Connect TV audio output to old stereo amp

Hi,

Not sure if this is the correct forum, but it is the only one I am familiar with.

I have an old audio system, Technics SU 8022 stereo amp attached to large quaulity technics speakers, works fine. Have a Sony Bravia LCD TV which has an audio output socket which I use for headphones occasionally. Does it make sense to attempt to connect the TV's audio output to the Technics amp to get better sound quality.

Sony TV Audio out:

500mVrms (100% modulation) More than 1 Vrms at max volume setting Impedance 47k ohms

Technics amp input: Phono 2.5mV 47k ohm Aux 150mV 27k ohm

I assume I will need some kind of voltage/impedance matching between the two units.

Al Moodie.

Reply to
Al Moodie
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There's no reason you shouldn't connect the TV. You will definitely get better sound. *

See if the TV has a regular pair of RCA audio-output jacks, which you should use instead of the headphone jack. Regardless of which you use, there will be no need for voltage or impedance matching. (I don't know where you got your specs, but the TV does not have a 47K audio output impedance. It's about 1/20 that.)

One possible problem... If your TV is connected to a cable system, you might have hum problems. You'll need an isolation transformer. The MCM 33-8700 is a good choice; I use it in my system. A double-male coupler (MCM 33-480) might also be handy.

  • Cheap speakers have gotten surprisingly good. If your Technics speakers are really old and really mediocre, there's a chance the speakers that came with the TV might have better over-all quality.
Reply to
William Sommerwerck

Thanks for your response.

I want to use the headphone jack for output because using the jack mutes the TVs speakers and allows me to control volume using the TV remote (the stereo amp does not have a remote).

I assume this is just a cabling problem, headphone jack male split to RCA audio plugs.

Al.

Reply to
Al Moodie

I'd recommend trying the RCA jacks first. Most (many) have circuitry that detects a connection and mutes the output. The headphone jack is likely low impedance and as such won't match the amplifer as well.

Reply to
Peter2

There's no need for matched impedance.

Reply to
William Sommerwerck

There are several issues.

First of all, do not use the phono input; it is designed for a magnetic cartridge, has RIAA equilization, and will seriously overamplify the bass frequencies.

Second, I would spend some time reading the manual for the TV, and studying the function of the audio output RCA jacks. If they can be configured to suit your purposes, they would be preferable to the headphone jack.

Third, you are setting up a situation where the TV will be turned off, but the amplifier will still be on. For a number of reasons, this is not desirable.

PlainBill

Reply to
PlainBill

Really? I've not heard of this function with an RCA socket, but I don't deal with much domestic audio equipment.

Can you or someone post a link to how this works?

Cheers,

Gareth.

Reply to
Gareth Magennis

Other than wasting electricity, what would they be? I've already pointed out the possible ground loop, but that occurs whether or not the TV is on.

Reply to
William Sommerwerck

I am using the AUX input.

I have used the headphone jack because it is accessible from the side of the TV. Works just fine and the sound quality has improved. To access the audio output jacks I will have to remove the TV from the wall to gain access, a pain, but will do so when I have more time.

Other than I forget to turn it off when I go to bed, how is this undesireable.

You have given me advice before on badcaps forum, small world, thanks again.

Thanks to all who posted.

Al.

Reply to
Al Moodie

I've seen mostly mechanical type switching. I've a TV that does just this, plug in to the RCAs and the speakers are muted.

Reply to
Peter2

I'm doing the same as you. I'm using a 55" LG set, Headphone out to an old (1985) Technics receiver and a pair of JBL speakers. I also have a solid state relay to turn on the receiver using one of the USB inputs of the TV to get the 5 Volts to run the SSR. The only 'quirk' is the LG will not allow balance, bass or treble adjustments when the headphone jack is used. I tried changing settings without the headphone jack and as soon as the headphone connector is used it resets center.

G=B2

Reply to
stratus46

uld

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Does the TV have a separate headphone amp, or does the headphone simply connect to the speaker amp? Audio power amps are meant to supply a great deal of current compared to what a high impedance input expects -- this would not present a problem for driving a preamp?

Reply to
spamtrap1888

Wasting electricity is the obvious problem. Possible transients as the set powers up and down is a second. Accelerated aging of the components in the amp would be a third.

PlainBill

Reply to
PlainBill

Ahh, technology.

Had a Vizio 32 inch in living room. Front facing speakers, and I hooked a little subwoofer, sounded Decent.

Upgraded to a 40 inch, nice picture by the way even though it a Coby. I spend about an hour trying to get any audio. Finally figured out my cable box does not have full HDMI out .iwas using a digital to HDMI cable, and separate audio in cable. I could not do that on the Coby, had to use RGB and audio. Also it has no audio line out. Must use optical out to amp. The big picture has like most bottom or side speakers, sucks. I attached two cardboard reflectors to get some good sound. Also no headphone output. I be installing a optical feed in the future. I might finish my entertainment room first, and that will have at least 3 tv's. The good thing about using this IPAD, I can control multiple cable boxes in the same room with comcasts app.

Greg

Reply to
GS

By the way, these color picture settings really suck. Way too much color and contrast. What are they thinking? I guess they look good in the show room. Maybe the better sets are better. I got the Coby looking good in custom. It's like I go around looking at different shows. Just like getting a good new set of speakers, I got to go through my library of songs.

Greg

Reply to
GS

Not sure I've ever seen any on a TV set, but phono (RCA) sockets with built in mechanical switches are certainly to be found on some amps. One that comes to mind is a big Yammy AV amp that uses them for the 5.1 discreet inputs, I think. The switches go bad resulting in intermittent or missing channels when it is working in 'normal' mode ...

Arfa

Reply to
Arfa Daily

My AV amp stays on all the time, and it doesn't cause me any problems ...

Arfa

Reply to
Arfa Daily

This is a good place to get the advice that you need, but please note, it is not a forum, it is a usenet newsgroup. Forums are typically web based and have moderators who have access to the content allowing them to edit or remove posts. Usenet news groups usually do not have any kind of moderation. You might be accessing this group via a web-based 'front end'. There are quite a few about now. It doesn't really make a lot of difference from a user point of view, unless you get into an argument. Also, replies posted on the group can be slow to be trawled by the front end site. If you are accessing via one of these websites, you might consider making use of one of the free usenet clients such as Xnews, for an altogether better experience.

Arfa

Reply to
Arfa Daily

I got a couple pseudo theater amps that shut down with no input. I also think some active subwoofers also shut Down.

Greg

Reply to
GS

Mine, however, is a 5.1 Sony home cinema amp with built in DVD (that I don't use), and remains fully powered with or without input. I am, however, fully familiar with the types that do shut down. I have repaired two in the last three weeks.

Arfa

Reply to
Arfa Daily

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