Simple Symetrical Amplifier - Page 397 - 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 15th February 2013, 12:41 PM   #3961
diyAudio Member
 
Join Date: Jul 2011
Mr.shaan, lc. ssa amplifier can be set klass a, anything that changed? i want to assemble the amplifier ssa in setting klass a. I own the following mr.nafiri assemble pleasant sound amplifier ssa ears, and sounded good and clear ... I myself also feel happy after hearing the sound the sound of the amplifier ssa
  Reply With Quote
Old 15th February 2013, 04:43 PM   #3962
shaan is offline shaan  India
diyAudio Member
 
shaan's Avatar
 
Join Date: Mar 2009
Location: Near the Ganges
Quote:
Originally Posted by sofianirawan View Post
Mr.shaan, lc. ssa amplifier can be set klass a, anything that changed? i want to assemble the amplifier ssa in setting klass a. I own the following mr.nafiri assemble pleasant sound amplifier ssa ears, and sounded good and clear ... I myself also feel happy after hearing the sound the sound of the amplifier ssa
hi sofianirawan.

Of course the ssa can be class-a by placing more diodes in series with the existing biasing diodes. But I personally doubt there will be any sonic difference or reduction of THD.

Congrats on your SSA build.
__________________
The PeeCeeBee Thread
  Reply With Quote
Old 15th February 2013, 07:35 PM   #3963
diyAudio Member
 
Esperado's Avatar
 
Join Date: Jul 2011
Location: France
Quote:
Originally Posted by shaan View Post
Of course the ssa can be class-a by placing more diodes in series with the existing biasing diodes. But I personally doubt there will be any sonic difference or reduction of THD.
Class A is better to keep a listening room warm atmosphere.
(Why the hell this class A audiophile legend ?)
__________________
Ultimate Protection and more.The Only Source of Knowledge is experience, everything else is just information” ©A. Einstein
  Reply With Quote
Old 15th February 2013, 07:44 PM   #3964
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Tutorial on the Design and Characterization of Class-B and AB Amplifiers - YouTube
  Reply With Quote
Old 16th February 2013, 06:08 AM   #3965
shaan is offline shaan  India
diyAudio Member
 
shaan's Avatar
 
Join Date: Mar 2009
Location: Near the Ganges
Quote:
Originally Posted by Esperado View Post
Class A is better to keep a listening room warm atmosphere.
Don't say. A pair of DOZ can give a mighty 15kelvin boost in room temp in 1 hour. Perfect room heater in a christmas night.

Quote:
Why the hell this class A audiophile legend ?
Coz those audiophile x-spurts couldn't find a way to minimize the crossover distortion other than sinfully using lots of unholy negative feedback which is destined to "suck the soul out of the music". Poor kids... if only they didn't assume the feedback signal cycles inside the input stage... alas.

No matter, they've got train-loads of bucks so they can solve the problem the global-warming way.
__________________
The PeeCeeBee Thread
  Reply With Quote
Old 18th February 2013, 03:08 PM   #3966
PauloPT is offline PauloPT  Portugal
diyAudio Member
 
Join Date: Jan 2010
Location: Lisboa, Portugal
Send a message via MSN to PauloPT
Hi!

Remember some posts ago I posted a spice simulation that didn't look too good?
Turns out I had a problem with the LTSpice directive. Now I got it right and the distortion spectrum at 20kHz is attached bellow. Looks much better!
THD @ 20kHz @ 22V is about 0.02%.

I also had reported an oscillation problem. Gate resistors + input snubber (20pF // 3.3K as recomended by Keantoken) + 680pF input filter cap + a new, shorter, shielded, decent input cable, and the oscillations are completly gone! It's obvious to me now the culprit was that stupid inductive long cable. Gave the cable to the cat. He's having lots of fun with it! The amp is rock stable!

This little amplifier has the most beautifull extended highs I have ever listen to, an envolving midrange and unbelievable strong bass! Thank you Lazy Cat, Shaan and all ther others who worked together to design this wonderfull piece of art! Thank you, thank you, a billion thanks!
Attached Images
File Type: jpg SSA20kHz.jpg (51.7 KB, 364 views)
__________________
Kind Regards,
Paulo.

Last edited by PauloPT; 18th February 2013 at 03:10 PM.
  Reply With Quote
Old 18th February 2013, 04:48 PM   #3967
PauloPT is offline PauloPT  Portugal
diyAudio Member
 
Join Date: Jan 2010
Location: Lisboa, Portugal
Send a message via MSN to PauloPT
Another thing: huge soundstage!

Hi Shaan,

Could you please post the pcb layout in jpeg format or in a pdf with the drawing at the begining of the page?

Thank you.
__________________
Kind Regards,
Paulo.
  Reply With Quote
Old 18th February 2013, 06:23 PM   #3968
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
Blog Entries: 2
The 3.3k is in series with the 20pF, and this goes between the input and ground. You put them in parallel?

No amp should have problems with an inductive source impedance; all sources are inductive. But many of them do. I would provide the optimal input compensation network but I don't know which specific version you're using.
  Reply With Quote
Old 18th February 2013, 06:29 PM   #3969
PauloPT is offline PauloPT  Portugal
diyAudio Member
 
Join Date: Jan 2010
Location: Lisboa, Portugal
Send a message via MSN to PauloPT
Sorry, no I meant to say 20pf in series with 3.3k.

The cable was really bad. I believe it was the main culprit. With a short shielded cable connecting the DVD player to the amp there's no oscillation I can perceive in the AM radio and the sound is amazing. I need yet to figure out how I'm going to connect the computer audio out to the amplifier, they're not that close.

I'm using Shaan version of the SSA.
__________________
Kind Regards,
Paulo.
  Reply With Quote
Old 18th February 2013, 07:13 PM   #3970
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
Blog Entries: 2
If the cable is short and there is minimal inductance to react, it should work fine, and can sound great. For a designer though, oscillation with long cables is a liability that should be corrected.

The problem could be your source. I think you should try a buffer between your computer and cable. Soundcard outputs may have several hundred ohms output impedance. A strange idea that popped into my head is using 300 ohm RF ribbon cable inside grounded metal conduit, but that's just strange.
  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
Symetrical schematics are alike plague in Brazil, do you like them? destroyer X Solid State 151 1st July 2010 02:09 PM
Symetrical out low Zout karsten21 Tubes / Valves 5 1st February 2010 10:19 PM
going balanced/symetrical - what benefits? weissi Solid State 15 20th October 2007 08:06 AM
Symetrical field, is this? Raka Multi-Way 6 14th September 2003 01:21 PM
Non-symetrical SMPS output cm961 Parts 4 21st August 2003 10:27 PM


New To Site? Need Help?

All times are GMT. The time now is 10:31 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