3-way input switching board (ebay) use as A/B switch?
Can anyone tell based on the pics if this board can be used the opposite way intended?
Three Way Input Audio Input Switching Board | eBay
I hope to use it as an A/B switch to audition different amps or blind testing so I would be using it as 1 input and 3 outputs.
Thanks,
Can anyone tell based on the pics if this board can be used the opposite way intended?
Three Way Input Audio Input Switching Board | eBay
I hope to use it as an A/B switch to audition different amps or blind testing so I would be using it as 1 input and 3 outputs.
Thanks,
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Thanks AndrewT,
Currently I'm using two simple switches on a couple tube preamps, 1 for the tweeters and 1 for the midrange on my active 3-way MiniDSP 2x8 set up, the switches take the tube pre's in and out of the signal path like an outboard EQ bypass switch would on a factory preamp. But with the existing switches there is noise when I push the button so I was thinking that this might mute any switching noise with the addition of the relays and possibly better channel separation between L&R A and L&R B. Am I thinking right here?
If the prototype works out I'll replace the switch on the board with a SPST and only use the 2 outside outputs (and replace those with better RCA jacks) and place 2 of these eBay units (1 for mids, 1 for tweets) in their own little enclosure.
This is my solution to building a couple of tube preamp kits and integrating them into the rest of the system. Once in the system though I wondered what their effect really was having on the sound and how much they were attenuating the signal. Using a switch I'm able to A/B and make sure I'm at the same dB level (so it doesn't screw up the x-over settings) and what sort of affect the "tube sound" is having on the signal.
I am open to better suggestions though if anyone has them.
Currently I'm using two simple switches on a couple tube preamps, 1 for the tweeters and 1 for the midrange on my active 3-way MiniDSP 2x8 set up, the switches take the tube pre's in and out of the signal path like an outboard EQ bypass switch would on a factory preamp. But with the existing switches there is noise when I push the button so I was thinking that this might mute any switching noise with the addition of the relays and possibly better channel separation between L&R A and L&R B. Am I thinking right here?
If the prototype works out I'll replace the switch on the board with a SPST and only use the 2 outside outputs (and replace those with better RCA jacks) and place 2 of these eBay units (1 for mids, 1 for tweets) in their own little enclosure.
This is my solution to building a couple of tube preamp kits and integrating them into the rest of the system. Once in the system though I wondered what their effect really was having on the sound and how much they were attenuating the signal. Using a switch I'm able to A/B and make sure I'm at the same dB level (so it doesn't screw up the x-over settings) and what sort of affect the "tube sound" is having on the signal.
I am open to better suggestions though if anyone has them.
The switches are most likely not the source of the problem (unless they're bad or really poor quality), and replacing them without doing anything else probably won't fix it. If the switches are DC coupled, the noise is usually caused by the DC level shifting when the contacts close or open. Proper AC coupling may solve the problem.
Mike
Mike
Thanks Michael,
The switches I'm using now are kind of crappy. They are salvaged from the parts box originally from a cheap Sony integrated and look similar to this:
They didn't make noise initially but with repeated use they are starting to. For most all day casual listening (system is in my work studio) I bypass the tube preamps and run the tweet and mid amps straight to save on tube life/shorten the signal path but I do like what the tube pre does to the midrange channel and have 8 sets of tubes to swap out for rolling.
I've googled around a bit but haven't stumbled across a simple AC coupled schematic for audio and I'm still learning about electronics/reading schematics so not sure if I could build one anyway. Does something like that exist out there or is there a way to modify the above board with a cap to achieve this?
The switches I'm using now are kind of crappy. They are salvaged from the parts box originally from a cheap Sony integrated and look similar to this:
They didn't make noise initially but with repeated use they are starting to. For most all day casual listening (system is in my work studio) I bypass the tube preamps and run the tweet and mid amps straight to save on tube life/shorten the signal path but I do like what the tube pre does to the midrange channel and have 8 sets of tubes to swap out for rolling.
I've googled around a bit but haven't stumbled across a simple AC coupled schematic for audio and I'm still learning about electronics/reading schematics so not sure if I could build one anyway. Does something like that exist out there or is there a way to modify the above board with a cap to achieve this?
Oh my...Yeah, I have had the unfortunate experience of trying to use switches like that, they're pretty much crap, as you found. So replacing them is a good idea. I concluded long ago that skimping on quality with switches and such is a waste of time and money. I'd like to add that cheap signal relays are also susceptible to the same problems. If you can use sealed reed relays they are much better in that respect.
Mike
Mike
Do you think then that replacing the switch might be an adequate solution? I agree about the quality parts thing whole heartedly, my existing switches were meant to be a temporary solution but then other things come up and busting out the soldering iron takes a back seat.
I have some 3 position rotary dials and could leave the middle position unused to isolate the 2 stereo channels. I'm not sure if they are make before break or other way around but leaving 2nd position open should alleviate any issues. I'm happy to purchase new parts too if anyone has a better solution.
Again, am I correct in my reasoning here?
Really appreciate everyones input on this, seems such a simple thing but....
I have some 3 position rotary dials and could leave the middle position unused to isolate the 2 stereo channels. I'm not sure if they are make before break or other way around but leaving 2nd position open should alleviate any issues. I'm happy to purchase new parts too if anyone has a better solution.
Again, am I correct in my reasoning here?
Really appreciate everyones input on this, seems such a simple thing but....
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noise during switching is as stated due to changing DC levels across the switch during the changeover.
Using a make before break switch can help with this.
The make before break also helps with not leaving the input "open circuit" during the switch over. Some inputs do not like open circuit !
As far as I know signal switching relays do not offer make before break.
Using a make before break switch can help with this.
The make before break also helps with not leaving the input "open circuit" during the switch over. Some inputs do not like open circuit !
As far as I know signal switching relays do not offer make before break.
Well, the eBay boards arrived today as I'd already ordered them. When I get a chance I'll hook one of them up and report back about noise or any other issues. It could be a month or so as I'm busy in the shop at the moment and can't spare the time.
AndrewT, the amps I'm using (currently) for the mids and tweets will tolerate an open circuit but I will certainly keep this in mind if I make a "future proof" project out of it. I'm also going to order some make before break rotary switches as that would be the simplest solution for the existing set up.
Thank you both for your thoughts on this.
AndrewT, the amps I'm using (currently) for the mids and tweets will tolerate an open circuit but I will certainly keep this in mind if I make a "future proof" project out of it. I'm also going to order some make before break rotary switches as that would be the simplest solution for the existing set up.
Thank you both for your thoughts on this.
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