R24 channel bleed in stereo pair

Discuss the Zoom HD and R series. Please don't "post and run". Participate in the discussion. Thanks.
Post Reply
flamesong
been here a while
been here a while
Posts: 55
Joined: Tue Jan 08, 2013 6:30 pm

R24 channel bleed in stereo pair

Post by flamesong » Wed Feb 13, 2019 11:53 am

I was just sticking some colour coded labels on my Zoom R24 and as I can't see the back easily, I disconnected the other ends of the inputs one by one to see which coloured cable went to each of four channels as two stereo pairs by observing the level LEDs as I strummed my guitar. Two of the channels were straight forward to identify but when I disconnected one of the other two, both channels' LEDs lit. When I disconnected the other of the stereo pair's cables, only one lit - so it seems that one of the stereo pairs is bleeding into the other.

At first, I wondered if the cable could be picking up a signal from the other so I disconnected it completely from the R24 and it still happened.

Can anybody offer any suggestions, please?
0 x

Wulfraed
The Force
The Force
Posts: 3228
Joined: Wed Jan 23, 2008 8:18 pm
Location: Lowell, MI

Re: R24 channel bleed in stereo pair

Post by Wulfraed » Wed Feb 13, 2019 12:38 pm

1) Are you talking just adjacent channels in mono mode used as a "pair", or channels that are in "stereo link" mode (which also means one fader [odd #] is used for both)

2) Are you using balanced XLR cables, or unbalanced TS cables (and are the cables shielded). Unbalanced cables are more susceptible to picking up external noise from wires running roughly parallel)

3) Is phantom power turned on for some of these inputs? I vaguely recall that someone once determined that the phantom power injection is a circuit shared by adjacent pairs, so an input source that draws on phantom power can have some "echo" bleed to the other side of the power injection.
0 x
--
Baron Wulfraed
IISS Elusive Unicorn (detached)

Superscope PSD-300; BOSS BR-600, Zoom HD16cd, Zoom R16, BOSS BR-800, Zoom H2n
Now to (re)learn to play an instrument

Lanikai S-C, SMC-E; GoldTone Banjo-Uke; Flatiron 1C, A5; Big Muddy M1-W; Ovation MM68AX, CSE-44; Orpheus Valley Fiesta FS; Taylor NS-72ce, T5-S1; Musima (4st, 20 fret, tenor-tuned) banjo; bongos, dumbeks, bodhrans, hand drum, tambourine; recorder: soprano, alto, tenor; Cedar Flute (5 sizes); Pennywhistle (3 keys); Casio keyboards

flamesong
been here a while
been here a while
Posts: 55
Joined: Tue Jan 08, 2013 6:30 pm

Re: R24 channel bleed in stereo pair

Post by flamesong » Wed Feb 13, 2019 2:11 pm

Hello,

Thanks for the reply.

1). I meant to say that they are stereo linked, I was probably using terminology from another application. They are controlled from a single fader.

2). I'm using XLR to mono jacks so they are unbalanced. As a side note, I never use jacks because they are impossible to get out without huge force involving holding the R24 between my knees whilst pushing down with one hand and pulling the jack with the other. I understand what you are getting at. Maybe I didn't explain it very well but after having disconnected at the instrument end and seen the audio on the LEDs, I actually removed the cable altogether so there is only the left cable connected but audio (at a lower level) on the right channel, so although it would normally be connected, during testing, there wasn't a cable to pick up external noise.

3). There is no phantom power on at all.
0 x

Wulfraed
The Force
The Force
Posts: 3228
Joined: Wed Jan 23, 2008 8:18 pm
Location: Lowell, MI

Re: R24 channel bleed in stereo pair

Post by Wulfraed » Wed Feb 13, 2019 2:40 pm

Forgot #4: Any insert effects that affect more than one channel? (Some devices have insert effects that can take a mono input and generate a stereo output).

And a last test... If you turn OFF the stereo link, and only have a single cable in place, do you still see the bleed?
0 x
--
Baron Wulfraed
IISS Elusive Unicorn (detached)

Superscope PSD-300; BOSS BR-600, Zoom HD16cd, Zoom R16, BOSS BR-800, Zoom H2n
Now to (re)learn to play an instrument

Lanikai S-C, SMC-E; GoldTone Banjo-Uke; Flatiron 1C, A5; Big Muddy M1-W; Ovation MM68AX, CSE-44; Orpheus Valley Fiesta FS; Taylor NS-72ce, T5-S1; Musima (4st, 20 fret, tenor-tuned) banjo; bongos, dumbeks, bodhrans, hand drum, tambourine; recorder: soprano, alto, tenor; Cedar Flute (5 sizes); Pennywhistle (3 keys); Casio keyboards

flamesong
been here a while
been here a while
Posts: 55
Joined: Tue Jan 08, 2013 6:30 pm

Re: R24 channel bleed in stereo pair

Post by flamesong » Wed Feb 13, 2019 6:19 pm

I have no effects on any channels as I am making raw recordings to import to Logic.

The last test sounds like a good call. It's a bit late to do anything right now but I will try tomorrow.

Thanks.
0 x

flamesong
been here a while
been here a while
Posts: 55
Joined: Tue Jan 08, 2013 6:30 pm

Re: R24 channel bleed in stereo pair

Post by flamesong » Fri Feb 15, 2019 5:30 pm

I checked the settings as you suggested but unlinking the stereo channels did not help. I think it is is something to do with the physical proximity of the two channels because controlling for all other variables, I found that I could eliminate the sound bleed by by not using adjacent channels; i.e. having two (currently empty) channels separating them. It's not ideal but it works for now.
0 x

Wulfraed
The Force
The Force
Posts: 3228
Joined: Wed Jan 23, 2008 8:18 pm
Location: Lowell, MI

Re: R24 channel bleed in stereo pair

Post by Wulfraed » Sat Feb 16, 2019 12:53 pm

May still be related to the phantom power circuits -- IF they are shared by adjacent channels.

Of course, since the R series are non-routing devices, not using adjacent inputs means not using adjacent tracks -- and that means one cannot stereo-link the tracks.
0 x
--
Baron Wulfraed
IISS Elusive Unicorn (detached)

Superscope PSD-300; BOSS BR-600, Zoom HD16cd, Zoom R16, BOSS BR-800, Zoom H2n
Now to (re)learn to play an instrument

Lanikai S-C, SMC-E; GoldTone Banjo-Uke; Flatiron 1C, A5; Big Muddy M1-W; Ovation MM68AX, CSE-44; Orpheus Valley Fiesta FS; Taylor NS-72ce, T5-S1; Musima (4st, 20 fret, tenor-tuned) banjo; bongos, dumbeks, bodhrans, hand drum, tambourine; recorder: soprano, alto, tenor; Cedar Flute (5 sizes); Pennywhistle (3 keys); Casio keyboards

flamesong
been here a while
been here a while
Posts: 55
Joined: Tue Jan 08, 2013 6:30 pm

Re: R24 channel bleed in stereo pair

Post by flamesong » Sat Feb 16, 2019 3:11 pm

As I mentioned earlier, I am not using any phantom power whatsoever.

I may not have explained the channel configuration very well but I had stereo inputs into 3/4 and 5/6 and there was audio from either 3 or 4 bleeding into 5. I moved the inputs 5/6 to 7/8 and the problem stopped. It isn't ideal as I had everything set up a certain way that I was used to but it works.
0 x

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest