New input/output Selector

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jam

jam

Member
Joined 2001
Russ,

I am trying to understand the reason for the resistors on the pcb, they would always be across the input to ground except for the input that that was active adding to load presented to the source. They are probably not needed or were they ment to be in series with the input.

Regards,
Jam
 
Russ White

Russ White

Member
Joined 2005
twistedpearaudio.com
jam said:
Russ,

I am trying to understand the reason for the resistors on the pcb, they would always be across the input to ground except for the input that that was active adding to load presented to the source. They are probably not needed or were they ment to be in series with the input.

Regards,
Jam
Click to expand...

They are there simply to provide a high impedance (100K or so) GND reference for unused sources and ouputs. They are only active when a source/output is "off". Some sources don't like "open" loads, and most amplifiers don't like open inputs. So really I am just keeping any inactive input/outputs from floating.

They can of course be omitted.

Cheers!
Russ
 
Russ White

Russ White

Member
Joined 2005
twistedpearaudio.com
here is the fixed version. :)
 

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jam

jam

Member
Joined 2001
Russ,

Works for me................just a thought but you could rewire the unused pin on the relay to short non-active inputs to ground thus eleminating a potential source of cross talk...........but then again some sources might not like their outputs shorted........;)

Regards,
Jam
 
Russ White

Russ White

Member
Joined 2005
twistedpearaudio.com
jam said:
Russ,

but then again some sources might not like their outputs shorted........;)
Click to expand...

Hi Jam,

Thank you very much for your input. I think the layout is safest the way it is. I don't want to have explain to every person who builds one of these which sources can be shorted and which can't. I think I will leave it as is and if some want to they can very easily throw on a jumper or a resistor from that pin to GND.

Cheers!
Russ
 
J

jleaman

Banned
Joined 2002
plus.google.com/photos/104656656065604242634/albums/5725366675475046257?banner=pwa&gpsrc
BrianDonegan said:
The second relay board is for balanced operation. With one relay board, you can do single-ended (R+, GND, L+). With two boards, one would switch R+, GND, R-, the other L+, GND, L-.

It was my mistake in not posting it correctly the first time. If you need balanced operation and already ordered, send me an email and we can work something out.
Click to expand...


And this is a perfect example of how Brian / Russ are ding such a good job.

Keep it up guy's.

Jase
 
J

jleaman

Banned
Joined 2002
plus.google.com/photos/104656656065604242634/albums/5725366675475046257?banner=pwa&gpsrc
Re: Kits

BrianDonegan said:
Here's a pic of the relay board with kit parts:

An externally hosted image should be here but it was not working when we last tested it.


Not shown in the pic are the two rotary switches (6-pos, 2-deck and 3-pos 4-deck) and the IDC wiring connector.
Click to expand...


Yet another nice kit.. Look for my order soon :)
 
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