Unbalanced vs balanced cables

[Ralph124C41]

What type of cable do I use to connect my modeling guitar amp to a P.A. system? I used it once or twice before when I owned a small P.A. system and I think I used a standard guitar cable (unbalanced). However I've read the manual and it recommends using a balanced TRS cable for the best results.

Huh? Can I use either type of cable? Do I run the risk of damaging either my amp or the P.A. system if I used the wrong type of cable?

The manual does not say one type or the other HAS to be used ... just that the balanced TRS cable will provide the optimal result.

[RoyBoy]

TRS is stereo 1/4" jack

[jonfields45]

This was last weeks discussion. It should cover all the pit falls.

https://www.acousticguitarforum.com/...41&postcount=4

[Ralph124C41]

Originally Posted by jonfields45

This was last weeks discussion. It should cover all the pit falls.

https://www.acousticguitarforum.com/...41&postcount=4

I'm sorry I missed that but I do not see the answer to my specfic question ... that is the cable connecting the line out (offered in stereo) to a PA system or to a mixer, if one is used. It would seem, as I suspect as I said from my past memory, that a TS cable could be used ... I'm just confused by the manual recommending a TRS cable. Why would it be explained like that?

[MarkF_48]

What is the modeling amp you are connecting to?

If the modeling amp manual states that a balanced TRS cable can be used, that suggests the amp is capable of a balanced connection and likely is not a stereo output on the amp. A balanced connection will provide a bit more signal and less susceptible to noise picked up from longer cable lengths. To be balanced throughout the PA system would also need inputs which are balanced as well. If interconnecting 1/4" balanced connections, either a cable with TS or TRS plugs will work. Using a TS cable will not cause any damage, but will deliver slightly less signal and 'may' pickup some noise on longer cable runs.

[Gordon Currie]

Originally Posted by Ralph124C41

I'm sorry I missed that but I do not see the answer to my specfic question ... that is the cable connecting the line out (offered in stereo) to a PA system or to a mixer, if one is used. It would seem, as I suspect as I said from my past memory, that a TS cable could be used ... I'm just confused by the manual recommending a TRS cable. Why would it be explained like that?

Because it will work either way. Theoretically, it might have slightly less noise with TRS. You may not be able to hear the difference.

Balanced signals matter most when the signal is low level (such as a microphone).

The people who would be concerned about this are audio engineers.

[Gordon Currie]

Originally Posted by MarkF_48

If the modeling amp manual states that a balanced TRS cable can be used, that suggests the amp is capable of a balanced connection and likely is not a stereo output on the amp.

This is my problem with TRS connectors. They can be used for balanced mono signals OR unbalanced 2 channel (most often stereo signals) OR loop send/receive (mono) signals.

It is impossible to tell from 'TRS' which mutually incompatible use case is being discussed.

[Ralph124C41]

Originally Posted by MarkF_48

What is the modeling amp you are connecting to?

If the modeling amp manual states that a balanced TRS cable can be used, that suggests the amp is capable of a balanced connection and likely is not a stereo output on the amp. A balanced connection will provide a bit more signal and less susceptible to noise picked up from longer cable lengths. To be balanced throughout the PA system would also need inputs which are balanced as well. If interconnecting 1/4" balanced connections, either a cable with TS or TRS plugs will work. Using a TS cable will not cause any damage, but will deliver slightly less signal and 'may' pickup some noise on longer cable runs.

It is an older Fender G-Dec 3 Thirty. When it came out it came with 100 general-purpose presets but you could also download selective sets so I downloaded the folk and country set which has maybe eight acoustic emulations ... dreadnoughts, jumbo and parlor guitars. And yes the manual says "These line level stereo outputs are suitable for connection to recording or sound reinforcement equipment. Use balanced (TRS) cables for the best performance."

And why stereo? The amp has backing tracks that can accompany the playing. The idea was you could opt to send the backing track of a song into a P.A. or similar system where it could be played in stereo while the guitarist plays through the amp's onboard speaker (a 10-inch in a closed cabinet.) Or you could send the guitar signal with the backing track to the P.A. or you could send just the guitar signal, which is what I would do. I imagine it would be in mono.

(The funny thing is I used this setup only once in a band I played in a couple of times. I brought the amp and told the band members what I wanted to do and I thought I told the sound guy or I told somebody to tell the sound guy, who was just a friend of a band member. Well I played the set in a large restaurant and got no complaint. After we tore down the band equipment I found out the sound guy had never connected my amp to the P.A. system! The audience just heard me playing through the monitor.)

[Ralph124C41]

Originally Posted by Gordon Currie

Because it will work either way. Theoretically, it might have slightly less noise with TRS. You may not be able to hear the difference.

Balanced signals matter most when the signal is low level (such as a microphone).

The people who would be concerned about this are audio engineers.

Then a TS cable will do just fine for me. thanks.

[sdelsolray]

Originally Posted by Ralph124C41

I'm sorry I missed that but I do not see the answer to my specfic question ... that is the cable connecting the line out (offered in stereo) to a PA system or to a mixer, if one is used. It would seem, as I suspect as I said from my past memory, that a TS cable could be used ... I'm just confused by the manual recommending a TRS cable. Why would it be explained like that?

You can use a TS cable, but you will suffer -6dB loss in signal strength and have a higher risk of RF interference being introduced into the signal.

[Ralph124C41]

Originally Posted by sdelsolray

You can use a TS cable, but you will suffer -6dB loss in signal strength and have a higher risk of RF interference being introduced into the signal.

that much of a signal strength loss? I know there is the risk of picking up some interference but I didn't know it could also degrade the signal to that extent.

Well now I'm thinking about getting a TRS cable.

[Peter Z]

An unbalanced connection has 2 wires: ground and signal.

A balanced connection has 3 wires:
1. ground
2. signal +
3. signal -, which is the phase inverted version of signal +

If your balanced cable is exposed to electromagnetic influences, both signal + and - will catch those. At the input, signal - will be phase inverted again and is the same as signal + then.
So. both wires carry the + signal again, but the noise is phase reverted and cancels out when mixed. At the same time you mix both, the signal + and the inverted signal - (that was also inverted and therefore signal + again) together. And that gives you 6db. The noise will cancel out, the useable signal will double.

TRS and XLR cables can also be used for stereo signals. Then you get ground, left channel and right channel on your 3 wires. But unbalanced!

You can also use them for them for inserts. Then your 3 wires carry ground, send and return. Also unbalanced!

And now I need jonfields to transfer this into understandable English. Sorry, thats not my native language.

[MarkF_48]

The Line outs on the Fender G-DEC amp are indeed TRS balanced outs as a Left and Right stereo pair. You can use either 1/4" TS or TRS cables with the TRS being a better option as noted in a couple previous posts.

[Ralph124C41]

Originally Posted by MarkF_48

The Line outs on the Fender G-DEC amp are indeed TRS balanced outs as a Left and Right stereo pair. You can use either 1/4" TS or TRS cables with the TRS being a better option as noted in a couple previous posts.

Wow! Thanks for the schematic as I will print it out if the amp needs repair. (Btw, I think this is an overlooked amp that was killed by its initial selling price of about $400 and its (to me at least) hard-to-understand instructions.)

I will definitely invest in a TRS cable and I thank everybody here for their help. As I said I don't much about cables ... in fact I had always assumed a speaker cable and a TRS cable were the same thing.