Today's Message Index:
----------------------
1. 10:00 AM - Low Audio Output (f1rocket@comcast.net)
2. 10:53 AM - Re: Low Audio Output (Brian Lloyd)
3. 11:29 AM - Re: Low Audio Output (Ross Mickey)
4. 12:49 PM - Re: Low Audio Output (f1rocket@comcast.net)
5. 01:06 PM - Re: Low Audio Output (John Slade)
6. 03:26 PM - Re: Low Audio Output (Brian Lloyd)
7. 03:46 PM - Re: Low Audio Output (John Slade)
8. 04:04 PM - Re: Low Audio Output (Rick Girard)
9. 04:05 PM - Re: Low Audio Output (royt.or@netzero.com)
10. 04:09 PM - Re: Low Audio Output (Richard Tasker)
11. 04:20 PM - Re: Low Audio Output (Brian Lloyd)
12. 04:30 PM - Re: Low Audio Output (Charlie England)
13. 05:05 PM - Re: Low Audio Output (Charlie England)
14. 06:12 PM - Re: Low Audio Output (Richard E. Tasker)
15. 06:36 PM - Re: Low Audio Output (Brian Lloyd)
16. 06:46 PM - Re: Low Audio Output (Charlie England)
17. 07:10 PM - Re: Low Audio Output (Brian Lloyd)
18. 07:10 PM - Re: Low Audio Output (John Slade)
19. 07:20 PM - Re: Low Audio Output (Brian Lloyd)
Message 1
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| Subject: | Low Audio Output |
0.5 MIME_BOUND_NEXTPART Spam tool pattern in MIME boundary
--> AeroElectric-List message posted by: f1rocket@comcast.net
I've been wandering around in the archives for a couple of hours searching for
resolutions to my problem of low audio output by my MP3 player into my PM3000
intercom. What's amazing is the number of people that have the problem but the
lack of documentation on what solved it.
I've been able to determine that the power output of the portable device in not
sufficient to drive the headphones or the intercom music circuit. Therefore,
an in-line amplifier is required.
Some folks have suggested The Muse, but with limited success. Some folks have
offered amplfiers, but their web sites no longer have the product. A Radio Shack
part (33-1109) has also been offered but no record of whether it worked or
not. Finally, Bob offers a mini-project to build your own. That appears a bit
much for me to complete.
Okay, so how have folks solved the problem? Do the small battery operated in-line
amplifiers work? I hate to bring another battery device into the cockpit.
Are there other products out there? Does someone offer Bob's amplifier already
built?
Inquiring minds want to know.
Randy
F1 Rocket
I've been wandering around in the archives for a couple of hours searching for
resolutions to my problem of low audio output by my MP3 player into my PM3000
intercom. What's amazing is the number of people that have the problem but the
lack of documentation on what solved it.
I've been able to determine that the power output of the portable device in not
sufficient to drive the headphones or the intercom music circuit. Therefore,
an in-line amplifier is required.
Some folks have suggested The Muse, but with limited success. Some folks have offered
amplfiers, but their web sites no longer have the product. A Radio Shack
part (33-1109) has also been offered but no record of whether it worked or not.
Finally, Bob offers a mini-project to build your own. That appears a bit much
for me to complete.
Okay, so how have folks solved the problem? Do the small battery operated in-line
amplifiers work? I hate to bring another battery device into the cockpit. Are
there other products out there? Does someone offer Bob's amplifier already
built?
Inquiring minds want to know.
Randy
F1 Rocket
Message 2
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Brian Lloyd <brianl@lloyd.com>
f1rocket@comcast.net wrote:
> I've been able to determine that the power output of the portable
> device in not sufficient to drive the headphones or the intercom
> music circuit. Therefore, an in-line amplifier is required.
Actually, power is not the issue. Most audio panels have a relatively high input
impedance for the music input so you really need voltage gain, not power gain.
A pair of op-amps would give enough gain to accomplish what you want.
OTOH, has anybody talked to the maker of the audio panel? This seems to be a pretty
common problem. OTOH, I have no problem with my PMA-7000 audio panels in
my airplanes. My iPod seems to have enough voltage drive to achieve a comfortable
listening level.
--
Brian Lloyd 6501 Red Hook Plaza
brianl@lloyd.com Suite 201
http://www.lloyd.com St. Thomas, VI 00802
+1.340.998.9447 (voice) +1.360.838.9669 (fax)
There is a time to laud one's country and a time to protest.
A good citizen is prepared to do either as the need arises.
Message 3
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| Subject: | Low Audio Output |
--> AeroElectric-List message posted by: "Ross Mickey" <rmickey@ix.netcom.com>
Brian,
Fortunately I had just purchased a 6000 series PS Engineering audio
panel when this whole issue of low volume levels was being discussed on
the list. The solution to the low volume issue by PS Engineering was to
design the 7000 series. Since I had not opened the box on my 6000
series, I was able to trade it in for a 7000. The main difference, in
this regard, is the 7000 series has a separate volume control for audio
inputs and the 6000 does not. Those with the 6000 series are left to
solve the problem with an add-on.
Ross Mickey
N9PT
-----Original Message-----
--> AeroElectric-List message posted by: Brian Lloyd <brianl@lloyd.com>
OTOH, has anybody talked to the maker of the audio panel? This seems to
be a pretty common problem. OTOH, I have no problem with my PMA-7000
audio panels in my airplanes. My iPod seems to have enough voltage
drive to achieve a comfortable listening level.
Message 4
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: f1rocket@comcast.net
>A pair of op-amps would give enough gain to accomplish what you want.
>
Sorry for being dense, but can you translate that into a product recommendation?
Thanks.
Randy
F1 Rocket
A pair of op-amps would give enough gain to accomplish what you want.
Sorry for being dense, but can you translate that into a product recommendation?
Thanks.
Randy
F1 Rocket
Message 5
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| Subject: | Low Audio Output |
--> AeroElectric-List message posted by: "John Slade" <sladerj@bellsouth.net>
> >A pair of op-amps would give enough gain to accomplish what you want.
> >
> Sorry for being dense, but can you translate that into a product
> recommendation? Thanks.
>
> Randy
> F1 Rocket
Don't feel dense, Randy.
I've had the same problem for 3 months, and have asked the same question.
I'm following this thread hoping (this time) for a solution. Other similar
threads have lead nowhere. I don't want to build anything. I just want to
buy some simple, cheap gizmo that'll boost the audio on my plug in portable
CD player so I can actually hear it.
Regards,
John Slade
Turbo Rotary Cozy IV
Message 6
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Brian Lloyd <brianl@lloyd.com>
f1rocket@comcast.net wrote:
> --> AeroElectric-List message posted by: f1rocket@comcast.net
>
>
>>A pair of op-amps would give enough gain to accomplish what you want.
>>
>
> Sorry for being dense, but can you translate that into a product recommendation?
Thanks.
Now it is my turn to be sorry. I spoke before thinking. I was thinking in terms
of building something but you are looking for an off-the-shelf solution. What
you need is a preamp. And, sorry, I can't think of any that are a) cheap,
b) small, and c) powered by 12V.
--
Brian Lloyd 6501 Red Hook Plaza
brianl@lloyd.com Suite 201
http://www.lloyd.com St. Thomas, VI 00802
+1.340.998.9447 (voice) +1.360.838.9669 (fax)
There is a time to laud one's country and a time to protest.
A good citizen is prepared to do either as the need arises.
Message 7
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| Subject: | Low Audio Output |
--> AeroElectric-List message posted by: "John Slade" <sladerj@bellsouth.net>
> > Sorry for being dense, but can you translate that into a
> product recommendation? Thanks.
How about this little baby?
2x7W 12V Walkman Stereo Amplifier Kit $29 fully assembled.
http://www.hobbytron.net/CK154A.html?AID=10289758&PID=1117139
Would this do the job for us?
John Slade
Message 8
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Rick Girard <fly.ez@verizon.net>
I realize this isn't exactly off the shelf, but what about the
amplifiers in cheap computer speakers? Go to a PC recycler, or take the
wife garage saleing for a day and buy a pair of computer speakers for a
dollar. There is also the option of buying amplified speakers made
specifically for walk men and ipod style personal stereos, but they're
not likely to be a buck. Tear the guts out, put it in an altoid box and
double back tape it out of the way. Just a PBI.
Rick Girard
Message 9
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| Subject: | RE: Low Audio Output |
--> AeroElectric-List message posted by: "royt.or@netzero.com" <royt.or@netzero.com>
I've been using a Radio Shack headphone booster (pn 33-1109)and portable CD/MP3 player in my plane with Garmin 340 audio panel, Peltor 7004 headset and/or Lightspeed XL20 headset. This has been marginal but not ideal. I've purchased parts to build HeadBanger headphone amp. This is also available prebuilt. See http://www.minidisc.org/headbanger.html I plan to run this from the plane with a 12v to 9v powersupply.
I recently installed a Headsets Inc ANR kit in my Peltor. See http://www.headsetsinc.com/ The volume output of the upgraded headset is much louder. If I always flew solo, I would be very happy with the portable player, Radio Shack booster and ANR'ed Peltors. I'm still planning to build the amp and power supply. I'll power the Headsets Inc ANR from the same power supply.
I'll report back when I have completed and installed the HeadBanger amp.
(Garmin also say's there are four surface mount resistors which can be removed
to increase the external audio volume and may increase the noise. My local shop
quote to do this seemed out rageous. Something like $150.)
Regards,
Roy
N601RT: CH601HDS, nose gear, Rotax 912ULS, All electric, IFR equipped, 230hrs,
320 landings
Message 10
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Richard Tasker <retasker@optonline.net>
Great but not what he needs. This would be perfect if one wanted to
take the output of the MP3 player and drive some speakers, but would not
work to just amplify the voltage to feed into the PS3000.
Sorry, Dick Tasker
John Slade wrote:
>--> AeroElectric-List message posted by: "John Slade" <sladerj@bellsouth.net>
>
>
>
>>>Sorry for being dense, but can you translate that into a
>>>
>>>
>>product recommendation? Thanks.
>>
>>
>How about this little baby?
> 2x7W 12V Walkman Stereo Amplifier Kit $29 fully assembled.
>
> http://www.hobbytron.net/CK154A.html?AID=10289758&PID=1117139
>
>Would this do the job for us?
>John Slade
>
>
>
>
Message 11
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Brian Lloyd <brianl@lloyd.com>
John Slade wrote:
> How about this little baby?
> 2x7W 12V Walkman Stereo Amplifier Kit $29 fully assembled.
>
> http://www.hobbytron.net/CK154A.html?AID=10289758&PID=1117139
>
> Would this do the job for us?
Yes, it should.
--
Brian Lloyd 6501 Red Hook Plaza
brianl@lloyd.com Suite 201
http://www.lloyd.com St. Thomas, VI 00802
+1.340.998.9447 (voice) +1.360.838.9669 (fax)
There is a time to laud one's country and a time to protest.
A good citizen is prepared to do either as the need arises.
Message 12
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Charlie England <ceengland@bellsouth.net>
f1rocket@comcast.net wrote:
>--> AeroElectric-List message posted by: f1rocket@comcast.net
>
>I've been wandering around in the archives for a couple of hours searching for
resolutions to my problem of low audio output by my MP3 player into my PM3000
intercom. What's amazing is the number of people that have the problem but the
lack of documentation on what solved it.
>I've been able to determine that the power output of the portable device in not
sufficient to drive the headphones or the intercom music circuit. Therefore,
an in-line amplifier is required.
>Some folks have suggested The Muse, but with limited success. Some folks have
offered amplfiers, but their web sites no longer have the product. A Radio Shack
part (33-1109) has also been offered but no record of whether it worked or
not. Finally, Bob offers a mini-project to build your own. That appears a
bit much for me to complete.
>Okay, so how have folks solved the problem? Do the small battery operated in-line
amplifiers work? I hate to bring another battery device into the cockpit.
Are there other products out there? Does someone offer Bob's amplifier already
built?
>Inquiring minds want to know.
>Randy
>F1 Rocket
>
Here's the link to the RS 33-1109:
http://www.radioshack.com/images/ProductCatalog/Manuals/OME33-1109.pdf
40 mW is .8 volts into a 16 ohm load & isn't likely to do the trick. I'd
want at least 2-3 volts output to give myself a little wiggle room.
Just for grins, here are some audiophile quality headphone amps that
could be made to work, but might be a little higher quality than what
you need.
http://www.headphone.com/layout.php?topicID=3&subTopicID=27
This has more gain than you really need & still costs too much...
http://www.opamplabs.com/m9c.htm
Does the desire for plug&play arise out of the need for speed &
convenience, or 'fear of soldering'? FWIW, if you can wire your airplane
you can assemble a simple kit of electronic parts. If you just 'must
have' plug & play, I'll call our local A/V supplier tomorrow & see
what's available.
Charlie
(electronics tech in a former life)
Message 13
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Charlie England <ceengland@bellsouth.net>
My experience with similar devices says it will work just fine. It's
capable of just over 4 volts output (should be plenty to drive the
intercom) into 4 ohms & it shouldn't care if it sees ~600 ohms instead
of 4 ohms. The higher impedance reduces the load on the amplifier. As
an analogy, think of your 500 amp battery supplying power to a comm.
transmitter with a 5 amp current demand.
Just start with the source output level at a midrange setting & the
amp's input controls near minimum, then bring up the amp's volume
slowwwly while playing something through the source.
Charlie
Richard Tasker wrote:
>--> AeroElectric-List message posted by: Richard Tasker <retasker@optonline.net>
>
>Great but not what he needs. This would be perfect if one wanted to
>take the output of the MP3 player and drive some speakers, but would not
>work to just amplify the voltage to feed into the PS3000.
>
>Sorry, Dick Tasker
>
>John Slade wrote:
>
>
>
>>--> AeroElectric-List message posted by: "John Slade" <sladerj@bellsouth.net>
>>
>>
>>
>>
>>
>>>>Sorry for being dense, but can you translate that into a
>>>>
>>>>
>>>>
>>>>
>>>product recommendation? Thanks.
>>>
>>>
>>>
>>>
>>How about this little baby?
>> 2x7W 12V Walkman Stereo Amplifier Kit $29 fully assembled.
>>
>> http://www.hobbytron.net/CK154A.html?AID=10289758&PID=1117139
>>
>>Would this do the job for us?
>>John Slade
>>
Message 14
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: "Richard E. Tasker" <retasker@optonline.net>
Well, you are probably right. I am an electrical engineer :-) and
look at it as not the correct device for the intended purpose - to do a
little preamplification of his MP3 player to feed to his PM3000 intercom.
While either should work (if the problem has been stated correctly) I
would suggest that this would be a more appropriate solution (from the
same source):
http://www.hobbytron.net/vk2572.html
Dick Tasker
Charlie England wrote:
>--> AeroElectric-List message posted by: Charlie England <ceengland@bellsouth.net>
>
>My experience with similar devices says it will work just fine. It's
>capable of just over 4 volts output (should be plenty to drive the
>intercom) into 4 ohms & it shouldn't care if it sees ~600 ohms instead
>of 4 ohms. The higher impedance reduces the load on the amplifier. As
>an analogy, think of your 500 amp battery supplying power to a comm.
>transmitter with a 5 amp current demand.
>
>Just start with the source output level at a midrange setting & the
>amp's input controls near minimum, then bring up the amp's volume
>slowwwly while playing something through the source.
>
>Charlie
>
Message 15
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Brian Lloyd <brianl@lloyd.com>
Richard Tasker wrote:
> --> AeroElectric-List message posted by: Richard Tasker <retasker@optonline.net>
>
> Great but not what he needs. This would be perfect if one wanted to
> take the output of the MP3 player and drive some speakers, but would not
> work to just amplify the voltage to feed into the PS3000.
Ah, but it would. The amp has voltage gain and is a single-ended output, i.e.
output relative to ground rather than a bridged or balanced output. It should
work just fine.
OTOH, some of the other "headphone boosters" might be better but you will find
they are almost the same design.
--
Brian Lloyd 6501 Red Hook Plaza
brianl@lloyd.com Suite 201
http://www.lloyd.com St. Thomas, VI 00802
+1.340.998.9447 (voice) +1.360.838.9669 (fax)
There is a time to laud one's country and a time to protest.
A good citizen is prepared to do either as the need arises.
Message 16
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Charlie England <ceengland@bellsouth.net>
The only potential glitch I see with this one is the 1k ohm output
impedance, typical for circuits designed to drive home stereo components
with ~50k ohm input impedance. If the intercom has a 600 ohm input
impedance (fairly common in a/c & pro audio gear) this device might be
strained a bit to produce a clean signal. I haven't looked at the TL072
spec sheet; it might be more than capable of driving a 600 load with a
resistor change in the ouput, but the idea was plug & play.
If the intercom has a >10k ohm input impedance, you have indeed found a
better device for this purpose.
BTW, neither device appears to include a case or connectors, so some
soldering & parts chasing will likely still be required with either device.
Charlie
(not an engineer; just an old southern boy who used to build & repair
similar gadgets for concert sound systems)
Richard E. Tasker wrote:
>--> AeroElectric-List message posted by: "Richard E. Tasker" <retasker@optonline.net>
>
>Well, you are probably right. I am an electrical engineer :-) and
>look at it as not the correct device for the intended purpose - to do a
>little preamplification of his MP3 player to feed to his PM3000 intercom.
>
>While either should work (if the problem has been stated correctly) I
>would suggest that this would be a more appropriate solution (from the
>same source):
>
>http://www.hobbytron.net/vk2572.html
>
>Dick Tasker
>
>Charlie England wrote:
>
>
>
>>--> AeroElectric-List message posted by: Charlie England <ceengland@bellsouth.net>
>>
>>My experience with similar devices says it will work just fine. It's
>>capable of just over 4 volts output (should be plenty to drive the
>>intercom) into 4 ohms & it shouldn't care if it sees ~600 ohms instead
>>of 4 ohms. The higher impedance reduces the load on the amplifier. As
>>an analogy, think of your 500 amp battery supplying power to a comm.
>>transmitter with a 5 amp current demand.
>>
>>Just start with the source output level at a midrange setting & the
>>amp's input controls near minimum, then bring up the amp's volume
>>slowwwly while playing something through the source.
>>
>>Charlie
>>
Message 17
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Brian Lloyd <brianl@lloyd.com>
Charlie England wrote:
> Just for grins, here are some audiophile quality headphone amps that
> could be made to work, but might be a little higher quality than what
> you need.
> http://www.headphone.com/layout.php?topicID=3&subTopicID=27
As an interesting offshoot of this discussion, has anyone considered the issue
of headphone audio quality? Since I have started carrying my iPod in the airplane
I have become much more interested in the quality of the headphone audio.
As a result, an interesting thing has occurred.
Several years back I popped for a LightSpeed 25XL headset for my wife in an attempt
to give her something she found quiet and comfortable. (They are very comfortable,
especially for women wearing earrings.) Since I flew more I found
myself often using her headset. OTOH, I didn't want to spend an ungodly amount
of money for every seat in the airplane so I popped for a set of LightSpeed
QFR headsets (no ANR) for passengers. These are supposed to be cheap headsets.
The problem is:
1. they provide better passive noise attenuation;
2. they have better audio quality.
I now find myself using the "cheap" LightSpeed QFR headsets in preference to the
25XLs. I have come to the conclusion after flying thousands of hours with ANR
headsets that they just aren't all that great. Give me a headset with lots
of passive noise attenuation and no active noise reduction (ANR) and I am much
happier.
BTW, this seems to hold true for the Bose and Telex DSP ANR systems as well.
Disclaimer: this is my personal preference. Your mileage may vary.
--
Brian Lloyd 6501 Red Hook Plaza
brianl@lloyd.com Suite 201
http://www.lloyd.com St. Thomas, VI 00802
+1.340.998.9447 (voice) +1.360.838.9669 (fax)
There is a time to laud one's country and a time to protest.
A good citizen is prepared to do either as the need arises.
Message 18
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| Subject: | Low Audio Output |
--> AeroElectric-List message posted by: "John Slade" <sladerj@bellsouth.net>
> http://www.hobbytron.net/CK154A.html?AID=10289758&PID=1117139
> would not work to just amplify the voltage to feed into the PS3000.
> Ah, but it would. The amp has voltage gain and is a single-ended ...
Thanks for all the input.
I ordered one. I'll report back on how well it handles the input to my RST
intercom.
John Slade
Message 19
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| Subject: | Re: Low Audio Output |
--> AeroElectric-List message posted by: Brian Lloyd <brianl@lloyd.com>
Charlie England wrote:
> --> AeroElectric-List message posted by: Charlie England <ceengland@bellsouth.net>
>
> The only potential glitch I see with this one is the 1k ohm output
> impedance, typical for circuits designed to drive home stereo components
> with ~50k ohm input impedance. If the intercom has a 600 ohm input
> impedance (fairly common in a/c & pro audio gear) this device might be
> strained a bit to produce a clean signal. I haven't looked at the TL072
> spec sheet; it might be more than capable of driving a 600 load with a
> resistor change in the ouput, but the idea was plug & play.
I used to drive Sennheiser headphones directly from the output of a TL071-based
preamp I designed. The TL072 is just dual TL071's in one DIP (without the DC
offset adjustment pins). It worked very well with only a very slight loss of
low-bass response. I was both surprised and pleased.
I think you will find that the input impedance of the music input of an intercom/audio-panel
is pretty high (greater than 10K at least). They are essentially
voltage inputs.
BTW, I used to make my living designing high-end audio amps and preamps back in
the late '70s.
--
Brian Lloyd 6501 Red Hook Plaza
brianl@lloyd.com Suite 201
http://www.lloyd.com St. Thomas, VI 00802
+1.340.998.9447 (voice) +1.360.838.9669 (fax)
There is a time to laud one's country and a time to protest.
A good citizen is prepared to do either as the need arises.
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