Plugging computer output into stereo problem

Guest
I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

Thanks

James W.
 
In article <pnqu06dd0b8see7aak4elch4og62e1j11j@4ax.com>,
<jameswaters@unlisted.com> wrote:
I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.
Click to expand...
A phono input is also equalised to the RIAA curve used by records. This
will cut the treble and boost the bass from your computer signal.

--
*When the going gets tough, use duct tape

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
On Wed, 09 Jun 2010 05:27:33 -0500, jameswaters@unlisted.comwrote:

I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

Thanks

James W.
Click to expand...
Don't plug it into the phono input.
 
On 09/06/2010 11:35, Dave Plowman (News) wrote:
In article<pnqu06dd0b8see7aak4elch4og62e1j11j@4ax.com>,
jameswaters@unlisted.com> wrote:
I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

A phono input is also equalised to the RIAA curve used by records. This
will cut the treble and boost the bass from your computer signal.
Click to expand...

Very true, but assuming that you can live with that / correct it enough
with the computer's graphic eq control panel, then you will need two
resistors for each channel, one in series and then one to ground to form
a potential divider. I would suggest initially trying about 10 : 1 so
suitable values might be 47k ohms in series with the 'live' leg of the
feed, and then 4.7k ohms from the 'amplifier' side of that new resistor,
to the 'ground' leg of the feed.

Arfa
 
On Wed, 09 Jun 2010 08:03:00 -0400, Meat Plow <mhywatt@yahoo.com>
wrote:

On Wed, 09 Jun 2010 05:27:33 -0500, jameswaters@unlisted.comwrote:

I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

Thanks

James W.

Don't plug it into the phono input.
Click to expand...
Right, and where should I plug it? I said there is no AUX and no
other inputs. The tape deck is built in, so no tape inputs either.
The phono is the ONLY input.

I'll try the resistors as posted.

I was also wondering what would happen if I put an equalizer in
between? Suppose all I can do it try it. I have a small 6 band one
that I'm not using. I guess that could compensate for the RIAA too.
Although I really find the bass and treble pretty much ok. Besides
using the bass and treble controls on the receiver, I can fine tune
the sound in Winamp.

Thanks
 
Try this...

http://sound.westhost.com/project80.htm
 
jameswaters@unlisted.com wrote:
On Wed, 09 Jun 2010 08:03:00 -0400, Meat Plow <mhywatt@yahoo.com
wrote:

On Wed, 09 Jun 2010 05:27:33 -0500, jameswaters@unlisted.comwrote:

I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

Thanks

James W.
Don't plug it into the phono input.

Right, and where should I plug it? I said there is no AUX and no
other inputs. The tape deck is built in, so no tape inputs either.
The phono is the ONLY input.

I'll try the resistors as posted.

I was also wondering what would happen if I put an equalizer in
between? Suppose all I can do it try it. I have a small 6 band one
that I'm not using. I guess that could compensate for the RIAA too.
Although I really find the bass and treble pretty much ok. Besides
using the bass and treble controls on the receiver, I can fine tune
the sound in Winamp.

Thanks

I dont know if you can find it, but there is a small gadget, that
Click to expand...
goes into a tapedeck, and feeds the signal to the tapereader head.
A friend of me uses it often.
 
In article <4c0fa0dc$0$14126$703f8584@textnews.kpn.nl>,
Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> wrote:
I dont know if you can find it, but there is a small gadget, that
goes into a tapedeck, and feeds the signal to the tapereader head.
A friend of me uses it often.
Click to expand...
Normally sold for car use. When cars had tape decks.

--
*24 hours in a day ... 24 beers in a case ... coincidence? *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
Hi!

Well, if you don't have an AUX connector, how about one for TAPE?

That should work properly with no modification required.

William
 
Hi!

Right, and where should I plug it?
 The tape deck is built in, so no tape inputs either.
Click to expand...
Oh. I guess the suggestion I just made won't work very well! :)

If the phono input shouldn't work, I see two other possibilities--a
cassette "shell" adapter with a stereo miniplug or even a low power FM
modulator, such as the kind that are sold for portable CD players,
iPods and such.

William
 
Assuming there is an FM tuner in the stereo, there are inexpensive RF
transmitters in stores for playing iPuds thru car radios or other systems.

I found one a while ago for maybe $3 at a discount place, but don't know how
it actually sounds, as I haven't tried using it.

--
Cheers,
WB
..............


<jameswaters@unlisted.com> wrote in message
news:pnqu06dd0b8see7aak4elch4og62e1j11j@4ax.com...
I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

Thanks

James W.
Click to expand...
 
In article <SrLPn.372$234.205@newsfe11.ams2>,
Arfa Daily <arfa.daily@ntlworld.com> wrote:

I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

A phono input is also equalised to the RIAA curve used by records. This
will cut the treble and boost the bass from your computer signal.

Very true, but assuming that you can live with that / correct it enough
with the computer's graphic eq control panel, then you will need two
resistors for each channel, one in series and then one to ground to form
a potential divider. I would suggest initially trying about 10 : 1 so
suitable values might be 47k ohms in series with the 'live' leg of the
feed, and then 4.7k ohms from the 'amplifier' side of that new resistor,
to the 'ground' leg of the feed.
Click to expand...
That assumption about being able to correct it adequately with the
computer's EQ may be a bit of a stretch... there are likely to be some
significant frequency errors.

The OP might want to try building a simple "inverse RIAA" equalization
circuit, which would also act as an attenuator. By inserting this
between the incoming signal and the PHONO input jack, it would cancel
out the PHONO input circuit's relatively high gain, and also reduce
the signal level enough to avoid overdriving. These really aren't all
that much more complex than just a two-resistor voltage divider...
only three more components are needed.

Take a look at the following document:

http://waltjung.org/PDFs/A_High_Accuracy_Inverse_RIAA_Network.pdf

It shows the designs for several different inverse-RIAA networks. The
intent was to provide readers with the ability to build an inverse
RIAA network which was accurate enough that it could be used to test
different phono preamplifiers and detect any inaccuracies in their
RIAA stages. The networks seem to have been designed on the
assumption that they are being fed from a signal generator /
oscillator, having a relatively high voltage level and a 300-ohm
output impedance. That's probably a good enough approximation for the
behavior of a computer sound card's LINE OUT jack for these circuits
to be used with acceptable results.

The circuits aren't complex. The oldest version (by Reg Williamson)
requires three resistors and two capacitors, per channel. I'd guess
that you can probably buy acceptably-close-to-the-right-value parts at
Radio Shack even today... if not, Mouser or Digi-Key will certainly
have them. Any electronics hobbyist you know, can probably find
acceptable parts in his/her junk box. The whole circuit could be
haywired together into the middle of a "quarter-inch stereo miniplug,
to two RCA plugs" jumper cable (again, even Radio Shack has these),
insulated with tape or heat-shrink tubing or "liquid electrical tape",
and you'd be good to




--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
 
On 6/9/2010 6:31 AM William R. Walsh spake thus:

Well, if you don't have an AUX connector, how about one for TAPE?
Click to expand...
Apparently you missed the part where the OP said "I said there is no AUX
and no other inputs."

Here's another suggestion to the OP: since you're contemplating doing a
little project where you have to solder up stuff, why not just tap
directly into the stereo's line-level input? Wouldn't be difficult at
all: just locate the volume control (undoubtedly a 2-gang
potentiometer), and wire a connector for the computer input across the
ground and high sides of each pot. Should work fine.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)
 
On Wed, 09 Jun 2010 16:10:36 +0200, Sjouke Burry
<burrynulnulfour@ppllaanneett.nnll> wrote:

jameswaters@unlisted.com wrote:
On Wed, 09 Jun 2010 08:03:00 -0400, Meat Plow <mhywatt@yahoo.com
wrote:

On Wed, 09 Jun 2010 05:27:33 -0500, jameswaters@unlisted.comwrote:

I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

Thanks

James W.
Don't plug it into the phono input.

Right, and where should I plug it? I said there is no AUX and no
other inputs. The tape deck is built in, so no tape inputs either.
The phono is the ONLY input.

I'll try the resistors as posted.

I was also wondering what would happen if I put an equalizer in
between? Suppose all I can do it try it. I have a small 6 band one
that I'm not using. I guess that could compensate for the RIAA too.
Although I really find the bass and treble pretty much ok. Besides
using the bass and treble controls on the receiver, I can fine tune
the sound in Winamp.

Thanks

I dont know if you can find it, but there is a small gadget, that
goes into a tapedeck, and feeds the signal to the tapereader head.
A friend of me uses it often.
From my experience, the tape head things sound really bad - no highs.
Click to expand...
It probably depends on how well the heads align, but I would rather
listen to unequalized RIAA than the particular tape head thing I had.

Another option is to open the stereo, find the phono preamp, and
bypass it. In other words, connect the wires that go from the
selector switch to the output of the phono preamp directly to the
phono input connectors.
 
Hi!

Apparently you missed the part where the OP said "I said there is
no AUX and no other inputs."
Click to expand...
I did, to wit:

On Jun 9, 8:33 am, "William R. Walsh" wrote:

Oh. I guess the suggestion I just made won't work very well! :)
Click to expand...
William
 
greenpjs@neo.rr.com writes:

From my experience, the tape head things sound really bad - no highs.
Click to expand...
They vary quite a bit -- I've got a cheapie Goodmans one that's awful,
and a Sony one that works very well. I don't think I'd want to use one
on something other than a car stereo, though; even if the sound
quality's OK, you're going to have the cassette deck's motor running all
the time.

Another option is to open the stereo, find the phono preamp, and
bypass it.
Click to expand...
That'd be my preference, if the OP's reasonably comfortable with
electronics or can find somebody else who is. A few minutes' careful
poking around will probably find a couple of tracks that can be cut to
inject line-level audio at the output of the preamp; you could even add
a switch if you want to retain the phono input. But I'd imagine the OP
will be quite happy just using an attenuator and fiddling the tone
controls...

--
Adam Sampson <ats@offog.org> <http://offog.org/>
 
On Wed, 09 Jun 2010 17:21:40 -0400, greenpjs@neo.rr.com wrote:

On Wed, 09 Jun 2010 16:10:36 +0200, Sjouke Burry
burrynulnulfour@ppllaanneett.nnll> wrote:

jameswaters@unlisted.com wrote:
On Wed, 09 Jun 2010 08:03:00 -0400, Meat Plow <mhywatt@yahoo.com
wrote:

On Wed, 09 Jun 2010 05:27:33 -0500, jameswaters@unlisted.comwrote:

I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

Thanks

James W.
Don't plug it into the phono input.

Right, and where should I plug it? I said there is no AUX and no
other inputs. The tape deck is built in, so no tape inputs either.
The phono is the ONLY input.

I'll try the resistors as posted.

I was also wondering what would happen if I put an equalizer in
between? Suppose all I can do it try it. I have a small 6 band one
that I'm not using. I guess that could compensate for the RIAA too.
Although I really find the bass and treble pretty much ok. Besides
using the bass and treble controls on the receiver, I can fine tune
the sound in Winamp.

Thanks

I dont know if you can find it, but there is a small gadget, that
goes into a tapedeck, and feeds the signal to the tapereader head.
A friend of me uses it often.
From my experience, the tape head things sound really bad - no highs.
It probably depends on how well the heads align, but I would rather
listen to unequalized RIAA than the particular tape head thing I had.

Another option is to open the stereo, find the phono preamp, and
bypass it. In other words, connect the wires that go from the
selector switch to the output of the phono preamp directly to the
phono input connectors.
Click to expand...
Another easy place to find is the top of the volume control, add
a changeover switch and series caps -- drawback is that you likely
lose the tone controls.

Grant.
--
http://bugs.id.au/
 
On 09/06/2010 13:54, jameswaters@unlisted.com wrote:
On Wed, 09 Jun 2010 08:03:00 -0400, Meat Plow<mhywatt@yahoo.com
wrote:

On Wed, 09 Jun 2010 05:27:33 -0500, jameswaters@unlisted.comwrote:

I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

Thanks

James W.

Don't plug it into the phono input.

Right, and where should I plug it? I said there is no AUX and no
other inputs. The tape deck is built in, so no tape inputs either.
The phono is the ONLY input.

I'll try the resistors as posted.

I was also wondering what would happen if I put an equalizer in
between? Suppose all I can do it try it. I have a small 6 band one
that I'm not using. I guess that could compensate for the RIAA too.
Although I really find the bass and treble pretty much ok. Besides
using the bass and treble controls on the receiver, I can fine tune
the sound in Winamp.

Thanks
Click to expand...
Yes, that was my contention. Everything that has been said about reverse
RIAA compensation etc is absolutely true, and yes, such a network is
reasonably easy to knock up, but I got the impression that, given that
you know that what you are doing is not ideal in the first place, but
the *only* way that you can do it, then it is just a QAD 'fix' that you
are looking for, and the simple two resistor potential divider network
will do that just fine. I am also sure that between the Winamp G.E. and
the tone controls on the stereo, you will be able to compensate
adequately (but not perfectly) for the non-linear frequency
characteristic of your phono input.

Arfa
 
On Wed, 09 Jun 2010 07:54:35 -0500, jameswaters@unlisted.comwrote:

On Wed, 09 Jun 2010 08:03:00 -0400, Meat Plow <mhywatt@yahoo.com
wrote:

On Wed, 09 Jun 2010 05:27:33 -0500, jameswaters@unlisted.comwrote:

I plugged my computer output into my stereo. Its an old 1970s stereo
with built in cassette tape deck and phono input. There is no AUX
input, so I put it in the phono input. It works but it's overdriven
and distorts unless I keep the computer level real low. I know what's
wrong. Phono inputs are highly pre-amped. Too much pre-amp for what
I'm doing. I believe they sell attenuators, (maybe Radio Shack), but
I was wondering if all I need to do is put a resistor on each channel
cable. There are no longer any Radio Shack stores nearby me. Will
the resistors work? Do I put them in series, or across the input to
the ground? What value should I use.

Thanks

James W.

Don't plug it into the phono input.

Right, and where should I plug it? I said there is no AUX and no
other inputs. The tape deck is built in, so no tape inputs either.
The phono is the ONLY input.

I'll try the resistors as posted.

I was also wondering what would happen if I put an equalizer in
between? Suppose all I can do it try it. I have a small 6 band one
that I'm not using. I guess that could compensate for the RIAA too.
Although I really find the bass and treble pretty much ok. Besides
using the bass and treble controls on the receiver, I can fine tune
the sound in Winamp.

Thanks
Click to expand...
It will sound like crap in the phono input even if you get the level
down to a few milivolts by padding the output of the PC. You didn't
mention if this old stereo rig had an fm tuner in it but if it did
what I would do is build a small fm transmitter from a few spare parts
and broadcast the pc on an unused channel. You can also buy those
things to play an Ipod or mp3 player on your auto's stereo.
 
I was also wondering what would happen if I put an equalizer in
between? Suppose all I can do it try it. I have a small 6 band one
that I'm not using. I guess that could compensate for the RIAA too.
Although I really find the bass and treble pretty much ok. Besides
using the bass and treble controls on the receiver, I can fine tune
the sound in Winamp.

Thanks

It will sound like crap in the phono input even if you get the level
down to a few milivolts by padding the output of the PC.
Click to expand...

Given that it will be highly compressed and messed-about-with MP3s played
via Winamp, the
additional tonal distortion introduced by flinging the signal into an RIAA
equalised phono input,
will be the least of the OP's problems ... :)

Arfa
 
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