[[email protected]]

I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

[Richard Crowley]

wrote:
I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

http://www.rdlnet.com/product.php?page=26

Vastly overpriced IMHO. If it were me, I would make my own
with a pot in a box, but if you have to buy something off the shelf,
the RDL people make all kinds of these little convienent gadgets.

[blackburst]

On Aug 12, 10:15*am, "Richard Crowley" wrote:
wrote:
I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

http://www.rdlnet.com/product.php?page=26

Vastly overpriced IMHO.

Interesting, and passive, too.

If it were me, I would make my own
with a pot in a box, but if you have to buy something off the shelf,
the RDL people make all kinds of these little convienent gadgets.-

[Scott Dorsey]

In article ,
wrote:
I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

Solder two resistors inside the plug?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[blackburst]

On Aug 12, 10:16*am, (Scott Dorsey) wrote:
In article ,





wrote:
I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

Solder two resistors inside the plug?
--scott
--
"C'est un Nagra. *C'est suisse, et tres, tres precis."- Hide quoted text -

- Show quoted text -

I just don't know exactly how much attenuation I need, or how that
translates to resistance values. An adjustable unit would let
me...well, adjust.

[Wecan do it]

"blackburst" wrote in message
...
On Aug 12, 10:16 am, (Scott Dorsey) wrote:
In article
,





wrote:
I'm looking for a low cost way to slightly attenuate
a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no
mixer:
Several devices (4 streams from a video server, several
tape and DVD
decks) feed into a routing switcher, then a
compressor/limiter, then
into modulators and out into the cable system. It is
important to have
all devices at the same approximate level; While they are
all -10db,
the only significant difference is the tuner. It is
noticeably louder
than all the other sources. The tuner is a Rolls RS80, and
it has no
adjustment for output level (except the front-panel
headphone jack,
which I am currently using. The protruding cable looks bad,
and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather
find one of
those little "audio solutions" boxes that will give me
control of the
level, definitely down, but perhaps up also. Any ideas?

Solder two resistors inside the plug?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."- Hide
quoted text -

- Show quoted text -

I just don't know exactly how much attenuation I need, or how
that
translates to resistance values. An adjustable unit would let
me...well, adjust.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~
You could try one of these
http://www.amazon.com/Koss-155954-VC.../ref=pd_cp_e_1
with the right adaptor cables.

peace
dawg

[Scott Dorsey]

blackburst wrote:

I just don't know exactly how much attenuation I need, or how that
translates to resistance values. An adjustable unit would let
me...well, adjust.

Measure it, then.

Or cut a cheap RCA-RCA cable, solder a pot in the middle, adjust it until
the level is right, and then you know what value resistors you need.

You should not spend more than ten minutes on the whole procedure.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Laurence Payne[_2_]]

On 12 Aug 2009 11:53:26 -0400, (Scott Dorsey) wrote:

Or cut a cheap RCA-RCA cable, solder a pot in the middle, adjust it until
the level is right, and then you know what value resistors you need.

Or leave it there and bodge up some sort of box round it.

[Marko L. Spilberg]

http://www.swee****er.com/store/detail/CleanBox/
wrote in message
...
I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

[Marko L. Spilberg]

ART CleanBOX
2-Way Stereo RCA Unbalanced / XLR Balanced Convertor Box with individual
Level Controls


http://www.swee****er.com/store/detail/CleanBox/






wrote in message
...
I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

[blackburst]

On Aug 12, 3:04*pm, "Marko L. Spilberg" wrote:
ART CleanBOX
2-Way Stereo RCA Unbalanced / XLR Balanced Convertor Box with individual
Level Controls

http://www.swee****er.com/store/detail/CleanBox/

Thanks! This looks like a definite possibility. I'll check to make
sure the level controls work on an RCA-RCA hookup.

[Marko L. Spilberg]

http://www.zzounds.com/item--BEHMX400





wrote in message
...
I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

[blackburst]

On Aug 12, 3:10*pm, "Marko L. Spilberg" wrote:
http://www.zzounds.com/item--BEHMX400


This one looks to have only a mono output.

[fredbloggstwo]

wrote in message
...
I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

If you know the approximate input impedance of the device you are connecting
to, you can use a single series resistor to pot it down. For example, if
the input impedance is 10k (this is the effective resistance in the input to
ground) a series resistance of 10K will attenuate the signal to one half, or
6dB. A resistor of 20K will attenuate it to one third - about 9.5 dB. In
this case I would use a 22K resistor to get about 10dB.

Cheers

Mike

[GregS[_3_]]

In article , "fredbloggstwo" wrote:

wrote in message
...
I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

If you know the approximate input impedance of the device you are connecting
to, you can use a single series resistor to pot it down. For example, if
the input impedance is 10k (this is the effective resistance in the input to
ground) a series resistance of 10K will attenuate the signal to one half, or
6dB. A resistor of 20K will attenuate it to one third - about 9.5 dB. In
this case I would use a 22K resistor to get about 10dB.


Likely to work but more susceptible to capacitance effects.

greg

[Arny Krueger]

"GregS" wrote in message

In article ,
"fredbloggstwo"
wrote:

wrote in message
...
I'm looking for a low cost way to slightly attenuate a
-10db stereo RCA output from an FM tuner.

This is a small cable studio's playout system. There is
no mixer: Several devices (4 streams from a video
server, several tape and DVD decks) feed into a routing
switcher, then a compressor/limiter, then into
modulators and out into the cable system. It is
important to have all devices at the same approximate
level; While they are all -10db, the only significant
difference is the tuner. It is noticeably louder than
all the other sources. The tuner is a Rolls RS80, and
it has no adjustment for output level (except the
front-panel headphone jack, which I am currently using.
The protruding cable looks bad, and I want to use the
rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd
rather find one of those little "audio solutions" boxes
that will give me control of the level, definitely
down, but perhaps up also. Any ideas?

If you know the approximate input impedance of the
device you are connecting to, you can use a single
series resistor to pot it down. For example, if the
input impedance is 10k (this is the effective resistance
in the input to ground) a series resistance of 10K will
attenuate the signal to one half, or 6dB. A resistor of
20K will attenuate it to one third - about 9.5 dB. In
this case I would use a 22K resistor to get about 10dB.


Likely to work but more susceptible to capacitance
effects.

I build many of my attenuators into plug shells. The plug goes directly into
the input connector. Aternatively, build the attenuator in-line, and
minimize the lengh of the cable on the output side. Most attenuators can be
built in-line, shrink-wrapped to prevent internal shorting, covered with a
short piece of plastic tubing, and shrink-wrapped again for mechanical
strength.

[fredbloggstwo]

"GregS" wrote in message
...
In article , "fredbloggstwo"
wrote:

wrote in message
...
I'm looking for a low cost way to slightly attenuate a -10db stereo
RCA output from an FM tuner.

This is a small cable studio's playout system. There is no mixer:
Several devices (4 streams from a video server, several tape and DVD
decks) feed into a routing switcher, then a compressor/limiter, then
into modulators and out into the cable system. It is important to have
all devices at the same approximate level; While they are all -10db,
the only significant difference is the tuner. It is noticeably louder
than all the other sources. The tuner is a Rolls RS80, and it has no
adjustment for output level (except the front-panel headphone jack,
which I am currently using. The protruding cable looks bad, and I want
to use the rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd rather find one of
those little "audio solutions" boxes that will give me control of the
level, definitely down, but perhaps up also. Any ideas?

If you know the approximate input impedance of the device you are
connecting
to, you can use a single series resistor to pot it down. For example, if
the input impedance is 10k (this is the effective resistance in the input
to
ground) a series resistance of 10K will attenuate the signal to one half,
or
6dB. A resistor of 20K will attenuate it to one third - about 9.5 dB. In
this case I would use a 22K resistor to get about 10dB.


Likely to work but more susceptible to capacitance effects.

greg

I would have thought 'most' likely to work if the input impedance is known,
and using good practice of attenuating as near to the destination as
possible, e.g. inside the device connector, would have minimal capacitance
effect within the audio band. As Arny suggests below, its quite easy to do
either inside the connector with small profile resistors etc.

Mike

[Mike Rivers]

fredbloggstwo wrote:

I would have thought 'most' likely to work if the input impedance is known,
and using good practice of attenuating as near to the destination as
possible, e.g. inside the device connector, would have minimal capacitance
effect within the audio band.

It's nice that so many people know the theory, but disappointing that so few
actually have experience, or understand the theory well enough to know what
matters or what doesn't.

This is a very simple problem, and any of the proposed solutions that would
work at all will work equally well for the application. You're not doing
laboratory
measurements to within a couple of dB of the theoretical noise floor, you're
just listening to the radio.

The fly in the ointment is that there's no inexpensive universal
off-the-shelf solution,
so unless the original poster is willing to spend $50-$100 to solve a
trivial problem,
a do-it-yourself approach is usually what we "pros" recommend. But if
he's not sure
which end of the soldering iron to hold, or doesn't have the necessary
tools to
determine the correct value of the ten cent resistors he needs (nobody
can simply
give him a number without knowning very specific details of the system),
then he's
best served with what's available off-the-shelf even though most of us
would not
take that approach.

Since I know that any source with peaks above +18 dBu will overload the
front end
of my portable recorder, I pack a set of cables with 10 dB attenuators
built into the
connectors. It took me about half an hour to make them (but 50 years of
experience
to know how).



--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)

[fredbloggstwo]

"Mike Rivers" wrote in message
...
fredbloggstwo wrote:

I would have thought 'most' likely to work if the input impedance is
known, and using good practice of attenuating as near to the destination
as possible, e.g. inside the device connector, would have minimal
capacitance effect within the audio band.

It's nice that so many people know the theory, but disappointing that so
few
actually have experience, or understand the theory well enough to know
what
matters or what doesn't.

This is a very simple problem, and any of the proposed solutions that
would
work at all will work equally well for the application. You're not doing
laboratory
measurements to within a couple of dB of the theoretical noise floor,
you're
just listening to the radio.

The fly in the ointment is that there's no inexpensive universal
off-the-shelf solution,
so unless the original poster is willing to spend $50-$100 to solve a
trivial problem,
a do-it-yourself approach is usually what we "pros" recommend. But if he's
not sure
which end of the soldering iron to hold, or doesn't have the necessary
tools to
determine the correct value of the ten cent resistors he needs (nobody can
simply
give him a number without knowning very specific details of the system),
then he's
best served with what's available off-the-shelf even though most of us
would not
take that approach.

Since I know that any source with peaks above +18 dBu will overload the
front end
of my portable recorder, I pack a set of cables with 10 dB attenuators
built into the
connectors. It took me about half an hour to make them (but 50 years of
experience
to know how).

Sorry Mike

Your point is .....

Mike

[blackburst]

On Aug 14, 6:39*am, Mike Rivers wrote:

I very much appreciate the advice given by all of the posters here. I
fully understand the comments by some that it's something that can be
easily accomplished with a soldering iron and a few resistors. But let
me add this perspective: In the audio and video fields, some people
gravitate toward becoming strong as ENGINEERS, and some become strong
as OPERATORS. In the audio field, my engineering skills are tolerable,
but not deep, while my operating skills are very good. (With the right
adapter kits, etc, I can match levels, etc and make things work well.)
In my chosen field, video, my engineering skills are excellent, as are
my operating skills. Rather than experiment with different value
resistors in a jerry-rig fashion, I would simply prefer to have a box
that will give me control of the level.

Skills: I can trust a box designed by experts better than my own
guesswork.

Flexibility: We may not always use this tuner, or this FM station. I
want to able to set the level BY EAR, to match adjacent channels, and
to match our actual program content.

Cost: We can afford it, and it's worth it for the flexibility.

Time: I'm something of a one-man-band. I spend a lot of time managing,
and it takes less time to just get a box.

Futu I won't always be at this job. The box with pots will be
easier for my successor to understand and operate.

But yes, I understand that a neophyte should be able to rig something
up. Maybe I'm just lazy.





fredbloggstwo wrote:
I would have thought 'most' likely to work if the input impedance is known,
and using good practice of attenuating as near to the destination as
possible, *e.g. inside the device connector, would have minimal capacitance
effect within the audio band. *

It's nice that so many people know the theory, but disappointing that so few
actually have experience, or understand the theory well enough to know what
matters or what doesn't.

This is a very simple problem, and any of the proposed solutions that would
work at all will work equally well for the application. You're not doing
laboratory
measurements to within a couple of dB of the theoretical noise floor, you're
just listening to the radio.

The fly in the ointment is that there's no inexpensive universal
off-the-shelf solution,
so unless the original poster is willing to spend $50-$100 to solve a
trivial problem,
a do-it-yourself approach is usually what we "pros" recommend. But if
he's not sure
which end of the soldering iron to hold, or doesn't have the necessary
tools to
determine the correct value of the ten cent resistors he needs (nobody
can simply
give him a number without knowning very specific details of the system),
then he's
best served with what's available off-the-shelf even though most of us
would not
take that approach.

Since I know that any source with peaks above +18 dBu will overload the
front end
of my portable recorder, I pack a set of cables with 10 dB attenuators
built into the
connectors. It took me about half an hour to make them (but 50 years of
experience
to know how).

--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)