare a nice site, with all informs needed to build the Dx Standard.... this was so great that i had not the courage to ask him to substitute BOM by part list..... this is a very small detail compared to the precious hard work he have done... this is the only thing i would change in his work...something very, very, very small to bother him.

regards,

Carlos
 
PhongVuTuan... to be more safe use voltage around 50 volts plus and minus

Power will be around 200 watts into 4 ohms... and transistors will share this power, this will be safe to them...even if you plug 4 ohms they will survive.

Use 15000uf each rail to the supply filtering, and this is to each channel

reduce your zener diodes voltage values, to 30 volts and 18 volts, and this, in series will result in 48 volts.

Just that!... and use the Precision I schematics provided.

Search of a good voltage amplifier transistor, something good as 2SC4793 or a lower capacitance unit...high speed unit that can hold more than 100 volts from colector to base...use heatsink on it....MJE15031/31 can be used..of course the NPN unit must be used (do not like them..but works...loves to oscilate too).

Yes Phong, i know your transistors are huge...they can hold more power...... not really too much power dear Phong.

They dissipate more power but under 25 degrées celsius.... in real world temperature, the good idea, safe idea, is never make them dissipate more than 60 watts each one.

Good luck Phong.

Carlos
 
Got around to takeing some measurments now.

Offset... well my meter is haveing a hard time reading any... kind of switches between 000 and 00.1mV surprisingly as it was a little higher before transproting the parts over to the factory board... checked vbe of front transistors and all looks good between 590 and 700mV... remember I am running off a higher than standard rail voltage. Also there can be up to 10% diffirence between models just because of zener diode tollerances....

It was pretty neat to see voltages measured compareing pretty well to simulated voltages Carlos supplied me with...

I recommend 2 BOM changes...
R16 still 10k but 3 to 5W... can be easily added under the board if too big for on top... I think I have a 2 or 3 watt in there and it is running too hot to my liking 120V over it....
R6 still 3k9 but 2 to 3 W... also because it runs very warm. seeing 40V+ over it.
 
Fully agreement Nordic..if you said.... it will be changed

Understand this stuff as already changed.

Near future we gonna ask Todd to include the watt value into the schematic.... for a while we gonna keep builders informed about that.

So, R6 and R16 to be changed by 2 or 3 watts resistance..same resistive value.... good... Hello Todd Johnson!... are you there?

regards,

Carlos
 
If it is unessecary will be unnecessary too

ahahaha.... gladly i have found someone that type so bad as i do.

Jion the culb of changing lettres.... join the club of changing letters.

Will go running to the dictionaire to see if unnecessary really exists...seems strange to me...maybe because the unessecary of something alike.

Interesting as our brain fill the gaps... if we have the first and the last letter correct we can read, no matter how confused can be the letters, how scrambled they can be...... if brain do that with the reading, the vision.... so, can do the same with audio...so...we complete gaps, reason why we can listen MP3 and some bad audio too...filling the gaps.

When we put a small portable radio against our ears, we cannot listen bass..because it do not reproduce bass...but we listen bass...so, my conclusion is that brain filled the gaps using our memory, or musical experience.

regards,

Carlos
 

taj

diyAudio Member
Joined 2005
Re: Fully agreement Nordic..if you said.... it will be changed

destroyer X said:

Near future we gonna ask Todd to include the watt value into the schematic.... for a while we gonna keep builders informed about that.

So, R6 and R16 to be changed by 2 or 3 watts resistance..same resistive value.... good... Hello Todd Johnson!... are you there?

I'm here brother Carlos. Make a list of things to be changed. I'm too busy now to make lists, but always happy to do everything on your list. :angel:

..Todd
 
It is just to write, into the schematic, the pdf file

to R6 and R16, that they must to be 3 watts resistance.

Just that my dear...and do not need to run with that.

We are already posting here and people are reading..so..they are informed...the schematic with those indications can wait several days if you need that time.

Just to put indications, near those resistances, that 3 watts resistance is needed there.

Thank you very much.

regards,

Carlos
 
Olalá...... Good to see ya around Fardo

My best regards to you.

I cannot show the boards by the other side vision... this is another amplifier, not a Dx Amplifier...this one even better.

Créu!

Carlos
 

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Hi Jose, I sent you a mail a while ago allready... there was a problem with your transaction... not your fault... the processing people just took too long, which made the authorisation expire...you were not charged. I did keep your envelope hopeing to hear from you...

Luckily it only happened with 3 people as it is quite a pain in the behind...

My wife is calling me to come eat, but when I am done I will drop you a mail again... just give me a shout if you do not receive it... I am haveing some problems with sending e-mail lately.. they go out... but are not delivered, nor do they return as undelivered...

My PC is realy due for a reinstall...
 
I am very sorry by that Fardo

Pôxa Fardo, eu sinto muitíssimo, já não é a primeira vez que minha gente acaba se dando mau.... já aconteceu de estraviar um pacote contendo placas de HRII... o nosso correio Brazuca deu sumiço.... essa foi a informação que chegou até o Nico e que êle me repassou.... muito chateado, muito constrangido com o ocorrido... parece que o prejudicado voltou a comprar kits e o Nordic tentou recompensá-lo pelo prejuizo, incluindo peças extras, portanto, tratamento VIP.

Well Fardo, i deeply sorry about that, it is not the first time that my own fellow citizens find problems.... already happened some loss... a package containing boards to HRII was lost... well.... this is the information some Brazilian folk sent to Nico.... well.... we never know who did the ship.... our brazilian mail have "eated" that package is what is inside our beliefs.... i am sure Nordic is honest...maybe this is one of his personal problems, to survive in a happy way facing the dirt world we are living now a days, in special in the South Hemisphere.... he is honest and decent .... in excess maybe.

Êle têve prejuízos na entrega das encomendas do HRII, acabou pagando do proprio bolso... eu tenho insistido para que êle coloque alguns centavos em cada nova encomenda, por conta do prejuízo havido, para reaver aquilo que foi perdido por falha administrativa...mesmo assim êle não fez... ficou com o prejuízo pra sí mesmo.

He had losses of money to face the HRII orders, and he finished paying that bill by himself... i have been trying to suggest him to include some cents in every new order he receive from forum folks, just to obtain his money back, in a very slow way..... but, the new orders are not beeing made by the same old folks that have ordered previously to obtain HRII kits, reason why he did not that... he accepted for himself, those losses of money ... was considered, by him as ; "losses that were consequence of bad management"... i think this is something very honest.... maybe in excess, evaluating using the reference of our own place... a highly corrupted environment where this kind of behavior use to be a rarity.

regards,

Carlos
 
Yes, the poor gentleman from Brasil said he tracked his package to a post office 2km form his house... after which the trail went dead...it just "dissapeared" at the postoffice... doing the group buy at cost obviously leaves me with no margin with which to replace lost mail articels, but so far I am only aware of 2, 1 to Brasil and 1 to Chile. Both countries many sites explicitly refuse to ship to. At least I try, and keep the stamped receipts from the post office.

I think between the 4 diffirent PCBs I produced now I havelearned all the mayor lessons of things that can go wrong and need to be done in advance to avoid hidden costs...
Priority one is to have the diffirent products weighed and change the sho[[ing cart to addapt the shipping cost by weight... this would lead to lower shipping prices for smaller orders and obviously tho opposit for larger orders, which at the moment is rapeing my bottomline... But I am gratefull for the orders, it is wonderfull to have such a challenge to wake up to every day...
Mailbox full with questions etc... Realy meeting nice people in the process...
 
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