Passive Balanced switching and Relay questions!! - 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 21st November 2011, 11:21 AM   #1
JAY X is offline JAY X  Spain
diyAudio Member
 
Join Date: Aug 2010
Exclamation Passive Balanced switching and Relay questions!!

Hi All,

MECHANICAL SWITCHING

I'm currently switching balanced line level audio signals with alps 4pdt switches. This model allows me to switch between TWO sources, and works very well.Ok so far.

To switch between THREE balanced sources is more complicated. I would need a LORLIN CK switch, but i don't know which model to choose. (3 pole or 4 pole, or any other...). The grounding scheme i usually use is the classic "Ground follows signal". I need a model suggestion.

RELAY SWITCHING


Recently i started switching audio line level signals with relays, (TAKAMISAWA RY24-K) 10 pin DPDT relays, with a 1n4148 diode across the coil. Powered with 18volts. ĦĦI'm a newbie with relays!!

I wire it up as i would do with a mechanical switch, taking care of the usual considerations relays need.

Once wired,(as a mute switch or a changeover switch) i test it and pass some audio thru it, and the result is not bad, (a bit harsh),but not that transparent as a mecahnical switch. żis this normal?

I switch signals coming out from a low impedance output OPAMP, to a High impedance input Opamp. żDo i need to put input resistors? (10k or so?) to the inputs of the relay?? Maybe i'm getting confused now...

Thank you for your help,
JAY X
  Reply With Quote
Old 23rd November 2011, 03:00 PM   #2
JAY X is offline JAY X  Spain
diyAudio Member
 
Join Date: Aug 2010
Hi,
Maybe i don't have explained myself well.
I just have two questions:

1) I'm looking for a Rotary switch to select from 3 balanced sources
żany maker/model?

2) when switching audio line level signals withs relays, the sound is a bit harsh, with a loss in low frequencies. żIs that normal?

The relay i use is a TAKAMISAWA A24W-K powered from 18v supply. The setup test: CD PLAYER----> RELAY-----> AKG 240 HEADPHONES.

Thank you for your help,
JAY X
  Reply With Quote
Old 29th November 2011, 02:21 PM   #3
diyAudio Member
 
Join Date: Sep 2007
Location: N38
Hi Jay,

Here is a 4 pole, 3 position rotary switch.

Digi-Key - 451-1030-ND (Manufacturer - C5P0403N-A)

- Richard
  Reply With Quote
Old 5th December 2011, 08:32 PM   #4
shanx is offline shanx  Canada
diyAudio Member
 
Join Date: Dec 2010
Location: Quebec
Quote:
2) when switching audio line level signals withs relays, the sound is a bit harsh, with a loss in low frequencies. żIs that normal?

The relay i use is a TAKAMISAWA A24W-K powered from 18v supply. The setup test: CD PLAYER----> RELAY-----> AKG 240 HEADPHONES.
The relay contacts you have on that W-K model should be good, gold plated etc, but you maybe a bit low on the operating voltage you are switching the coil with. The guaranteed must operate is at 16.8 VDC and your supply is only 1.2 V above that so might not be applying a good holding current..you could try the version with 18 VDC nominal RY 18 W-K. are you controling with a mechanical switch or electronically?

If you are hearing an audible click you could try using a 1 Meg resistor across signal and ground, after the switch towards input side of your preamp. That can help, reduces some transients and pops from capacitors discharging and charging when you switch sources, and doesn't load down signal too much.
  Reply With Quote
Old 5th December 2011, 08:37 PM   #5
shanx is offline shanx  Canada
diyAudio Member
 
Join Date: Dec 2010
Location: Quebec
Quote:
2) when switching audio line level signals withs relays, the sound is a bit harsh, with a loss in low frequencies. żIs that normal?

The relay i use is a TAKAMISAWA A24W-K powered from 18v supply. The setup test: CD PLAYER----> RELAY-----> AKG 240 HEADPHONES.
The relay contacts you have on that W-K model should be good, gold plated etc, but you maybe a bit low on the operating voltage you are switching the coil with. The guaranteed must operate is at 16.8 VDC and your supply is only 1.2 V above that so might not be applying a good holding current..you could try the version with 18 VDC nominal RY 18 W-K. are you controling with a mechanical switch or electronically?

If you are hearing an audible click you could try using a 1 Meg resistor across signal and ground, after the switch towards input side of your preamp. That can help, reduces some transients and pops from capacitors discharging and charging when you switch sources, and doesn't load down signal too much.
  Reply With Quote
Old 6th December 2011, 02:25 PM   #6
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
If the sound coming through the Mechanical switch is different from that coming through the Relay switch, then I would suggest it is down to the self cleaning of the switch contacts in either case.
The forces between the contacts and the method of "wiping" will be quite different. Whereas the materials used for the contacts and for the poles to the outside world could be sourced to be identical. The materials should not change the sound if they are the same.
__________________
regards Andrew T.
  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
Passive Balanced Volume Control Questions SilverStrings Analog Line Level 9 5th November 2011 08:53 PM
Switching loudspeaker with relay quietdragon Solid State 8 3rd November 2011 04:46 AM
need dpdt switching relay help subaruzero Parts 1 27th September 2006 07:27 PM
Relay switching circuit please jnewbold Solid State 10 3rd March 2005 06:39 AM
Switching audio signals with relay niral622 Solid State 11 19th April 2004 03:28 PM


New To Site? Need Help?

All times are GMT. The time now is 12:32 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright İ1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2