Simple Symetrical Amplifier - Page 301 - 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 8th September 2012, 06:57 PM   #3001
sonnya is offline sonnya  Denmark
diyAudio Member
 
sonnya's Avatar
 
Join Date: Oct 2001
Location: Denmark
If i could give just one advice, then it would be ... wear sunscr...... Sorry!! .... only do Current feedback where it is possible...

Another mather... When you raise the bandwidth, what about stability into capacitive loads???????

I do not use Zobel or inductor, and maintain low distortion, high bandwidth (500KHz) and in my test protoamp i have a Zout of less than 30mOhm @ 20KHz. And still it is stable into 10uF load.

Sim of the final circuit tells me less than 2mOhm of the final amp at 20KHz.

Before asking how it is done. This does not leave my doorstep, but it can be done....

So the DFin my final circuit is equal to the Hypex NCD400.
  Reply With Quote
Old 8th September 2012, 07:42 PM   #3002
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
Quote:
Originally Posted by sonnya View Post
If i could give just one advice, then it would be ... wear sunscr...... Sorry!! .... only do Current feedback where it is possible...
Yes yes yes

Quote:
Originally Posted by sonnya View Post
Another mather... When you raise the bandwidth, what about stability into capacitive loads???????

I do not use Zobel or inductor, and maintain low distortion, high bandwidth (500KHz) and in my test protoamp i have a Zout of less than 30mOhm @ 20KHz. And still it is stable into 10uF load.
You mean 10 uF parallel to 8 ohm resistor or 10 uF alone as a load?

Quote:
Originally Posted by sonnya View Post
Sim of the final circuit tells me less than 2mOhm of the final amp at 20KHz.
Is this new amp a merge of Mirand and TSSA as you already mentioned lately?
  Reply With Quote
Old 8th September 2012, 08:58 PM   #3003
diyAudio Member
 
Esperado's Avatar
 
Join Date: Jul 2011
Location: France
Quote:
Originally Posted by sonnya View Post
I do not use Zobel or inductor
Serial inductor is not always required against oscillation. But it helps to protect feedback to carry HF, induced in the Loudspeakers wires witch can be worse than the same hf in the input.

The same remark applies at the Preamp output, reason why the cabling i suggested earlier was done the way it is.

I wonder why no audiophile cable guru has never thought to sell shielded loudspeaker's wires, instead of alloy gallium plated ones, isolated by Teflon/bamboo with cryogenic treatment.
__________________
Ultimate Protection and more.The Only Source of Knowledge is experience, everything else is just information” ©A. Einstein
  Reply With Quote
Old 8th September 2012, 09:10 PM   #3004
sonnya is offline sonnya  Denmark
diyAudio Member
 
sonnya's Avatar
 
Join Date: Oct 2001
Location: Denmark
Quote:
Originally Posted by Lazy Cat View Post
Yes yes yes



You mean 10 uF parallel to 8 ohm resistor or 10 uF alone as a load?



Is this new amp a merge of Mirand and TSSA as you already mentioned lately?
It is into 8r and 10uf load.

This new AMP is made of sub parts of both designs plus extra's.
  Reply With Quote
Old 8th September 2012, 09:20 PM   #3005
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
Quote:
Originally Posted by sonnya View Post
This new AMP is made of sub parts of both designs plus extra's.
Will it be commercial product only or DIY published group buy as Mirand, TSSA?
  Reply With Quote
Old 8th September 2012, 10:35 PM   #3006
mikelm is offline mikelm  England
diyAudio Member
 
Join Date: May 2003
Location: England
Send a message via Yahoo to mikelm
Quote:
Originally Posted by Esperado View Post
Oh, my god, i hope i'm not boring everybody here, talking like an old school teacher. If yes, please, let me know.
Thanks for clarifying this
  Reply With Quote
Old 8th September 2012, 10:41 PM   #3007
mikelm is offline mikelm  England
diyAudio Member
 
Join Date: May 2003
Location: England
Send a message via Yahoo to mikelm
Quote:
Originally Posted by Esperado View Post
I wonder why no audiophile cable guru has never thought to sell shielded loudspeaker's wires, instead of alloy gallium plated ones, isolated by Teflon/bamboo with cryogenic treatment.
You could try screened Cat 6 network cable ( CAT 6 STP )

Try it before you laugh - You might be pleasantly surprised - it takes a pretty high spec cable to carry a 1000Mb/s signal.
  Reply With Quote
Old 8th September 2012, 11:46 PM   #3008
diyAudio Member
 
Esperado's Avatar
 
Join Date: Jul 2011
Location: France
Quote:
Originally Posted by mikelm View Post
You could try screened Cat 6 network cable ( CAT 6 STP )
Try it before you laugh - You might be pleasantly surprised - it takes a pretty high spec cable to carry a 1000Mb/s signal.
Nb: It can carry such a bandwidth only if source and target impedance is 100 Ohms for a perfect "transmission line".

I will not laugh as i use them between my digital filter and my active speakers (one pair for basses, one pair for treeble, one pair for power on/off command, one pair for volume remote control of the power amps). With balanced 100 Ohms audio lines as required ;-)

Forget about that flat bandwitch for the < 0.1 ohms source of a power amplifier and a > 8 ohm loudspeaker, but who care ?
__________________
Ultimate Protection and more.The Only Source of Knowledge is experience, everything else is just information” ©A. Einstein

Last edited by Esperado; 8th September 2012 at 11:49 PM.
  Reply With Quote
Old 9th September 2012, 01:44 AM   #3009
Jay is offline Jay  Indonesia
diyAudio Member
 
Join Date: Feb 2003
Location: Jakarta
Quote:
Originally Posted by Esperado View Post
Serial inductor is not always required against oscillation. But it helps to protect feedback to carry HF, induced in the Loudspeakers wires witch can be worse than the same hf in the input
Cool, I think this is the first time I listen to something like this (those other times I might not listening). So that's why some use zobel at both ends of the inductor?

Quote:
Originally Posted by Esperado View Post
I wonder why no audiophile cable guru has never thought to sell shielded loudspeaker's wires, instead of alloy gallium plated ones, isolated by Teflon/bamboo with cryogenic treatment.
I think it will become a capacitive load for the amp? Do you mean the negative cable shielding the positive one??? I have been wondering about that many times. But I just didn't want to "re-invent" the mistake.

With CAT5, CAT6, and similar telecom cables, I still use it. Sometimes I have worry with the stranded cables but it has been years and I cannot see issue with oscillation.

But it is hard to find cables for such application that doesn't sound "hard". Indeed the resolution is its hallmark but the hard sound can be fatiguing sometimes. Don't know if this is a "true to the sound" issue. But I like the soft sound of silver wire. Or may be I cannot decide until now
  Reply With Quote
Old 9th September 2012, 06:19 AM   #3010
mikelm is offline mikelm  England
diyAudio Member
 
Join Date: May 2003
Location: England
Send a message via Yahoo to mikelm
Quote:
Originally Posted by Jay View Post
I think it will become a capacitive load for the amp? Do you mean the negative cable shielding the positive one??? I have been wondering about that many times. But I just didn't want to "re-invent" the mistake.
Using shielded cat 6 as an example, I would try using the inner pairs for loudspeaker send & return - all coloured wires for send, all whites for return.

Connect the screen at one end only for shielding duties. I'm guessing amp end grounded to casing would be best - but I would try both options - the other option being running a case ground to the speaker to earth the far end of the screen - could try earthing the driver chassis as well.

I have used Cat6 or the pairs inside Cat6 for nearly all duties for a few years now - There may be better cables out there but I also know that there are many that are worse. For anyone on a budget it provides incredible value for money.

I recently upgraded a £20 pound interconnect cable to 2 x Cat 6 twisted pairs and the improvement was amazing - cost was more because I elected to use Eichmann plugs but the interconnects effectively become the cost of the plugs you choose. There is no screen on regular CAT 6 so I keep i/p impedance low - 10K or less

I think I'll order some screened Cat6 tmrw for speaker leads and see it I can hear any difference !

Last edited by mikelm; 9th September 2012 at 06:21 AM.
  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 08:06 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