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 27th January 2013, 04:59 PM   #2641
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by bcarso View Post
I posted this a few months ago and someone was nice enough to decode all the colors, I lost track but it is here somewhere. One thing is obvious no sweeping generalizations about all SMT resistors apply.
__________________
“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.”

Last edited by scott wurcer; 27th January 2013 at 05:05 PM.
  Reply With Quote
Old 27th January 2013, 05:21 PM   #2642
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Quote:
Originally Posted by scott wurcer View Post
I posted this a few months ago and someone was nice enough to decode all the colors, I lost track but it is here somewhere. One thing is obvious no sweeping generalizations about all SMT resistors apply.
We know which of the THole types are the better ones..noise AND THD; So i am going with that until i know which sm are the best or better than the th type.
For example, the Dale metfilms th types are available everywhere and do very well at both noise and thd and are cheap to boot! I suspect the formulations used on th and sm are the same (?) and thus might go blindly for Dale with sm as well. Until shown other wise.

-Thx RNMarsh

Last edited by RNMarsh; 27th January 2013 at 05:44 PM.
  Reply With Quote
Old 27th January 2013, 09:07 PM   #2643
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
This is the input stage that I tested with the output stage I posted a week or so ago. Everything looked good, the distortion was hard to measure and the amp was stable well below a gain of 10, so I see no problems in proceeding. I have spent a lot of my personal time on this and will stop now.
Attached Images
File Type: jpg input.JPG (52.9 KB, 375 views)
__________________
“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 28th January 2013, 12:39 AM   #2644
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Default Retired SW-OPA

SW --- you said you could and then you would. And, now you did. Thank you for an enjoyable ride thru this. Well done. Learned a lot and had fun, too. Now the SW-OPA is a part of the universe/internet forever.
Soon you'll retire yourself as well. Then what, i wonder. Will there ever be a SW-OPA-2 in the furture? A sequel? :-) Thx, Scott - Dick Marsh

Last edited by RNMarsh; 28th January 2013 at 01:01 AM.
  Reply With Quote
Old 28th January 2013, 12:59 AM   #2645
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Default sm R noise and thd --

Well, I also have a Quan-Tech 315B Resistor noise analyzer. (Of course; what did you expect of a test equipment junky?)
I guess I'll have to do some comparison tests with Dale (Vishay) th and sm. :-(

Thx-RNMarsh

Last edited by RNMarsh; 28th January 2013 at 01:03 AM.
  Reply With Quote
Old 28th January 2013, 06:17 AM   #2646
diyAudio Member
 
Join Date: Sep 2007
Send a message via Yahoo to linuxguru
Quote:
Originally Posted by scott wurcer View Post
... I see no problems in proceeding. I have spent a lot of my personal time on this and will stop now.
Scott, great work and thanks for the contribution of your valuable time and energy to this project.
  Reply With Quote
Old 28th January 2013, 10:02 AM   #2647
PHEONIX is offline PHEONIX  Australia
diyAudio Member
 
Join Date: Jul 2004
Location: Australia
Hello Scott ,

In post 2591 :-

Discrete Opamp Open Design

The hardware that you show is it designed to fit into a standard dip 8 footprint.

Regards
Arthur
  Reply With Quote
Old 28th January 2013, 01:51 PM   #2648
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by PHEONIX View Post
Hello Scott ,

In post 2591 :-

Discrete Opamp Open Design

The hardware that you show is it designed to fit into a standard dip 8 footprint.

Regards
Arthur
No that would take some work, I'm happy with 1"x1". You could probably make a tall doubleSIP style with two boards and have a DIP footprint.

EDIT - I'll continue to answer questions here and there, just the board layout and building is taking a little too much time away from other things.
__________________
“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.”

Last edited by scott wurcer; 28th January 2013 at 01:53 PM.
  Reply With Quote
Old 28th January 2013, 03:38 PM   #2649
sidiy is offline sidiy  Canada
diyAudio Member
 
sidiy's Avatar
 
Join Date: Sep 2005
Location: Montreal
Concerning thin film resistor noise, I use these rules of thumb when doing parts selection.

0402 (or smaller ): don't bother
0603 : ok up to 2k
0805 : ok up to 20k
1206 : anytime if space allows

Of course we still need to consider max. Pd, drift, max. voltage, tol. ...

I cropped a few graphs useful to ilustrate the "size matters" aspect. The last one shows the thick films...in a class of their own
Attached Images
File Type: jpg MCx_pro_thin_film_current_noise.jpg (177.4 KB, 272 views)
File Type: jpg TNPW_thin_film_current_noise.jpg (182.1 KB, 252 views)
File Type: jpg RCWE3_thick_film_current_noise.jpg (278.4 KB, 242 views)
__________________
Make two for stereo
  Reply With Quote
Old 28th January 2013, 03:55 PM   #2650
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by sidiy View Post
Concerning thin film resistor noise, I use these rules of thumb when doing parts selection.


I cropped a few graphs useful to ilustrate the "size matters" aspect. The last one shows the thick films...in a class of their own
Interesting but there are counter examples of thick film on ceramic hybrid circuits of excellent performance or how about strain gages which operate at large DC currents.

Then there's IC thin film resistors orders of magnitude smaller where excess noise is nearly non-existant.
__________________
“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

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 01:00 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