stereo to mono

The ccts shown are for inputs to the amp, you should be able to just use one channel if you desire. Depending on the amp it may be possible to bridge the outputs.

Very likely that if you feed the speaker from both + outputs (ie. do not connect the - terminals just each + terminal) you will have the effect you want.

Stereo to mono conversion is a dangerous process. There is a caveat: broadc asters often apply stereo wide expansion effects done by inverting one chan nel which do not add to mono very well. My all purpose safe solution is to take only the left channel and look in the device configuration for options to switch to mono.

I've lived that first hand. One user connected a cheap wireless headphone t o a TV set. The headphones had a switch to set Normal (Stereo) mode or TV ( Mono) mode, TV mode had to be used to stop a high pitch noise. The user com plained that it worked fine most of the time but her favourite program woul d sound very faint and turning the volume up would result in very distorted sound. I found that switching the headphones to stereo would cure the prob lem but it resulted in the high pitched noise back. So that was it, that pr ogram was broadcast in wide stereo made by inverting one audio channel and the headphones summing of both channels resulted in almost no sound. As a curiosity, enabling the TV builtin stereo enhacer did invert the situa tion: the affected program sounded good and any other had a very faint audi o.

My solution: I disassembled the base station, unsoldered the right channel and connected the left channel to both inputs. Not a high tech solution but she was very happy with it.

The simplest way to do this is to use an RCA Y adapter and connect the sing le input to both the left and right channels. This is a common practice an d will not harm the unit. Any attempt to combine the separate outputs coul d result in damage to the amp. It was not designed to have that occur.

Pick up a y-cable. Should be less than $5.00

Dan

On Monday, February 2, 2015 at 7:32:54 PM UTC-5, snipped-for-privacy@yahoo.com wrote :

ngle input to both the left and right channels. This is a common practice and will not harm the unit. Any attempt to combine the separate outputs co uld result in damage to the amp. It was not designed to have that occur.

That's backwards. I don't have a single input, I have two channels output from an amplifier, an amplifier that has no mono switch and will output onl y stereo, and also it's an amplifier not otherwise in use anywhere else.

I want to put it into a single speaker, because I happen to have a Pioneer tower speaker about 4 foot high for which I have no other use. I don't hav e a pair of them, I bought something at a yard sale as it was closing for $

5, and the guy wouldn't sell it unless I took the speaker too.

The amplifier has output speaker terminals to which I can connect wires. F or two channels, four wires.

The speaker has terminals to which I can connect wires. One speaker, two w ires.

I had hoped there was some kind of simple resistive network I could put tog ether that would take four wires in and have two wires out.

I found that circuit in the wye article but it really looked like signal le vel, as someone here confirmed.

There may be no good way to do this and that's okay, it's not like I'm out any money.

Anybody want half of a Pioneer speaker pair?

Sorry, I read that backwards. As it stands, without an external circuit to allow for the use of both channels in "bridge" mode, what you seek is not possible. The amp sections were not designed ot be used in bridge mode (which is what you are asking).

Dan

As others have pointed out, trying to bridge the amplifier at its output is risky. Fortuneately, you don't need to do that. Just use one channel of the amplifier driving your single speaker. If you do that, the only problem you have left is making sure that single channel (mono) contains both the left and right from the TV. You can easily bridge the low level signals that go into the amp. Now, what does the output from the TV look like? If it is RCA connectors (typically red and white), you can just use a "Y" cable as others have suggested and your are done. If, however, you are trying to tap into the speaker wires coming from the TV, you will want something like some of those circuits you mentioned in your first post. You need to combine the two outputs without shorting the TV amplifier's two outputs together.

It's also very likely that (when/if a monaural source is connected) this will produce zero output sound.

Ah, you are suggesting bridging the signal level inputs instead of the outputs.

That makes sense to me, but............isn't that what those circuits I linked do? Are you sure a Y-cable will work?

Do it all the time. Works great.

Dan

Yes. But, what outputs from the TV are you using to drive those signal level inputs? If they are regular line level outputs, just bridge them. Line level outputs are very forgiving. If, however, you are using external speaker outputs, you will need one of "those circuits" to avoid problems with the amplifier inside the TV.

Okay, I'm way above my head with this stuff. (Long ago I knew a little more, I had an Extra class amateur radio license.) But this isn't making sense to me.

When we were talking about the amplifier, the consensus was that the bridging circuits shown on the "why not wye" page were only for line level inputs and should not be used on the speaker outputs.

Now that we're talking about the tv, you're saying that the line level outputs don't need bridging but the speaker outputs do.

I'm far more wary about damaging the tv than I am this amp, which cost me only $5 and isn't used often. The tv still works though it is an older tube type, like the 3 spares in the garage I can't get rid of.

If the TV has audio output connectors, you are all set using a Y adapter to "connect" both left and right into one channel on the amp. If all you hav e on the TV is speaker outputs, than you cannot use a Y adapter. The probl em will be the same as attempting to connect the amp's speakers together... don't do it.

Dan

One of the reasons this is confusing is that line level (or signal level as you called it) is about 1.5 volts max. The voltage going to small speakers is often a similar voltage. The difference is that line level drives high impedance inputs so the current is very low and not much power is transferred. However, with speakers, they often have a much lower impedance (eg, 8 ohms) and therefore draw more current and therefore more power. Outputs designed to drive speakers can therefore be more easily damaged if shorted to ground or each other. Since the voltages in question are similar, both can be used to drive the input of your amplifier. We can't be sure how to answer your question without knowing about the output of the TV. One very simple circuit you can use if the TV only has speaker outputs is to simply place some resistors in series with the signal. Almost any value 1K, 10K, even 100K will do. The result is complete protection for the amp in the TV because it is designed to drive speakers (8 ohm or 4 ohm or similarly low values) and now you have thousands of ohms in series with it. The signal after the resister can no longer drive speakers but it can still drive the high impedence inputs of your external amp.

Once again, though, if your TV has line level audio out (usually white and red RCA connectors), you can just bridge them together and not worry about any of this.

Good Luck, Pat

While the hints and arguments provided in these posts are correct I wonder if anyone did read my previous post which I think is relevant to all this. Mixing the two channels with a Y cord may produce a faint or no sound if wi de stereo techniques are applied in the broadcast. I find that using only t he left channel is safer.

I would think that if the problem you describe is widespread, we would be hearing about it a lot more. But, I have no doubt it happens at times. To the original poster, there is no risk in giving this suggestion a try. Most "main dialog" in today's show is in the center (ie, equal in both channels). So, the only thing you might miss by using only the left channel is an ocassional door closing sound effect that is only in the right channel. Music shows might be a problem, too. Try it and see if it works for you.

2nd !!

r if anyone did read my previous post which I think is relevant to all this . Mixing the two channels with a Y cord may produce a faint or no sound if wide stereo techniques are applied in the broadcast.

** FM broadcasters are required to produce a mono compatible signal - or at least they were in the past. Studios use a "stereo modulation monitor" tha t shows when the signal lacks compatibility by metering the difference sign al (L-R) and this must not be greater than either L or R.

True story:

A customer had made a commercial (on 1/4 inch tape) for use on FM radio and it was rejected on the grounds that it was "out of phase". I was asked to check it and found the tape seemed OK.

It took some effort to get through to the "engineer" who had made the judge ment and he explained how he used such a meter reach his conclusion.

The recording had a bass guitar, piano and drum kit plus vocal, none of whi ch were out of phase. However, the bass guitar had been panned to the left side, almost completely, which made the difference meter reading unusually high. Hence the mad conclusion the whole tape was "out of phase".

I told the customer to do a re-mix and pan the bass to the centre - problem solved.

The correct way is to pan a bass guitar to the left is to split the signal into low and high frequency bands, at say 150Hz, then pan the highs to the left and the lows to the centre.

This suits most broadcasters and would be essential if cutting an LP to avo id excessive vertical modulation.

... Phil

More likely smoke if you connect the +s togther. You can only do that to am ps that asre designed for it. Some commercial amps are but I know of no con sumer amps that are.

The problem is the amps won't share current well and one will be feeding th e other. That is very bad because the outputs are passing current but the v oltage across them is not dropping.

You can sum the channels with resistors, like 4 ohm at least. But don't cen noct them directly together.

Think also if it is a DC coupled amp and the offset is off say 250 mV and t he DC damping factor is 10 @ 8 ohms load, that thing is likely to idle hot. That is on top of all the L-R material working into the emitter resistors which are probably 0.47 ohm.

Amps that you can parallel have special feedback, actually more accurate, s o there is alot less imbalnce, both AC and DC. They also do not allow you t o connect to or control the channels separately in that mode. Also, they ae re built a hell of alot better than most consumer equipment.

I think most Crowns would be OK doing that, but look at what they cost.