Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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

+4dBu  to  -10dBV line attenuation?
+4dBu  to  -10dBV line attenuation?
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 November 2017, 12:56 AM   #11
rayma is offline rayma  United States
diyAudio Member
 
Join Date: Apr 2011
Quote:
Originally Posted by Cableaddict View Post
No one can just calculate the values?
For a matched 600R source, with the output -12dB (with a light load),
the series resistors are each 150R, and the shunt resistor is 300R.

Last edited by rayma; 19th November 2017 at 01:07 AM.
  Reply With Quote
Old 19th November 2017, 10:03 AM   #12
AndrewT is offline AndrewT  Scotland
R.I.P.
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by AndrewT View Post
A Jensen app note has the resistor network for this conversion.
I don't remember which one. There are over a dozen, so it will take some searching.
I had a look through my Jensen AN last night and did not see the resistor network.
Maybe it was another of the balanced retailers that published it.

I do remember having to work through it because intuitively it did not make sense. Took a little while to understand why they placed the resistors in the arrangement they showed.
__________________
regards Andrew T.
  Reply With Quote
Old 19th November 2017, 10:18 PM   #13
Cableaddict is offline Cableaddict
diyAudio Member
 
Join Date: Nov 2016
Thanks, Rayma !


- And thanks to all for the help.
  Reply With Quote
Old 19th November 2017, 10:26 PM   #14
rayma is offline rayma  United States
diyAudio Member
 
Join Date: Apr 2011
Quote:
Originally Posted by Cableaddict View Post
Thanks, Rayma ! And thanks to all for the help.
Remember this calculation relies on the source impedance being 600R,
and also the load being >>300R (say at least 3k or more).
  Reply With Quote
Old 20th November 2017, 12:15 AM   #15
PRR is offline PRR  United States
diyAudio Member
 
PRR's Avatar
 
Join Date: Jun 2003
Location: Maine USA
Quote:
Originally Posted by Cableaddict View Post
..... No one can just calculate the values?
I just did. The "true 600r" case and a more real-world case around 2,400r.

Is my image not showing for you?
  Reply With Quote
Old 20th November 2017, 04:48 AM   #16
Blues is offline Blues  United States
diyAudio Member
 
Blues's Avatar
 
Join Date: Sep 2003
Location: The Milky Way
Two L-pads connected in Balanced mode. Try 2250R for the 2 series resistors and 750R for the 2 shunts with their midpoint connected to audio ground. Input/output impedances are 6000R and 1125R Balanced respectively.





Quote:
Originally Posted by Cableaddict View Post
SO.....


No one can just calculate the values?


I'm totally stuck here.
  Reply With Quote
Old 30th November 2017, 05:37 PM   #17
jvhb is offline jvhb  Europe
diyAudio Member
 
Join Date: Nov 2013
Location: Countryside Zealand, DK
+4dBu  to  -10dBV line attenuation?
Quote:
Originally Posted by PRR View Post
I just did. The "true 600r" case and a more real-world case around 2,400r.

Is my image not showing for you?
Nice walkthrough/example. Textbook quality stuff
__________________
www.audioberg.dk
  Reply With Quote
Old 1st December 2017, 03:59 AM   #18
PRR is offline PRR  United States
diyAudio Member
 
PRR's Avatar
 
Join Date: Jun 2003
Location: Maine USA
Quote:
Originally Posted by jvhb View Post
Textbook quality stuff
It's a matchbook size problem. Dunno why it needed so much thread space.
  Reply With Quote
Old 2nd December 2017, 11:39 PM   #19
Blues is offline Blues  United States
diyAudio Member
 
Blues's Avatar
 
Join Date: Sep 2003
Location: The Milky Way
Default Design decisions!

If you want to keep the 600R output Z of your source (to keep its character, allegedly into your preamp) use 1200R for series resistors and 400R for shunts. It's still a healthy 3200R balanced load...5.33x.

  Reply With Quote
Old 7th February 2018, 01:07 AM   #20
Cableaddict is offline Cableaddict
diyAudio Member
 
Join Date: Nov 2016
Quote:
Originally Posted by PRR View Post
It's a matchbook size problem. Dunno why it needed so much thread space.
Well, I have a matchbook-sized understanding of such things.

But actually, given the somewhat wide swing in the responses, maybe it's not really so simple?
  Reply With Quote

Reply


+4dBu  to  -10dBV line attenuation?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Stupid question regarding -10dBV and +4dBu levels MAAC0 PA Systems 9 13th July 2017 04:59 AM
Handling +4dBu/-10dBv and un/balanced jordanstreet Analog Line Level 3 18th June 2013 07:39 PM
Looking to DIY a DI box -10dBv to +4dBu NEO Dan Analog Line Level 10 23rd August 2012 09:27 AM
line stage attenuation options marc brown Parts 3 3rd February 2009 01:49 PM
Line Level attenuation habana Analogue Source 13 14th May 2003 07:45 PM


New To Site? Need Help?

All times are GMT. The time now is 03:52 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki