I've seen the notes in the Wiki about TRS & TS (balanced & unbalanced) jacks, and want to confirm what I think I know:

On the T1:
Channel 1,2,3 inputs are TS (the 1/4" only)
Channel 1,2,3 pre-outs are TRS
Channel 4/5 inputs are TRS
Master and Auz outs are TRS

On the L1 Model II
Analog Input is TRS
Bass output is TRS

Assuming the above is correct (please advise if not), here are two questions:

1) We have 4 T1s going into 3 L1s. The 4th T1 connects via the master out to the L1 analog input, and will have a 50 ft cable. I know in most situations an unbalanced cable will be fine, but I don't want to be surprised with lots of noise at some future gig. Is it worth the clams to purchase a 50ft balanced cable, TRS male on both ends?

2) We ran into a situation where someone needed to plug an iPod into our Bose. We quickly located a 1/8 to 1/4 stereo adapter. It sounded like half the information was missing using channel 4. It seemingly worked fine in channel 3. Is that correct, or should I have a different cable available if this situation occurs again?

Thanks
--Bruce Morris

Hi Bruce,

All the ¼ inch jack inputs will physically accept a Tip-Sleeve or Tip-Ring-Sleeve jack.


Now if we substitute Tip-Ring-Sleeve with Balanced, and Tip-Sleeve with Unbalanced, then what you've written works.

On the T1:
Channel 1,2,3 inputs are Unbalanced (the 1/4" only)
Channel 1,2,3 pre-outs are Balanced
Channel 4/5 inputs are Balanced
Master and Auz outs are Balanced

On the L1 Model II
Analog Input is Balanced
Bass output is Balanced

In all cases above you can use an Unbalanced (Tip-Sleeve connection) but if the connection is designed to be Balanced, you will have a lower (but likely still acceptable) signal.

More coming.

Hi Bruce,

quote:

Originally posted by RadicalDad:

Assuming the above is correct (please advise if not), here are two questions:

1) We have 4 T1s going into 3 L1s. The 4th T1 connects via the master out to the L1 analog input, and will have a 50 ft cable. I know in most situations an unbalanced cable will be fine, but I don't want to be surprised with lots of noise at some future gig. Is it worth the clams to purchase a 50ft balanced cable, TRS male on both ends?

Using the balanced cable should reduce the likelihood of problems you might encounter with an unbalanced cable.

quote:

2) We ran into a situation where someone needed to plug an iPod into our Bose. We quickly located a 1/8 to 1/4 stereo adapter. It sounded like half the information was missing using channel 4. It seemingly worked fine in channel 3. Is that correct, or should I have a different cable available if this situation occurs again?

Thanks
--Bruce Morris

Bruce, I would get a different cable and run that to T1® Channel 4/5. See T1® and Backing Tracks for pictures and details about the cable.

Thanks ST -

To keep ground loop issues to a minimum, I always take one tap off the house AC using a multi-outlet surge protector, and then plug all our equipment into that surge protector - L1s, the extra T1, electric pianos, etc. (This was my practice even before my Bose days.) We are now putting our T1's on the mic stands, and will need a long power cord from the back of the stage, near the L1s, to the front of the stage to plug in the extra T1. I have some concern that the combination of the long power cord and long audio cable will create differing ground potentials, and resulting ground loop hum. Am I worrying about nothing?

As for the iPod issue, you mean you want me to do it right???? I've never figured out the rules for mono/stereo interconnection. Seems like a mono plug (male) into a stereo jack (female) never works - only delivers signal to one channel, but a stereo plug (male) into a mono unbalanced jack (female) works fine. Am I wrong about that? Does it never work either way?

quote:

Originally posted by RadicalDad:
... a mono plug (male) into a stereo jack (female) ... a stereo plug (male) into a mono unbalanced jack (female) ... Does it never work either way?

Yes ... it never works.

Now, it may sometimes sound like it's sort of working, but it depends on both the particular source equipment (does it have a high level of cross-talk between L & R?) and on the actual source material (is most of the musical content available adequately on the one channel actually connected?).

What is worse is the third situation -- a stereo plug (male) into a balanced mono jack (female) -- when the source material is truly recorded stereo, the "balanced mono" connection will actually end up "subtracting" (not summing) the Left and Right channels ... giving a rather anemic output.

This message has been edited. Last edited by: Dan Cornett,

quote:

Originally posted by RadicalDad:
Thanks ST -

To keep ground loop issues to a minimum, I always take one tap off the house AC using a multi-outlet surge protector, and then plug all our equipment into that surge protector - L1s, the extra T1, electric pianos, etc. (This was my practice even before my Bose days.) We are now putting our T1's on the mic stands, and will need a long power cord from the back of the stage, near the L1s, to the front of the stage to plug in the extra T1. I have some concern that the combination of the long power cord and long audio cable will create differing ground potentials, and resulting ground loop hum. Am I worrying about nothing?

I have done this too (long power cable to T1®s at the front of the stage) on many occasions without problems.

I just recently got around to making a couple of snakes that have a ¼ inch jack Balanced (Tip-Ring-Sleeve) cable and a Cat-5 cable (that connects to the T1® power supply). This lets me plug the T1® into an L1® at the back of the stage and the power supply gets plugged in with everything else (also at the back of the stage).

I prefer to strap all my microphone, instrument, and T1® cables to my microphone stand. I also leave the microphone stand adapter clamp attached to the stand. Then I pack the stand with the cables in an old L1 Cylindrical Radiator® zipper-bag. Now the snake goes in zipper bag too. This is super fast to set up: unzip the case. Snake connects to the L1® and power at the back. T1® goes on the bracket and all the cables are right there. It is really quick.

quote:

As for the iPod issue, you mean you want me to do it right???? I've never figured out the rules for mono/stereo interconnection. Seems like a mono plug (male) into a stereo jack (female) never works - only delivers signal to one channel, but a stereo plug (male) into a mono unbalanced jack (female) works fine. Am I wrong about that? Does it never work either way?

Yes - I'll try to err on the side of most-likely-to-work-most-of-the-time. (doing it right).
but a stereo plug (male) into a mono unbalanced jack (female) works fine.

Whether or not this works and how well it works is going to depend on how the designer of the input designed it. If s/he anticipated that you might do this, and s/he wanted you to be able to hear both channels even though the input is actually mono - then you will probably hear both sides. I wouldn't want to assume that this will be the case most of the time.

Does that help?

quote:

Originally posted by ST:

I just recently got around to making a couple of snakes that have a ¼ inch jack Balanced (Tip-Ring-Sleeve) cable and a Cat-5 cable (that connects to the T1® power supply). This lets me plug the T1® into an L1® at the back of the stage and the power supply gets plugged in with everything else (also at the back of the stage).

What did you use for the T1 power connection? A standard female Ethernet connector won't mate with the Ethercon NE8MC. Did you buy the Neutrik female Ethercon (NE8FBH-S or similar) and mount it to a stage box?

quote:

Originally posted by ST:

I prefer to strap all my microphone, instrument, and T1® cables to my microphone stand. I also leave the microphone stand adapter clamp attached to the stand. Then I pack the stand with the cables in an old L1 Cylindrical Radiator® zipper-bag. Now the snake goes in zipper bag too. This is super fast to set up: unzip the case. Snake connects to the L1® and power at the back. T1® goes on the bracket and all the cables are right there. It is really quick.

Yeah, moving the T1s to the front is new for us and we haven't reconfigured our setup yet. Next thing to do - will make setup much faster I'm sure. And readers of this thread should know that you don't need a spare Cylindrical Radiator bag to do this. You can get mic stand bags pretty cheap that will do the same thing.

quote:

Originally posted by ST:

but a stereo plug (male) into a mono unbalanced jack (female) works fine.

Whether or not this works and how well it works is going to depend on how the designer of the input designed it. If s/he anticipated that you might do this, and s/he wanted you to be able to hear both channels even though the input is actually mono - then you will probably hear both sides. I wouldn't want to assume that this will be the case most of the time.

Do you know what the design of the T1 channels 1-3 is regarding stereo inputs? Did they allow for that? Dan Cornett doesn't seem to think this ever works. And the more I think about it, this can't work if the input is expecting something balanced. The two channels will just negative sum against each other and all you'll get is the difference. In order for this to work, it seems that you must have a TRS (stereo) female jack, and the circuit has to sense whether the ring is touching a separate ring on the plug or is shorted against the sleeve - and then act accordingly.

Ahh, the brains I wasn't born with. That's why I play bass!

Bruce Morris
The Mighty Filberts

Hi Bruce,

quote:

Originally posted by RadicalDad:

What did you use for the T1 power connection? A standard female Ethernet connector won't mate with the Ethercon NE8MC. Did you buy the Neutrik female Ethercon (NE8FBH-S or similar) and mount it to a stage box?

I removed the outer shell just twist the part closest to the cable and the whole thing disassembles. I had a simple female:female rj45 connector lying around and that's working just fine.

quote:

quote:

Originally posted by ST:
[...]And readers of this thread should know that you don't need a spare Cylindrical Radiator bag to do this. You can get mic stand bags pretty cheap that will do the same thing.

I just happened to have a few unused original Cylindrical Radiator® bags because early in the game I got the heavy duty bags (now discontinued unfortunately). Until tonight I had never seen a microphone stand bag, but after reading your post I found some here.
http://www.gatorcases.com/Prod...il.aspx?LID=4&PID=77
http://www.americanmusical.com...ne-Stand-Bags--m-686

In the pre-L1® days I used to carry microphone stands in a lightweight nylon golf bag.

quote:

Originally posted by ST:

but a stereo plug (male) into a mono unbalanced jack (female) works fine.

Whether or not this works and how well it works is going to depend on how the designer of the input designed it. If s/he anticipated that you might do this, and s/he wanted you to be able to hear both channels even though the input is actually mono - then you will probably hear both sides. I wouldn't want to assume that this will be the case most of the time.

Do you know what the design of the T1 channels 1-3 is regarding stereo inputs? Did they allow for that? Dan Cornett doesn't seem to think this ever works. And the more I think about it, this can't work if the input is expecting something balanced. The two channels will just negative sum against each other and all you'll get is the difference. In order for this to work, it seems that you must have a TRS (stereo) female jack, and the circuit has to sense whether the ring is touching a separate ring on the plug or is shorted against the sleeve - and then act accordingly.

Ahh, the brains I wasn't born with. That's why I play bass!

Bruce Morris
The Mighty Filberts

The T1® Channels 1,2,3 are unbalanced. Inserting a ¼ inch jack into the T1® Channels 1,2,3 inputs I cannot feel a separate ring connection in the way that I clearly can with Channels 4/5.

I don't know how Channels 1,2,3 are wired. But rather than spend a lot of time on this (because we could), let me go back to my original suggestion that I am confident will work with your T1®.

"Bruce, I would get a different cable and run that to T1® Channel 4/5. See T1® and Backing Tracks for pictures and details about the cable."