Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 22nd January 2013, 12:46 PM   #471
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default The dissipation into these series pass transistors

The ones are in the Dx Supply, made to be used together the Dx Super A audio power amplifier.

We gonna have, as the worst case scenario, (when transformer have no voltage... but this is almost impossible....but for safety reasons we take this into our calculations) a voltage drop of 18 volts (60 to 42C) into the series pass transistors, so, multiply this voltage drop by the rail current (that gonna depend your case/choice)... then you will have the power developed into the series pass transistor colector to emitter junctions (input to output of the series pass regulator transistors)

As an example, to clarify the subject, if you have TWO Dx Super A channels, driving 8 ohms loads, operating full power (undistorted), draining energy from a single Dx Supply, will result in 54 plus 54 Watts of power dissipation.... in real world this use to be much less, because we have voltage drop into the Dx Supply input, so, voltage drop from colector to emitter being reduces will reduce the result of the multiplication of current by the voltage that results in the power.

My Dear WilJJ78, your case is a little bit complicated, as you want to enter a higher voltage into the Dx Supply input....much higher than we have calculated.

52 Volts AC means aprox. 73 Volts DC, so, your voltage drop into the series pass transistors (adjusting 42 volts at the regulator output) will be 31 Volts, so, i strongly suggest you , dear Bahrain, to build two Dx Supplies feeding your stereo with two separated power supplies, one to each channel... and each one of your channels will need three output pairs, so, you will have to install an extra pair the way you can...also rectifier must be checked, it must be minimum of 15A, also the first condensers, the main filters after rectification should be reinforced..you have to prepare extra boards to put more units in parallel with the ones are in the Dx Supply board...all this special because you case is special.... your dissipation power into the series pass transistors may reach 200 Watts each rail and this is huge..and all that stuff is due to the higher input voltage you will use...this is what will create all troubles....you gonna be using 10AC volts more...this increases the load into the series pass transistors a lot!

Another option is never use 2 ohms..then you can try the standard Supply with 4 ohms loads...but use two supplies....if you decide to use 8 ohms only..then a single supply will be good enough.

In all cases, your power dissipation into the supply series pass transistor will be huge.... the difference in between the input voltage (73) and the output adjusted voltage (42) is too much big... and you cannot increase the supply voltage because it is already in the limit to the power amplifier to operate at 2 ohms...so... cannot increase to reduce your heat.

I do Think your transformer is no good...too much high voltage...will create troubles to us.

regards,

Carlos
__________________
Dx Blame ST with a tube preamp. recorded with Xperia cell phone, https://www.youtube.com/watch?v=Qjs32J0gdj0; https://www.youtube.com/watch?v=nhrZ...vDnDhEpNv_XVxg
  Reply With Quote
Old 22nd January 2013, 02:00 PM   #472
wiljj78 is offline wiljj78  Philippines
diyAudio Member
 
wiljj78's Avatar
 
Join Date: Mar 2012
Location: Bahrain
Default Thank you soo much for this helpful tips my dear Uncle Charlie...

Most probably an identical transformer of 29VAC X 2 @ 300VAC each one will suit in this DX supply and that would be enough for super A stereo. I believe in a bit lower of the required 42VDC is more safe to operate rather than exceeding to the max of 42VDC (pls. correct me if I’m wrong).

You’re the man Uncle Charlie…. Many thanks indeed.

Regards,
Wiljj78

Last edited by wiljj78; 22nd January 2013 at 02:03 PM.
  Reply With Quote
Old 22nd January 2013, 02:17 PM   #473
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Yes, you are right Bahrain.

regards,

Carlos
__________________
Dx Blame ST with a tube preamp. recorded with Xperia cell phone, https://www.youtube.com/watch?v=Qjs32J0gdj0; https://www.youtube.com/watch?v=nhrZ...vDnDhEpNv_XVxg
  Reply With Quote
Old 22nd January 2013, 09:34 PM   #474
diyAudio Member
 
vargasmongo3435's Avatar
 
Join Date: May 2011
Location: Quebradillas, Puerto Rico
Send a message via Yahoo to vargasmongo3435
Default Dx Super A Stereo

All done! I have both channels working great!, sounds great! and the must important thing, I'm having fun!!!!


1. thermally stable didn't not get that hot even with out a fan.


2. responds really good like the first board.


3. adjustment same way no problems at all.


4. bass is nice.


5. the woofer is 8 ohms so it will stay on the safe margin so is cool.



6. at the moment I'm writhing this the music I play is destroying my 15" woofer. jejejejejejejeje


7. no guys, but seriously this an amplifies to have in a nice chassis nice volume knobs, to enjoy music in the living room and relax, I like lot of style of music so is double the enjoyment for me.



now I have my A, ready... later the regulator is need it. and going to get a nice cold Coca Cola really cold bien fria!!!!!!!!! really cold!!!!




oh yeah that is Robi,










Regards




Juan
Attached Images
File Type: jpg 12.jpg (342.4 KB, 272 views)
File Type: jpg 13.jpg (850.6 KB, 268 views)

Last edited by vargasmongo3435; 22nd January 2013 at 09:37 PM. Reason: grammar error
  Reply With Quote
Old 22nd January 2013, 09:53 PM   #475
diyAudio Member
 
Join Date: Oct 2011
Very nice going
__________________
www.harrisonaudiolabs.com
  Reply With Quote
Old 22nd January 2013, 10:32 PM   #476
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Thank you dear Juan.... very nice

Speakers to be used together Dx Super A have just arrived from Lira (São Paulo).... noise is from the air conditioned machine.

Dx Speaker arrived from Lira - YouTube

Some photographs too..not that good..but good as a historical document.

Dx Speakers from Lira photographs - YouTube

regards,

Carlos
__________________
Dx Blame ST with a tube preamp. recorded with Xperia cell phone, https://www.youtube.com/watch?v=Qjs32J0gdj0; https://www.youtube.com/watch?v=nhrZ...vDnDhEpNv_XVxg
  Reply With Quote
Old 23rd January 2013, 05:47 AM   #477
wiljj78 is offline wiljj78  Philippines
diyAudio Member
 
wiljj78's Avatar
 
Join Date: Mar 2012
Location: Bahrain
Default SANKEN Transistors 2SC3264/2SA1295

Hello Uncle Charlie,

I found this Sanken Transistor 2SC3264/2SA1295 its available in a tiny local market in Bahrain, please let me know if this is better replacement for MJL instead of 5200/1943.

Regards,
Wiljj78
  Reply With Quote
Old 23rd January 2013, 05:50 AM   #478
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Yes, they are very good!

Audio power transistors are alike a family.... all them look the same.

This monster will be good, problem is if you will have room for them...i do think the pcboard has no room for them.

regards,

Carlos
__________________
Dx Blame ST with a tube preamp. recorded with Xperia cell phone, https://www.youtube.com/watch?v=Qjs32J0gdj0; https://www.youtube.com/watch?v=nhrZ...vDnDhEpNv_XVxg
  Reply With Quote
Old 23rd January 2013, 06:09 AM   #479
wiljj78 is offline wiljj78  Philippines
diyAudio Member
 
wiljj78's Avatar
 
Join Date: Mar 2012
Location: Bahrain
Quote:
Originally Posted by destroyer X View Post
Audio power transistors are alike a family.... all them look the same.

This monster will be good, problem is if you will have room for them...i do think the pcboard has no room for them.

regards,

Carlos
No worries Uncle Charlie, i will do something to accommodate this transistor on board and i will post my version of Super A when its completed, anyway thanks for your confirmation and support.

Regards,
Wiljj78
  Reply With Quote
Old 23rd January 2013, 03:36 PM   #480
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Good WilJJ78, i am playing with speakers today

Enjoy crazy uncle charlie:

Temporary enclosure to Lira speaker - YouTube

Song Juan Vargas sent to me. - YouTube

Temporary enclosure to Lira Speaker - photos. - YouTube

regards,

Carlos
__________________
Dx Blame ST with a tube preamp. recorded with Xperia cell phone, https://www.youtube.com/watch?v=Qjs32J0gdj0; https://www.youtube.com/watch?v=nhrZ...vDnDhEpNv_XVxg
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Dx Blame ST - Builder's thread - post pictures, reviews and comments here please. destroyer X Solid State 1670 11th April 2014 06:36 AM
Overheating on NEW DX Blame super DIYGEEK Solid State 22 28th March 2012 02:30 AM
Where is the original DX Blame ST thread? johngalt47 Solid State 5 17th March 2012 01:03 PM
Dx Blame MKII, an obvious evolution from the Dx Blame ES/ST destroyer X Solid State 4 25th September 2010 06:41 PM
Dx Blame ST, operating from 18 to 24 Volts (unloaded) - Class A destroyer X Solid State 51 15th June 2010 10:26 AM


New To Site? Need Help?

All times are GMT. The time now is 07:01 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