How to put a stereo line-out on a digital piano that doesn't have one?

[[email protected]]

I discovered that the model of digital piano I'm waiting on doesn't have a line out. As I understand it you want to solder it into the lines going into the amp. how do you identify the amp?

What considerations are there that I might not be aware of?

It's a used ebay unit, so warranty isn't an issue.

Thanks.

[Les Cargill[_4_]]

wrote:
> I discovered that the model of digital piano I'm waiting on doesn't have a line out. As I understand it you want to solder it into the lines going into the amp. how do you identify the amp?
>
> What considerations are there that I might not be aware of?
>
> It's a used ebay unit, so warranty isn't an issue.
>
> Thanks.
>


Just use the headphone out.

--
Les Cargill

[Gareth Magennis]

wrote in message
...

I discovered that the model of digital piano I'm waiting on doesn't have a
line out. As I understand it you want to solder it into the lines going into
the amp. how do you identify the amp?

What considerations are there that I might not be aware of?

It's a used ebay unit, so warranty isn't an issue.

Thanks.





Tap off the volume pot/slider.


Gareth.

[geoff]

On 13/07/2015 7:31 p.m., Gareth Magennis wrote:
>
>
> wrote in message
> ...
>
> I discovered that the model of digital piano I'm waiting on doesn't have
> a line out. As I understand it you want to solder it into the lines
> going into the amp. how do you identify the amp?
>
> What considerations are there that I might not be aware of?
>
> It's a used ebay unit, so warranty isn't an issue.

I'd suggest give up trying to polish a turd. Why does the output need
to be stereo, if it is in fact mono ? And is it worth the effort ?

geoff

PS You can polish a turd, but you hare to freeze it first ;-O

[Trevor]

On 13/07/2015 6:05 PM, geoff wrote:
> PS You can polish a turd, but you hare to freeze it first ;-O

Petrified turds are much better for polishing, and don't thaw out while
trying to polish them like frozen ones do! ;-)

Trevor.

[[email protected]]

On Monday, July 13, 2015 at 4:06:06 AM UTC-4, geoff wrote:
..
>
> I'd suggest give up trying to polish a turd. Why does the output need
> to be stereo, if it is in fact mono ? And is it worth the effort ?


Because the unit is stereo.

[JackA]

On Monday, July 13, 2015 at 3:31:07 AM UTC-4, Gareth Magennis wrote:
> wrote in message
> ...
>
> I discovered that the model of digital piano I'm waiting on doesn't have a
> line out. As I understand it you want to solder it into the lines going into
> the amp. how do you identify the amp?
>
> What considerations are there that I might not be aware of?
>
> It's a used ebay unit, so warranty isn't an issue.
>
> Thanks.
>
>
>
>
>
> Tap off the volume pot...

Not necessary to bring weed into this situation :-)

Jack
>
>
> Gareth.

[Mike Rivers[_2_]]

On 7/13/2015 7:45 AM, wrote:
> Because the unit is stereo.

Does it have a stereo headphone jack? If so, that will make a perfectly
workable line output. No soldering involved other than perhaps making a
cable with all the right connectors.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[JackA]

On Monday, July 13, 2015 at 6:40:48 AM UTC-4, Trevor wrote:
> On 13/07/2015 6:05 PM, geoff wrote:
> > PS You can polish a turd, but you hare to freeze it first ;-O
>
> Petrified turds are much better for polishing, and don't thaw out while
> trying to polish them like frozen ones do! ;-)
>
> Trevor.

You guys are grotesque and eerie!

(Stereo) Jack :)

[[email protected]]

On Monday, July 13, 2015 at 8:41:59 AM UTC-4, Mike Rivers wrote:

> Does it have a stereo headphone jack? If so, that will make a perfectly
> workable line output.


The output from the headphone is line-level?

[[email protected]]

On Monday, July 13, 2015 at 8:41:59 AM UTC-4, Mike Rivers wrote:

> Does it have a stereo headphone jack? If so, that will make a perfectly
> workable line output. No soldering involved other than perhaps making a
> cable with all the right connectors.


Okay, let's say I want to install a line-level jack with L/R RCA outputs just as an exercise in doing it, what's involved?

[Mike Rivers[_2_]]

On 7/13/2015 9:35 AM, wrote:

> The output from the headphone is line-level?

Assuming that there's a volume control, the headphone output will follow
it, but yes, you can get enough level from any reasonable headphone
output to drive a line level input. "Line level" isn't a specific
number, just a ballpark range. The two nominal ones are +4 dBu and -10
dBV, and most headphone outputs, unless you're talking about a low power
device like a mobile phone, when turned up full (nothing wrong with
doing that) will be close to the nominal +4 dBu level.

I'll be unbalanced, if you care about that, but it probably won't
matter. What is this mysterious digital piano and what do you want to
connect it to?

When the piano arrives, try using the headphone output. You won't blow
anything up.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[Neil[_9_]]

On 7/13/2015 9:38 AM, wrote:
> On Monday, July 13, 2015 at 8:41:59 AM UTC-4, Mike Rivers wrote:
>
>> Does it have a stereo headphone jack? If so, that will make a perfectly
>> workable line output. No soldering involved other than perhaps making a
>> cable with all the right connectors.
>
>
> Okay, let's say I want to install a line-level jack with L/R RCA outputs just as an exercise in doing it, what's involved?
>
Having read the responses that suggest using the headphone jack: +1

If you must attach RCA outputs to the piano, take a tap off of the
headphone jack. You won't blow anything up, and it's unlikely that you'd
use both at the same time... not that it would matter if you did.

--
Best regards,

Neil

[Scott Dorsey]

> wrote:
>On Monday, July 13, 2015 at 8:41:59 AM UTC-4, Mike Rivers wrote:
>
>> Does it have a stereo headphone jack? If so, that will make a perfectly
>> workable line output.
>
>The output from the headphone is line-level?

More or less kind of. Whatever line-level is, and whatever you set the
volume to. But you should be able to drive a +4 input without a problem.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[JackA]

On Monday, July 13, 2015 at 11:25:43 AM UTC-4, Neil wrote:
> On 7/13/2015 9:38 AM, wrote:
> > On Monday, July 13, 2015 at 8:41:59 AM UTC-4, Mike Rivers wrote:
> >
> >> Does it have a stereo headphone jack? If so, that will make a perfectly
> >> workable line output. No soldering involved other than perhaps making a
> >> cable with all the right connectors.
> >
> >
> > Okay, let's say I want to install a line-level jack with L/R RCA outputs just as an exercise in doing it, what's involved?
> >
> Having read the responses that suggest using the headphone jack: +1
>
> If you must attach RCA outputs to the piano, take a tap off of the
> headphone jack. You won't blow anything up, and it's unlikely that you'd
> use both at the same time... not that it would matter if you did.
>
> --
> Best regards,
>
> Neil

Why not purchase a 3.5mm stereo plug to RCA female or male, less than $5 USD.

ex: http://www.apogeekits.com/3_5mm_stereo_male_to_rca_female.htm

Jack

[Gareth Magennis]

wrote in message
...

I discovered that the model of digital piano I'm waiting on doesn't have a
line out. As I understand it you want to solder it into the lines going into
the amp. how do you identify the amp?

What considerations are there that I might not be aware of?

It's a used ebay unit, so warranty isn't an issue.

Thanks.






Note that using the headphone jack as the line output will mute the built in
speakers.
You may not want this to happen.

You could modifiy the headphone jack circuit to prevent this though.



Gareth.

[Frank Stearns]

Neil > writes:

>On 7/13/2015 9:38 AM, wrote:
>> On Monday, July 13, 2015 at 8:41:59 AM UTC-4, Mike Rivers wrote:
>>
>>> Does it have a stereo headphone jack? If so, that will make a perfectly
>>> workable line output. No soldering involved other than perhaps making a
>>> cable with all the right connectors.

Maybe (and it really should work), but here's a weird one:

For years, in a pinch when line outs are not provided, I've used the headphone out
of electric pianos, electronic drums, computer headphone jacks, et al, with a
conventional passive transformer DI to feed a PA system and/or my recording rig with
or without the splitter. No problems. (I could either grab the tip signal and feed a
mono DI foregoing the right channel, or with the correct breakout cable use tip and
ring to feed a stereo DI.)

In the past few months, however, using that same technique I've gotten ZERO signal
and HUGE amounts of hum and buzz from three newer pieces of gear. Ground lift only
slightly changes the character, but not the level. Still all hum and buzz, no
signal *at all*, not even buried deep in the hum and buzz.

This has happened with different passive DIs from different manus, and has occurred
with newer pianos, pad drums, and electric pianos. (In the case of the pad drums,
the signal was fine when "buffered" by the band's little toy PA mixer. The signal
was successfully fed to the passive DI from an aux out of the mixer.)

The killer is that those horridly unreliable Behringer active DIs (phantom powered
with some electronics inside and a teeny transformer) have no problems in these
same situations. Clean as a whistle.

(That's all well and good; I just don't trust the Behringers not to simply quit
working in the middle of a show. I always prefer passive DIs for that reason.)

So here's the question: has something changed in the basic output design of these
newer consumer devices such that a passive transformer connection no longer works?

Should there by some kind of modest shunt load on the high Z input side of the
transformer to help make things work?

Are all of these newer consumer devices perhaps using the same commodity output chip
(or cheesy power & ground configuration) that in some way is "breaking the rules"?

It's too common to be an isolated issue -- unless there's something wrong with the
console or system where I do the occasional PA gig (Yamaha M7CL-48). Everything
seems fine otherwise.

Anyone run into anything similar in recent years?

Thanks in advance,
Frank
Mobile Audio
--

[Mike Rivers[_2_]]

On 7/13/2015 3:30 PM, Frank Stearns wrote:

> In the past few months, however, using that same technique I've gotten ZERO signal
> and HUGE amounts of hum and buzz from three newer pieces of gear. Ground lift only
> slightly changes the character, but not the level. Still all hum and buzz, no
> signal *at all*, not even buried deep in the hum and buzz.

Are you splitting the headphone output into separate left and right
cables? Or are you putting a single plug (TS or TRS, please?) into the
jack and plugging that into the DI? It could be that when one headphone
channel gets shorted to ground, things get unhappy.

> So here's the question: has something changed in the basic output design of these
> newer consumer devices such that a passive transformer connection no longer works?

If a change can make it cheaper, it's probably been made. Likely there's
a single chip that's the headphone amplifier (and perhaps other things)
and grounding one of the outputs makes it go bananas.

A real analysis of what's coming out of the headphone jack and what the
left/right common is connected to is what's called for in order to
figure out how to best deal with the problem without a Behringer DI. I
wouldn't use a DI at all unless you need a mic level signal or are
passing it through a long enough cable to make balancing it at the
keyboard end worth while.



--
For a good time, visit http://mikeriversaudio.wordpress.com

[JackA]

On Monday, July 13, 2015 at 4:51:07 PM UTC-4, Mike Rivers wrote:
> On 7/13/2015 3:30 PM, Frank Stearns wrote:
>
> > In the past few months, however, using that same technique I've gotten ZERO signal
> > and HUGE amounts of hum and buzz from three newer pieces of gear. Ground lift only
> > slightly changes the character, but not the level. Still all hum and buzz, no
> > signal *at all*, not even buried deep in the hum and buzz.
>
> Are you splitting the headphone output into separate left and right
> cables? Or are you putting a single plug (TS or TRS, please?) into the
> jack and plugging that into the DI? It could be that when one headphone
> channel gets shorted to ground, things get unhappy.
>
> > So here's the question: has something changed in the basic output design of these
> > newer consumer devices such that a passive transformer connection no longer works?
>
> If a change can make it cheaper, it's probably been made. Likely there's
> a single chip that's the headphone amplifier (and perhaps other things)
> and grounding one of the outputs makes it go bananas.

Don't think banana plugs are the way to go!

Sorry, my dry humor.

Why not purchase 3.5mm to RCA female or male adapter. If worried the speakers will get disconnected (we're not sure they will), don't push the 3.5mm plug in all the way, tape it in place, still has line-out and speakers.

I think I should be awarded a Grammy! :-)

Jack

>
> A real analysis of what's coming out of the headphone jack and what the
> left/right common is connected to is what's called for in order to
> figure out how to best deal with the problem without a Behringer DI. I
> wouldn't use a DI at all unless you need a mic level signal or are
> passing it through a long enough cable to make balancing it at the
> keyboard end worth while.
>
>
>
> --
> For a good time, visit http://mikeriversaudio.wordpress.com

[Gareth Magennis]

Why not purchase 3.5mm to RCA female or male adapter. If worried the
speakers will get disconnected (we're not sure they will), don't push the
3.5mm plug in all the way, tape it in place, still has line-out and
speakers.

I think I should be awarded a Grammy! :-)

Jack




A headphone socket WILL disconnect the speakers, headphones are for
listening in private without disturbing anyone else.

You might get away with only losing one speaker by not quite pushing the
3.5mm jack in all the way, but you will definitely lose the speaker from the
ring connection.


Where's my Nobel?



Gareth.

[Frank Stearns]

"Gareth Magennis" > writes:

>A headphone socket WILL disconnect the speakers, headphones are for
>listening in private without disturbing anyone else.

>You might get away with only losing one speaker by not quite pushing the
>3.5mm jack in all the way, but you will definitely lose the speaker from the
>ring connection.


>Where's my Nobel?

Good question. It was indeed a dynamite post.

Frank
Mobile Audio
--

[Scott Dorsey]

Frank Stearns > wrote:
>
>For years, in a pinch when line outs are not provided, I've used the headphone out
>of electric pianos, electronic drums, computer headphone jacks, et al, with a
>conventional passive transformer DI to feed a PA system and/or my recording rig with
>or without the splitter. No problems. (I could either grab the tip signal and feed a
>mono DI foregoing the right channel, or with the correct breakout cable use tip and
>ring to feed a stereo DI.)
>
>In the past few months, however, using that same technique I've gotten ZERO signal
>and HUGE amounts of hum and buzz from three newer pieces of gear. Ground lift only
>slightly changes the character, but not the level. Still all hum and buzz, no
>signal *at all*, not even buried deep in the hum and buzz.

The ONLY thing that I can think of is that you have a balanced input DI
and a stereo headphone output, and you're using a TRS-TRS cable to connect
the two and getting the difference between the two channels.

But... the secret to diagnosing problems like these is to plug a pair of
headphones into everything.... plug phones into the keyboard and make sure
it's okay, then plug the cable into the keyboard and touch the 1/4" on the
other end of the cable to the 1/4" on the headphones tip-to-sleeve and
see if you're getting signal on the other end of the cable. Then into the
DI and if the DI has a through, plug the headphones in there and make sure
there is signal.

Now get headphones with a mini phone plug and bridge the tip and ring across
pins 2 and 3 of the DI output and listen.... signal will be greatly reduced
but you should hear something. Just go on down the line, one item after the
other, using the headphones.

>Should there by some kind of modest shunt load on the high Z input side of the
>transformer to help make things work?

No.

>Are all of these newer consumer devices perhaps using the same commodity output chip
>(or cheesy power & ground configuration) that in some way is "breaking the rules"?

Maybe, but a passive DI should just be a box with a transformer in it. Maybe
a pad on the front, maybe a ground lift switch, but it's really just a
transformer. There is nothing to go wrong except incorrect connections and
wiring.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Frank Stearns]

(Scott Dorsey) writes:

>Frank Stearns > wrote:
>>
>>For years, in a pinch when line outs are not provided, I've used the headphone out
>>of electric pianos, electronic drums, computer headphone jacks, et al, with a
>>conventional passive transformer DI to feed a PA system and/or my recording rig with
>>or without the splitter. No problems. (I could either grab the tip signal and feed a
>>mono DI foregoing the right channel, or with the correct breakout cable use tip and
>>ring to feed a stereo DI.)
>>
>>In the past few months, however, using that same technique I've gotten ZERO signal
>>and HUGE amounts of hum and buzz from three newer pieces of gear. Ground lift only
>>slightly changes the character, but not the level. Still all hum and buzz, no
>>signal *at all*, not even buried deep in the hum and buzz.

>The ONLY thing that I can think of is that you have a balanced input DI
>and a stereo headphone output, and you're using a TRS-TRS cable to connect
>the two and getting the difference between the two channels.

Nope. Again, this is with conventional xformer DIs, unbalanced hi-z primary
(50K or so); low Z balanced secondary with typical ground lifting (and on
my personal boxes, the Jensen-suggested series 10 nf cap with a 51 ohm resister
to maintain RF ground when the ground lift switch is opened).

>But... the secret to diagnosing problems like these is to plug a pair of
>headphones into everything.... plug phones into the keyboard and make sure
>it's okay, then plug the cable into the keyboard and touch the 1/4" on the
>other end of the cable to the 1/4" on the headphones tip-to-sleeve and
>see if you're getting signal on the other end of the cable. Then into the
>DI and if the DI has a through, plug the headphones in there and make sure
>there is signal.

Again...

a. this stuff used to work

b. the active Behringers worked, with the SAME breakout cables

c. the outputs worked into other gear, such as a commodity toy mixer.

>Now get headphones with a mini phone plug and bridge the tip and ring across
>pins 2 and 3 of the DI output and listen.... signal will be greatly reduced
>but you should hear something. Just go on down the line, one item after the
>other, using the headphones.

I could do this, but see points B and C. Also, multiple DIs got swapped into this
with the thought that we had a broken DI.

>>Should there by some kind of modest shunt load on the high Z input side of the
>>transformer to help make things work?

>No.

Well, I only mention this because many years ago while on remote with a PBS crew
covering a full solar eclipse from a mountain top near Goldendale, WA state, I
was asked to get the audio from a Motorola comm radio into a mixer. The only
accessible output was the earphone jack. When plugged in this way, the damn thing
put out no signal but instead started to motorboat (still no signal).

Swapped back to an ear phone and things were fine. "What's the difference?" I asked
myself. Load!!! I grabbed a 47 ohm resister from the audio truck's junk box and
wired it across the tip and ring. Motorboating gone, signal appeared...


>>Are all of these newer consumer devices perhaps using the same commodity output chip
>>(or cheesy power & ground configuration) that in some way is "breaking the rules"?

>Maybe, but a passive DI should just be a box with a transformer in it. Maybe
>a pad on the front, maybe a ground lift switch, but it's really just a
>transformer. There is nothing to go wrong except incorrect connections and
>wiring.

So very true. You understand my consternation.

Frank
Mobile Audio

--

[JackA]

On Monday, July 13, 2015 at 6:05:01 PM UTC-4, Gareth Magennis wrote:
> Why not purchase 3.5mm to RCA female or male adapter. If worried the
> speakers will get disconnected (we're not sure they will), don't push the
> 3.5mm plug in all the way, tape it in place, still has line-out and
> speakers.
>
> I think I should be awarded a Grammy! :-)
>
> Jack
>
>
>
>
> A headphone socket WILL disconnect the speakers, headphones are for
> listening in private without disturbing anyone else.
>
> You might get away with only losing one speaker by not quite pushing the
> 3.5mm jack in all the way, but you will definitely lose the speaker from the
> ring connection.
>
>
> Where's my Nobel?
>
>
>
> Gareth.

Gareth, from my experience, if you don't push the (assumed) 3.5mm stereo plug in, you won't open the switches, but you'll obtain a signal, that's all. It may be touch and go, but I feel the modification is a bit too much for the person asking. We may think it's the modification is simple, but to some, it may be their next nightmare. I feel, keep it simple, don't assume.

A Nobel Prize? Only a US President that can cut the deficit spending by two-thirds deserves that! In others words, we haven't had any.

Jack

[Gareth Magennis]

"JackA" wrote in message
...

On Monday, July 13, 2015 at 6:05:01 PM UTC-4, Gareth Magennis wrote:
> Why not purchase 3.5mm to RCA female or male adapter. If worried the
> speakers will get disconnected (we're not sure they will), don't push the
> 3.5mm plug in all the way, tape it in place, still has line-out and
> speakers.
>
> I think I should be awarded a Grammy! :-)
>
> Jack
>
>
>
>
> A headphone socket WILL disconnect the speakers, headphones are for
> listening in private without disturbing anyone else.
>
> You might get away with only losing one speaker by not quite pushing the
> 3.5mm jack in all the way, but you will definitely lose the speaker from
> the
> ring connection.
>
>
> Where's my Nobel?
>
>
>
> Gareth.

Gareth, from my experience, if you don't push the (assumed) 3.5mm stereo
plug in, you won't open the switches, but you'll obtain a signal, that's
all. It may be touch and go, but I feel the modification is a bit too much
for the person asking. We may think it's the modification is simple, but to
some, it may be their next nightmare. I feel, keep it simple, don't assume.

A Nobel Prize? Only a US President that can cut the deficit spending by
two-thirds deserves that! In others words, we haven't had any.

Jack





Jack, you try that with a pair of headphones into your hi-f- amp and tell me
whether you can get both speakers and both sides of the headphones working
properly at once.



Gareth.

[Mike Rivers[_2_]]

On 7/14/2015 12:28 PM, Gareth Magennis wrote:

> "JackA" wrote in message
> Gareth, from my experience, if you don't push the (assumed) 3.5mm stereo
> plug in, you won't open the switches, but you'll obtain a signal, that's
> all. It may be touch and go

> Jack, you try that with a pair of headphones into your hi-f- amp and
> tell me whether you can get both speakers and both sides of the
> headphones working properly at once.

Indeed it's "touch-and-go." If you push the plug in gently so that the
tip touches the first (ring) contact without the contact actually moving
the ring contact away from its normalling contact, you'll get the ring
signal on the tip of the plug. If the ring of the plug touches the
sleeve (ground) of the jack when the plug tip is touching the ring,
you'll get the ring signal in both headphones since current goes through
both headphones on its way from ring to ground.

Very flaky, and it's really no different, functionally, other than that
you'll get the left channel instead of the right channel signal, than
shoving the plug in all the way, letting the tip make contact as it's
supposed to. Nothing flaky about that other than that with a TS plug,
you'll short out the left headphone amplifier channel. It probably won't
blow up.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[Gareth Magennis]

"JackA" wrote in message
...

On Tuesday, July 14, 2015 at 12:28:58 PM UTC-4, Gareth Magennis wrote:
> "JackA" wrote in message
> ...
>
> On Monday, July 13, 2015 at 6:05:01 PM UTC-4, Gareth Magennis wrote:
> > Why not purchase 3.5mm to RCA female or male adapter. If worried the
> > speakers will get disconnected (we're not sure they will), don't push
> > the
> > 3.5mm plug in all the way, tape it in place, still has line-out and
> > speakers.
> >
> > I think I should be awarded a Grammy! :-)
> >
> > Jack
> >
> >
> >
> >
> > A headphone socket WILL disconnect the speakers, headphones are for
> > listening in private without disturbing anyone else.
> >
> > You might get away with only losing one speaker by not quite pushing the
> > 3.5mm jack in all the way, but you will definitely lose the speaker from
> > the
> > ring connection.
> >
> >
> > Where's my Nobel?
> >
> >
> >
> > Gareth.
>
> Gareth, from my experience, if you don't push the (assumed) 3.5mm stereo
> plug in, you won't open the switches, but you'll obtain a signal, that's
> all. It may be touch and go, but I feel the modification is a bit too much
> for the person asking. We may think it's the modification is simple, but
> to
> some, it may be their next nightmare. I feel, keep it simple, don't
> assume.
>
> A Nobel Prize? Only a US President that can cut the deficit spending by
> two-thirds deserves that! In others words, we haven't had any.
>
> Jack
>
>
>
>
>
> Jack, you try that with a pair of headphones into your hi-f- amp and tell
> me
> whether you can get both speakers and both sides of the headphones working
> properly at once.
>
>
>
> Gareth.

Garth, if I may, it's is tricky (may have to tape/hold plug in place), but
it is a possibility.


Jack





So are you saying that the switch-operating ring contact can touch the ring
of the jack plug without breaking the switch?

I think I need a second opinion on that.


Gareth.

[Gareth Magennis]

"Mike Rivers" wrote in message ...

On 7/14/2015 12:28 PM, Gareth Magennis wrote:

> "JackA" wrote in message
> Gareth, from my experience, if you don't push the (assumed) 3.5mm stereo
> plug in, you won't open the switches, but you'll obtain a signal, that's
> all. It may be touch and go

> Jack, you try that with a pair of headphones into your hi-f- amp and
> tell me whether you can get both speakers and both sides of the
> headphones working properly at once.

Indeed it's "touch-and-go." If you push the plug in gently so that the
tip touches the first (ring) contact without the contact actually moving
the ring contact away from its normalling contact, you'll get the ring
signal on the tip of the plug. If the ring of the plug touches the
sleeve (ground) of the jack when the plug tip is touching the ring,
you'll get the ring signal in both headphones since current goes through
both headphones on its way from ring to ground.

Very flaky, and it's really no different, functionally, other than that
you'll get the left channel instead of the right channel signal, than
shoving the plug in all the way, letting the tip make contact as it's
supposed to. Nothing flaky about that other than that with a TS plug,
you'll short out the left headphone amplifier channel. It probably won't
blow up.

--




OK, I think you and Jack are talking about touching the ring contact with
the tip of the plug without breaking the ring switch.

This is not what I said, and not what the OP wants AIUI.
He wants his piano in Stereo, not one side missing.
As would I.
Many digital pianos are panned so the bass notes are somewhat biased towards
the left and the high notes to the right.
One half of the usually included stereo reverb might also sound a bit odd.

What I am talking about, connection wise, is not possible without
modification, AFAIK.


> Jack, you try that with a pair of headphones into your hi-f- amp and
> tell me whether you can get both speakers and both sides of the
> headphones working properly at once.




Gareth.

[John Williamson]

On 14/07/2015 20:37, Gareth Magennis wrote:
>
>
> "Mike Rivers" wrote in message ...
>
> On 7/14/2015 12:28 PM, Gareth Magennis wrote:
>
>> "JackA" wrote in message
>> Gareth, from my experience, if you don't push the (assumed) 3.5mm stereo
>> plug in, you won't open the switches, but you'll obtain a signal, that's
>> all. It may be touch and go
>
>> Jack, you try that with a pair of headphones into your hi-f- amp and
>> tell me whether you can get both speakers and both sides of the
>> headphones working properly at once.
>
> Indeed it's "touch-and-go." If you push the plug in gently so that the
> tip touches the first (ring) contact without the contact actually moving
> the ring contact away from its normalling contact, you'll get the ring
> signal on the tip of the plug. If the ring of the plug touches the
> sleeve (ground) of the jack when the plug tip is touching the ring,
> you'll get the ring signal in both headphones since current goes through
> both headphones on its way from ring to ground.
>
> Very flaky, and it's really no different, functionally, other than that
> you'll get the left channel instead of the right channel signal, than
> shoving the plug in all the way, letting the tip make contact as it's
> supposed to. Nothing flaky about that other than that with a TS plug,
> you'll short out the left headphone amplifier channel. It probably won't
> blow up.
>
You could try bridging the opened contacts with a resistor, so that when
they are open, there is still some drive to the main speaker amp. As
long as the total load on the output is less than 32 ohms or so, the
headphone amp won't care. Of course, it it always possible that a switch
opened by the earth ring on the headphone socket turns the main amp off
when the headphones are plugged in, which means you need to short that
switch out, and the main amp will work as normal.

Doing this will, of course, involve opening the case.

--
Tciao for Now!

John.

[John Williamson]

On 14/07/2015 20:45, John Williamson wrote:
> On 14/07/2015 20:37, Gareth Magennis wrote:
>>
>>
>> "Mike Rivers" wrote in message ...
>>
>> On 7/14/2015 12:28 PM, Gareth Magennis wrote:
>>
>>> "JackA" wrote in message
>>> Gareth, from my experience, if you don't push the (assumed) 3.5mm stereo
>>> plug in, you won't open the switches, but you'll obtain a signal, that's
>>> all. It may be touch and go
>>
>>> Jack, you try that with a pair of headphones into your hi-f- amp and
>>> tell me whether you can get both speakers and both sides of the
>>> headphones working properly at once.
>>
>> Indeed it's "touch-and-go." If you push the plug in gently so that the
>> tip touches the first (ring) contact without the contact actually moving
>> the ring contact away from its normalling contact, you'll get the ring
>> signal on the tip of the plug. If the ring of the plug touches the
>> sleeve (ground) of the jack when the plug tip is touching the ring,
>> you'll get the ring signal in both headphones since current goes through
>> both headphones on its way from ring to ground.
>>
>> Very flaky, and it's really no different, functionally, other than that
>> you'll get the left channel instead of the right channel signal, than
>> shoving the plug in all the way, letting the tip make contact as it's
>> supposed to. Nothing flaky about that other than that with a TS plug,
>> you'll short out the left headphone amplifier channel. It probably won't
>> blow up.
>>
> You could try bridging the opened contacts with a resistor, so that when
> they are open, there is still some drive to the main speaker amp. As
> long as the total load on the output is less than 32 ohms or so, the
> headphone amp won't care. Of course, it it always possible that a switch
> opened by the earth ring on the headphone socket turns the main amp off
> when the headphones are plugged in, which means you need to short that
> switch out, and the main amp will work as normal.
>
> Doing this will, of course, involve opening the case.
>
Sorry, I should clarify that the total *impedance* of the load presented
to the headphone amp should be more than 32 ohms or so. To get a mono
signal out to a PA system, link the tip and ring with a pair of 33 ohm
resistors in series, and use the connection between the resistors as the
output connection, with the sleeve a earth. This should feed a DI box
quite nicely if all you have spare is a microphone input.

--
Tciao for Now!

John.

[JackA]

On Tuesday, July 14, 2015 at 3:08:30 PM UTC-4, Mike Rivers wrote:
> On 7/14/2015 12:28 PM, Gareth Magennis wrote:
>
> > "JackA" wrote in message
> > Gareth, from my experience, if you don't push the (assumed) 3.5mm stereo
> > plug in, you won't open the switches, but you'll obtain a signal, that's
> > all. It may be touch and go
>
> > Jack, you try that with a pair of headphones into your hi-f- amp and
> > tell me whether you can get both speakers and both sides of the
> > headphones working properly at once.
>
> Indeed it's "touch-and-go." If you push the plug in gently so that the
> tip touches the first (ring) contact without the contact actually moving
> the ring contact away from its normalling contact, you'll get the ring
> signal on the tip of the plug. If the ring of the plug touches the
> sleeve (ground) of the jack when the plug tip is touching the ring,
> you'll get the ring signal in both headphones since current goes through
> both headphones on its way from ring to ground.
>
> Very flaky, and it's really no different, functionally, other than that
> you'll get the left channel instead of the right channel signal, than
> shoving the plug in all the way, letting the tip make contact as it's
> supposed to. Nothing flaky about that other than that with a TS plug,
> you'll short out the left headphone amplifier channel. It probably won't
> blow up.
>
> --
> For a good time, visit http://mikeriversaudio.wordpress.com

Mike, my point is, if the Subject poster is asking if it is possible to add a line-out jack to something, I do not feel he's capable of accomplishing it or else it would be done. It was immediately assumed loss of speaker output was an issue without asking the poster.

And, for the record, I was not teasing Frank about misspelling resistor. One thing I greatly valued was Usenet posters with decent writing skills. I used to fear writing a single sentence.

Thanks.

Jack

[Scott Dorsey]

Frank Stearns > wrote:
>
>a. this stuff used to work

With the same keyboards?

>b. the active Behringers worked, with the SAME breakout cables

The active Behringers should have had a higher input Z than any transformer.

>c. the outputs worked into other gear, such as a commodity toy mixer.

What if you use a Y cable and Y the output into a toy mixer or a pair of
headphones and into the DI box? You still get signal out of the headphones
or the toy mixer and not the DI feed?

>>Now get headphones with a mini phone plug and bridge the tip and ring across
>>pins 2 and 3 of the DI output and listen.... signal will be greatly reduced
>>but you should hear something. Just go on down the line, one item after the
>>other, using the headphones.
>
>I could do this, but see points B and C. Also, multiple DIs got swapped into this
>with the thought that we had a broken DI.

I know. I'm just a big fan of starting at the beginning and being very
systematic every time something mysterious happens, just because you might
be missing a clue somewhere otherwise.

>>>Should there by some kind of modest shunt load on the high Z input side of the
>>>transformer to help make things work?
>
>>No.
>
>Well, I only mention this because many years ago while on remote with a PBS crew
>covering a full solar eclipse from a mountain top near Goldendale, WA state, I
>was asked to get the audio from a Motorola comm radio into a mixer. The only
>accessible output was the earphone jack. When plugged in this way, the damn thing
>put out no signal but instead started to motorboat (still no signal).
>
>Swapped back to an ear phone and things were fine. "What's the difference?" I asked
>myself. Load!!! I grabbed a 47 ohm resister from the audio truck's junk box and
>wired it across the tip and ring. Motorboating gone, signal appeared...

If this is the case, then a Y cable feeding both a pair of headphones and the
DI box will allow the headphones to provide whatever load the keyboard wants.
But if that were the case, I'd expect the Behringer not to work.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Gareth Magennis]

"John Williamson" wrote in message ...

On 14/07/2015 20:37, Gareth Magennis wrote:
>
>
> "Mike Rivers" wrote in message ...
>
> On 7/14/2015 12:28 PM, Gareth Magennis wrote:
>
>> "JackA" wrote in message
>> Gareth, from my experience, if you don't push the (assumed) 3.5mm stereo
>> plug in, you won't open the switches, but you'll obtain a signal, that's
>> all. It may be touch and go
>
>> Jack, you try that with a pair of headphones into your hi-f- amp and
>> tell me whether you can get both speakers and both sides of the
>> headphones working properly at once.
>
> Indeed it's "touch-and-go." If you push the plug in gently so that the
> tip touches the first (ring) contact without the contact actually moving
> the ring contact away from its normalling contact, you'll get the ring
> signal on the tip of the plug. If the ring of the plug touches the
> sleeve (ground) of the jack when the plug tip is touching the ring,
> you'll get the ring signal in both headphones since current goes through
> both headphones on its way from ring to ground.
>
> Very flaky, and it's really no different, functionally, other than that
> you'll get the left channel instead of the right channel signal, than
> shoving the plug in all the way, letting the tip make contact as it's
> supposed to. Nothing flaky about that other than that with a TS plug,
> you'll short out the left headphone amplifier channel. It probably won't
> blow up.
>
You could try bridging the opened contacts with a resistor, so that when
they are open, there is still some drive to the main speaker amp. As
long as the total load on the output is less than 32 ohms or so, the
headphone amp won't care. Of course, it it always possible that a switch
opened by the earth ring on the headphone socket turns the main amp off
when the headphones are plugged in, which means you need to short that
switch out, and the main amp will work as normal.

Doing this will, of course, involve opening the case.

--
Tciao for Now!

John.



We don't know what the OP intends to do with the line outs, but one idea
would be to try taking the line out from the volume control "pre fader".
Then the pianist can have as much volume to his speakers as he wants without
affecting the line output.

I believe he was talking about opening the case.


I have seen circuits where the headphone socket's switched Ground contact
cuts the ground returns from the speakers, and the headphones use the same
power amps with some series power resistors.

Gareth.

[Mike Rivers[_2_]]

On 7/14/2015 3:08 PM, Mike Rivers wrote:
> If you push the plug in gently so that the tip touches the first (ring)
> contact without the contact actually moving the ring contact away from
> its normalling contact, you'll get the ring signal on the tip of the
> plug. If the ring of the plug touches the sleeve (ground) of the jack
> when the plug tip is touching the ring, you'll get the ring signal in
> both headphones since current goes through both headphones on its way
> from ring to ground.

No, I didn't really mean that. You'll get the signal in both headphones,
but it will be left minus right since the lead that's common to the
headphones doesn't go to ground.


--
For a good time, visit http://mikeriversaudio.wordpress.com

[Mike Rivers[_2_]]

On 7/14/2015 3:37 PM, Gareth Magennis wrote:
> He wants his piano in Stereo, not one side missing.
> As would I.

And the only way to do that is with a cable that has two plugs on the
destination end, one to tip-sleeve and the other to ring-sleeve.

Jack's just being Jack, coming up with a jacked-off arrangement that
will give you a signal, but not stereo.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[JackA]

On Tuesday, July 14, 2015 at 4:51:50 PM UTC-4, Mike Rivers wrote:
> On 7/14/2015 3:37 PM, Gareth Magennis wrote:
> > He wants his piano in Stereo, not one side missing.
> > As would I.
>
> And the only way to do that is with a cable that has two plugs on the
> destination end, one to tip-sleeve and the other to ring-sleeve.
>
> Jack's just being Jack, coming up with a jacked-off arrangement that
> will give you a signal, but not stereo.
>
> --
> For a good time, visit http://mikeriversaudio.wordpress.com

Mike, you may call my ideas jacked-off or whatever. But, I'm superior in logic. Look at this thread, talk of passive components, RFI, etc.. What on earth does that have to do with adding a line-out jack? Nothing. But I do not see you claiming they are off topic, like you did with me. Favoritism, perhaps?

Not to criticize Scott over that switch, where he basically told the poster to learn how to solder. But I asked, is the switch component capable (temperature) of being soft-soldered without destruction.

And it was I who was asked by a licensed electrical engineer, Sy Heberlig, "Jack, I'm at a loss, how can you repair/modify electronics without any formal training/education"? I told him, a basic understanding coupled with great logic goes a long way. Actually, I was moved into the engineering dept. from the shop, after I showed the test personnel what they were doing wrong..

Jack

a p.s. OT comment. People like TheKMARocks are against remixing, while I'm not. I enjoyed this song from day one, Cry Me A River, by Joe Cocker (RIP). From day one, someone mixed the first verse too low in volume, while probably puffing a joint. While remixing, someone corrected it, a name I didn't recognize. Just nice to hear before my time expires on Earth...

http://www.angelfire.com/empire/abpsp/images/crymeariver.mp3

[Frank Stearns]

(Scott Dorsey) writes:

snips

>I know. I'm just a big fan of starting at the beginning and being very
>systematic every time something mysterious happens, just because you might
>be missing a clue somewhere otherwise.

more snips

Agreed. We really haven't yet applied careful methodology to this problem. But we
have had a range of performers bring various pieces of gear into the theater and
this started happening over and over -- but only with commodity digital instruments.
Other more typical DI applications (such as with pickups on acoustic instruments)
continue to work fine.

I was wondering if perhaps others had seen this and had discovered the cause, such
as "combo computer/DSP/output drivers on the ABC123 chip, used on a wide range of
digital musical instruments and newer notebooks, is known to have grounding issues,
doesn't like transformer loads, whatever."

But, it looks like we're now going to have to dig deeper and more carefully, which
can be moderately difficult when you're in the middle of trying to get a show up and
running.

I'll report back if we discover anything definitive.

Thanks for the replies.

Frank
Mobile Audio

--

[Mike Rivers[_2_]]

On 7/14/2015 6:07 PM, Frank Stearns wrote:
> started happening over and over -- but only with commodity digital instruments.

Remember any makes and models? Maybe there's something for the Googlers
to look up.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[Gareth Magennis]

"Frank Stearns" wrote in message
...

(Scott Dorsey) writes:

snips

>I know. I'm just a big fan of starting at the beginning and being very
>systematic every time something mysterious happens, just because you might
>be missing a clue somewhere otherwise.

more snips

Agreed. We really haven't yet applied careful methodology to this problem.
But we
have had a range of performers bring various pieces of gear into the theater
and
this started happening over and over -- but only with commodity digital
instruments.
Other more typical DI applications (such as with pickups on acoustic
instruments)
continue to work fine.

I was wondering if perhaps others had seen this and had discovered the
cause, such
as "combo computer/DSP/output drivers on the ABC123 chip, used on a wide
range of
digital musical instruments and newer notebooks, is known to have grounding
issues,
doesn't like transformer loads, whatever."

But, it looks like we're now going to have to dig deeper and more carefully,
which
can be moderately difficult when you're in the middle of trying to get a
show up and
running.

I'll report back if we discover anything definitive.

Thanks for the replies.

Frank
Mobile Audio

--
..


I engineered a festival last year and amongst other things hired 6 Radial
DI's.
2 were active and out of the 4 passive ones, 3 didn't work.
http://www.radialeng.com/jdi.php

It took me a long time to fully establish that, really, 3 of them really
didn't work.
I still don't quite believe it.


Incidentally I once watched a sound engineer line check his DI boxes using
an SM58 and an XLR to jack cable.
Thought that was quite a good idea.



Gareth.

[Frank Stearns]

"Gareth Magennis" > writes:

-snips-

>I engineered a festival last year and amongst other things hired 6 Radial >DI's.
>2 were active and out of the 4 passive ones, 3 didn't work.
>http://www.radialeng.com/jdi.php
>
>It took me a long time to fully establish that, really, 3 of them really
>didn't work.
>I still don't quite believe it.

Geez. That is unreal. Radial has been one of the better names. Had they been
mercilessly bounced around, run over, pepsi poured into the switches, zapped with
7KV local power distribution voltages? Something crazy like that? I assume they got
sent back to Radial. Did they have anything to say?

>Incidentally I once watched a sound engineer line check his DI boxes using
>an SM58 and an XLR to jack cable.
>Thought that was quite a good idea.

Sure. That, or carry a pocket oscillator/cable tester. Would never be without
mine. :)

Frank
Mobile Audio

--

[Trevor]

On 17/07/2015 2:42 AM, Frank Stearns wrote:
> "Gareth Magennis" > writes:
>> Incidentally I once watched a sound engineer line check his DI boxes using
>> an SM58 and an XLR to jack cable.
>> Thought that was quite a good idea.
>
> Sure. That, or carry a pocket oscillator/cable tester. Would never be without
> mine. :)

Or simply any portable media player with a few test files these days,
and a suitable cable.

Trevor.

[Gareth Magennis]

"Frank Stearns" wrote in message
...

"Gareth Magennis" > writes:

-snips-

>I engineered a festival last year and amongst other things hired 6 Radial
> >DI's.
>2 were active and out of the 4 passive ones, 3 didn't work.
>http://www.radialeng.com/jdi.php
>
>It took me a long time to fully establish that, really, 3 of them really
>didn't work.
>I still don't quite believe it.

Geez. That is unreal. Radial has been one of the better names. Had they been
mercilessly bounced around, run over, pepsi poured into the switches, zapped
with
7KV local power distribution voltages? Something crazy like that? I assume
they got
sent back to Radial. Did they have anything to say?





No rough treatment I could see, they were new looking.

I did ask the hire company in a later email if they really were all faulty,
or was it just me being a numpty, but they did not reply.
(But then they might not reply if it meant admitting they weren't prepped
properly)

I was pretty convinced it wasn't me, because I was able to A/B them against
the one working one, using an SM58 and an XLR to jack cable.
Didn't open them up because I had a festival to do and had enough
replacements kicking around.


Like you, I can't see how that was likely/possible, but there you go.
Perhaps someone did do something stupid, then did it twice more.



Gareth.

[Gareth Magennis]

I had wondered whether it is possible to disable a DI transformer by passing
current through it and magnetising/saturating the core or whatever, either
temporarily or permanently.

Maybe someone can clarify, I don't have that sort of knowledge.



Gareth.

[Scott Dorsey]

Gareth Magennis > wrote:
>
>I had wondered whether it is possible to disable a DI transformer by passing
>current through it and magnetising/saturating the core or whatever, either
>temporarily or permanently.

Doesn't disable it, but all your low end goes away.

Some have input transformers to prevent that.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers[_2_]]

On 7/20/2015 5:05 PM, Gareth Magennis wrote:
> I had wondered whether it is possible to disable a DI transformer by
> passing current through it and magnetising/saturating the core or
> whatever, either temporarily or permanently.

Back in the "never apply phantom power to mic that doesn't require it"
days, this was one of the reasons given. I don't know if there was any
actual proof of permanently magnetizing the core. But even if it was
magnetized, that would increase distortion, not prevent it from passing
audio. Only opening the winding will do that, and even then, you could
be fooled into thinking it's working but it sucks as a result of some
audio getting through via capacitive coupling.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[[email protected]]

On Monday, 13 July 2015 09:06:06 UTC+1, geoff wrote:
> I'd suggest give up trying to polish a turd.
> PS You can polish a turd, but you hare to freeze it first ;-O

You can also cover it in glitter :-)

Owain