Destroyer x Amplifier...Dx amp...my amplifier - Page 599 - diyAudio
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 17th April 2009, 09:30 AM   #5981
SDF is offline SDF  France
diyAudio Member
 
Join Date: Jun 2002
Location: FRANCE
Can I use only one pair of output transistor with supply rail of +/-40V ?...and without changing anything else in the schematic?
  Reply With Quote
Old 17th April 2009, 01:01 PM   #5982
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Yes, you can.. and without need to change things


No problems.

regards,

Carlos
__________________
Power supply; ripple, filter, noise, stability and the use of capacitance multiplier... Portuguese and English; https://www.youtube.com/watch?v=sSm0ku1eIgg
  Reply With Quote
Old 17th April 2009, 01:38 PM   #5983
SDF is offline SDF  France
diyAudio Member
 
Join Date: Jun 2002
Location: FRANCE
Thanks!
  Reply With Quote
Old 17th April 2009, 09:22 PM   #5984
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Sounds alike this one


http://www.youtube.com/watch?v=warJLziW6gk

This one uses the same schematic, same topologie...sound is almost the same.

Also you have, into youtube, audio testing made with the Dx Amplifier:

http://www.youtube.com/watch?v=SoZA5f7wJhM

regards,

Carlos
__________________
Power supply; ripple, filter, noise, stability and the use of capacitance multiplier... Portuguese and English; https://www.youtube.com/watch?v=sSm0ku1eIgg
  Reply With Quote
Old 18th April 2009, 10:44 PM   #5985
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default It is very important to use a good supply to the Dx Amplifier


I will show you my supply, the one used to test.

It is using, now a days, 27000uf plus 27000uf.

The voltage without load is 44 plus 44 volts.

When i am draining 2.6 amperes each rail the voltage goes to the nominal voltage suggested to the Dx Amplifier, 36 plus 36 volts.

So, the supply is correct to the amplifier.... when producing 100 watts over 4 ohms loads, the voltage will be the correct one....

Using it to 8 ohms loads you gonna have much more than 50 watts RMS, as voltage drop will be smaller.

Here you can see the supply voltage.

Under load conditions... supply is loaded with 14 ohms resistance (2 resistances of 7 ohms and 70 watts each one of them)

regards,

Carlos
  Reply With Quote
Old 18th April 2009, 10:46 PM   #5986
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Here you can see the current beeing measured


The supply was measured using 7500uf plus 7500uf as filters.

regards,

Carlos
Attached Images
File Type: jpg rail consumption when voltage is 36 volts.jpg (88.2 KB, 408 views)
  Reply With Quote
Old 18th April 2009, 10:50 PM   #5987
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Here you can see the ripple.... and this was measured


while the supply was loaded..... a rail beeing loaded and the ripple was around 1 volt peak to peak.

Observe the scope channel two is adjusted to 1 volts peak to peak... this represents a very small power into 8 ohms speaker.

The amplifier will be producing more than 100 watts RMS, while the mains noise, the ripple power, will be lower than 50 miliwatts RMS...so... you will not even listen.

So.... when reproducing music, full power, you will not have strong mains frequency noises (ripple) mixed with your audio.

regards,

Carlos
Attached Images
File Type: jpg 25k filters, even this way, this is ripple..jpg (98.7 KB, 396 views)
  Reply With Quote
Old 18th April 2009, 10:57 PM   #5988
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default What this really means.


If you plug a 8 hertz tone into your amplifier, and adjust to full power.... or 100 watts RMS into 4 ohms loads, then you will not listen audio, as 8 hertz is not audible to humans...you feel vibrations only..... but if you have ripple, then you will listen the ripple..in our case..this small ripple is almost inaudible..you have to almost touch the speaker diafragm with your ears to listen it clear...and may receive a big punch from the speaker into your

face.... be carefull with that..also air pressure into your ears may be dangerous..use some cotton to attenuate.

Well...you may say:

- "What a hell.... who cares about no audible tones.... what's the advantage not to listen noises when i am also not listening to the tones"

Well..this will happens with music too..with the tones you listen..they will not have this dirty ripple poluting your audio clarity.

5000uf each rail to each ampere is the minimum filter...better to use more than that.... i am using, now a days, 27000uf each rail, not only to the Dx Amplifier, but also to the DHR Turbo.

regards,

Carlos
Attached Images
File Type: jpg dhr turbo supply.jpg (90.3 KB, 395 views)
  Reply With Quote
Old 18th April 2009, 11:03 PM   #5989
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default I have increased my DHR Turbo supply that was not using all the capacitance needed


This way i have reduced the 2.8 volts peak to peak ripple to less than 1 volts peak to peak.

Capacitance increased from 12.000uf plus 12.000uf to 27.000uf plus 27.000uf.

And i really think that 40K each rail would be even better.

regards,

Carlos

.................................................. ............................................

Before this encreasing in capacitance i was able to listen some noise..some ripple...not difficult to listen...but now a days sittuation is much better.
Attached Images
File Type: jpg fotos 3480.jpg (40.3 KB, 416 views)
  Reply With Quote
Old 21st April 2009, 05:08 AM   #5990
lgreen is offline lgreen  United States
diyAudio Member
 
lgreen's Avatar
 
Join Date: May 2003
Location: San Diego, USA
Default Re: I have increased my DHR Turbo supply that was not using all the capacitance needed

Quote:
Originally posted by destroyer X

This way i have reduced the 2.8 volts peak to peak ripple to less than 1 volts peak to peak.

Capacitance increased from 12.000uf plus 12.000uf to 27.000uf plus 27.000uf.

And i really think that 40K each rail would be even better.

regards,

Carlos

.................................................. ............................................

Before this encreasing in capacitance i was able to listen some noise..some ripple...not difficult to listen...but now a days sittuation is much better.


Carlos, would you recommend CRC with 15,000 uF --R-- 15,000 uF or is it better to drop the resistor and do a 30,000K straight capacitor power supply (each rail) with DX II?
__________________
Retired from DIY (2010) but still lurking now and again. My DIY audio projects- PartTimeProjects.com.
  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 02:01 AM.


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