Go Back   Home > Forums > Source & Line > Analog Line Level

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

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 5th November 2012, 10:29 PM   #1991
diyAudio Member
 
Join Date: Nov 2011
Location: Cooktown, Oz
Quote:
Originally Posted by PHEONIX View Post
What is your desired ultimate spec THD into 15R @ 20KHz @ 3.162Vp that you seek to attain.
O2 headphone amp has -90dB THD + noise at that output level using cheapo NJM OPAs.

I'd like to see that with +/- 9V supplies too but that would be too stringent for some of our more exotic topologies. Personally, I like much simpler circuits if they can equal complex stuff. Easier to build, unnerstan and much more reliable. Less quiescent current too if THD remains low and low order like a Class A amp.

Last edited by kgrlee; 5th November 2012 at 10:57 PM.
  Reply With Quote
Old 6th November 2012, 02:14 AM   #1992
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by kgrlee View Post
O2 headphone amp has -90dB THD + noise at that output level using cheapo NJM OPAs.

I'd like to see that with +/- 9V supplies too but that would be too stringent for some of our more exotic topologies. Personally, I like much simpler circuits if they can equal complex stuff. Easier to build, unnerstan and much more reliable. Less quiescent current too if THD remains low and low order like a Class A amp.
If you want that stuff go for it, I'm not sure that Artero La Mancha wine rings my bell either. If just numbers are what you want the cheap NJM op-amps are fine.
__________________
“The earth's rotation will slow within days and stop for several days just prior to the pole shift. This is when you and your loved ones should be situated at your safe location.”
  Reply With Quote
Old 6th November 2012, 02:29 AM   #1993
bcarso is offline bcarso  United States
diyAudio Member
 
Join Date: May 2005
Location: Canoga Park, California
Quote:
Originally Posted by scott wurcer View Post
If you want that stuff go for it, I'm not sure that Artero La Mancha wine rings my bell either. If just numbers are what you want the cheap NJM op-amps are fine.
I have found myself defending, lately and repeatedly, what I am drinking against two-buck chuck.
  Reply With Quote
Old 6th November 2012, 02:46 AM   #1994
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by bcarso View Post
I have found myself defending, lately and repeatedly, what I am drinking against two-buck chuck.
I don't go for it much lately, but we did enjoy a 1976 Rumier Bonnes Mares a few weeks ago, but then again I don't think there is a two buck pinot noir.
__________________
“The earth's rotation will slow within days and stop for several days just prior to the pole shift. This is when you and your loved ones should be situated at your safe location.”
  Reply With Quote
Old 6th November 2012, 02:56 AM   #1995
diyAudio Member
 
Join Date: Nov 2011
Location: Cooktown, Oz
Quote:
Originally Posted by scott wurcer View Post
If you want that stuff go for it, I'm not sure that Artero La Mancha wine rings my bell either. If just numbers are what you want the cheap NJM op-amps are fine.
Pace Lord Shiva. This is a Discrete OPA thread and I'm having fun trying to beat OPA627 etc and learning from Guru Wurcer at the same time.

But I'm sure you would like to at least equal the numbers of cheapo stuff but also your AD797. I was just answering Pheonix's query.

FWIW, my poor efforts with LTspice, show both SW-OPA & my hacked FET990 meet this spec with 4401/3s .. even w/o increasing Iq. I mention the +/- 9V cos I would like it .. but am not using it as a criteria as it would be unfair.

One shows more xover but with all harmonics below -100dB, I'm not sure I'm going to complain. Gotta figure out an easy way to either show distortion residual or sum THD with something like BBC weighting.

I gather Artero La Mancha is a cheapo wine which is highly regarded. I used to be an inverted wine snob who used to delight in confounding connoisseurs with cheapo bottles in blind tastings against expensive ones. You do have to work hard to find these. But the best red I have ever tasted was a 1975 Volnay.

Alas, this beach bum can no longer afford to drink what he likes, either cheapo or Burgundy.

PS I used to like several Tempranillo wines including one called La Mancha but that was definitely last millenium so dunno if this is the same.
  Reply With Quote
Old 6th November 2012, 03:09 AM   #1996
diyAudio Member
 
Join Date: Mar 2002
http://www.ti.com/lit/ds/snosbq5a/snosbq5a.pdf

I always liked this one ^
  Reply With Quote
Old 6th November 2012, 03:09 AM   #1997
diyAudio Member
 
Join Date: Nov 2011
Location: Cooktown, Oz
Quote:
Originally Posted by scott wurcer View Post
If just numbers are what you want the cheap NJM op-amps are fine.
I ask this question in fear & trembling but .. if numbers are not the main criteria for this thread, what is?

Yus gurus, please be frank but gentle to this beach bum.

PS: I did attempt to study the whole thread but I admit to giving up after about 160 pages and skipped to the last pages. Mea maxima culpa.
  Reply With Quote
Old 6th November 2012, 03:32 AM   #1998
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by kgrlee View Post
Yus gurus, please be frank but gentle to this beach bum.
We want numbers and the simplest signal path, anything else would be dis-harmonious and unmutual.
__________________
“The earth's rotation will slow within days and stop for several days just prior to the pole shift. This is when you and your loved ones should be situated at your safe location.”
  Reply With Quote
Old 6th November 2012, 03:39 AM   #1999
bcarso is offline bcarso  United States
diyAudio Member
 
Join Date: May 2005
Location: Canoga Park, California
Quote:
Originally Posted by scott wurcer View Post
I don't go for it much lately, but we did enjoy a 1976 Rumier Bonnes Mares a few weeks ago, but then again I don't think there is a two buck pinot noir.
Roumier, a name that is a distant recollection That year btw obtainable today at about 450 US.

One of my top twenty or so was a rebottled 1934 Bonnes Mares (I didn't save the bottle and don't remember the specific maker). That and a couple of other much-too-old burgundies showed up at Vendome, a now-defunct retailer in Westwood. I had two of the Bonnes Mares, and my friend Kathryn still remembers the wine and the evening in 1973. We began with some of a 1964 DRC Echezeaux!

There was a good deal of telepathy in evidence. Certainly an evening for the Journal of Irreproducible Results. We sat on barber chairs which slowly, undetectably, but inexorably, sank towards the center of the planet.
  Reply With Quote
Old 6th November 2012, 03:42 AM   #2000
bcarso is offline bcarso  United States
diyAudio Member
 
Join Date: May 2005
Location: Canoga Park, California
Quote:
Originally Posted by kgrlee View Post
P

I gather Artero La Mancha is a cheapo wine which is highly regarded. I used to be an inverted wine snob who used to delight in confounding connoisseurs with cheapo bottles in blind tastings against expensive ones. You do have to work hard to find these. But the best red I have ever tasted was a 1975 Volnay.
Almost certainly a 76. 75 was quite poor in general.
  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
Discrete OPAMP audio-gd Vendor's Bazaar 27 20th September 2012 04:02 PM
discrete opamp help blackpowderaudio Parts 0 16th December 2009 03:46 PM
THAT transistor headphone amp (250ma discrete opamp) design sanity check. Russ White Headphone Systems 19 13th December 2007 12:52 PM


New To Site? Need Help?

All times are GMT. The time now is 02:02 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