Destroyer x Amplifier DX HDII version. - Page 65 - diyAudio
Go Back   Home > Forums > Commercial Sector > Group Buys

Group Buys Members group buys

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th February 2008, 08:43 PM   #641
suds is offline suds  India
Banned
 
Join Date: Feb 2006
Location: Bangalore
Default DX HDII Clone PCB.

Hello,

Thanks to authors, carlos and nordic.

With their permission, and conditions.. I offer to provide custom PCB for DX HDII Amplifier.

PCB are made by me from Original schematic from authors website.
Designs are modified, Track Routing are modified for Double side PCB. These are not same / copy of PCB's sold by Authors. Schematic Part Values are not changed,

Before actual manufacturing of PCB, Prototype PCB will be assembled and checked.

Both Power Supply and Amplifier PCB Layout are complete.
Image of PCB will me made available.



Thanks
Sudheer.
  Reply With Quote
Old 16th February 2008, 11:22 PM   #642
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default I thank you very much, but the board manufacturer charge is into


Nordic responsability...he is producing layout and ordering boards and feeding forum folks with non profit boards into the group buy.

He is the one produces the layout, he decides the board supplier and evaluate if the board is well made or not... i just ask him to folow some ideas from me related parts position, shape, beauty and those secondary works.

Of course, your offer is nice and you can post your ideas if you want, you can show your boards and, of course, if someone turn interested to have them you can organize a group buy to them.

But really, it is now too late..... people already have bougth 100 boards that are around the world, many of them already assembled and playing nice sound.

But of course you are free to expose your works with my thank by your attention and kindness to try to help us.

Nordic is partner into this enterprise, i have to thank him very much by all his effort and repeat, in a very clear way, that the charge belongs to him as he is Dx Corporation Official distributor of boards and parts.... and the layout designer.

Your boards, ideas, layouts, cooperation, picture and all those things are very welcome.

Many thanks by your attention and kindness to spend time and effort into my amplifier.

regards,

Carlos
__________________
Dx Super A, Hajame test, 35V, 4 Ohms, T-line speaker, flat https://www.youtube.com/watch?v=bYIZejeSoeQ
  Reply With Quote
Old 18th February 2008, 03:03 AM   #643
diyAudio Member
 
Join Date: Jun 2004
Location: Champaign, Illinois
Default Re: ATTENTION, atenção, atencion, achtung, atento!

Quote:
Originally posted by destroyer X
ATTENTION!.... easier bias adjustment to HRII Post #4761. I found it boring ......

<snip>

1).....i have tried and result fine with 68pF into the Miller compensation....but 82pf will be good and 100pf will be excelent....not really needed to use 150pf.... reduce it as audio overall quality will increase a lot.

2) I felt not really needed condenser into the VBE multiplier, from coletor to emitter...but, if you like it...install 2uF there..positive to colector.

<snip>

3) I decide to adjust it to low bias...was not bigger than 40 miliamps
__________________
http://users.tpg.com.au/users/gerskine/dxamp/
Dear Carlos, thank you sincerely for continuing to improve HRII. After you heard Precision you perhaps found HRII just a bit "boring" (as you said) and being the tweeker you can't help but tweek! I have completed my boards but have not mounted them on the heatsinks, so I can easily make the tweeks you recommend.

But I wanted to make sure I understand you correctly.

1) Which is the recommended value? 68pF, 82pF, 100pF? Are you still suggesting to start with 150 pF and if no oscillation shows up to go lower, repeating until we get the lowest pF value that does not oscillate?

2) I'm not sure where this refers to - is it on the bias board?

3) Why did you decide on 40 mA? I thought more class A is better.

Regards,
Francois

P.S. I have finished the PC boards for the HRII as well as Symasym and will put both amplifiers in the same box, with a switch between the stereo amplifiers. (I'm using a 1.2 KVA tranformer with separate windings for the different amps, so I will have sufficient capacity to drive all.) This should give me some insight into how solid state amplifiers can sound differently. (To date I have built several tube amps and know they sound differently) After experimentation I plan to use the Symasym to drive a bi-amplified subwoofer section, and HRII from ~100 Hz up.
  Reply With Quote
Old 18th February 2008, 08:33 AM   #644
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Good system...the marriage with Symassym is perfect


Dinamics and bass, into Symassym is awsome...very good!... also trebles are good too.

47pf is the value i am using into my home...this is dangerous to publish.... some people may have problems using 47pf..it is very near the threshold..... but is the value i am using into my channels.

The condenser is to VBE multiplier....i works, but the advantage is small...can be avoided too....and i found it a little problematic to adjustment..counter reacts to adjustment, as condensers do not like voltage variations into it's extremes..the condensers work is to go against variations..and when we adjust we change voltage..and we have to wait, a little to stabilize...i do not like the slow reaction on that.. just subjective feelings about, nothing that should worry you my dear.

I had problems exactly into the low bias... and i have worked to fix that.... when biasing this way i had a lot of current into the output and the drivers was very near to be cutted....near to be off..the voltage distribution there was not good...the 2.4 volts produced into the VBE multiplier (from colector to emitter) should be divided by four.... feeding 600 milivolts to each transistor..this was something i have not found...because of that i decide to tweak a little..... the low bias with a good share of VBEs was my target... and i succed on that.

The bias can be bigger if you prefer, but do that listening to low level of audio..into a headphone...very low power, and observe the result by yourself to find the better point to your ears/needs.

The bias informed is "suggestion" only.... you do not have to follow that....i feel that will be better to decide by yourself, listening, as this is the best way we have to fit bias setup.

regards,

Carlos
__________________
Dx Super A, Hajame test, 35V, 4 Ohms, T-line speaker, flat https://www.youtube.com/watch?v=bYIZejeSoeQ
  Reply With Quote
Old 18th February 2008, 04:01 PM   #645
diyAudio Member
 
Join Date: Jun 2004
Location: Champaign, Illinois
Default Thanks!

Carlos,

Thank you for your patient reply to my questions. Meanwhile I have also read the forum on DX amplifier where most of my question were discussed already.

Today I'm going to hook up my power supply to the Symasym pair for some testing; Friday it will be HRII's turn.

Regards,
Francois
  Reply With Quote
Old 18th February 2008, 04:46 PM   #646
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default No problems François..we know when people have just landed using parachute

Into the thread and go asking things.... some people lazy to read.

We can perceive the character of each one...you are old into the thread, a Dx Corporation Customer.... and deserve all respect to be a forum member and an aditional attention because customer..non profit customer but gave the preference to the brand.

I am very happy today, as the 1 Kilowatt amplifier.... 1088 watts undistorted was released to brasil today...only boards and customized schematic only for customers...this is exclusive to be sold in brasil...for us, native, will cost around 35 dollares two boards and 4 trimpots ,plus exclusive, customised, high power design to use their own supply...going from 42 volts to 75 plus 75 volts.

Also people in my country will use a cheaper method:

220 VAC transformer into Primary and having 110 into the secondary.

This one, connected to 110 volts will give you 55 AC into the secondary, and we have kilowatt units very cheap here... more or less 30 US dollares in brasil..heavy huge monsters.

So..connecting two of those transformers, you will have 55 plus 55 volts with enormous power...pluging it into 110 volts mains.....and if the one has 220 VAC mains can use the Kilowatt step down stabilizers (auto transformers with electronics and relays inside) we normally use together our computers.

So.... easy to them to have 110 volts too.. every brasilian has this stuff into their home..those power regulators.... AC power regulators that have taps and relays to switch.... a chip control and the relay makes the work...so....no problem to them to have 110 volts.... or they leave in 110 volts area, or they have computer AC voltage converter in their home.

This is not to sell to forum people..only to brasil and people that use to read Orkut...no business here into the www.diyaudio forum

All we are offering , here, is the non profit HRII and near future the non profit Precision I (one).... others will not be offered here.

regards,

Carlos
__________________
Dx Super A, Hajame test, 35V, 4 Ohms, T-line speaker, flat https://www.youtube.com/watch?v=bYIZejeSoeQ
  Reply With Quote
Old 23rd February 2008, 06:53 AM   #647
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Final layout to Precision I boards


Boards will be ordered this way.

regards,

Carlos
Attached Images
File Type: gif placa azul.gif (74.0 KB, 314 views)
__________________
Dx Super A, Hajame test, 35V, 4 Ohms, T-line speaker, flat https://www.youtube.com/watch?v=bYIZejeSoeQ
  Reply With Quote
Old 23rd February 2008, 07:41 AM   #648
es44 is offline es44  Denmark
diyAudio Member
 
es44's Avatar
 
Join Date: Apr 2005
Location: Fredericia, DK
Congratulations Carlos That's a very nice looking board.

Best regards
Ebbe
  Reply With Quote
Old 23rd February 2008, 09:13 AM   #649
Nordic is offline Nordic  South Africa
diyAudio Member
 
Nordic's Avatar
 
Join Date: Sep 2005
I am just tidying up the BOM then I will post it...
  Reply With Quote
Old 23rd February 2008, 10:02 AM   #650
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Yes... WE made nice work.... Nordic have the biggest work and i was bothering him as


usual,... saying:

"Change here... change there!"

Nordic was very patient, have not said any bad word to uncle Charlie.

ahahahaha!

Here is the last revised schematic.... i think this one will be the last if we do not find some error i could not see till this moment.

The technical good operation was Nordic work... he worried about everything, even the Feedback line point to have connections...following Dr. Self ideas about NFB copper lines...were to pick the signal.

I have more responsability related how the board looks... also Nordic worked to make it pretty too.

We have to thank Nordic, to be so competent and to tolerate my obsessive needs related parts position, letters size, colour, condenser size, simetry and that stuff.

Todd Johnson, our TAJ, made the schematic using his Adobe Illustrator software... he is good, very skilled into this work... i have to thank him once more.

Thank you Ebbe, by your kind support.

regards,

Carlos
Attached Files
File Type: pdf dx precision 7v9 - todd.pdf (32.9 KB, 79 views)
__________________
Dx Super A, Hajame test, 35V, 4 Ohms, T-line speaker, flat https://www.youtube.com/watch?v=bYIZejeSoeQ
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 04:21 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2