Yamaha DTXpress/DTXplorer/DTXtreme

Just got my module back from the tech Yamaha had my local music store 
send it to.  He claims not to be able to re-create the problem I'm 
having, and I wondered if anyone here has a similar issue with the 
DTX III.

I have two keyboards & the DTX (Special) pads as controllers, and a 
number of sound modules hooked up to a mixer.  Two problems:

1. The only sound module I need to add gain to is the DTX III.  For 
some reason, it has the weakest signal of all my modules.

2. This is the wierd one, which I probably wouldn't even hear if not 
for #1.  If I play either of the keyboards, which send MIDI note 
messages to the DTX, I can hear clicking coming out of the DTX's 
audio channel even if the DTX is turned off.  I've isolated this to 
the DTX itself.  If I connect a keyboard's MIDI out to the DTX's MIDI 
in, turn off the DTX, and play the keyboard with Local Off and all 
other mixer channels muted, I can hear faint clicks coming out of the 
DTX's audio outputs in response to the Note On messages coming into 
its MIDI in.  Unplug the MIDI in from the DTX, or the audio outs, and 
the problem goes away.

Anyone else have these issues with the DTX III?  Any advice now that 
the repair guy can't hear this?

Thanks.

--- In DTXpress@yahoogroups.com, "markalias" <markalias@y...> wrote:

> If I play either of the keyboards, which send MIDI note 
> messages to the DTX, I can hear clicking coming out of the DTX's 
> audio channel even if the DTX is turned off.  I've isolated this to 
> the DTX itself.  If I connect a keyboard's MIDI out to the DTX's 
MIDI 
> in, turn off the DTX, and play the keyboard with Local Off and all 
> other mixer channels muted, I can hear faint clicks coming out of 
the 
> DTX's audio outputs in response to the Note On messages coming into 
> its MIDI in.  Unplug the MIDI in from the DTX, or the audio outs, 
and 
> the problem goes away.

Do you still get the clicks through the output over headphones if you 
don't go through the mixer? Do you get the clicks when you listen 
through the DTXP's headphone jack instead of the output? Do you get 
them when you play a pad to access a voice in one of the kits, rather 
than to access a GM sound? Maybe we can isolate the clicks further. 
Then you can definitely put someone in the right situation to hear 
them.

Hi,

And you've checked the manual, making sure there's no global or master audio output gain settings for the module that need to be raised (aside from the sldiers)?

You're right, though: if you can't get hot signals from the output of a module, you'll be forced to raise gain at the downstream stages, and thus start to hear alot of background noise (induced or otherwise) that gets amplified at the mixer's pres, etc.  All the buzzes and hums seemingly come out of the woodwork...

As far as the clicking, that sounds alot like something called a "MIDI Ground Loop".   Do a search on Yahoo!, and you should get some info on what it is, and how to address it...

But a simpler first step to run out induced noise would be to make sure you're running different cable types separately, NOT parallel to each other (if they must cross, run them at right angles).  

A 'clean install' for a studio usually runs different types of cables (MIDI, audio, power, speakers, SCSI, etc) as far away from each other as possible.  It makes a BIG difference.

Chris

--- In DTXpress@yahoogroups.com, "markalias" <markalias@y...> wrote:

> Just got my module back from the tech Yamaha had my local music store
> send it to.  He claims not to be able to re-create the problem I'm
> having, and I wondered if anyone here has a similar issue with the
> DTX III.
>
> I have two keyboards & the DTX (Special) pads as controllers, and a
> number of sound modules hooked up to a mixer.  Two problems:
>
> 1. The only sound module I need to add gain to is the DTX III.  For
> some reason, it has the weakest signal of all my modules.
>
> 2. This is the wierd one, which I probably wouldn't even hear if not
> for #1.  If I play either of the keyboards, which send MIDI note
> messages to the DTX, I can hear clicking coming out of the DTX's
> audio channel even if the DTX is turned off.  I've isolated this to
> the DTX itself.  If I connect a keyboard's MIDI out to the DTX's MIDI
> in, turn off the DTX, and play the keyboard with Local Off and all
> other mixer channels muted, I can hear faint clicks coming out of the
> DTX's audio outputs in response to the Note On messages coming into
> its MIDI in.  Unplug the MIDI in from the DTX, or the audio outs, and
> the problem goes away.
>
> Anyone else have these issues with the DTX III?  Any advice now that
> the repair guy can't hear this?
>
> Thanks.

> Do you still get the clicks through the output over headphones if 
you 
> don't go through the mixer? Do you get the clicks when you listen 
> through the DTXP's headphone jack instead of the output? Do you get 
> them when you play a pad to access a voice in one of the kits, 
rather 
> than to access a GM sound? Maybe we can isolate the clicks further. 
> Then you can definitely put someone in the right situation to hear 
> them.

Thanks for the reply.

No, I don't hear it through the headphones.  I also eliminated the 
mixer by going directly to powered monitors and still hear it.  Since 
the DTX output signal is so weak, I needed to turn the monitors all 
the way up.  Very annoying.  (The tech that Yamaha had me ship the 
unit to also didn't think the level was low, which makes me think he 
didn't even connect the thing, but I talked to him on the phone 
several times.)

I guess I'll try calling Yamaha myself and see what they say.  I've 
been planning to check out BFD and go the soft-synth route, but I 
hate to just forget using the onboard sounds because of this problem.

Thanks for the reply & suggestions, Chris.

> And you've checked the manual, making sure there's no global or 
master audio output gain settings for the module that need to be 
raised (aside from the sldiers)?

I did now.  It's in the UTIL menu, master volume, already set to 127, 
which is its max.

> As far as the clicking, that sounds alot like something called 
a "MIDI Ground Loop".   Do a search on Yahoo!, and you should get 
some info on what it is, and how to address it...

I couldn't find abything about this, but it sure sounds interesting.  
Speaking to the tech, he mentioned that all MIDI boxes have an opto-
isolator between the MIDI and audio circuits, and that he checked for 
any DC connectivitiy.  Still, since he was unable to re-create the 
problem (and didn't even agree the output level was low, which it 
most definitely is), so I'm really not so sure about this guy.
 
> But a simpler first step to run out induced noise would be to make 
sure you're running different cable types separately, NOT parallel to 
each other (if they must cross, run them at right angles).  

I'll do that right now...

Just audio to powered speakers and keyboard to MIDI in, no wires 
crossed or even close to each other until they get to the DTX.  Same 
problems.  Level too low, so speakers all the way up, turn DTX either 
off or on, play keys and hear faint little clicks coming out of the 
tweeters.

--- In DTXpress@yahoogroups.com, "markalias" <markalias@y...> wrote:
> No, I don't hear it through the headphones.  I also eliminated the 
> mixer by going directly to powered monitors and still hear it.  
Since 
> the DTX output signal is so weak, I needed to turn the monitors all 
> the way up.  Very annoying.  (The tech that Yamaha had me ship the 
> unit to also didn't think the level was low, which makes me think 
he 
> didn't even connect the thing, but I talked to him on the phone 
> several times.)
> 
> I guess I'll try calling Yamaha myself and see what they say.  I've 
> been planning to check out BFD and go the soft-synth route, but I 
> hate to just forget using the onboard sounds because of this 
problem.

So the clicks emanate from the output section, since they are not 
audible when heard through headphones. Unless your monitors are 
underpowered, the clicks and the weak signal from the outputs may be 
linked somehow. The DTXpress doesn't have scads of volume, but under 
normal conditions, it shouldn't require a setting of 11 on your amp. 
I have never heard of anyone complaining about these clicks. Is the 
volume okay when you listen from the headphone jack?  As Chris 
suggested, did you raise the volume in the utility menu as well as on 
the front panel?  Otherwise, why don't you call Dave Ksycki at 
800.892.6242 ext. 4964 and/or email him at dksycki@... and 
leave a message that you were referred to him by the DTXpress Group.

Ed