Resistors valus for shunt stepped attenuator? - diyAudio
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 24th October 2010, 02:25 PM   #1
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Default Resistors valus for shunt stepped attenuator?

I want do do a shunt stepped attenuator 10K with 23 steps, the question: is this table showing the right values?

Step 1, Attenuation = Infinity dB, Rx = 10000 ohms, Ry = 0 ohms.
Step 2, Attenuation = 75 dB, Rx = 10000 ohms, Ry = 2 ohms.
Step 3, Attenuation = 72 dB, Rx = 10000 ohms, Ry = 3 ohms.
Step 4, Attenuation = 69 dB, Rx = 10000 ohms, Ry = 4 ohms.
Step 5, Attenuation = 66 dB, Rx = 10000 ohms, Ry = 5 ohms.
Step 6, Attenuation = 63 dB, Rx = 10000 ohms, Ry = 7 ohms.
Step 7, Attenuation = 60 dB, Rx = 10000 ohms, Ry = 10 ohms.
Step 8, Attenuation = 58 dB, Rx = 10000 ohms, Ry = 13 ohms.
Step 9, Attenuation = 56 dB, Rx = 10000 ohms, Ry = 16 ohms.
Step 10, Attenuation = 54 dB, Rx = 10000 ohms, Ry = 20 ohms.
Step 11, Attenuation = 52 dB, Rx = 10000 ohms, Ry = 25 ohms.
Step 12, Attenuation = 50 dB, Rx = 10000 ohms, Ry = 32 ohms.
Step 13, Attenuation = 48 dB, Rx = 10000 ohms, Ry = 40 ohms.
Step 14, Attenuation = 46 dB, Rx = 10000 ohms, Ry = 50 ohms.
Step 15, Attenuation = 44 dB, Rx = 10000 ohms, Ry = 63 ohms.
Step 16, Attenuation = 42 dB, Rx = 10000 ohms, Ry = 80 ohms.
Step 17, Attenuation = 40 dB, Rx = 10000 ohms, Ry = 101 ohms.
Step 18, Attenuation = 38 dB, Rx = 10000 ohms, Ry = 127 ohms.
Step 19, Attenuation = 36 dB, Rx = 10000 ohms, Ry = 161 ohms.
Step 20, Attenuation = 34 dB, Rx = 10000 ohms, Ry = 204 ohms.
Step 21, Attenuation = 32 dB, Rx = 10000 ohms, Ry = 258 ohms.
Step 22, Attenuation = 30 dB, Rx = 10000 ohms, Ry = 327 ohms.
Step 23, Attenuation = 28 dB, Rx = 10000 ohms, Ry = 415 ohms.

Thanks for help.
  Reply With Quote
Old 24th October 2010, 02:31 PM   #2
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Parallel Resistor Calculator Find Optimum Resistors to Place in Parallel to Create Non-Std Value - PARALLELRESCALC - TI Tool Folder
__________________
/Per-Anders (my first name) or P-A as my friends call me
Tube Buffered Gainclone in work |Thread || Diamond buffer |Thread for the group buy | Wiki
  Reply With Quote
Old 24th October 2010, 02:35 PM   #3
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Thanks for help PA, my posted table are the rights values? I understand that you posted the TI link to get exact values right?

Last edited by merlin el mago; 24th October 2010 at 03:03 PM.
  Reply With Quote
Old 24th October 2010, 04:26 PM   #4
Banned
 
Join Date: Jan 2008
Blog Entries: 2
Here's the attenuation with R1 as series element followed by R2 to ground, signal taken at junction of R1, R2.

shunt.jpg

W
  Reply With Quote
Old 24th October 2010, 04:57 PM   #5
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
So it's OK the values for 23 steps 10K shunt, right?
  Reply With Quote
Old 24th October 2010, 05:02 PM   #6
Banned
 
Join Date: Jan 2008
Blog Entries: 2
Here's the exact values:

shunt2.jpg

w
  Reply With Quote
Old 24th October 2010, 05:07 PM   #7
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Thank you wakiwaki, I do a mistake step 23 Ry without resistor only Rx resistor 10K in series.
  Reply With Quote
Old 25th October 2010, 02:10 PM   #8
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Now the Shallco 23 stepped attenuator is with these resistors & sounds very good:

Step 1, Rx = 10000 ohms, Ry = 0 ohms.
Step 2, Rx = 10000 ohms, Ry = 2 ohms.
Step 3, Rx = 10000 ohms, Ry = 3.6 ohms.
Step 4, Rx = 10000 ohms, Ry = 6.8 ohms.
Step 5, Rx = 10000 ohms, Ry = 13 ohms.
Step 6, Rx = 10000 ohms, Ry = 22ohms.
Step 7, Rx = 10000 ohms, Ry = 39 ohms.
Step 8, Rx = 10000 ohms, Ry = 68 ohms.
Step 9, Rx = 10000 ohms, Ry = 120 ohms.
Step 10, Rx = 10000 ohms, Ry = 180 ohms.
Step 11, Rx = 10000 ohms, Ry = 270 ohms.
Step 12, Rx = 10000 ohms, Ry = 360 ohms.
Step 13, Rx = 10000 ohms, Ry = 510 ohms.
Step 14, Rx = 10000 ohms, Ry = 820 ohms.
Step 15, Rx = 10000 ohms, Ry = 1K1 ohms.
Step 16, Rx = 10000 ohms, Ry = 1K6 ohms.
Step 17, Rx = 10000 ohms, Ry = 2K4 ohms.
Step 18, Rx = 10000 ohms, Ry = 3K ohms.
Step 19, Rx = 10000 ohms, Ry = 4K7 ohms.
Step 20, Rx = 10000 ohms, Ry = 6K8 ohms.
Step 21, Rx = 10000 ohms, Ry = 9K ohms.
Step 22, Rx = 10000 ohms, Ry = 15K ohms.
Step 23, Rx = 10000 ohms, Ry = without resistor / not connected

There is a mistake or something wrong?
  Reply With Quote
Old 26th October 2010, 01:04 PM   #9
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Question Please help?

Please help?
  Reply With Quote
Old 26th October 2010, 01:36 PM   #10
Banned
 
Join Date: Jan 2008
Blog Entries: 2
I'm not quite sure what the problem is.

You could try these numbers:

shunt3.jpg

If you want a stage with NO attenuation, then try this:

shunt4.jpg

w
  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
Calculation of stepped shunt attenuator Mick_F Chip Amps 2 25th January 2014 10:49 AM
Resistors for Stepped Attenuator stl Tubes / Valves 27 18th February 2009 05:07 PM
Calculating a stepped attenuator resistors values... youyoung21147 Parts 3 13th June 2005 07:07 AM
Carbon film vs metal film resistors in a stepped attenuator? G Tubes / Valves 17 22nd August 2004 12:22 AM
Shunt volume controll (scaling the shunt resistors) Freddie Solid State 7 30th August 2001 09:47 PM


New To Site? Need Help?

All times are GMT. The time now is 05:02 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