John Curl's Blowtorch preamplifier part II - Page 3299 - diyAudio
Go Back   Home > Forums > Member Areas > The Lounge
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

The Lounge A place to talk about almost anything but politics and religion.

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 19th January 2013, 07:10 PM   #32981
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 2
Quote:
Originally Posted by Waly View Post

You would pull anything out of thin air to make a point, isn't it?
Even with cheating, the number is ridiculously low.

The tip o' the hat to John is Ed's use of 1968 components for examples, so even my numbers were enormously higher noise than you get from modern ICs.
__________________
"You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is."
  Reply With Quote
Old 19th January 2013, 07:22 PM   #32982
Banned
 
Join Date: Jul 2011
Location: Portugal
Ampex ATR-102 half-inch two-track, (not modified by John curl :-) with extended low frequency heads, 30 IPS. This is at Studio X in Seattle.
Click the image to open in full size.

And this a Pc based with Starmax MT3200 computer's onboard A/D converter
Click the image to open in full size.
  Reply With Quote
Old 19th January 2013, 07:23 PM   #32983
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
What I like best is the 1966 voltage regulators made by National. They were quieter than almost anything, today!
__________________
"Condemnation without Examination is Prejudice"
  Reply With Quote
Old 19th January 2013, 07:24 PM   #32984
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Great bass with digital. Too bad about the higher frequencies.
__________________
"Condemnation without Examination is Prejudice"
  Reply With Quote
Old 19th January 2013, 07:37 PM   #32985
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
To rephrase a point JC was making ---

1. The IC's neg feedback network is in parallel with its load Z ... giving a much lower Z than the input of the power amp would imply.

2. In order to obtain the noise level spec of the IC, it would need very low Z in the neg feedback network.

3. low Z feedback network reduces the max output in the spec sheet.

4. You cant get all the specs in one circuit with fixed values.

have I got that right, JC?

-Thx- RNMarsh
  Reply With Quote
Old 19th January 2013, 07:38 PM   #32986
Banned
 
Join Date: Jul 2011
Location: Portugal
Quote:
Originally Posted by john curl View Post
Great bass with digital. Too bad about the higher frequencies.
This is a 48 KHz recording. Double the frequency for a 96, quadruple with a 192kHz, while i doubt you will hear any listening difference.
May-be asking your dog on his paws crafted enclosures ?
  Reply With Quote
Old 19th January 2013, 07:39 PM   #32987
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Thanks Richard. A-OK
__________________
"Condemnation without Examination is Prejudice"
  Reply With Quote
Old 19th January 2013, 07:40 PM   #32988
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
My analog tape recorders could record to 45KHz, so there! '-)
__________________
"Condemnation without Examination is Prejudice"
  Reply With Quote
Old 19th January 2013, 07:48 PM   #32989
Waly is offline Waly  Tonga
diyAudio Member
 
Waly's Avatar
 
Join Date: Jan 2011
Location: Nukuʻalofa
Quote:
Originally Posted by john curl View Post
What I like best is the 1966 voltage regulators made by National. They were quieter than almost anything, today!
Hear, hear, the golden 60's .

Ever tried the TPS7A470 and it's negative version TPS7A3301? 16uV noise in 100KHz BW, one order of magnitude lower than the National 60's negative regulators. And 4uV for the positive version.
  Reply With Quote
Old 19th January 2013, 07:54 PM   #32990
Banned
 
Join Date: Jul 2011
Location: Portugal
Quote:
Originally Posted by RNMarsh View Post
4. You cant get all the specs in one circuit with fixed values
You yet knew all that very well, Richard :-)
This said, we can notice that, when we need gain and low noise, we do not need high output levels and currents, and when we need current for output buffers, we do not have to care too much about gain or noise.
  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 11:16 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright 1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2
Wiki