balanced vs unbalanced

Do you notice an improvement in balanced vs unbalanced connection
with a good amp?
If an amp has balanced and unbalanced connections, and I use unbalanced connection, am I supposed to use a jumper over the balanced connections?
1. Rarely but possible.
2. Does the amp have a switch to select between the two inputs? If not, you probably need the jumper.

I found that it depends on the amp. I had a Audio Research VT100 Mk II that I used single-ended for a few years. Then I switched to a front-end with balanced outs, so I switched to balanced interconnects and the sound improved significantly. The most obvious improvement is better bass extension with balanced compared to single-ended.

I would suggest finding out if your amp is a balanced design. If so, try using balanced. But ultimately, trust your ears.

All things being equal, and assuming that the balanced is properly implemented (a lot of times it isn't!), balanced is the way to go.

Depending on the circuit details........some may need jumpers, others will not.
If your equipment is working fine, you have no ground loops, long interconnect runs between components or some noisy electromagnetic sources/wires very close by (like an AC) then I doubt you can hear any difference.

Balanced will be better in any of the above conditions but in practice RCA is good enough.
What is it about the performance of your current setup that leaves you unsatisfied?

In other words, just because we CAN do something doesn't necessarily mean that we should.

If you have not identified a specific improvement criteria, then blindly making changes may or may not do many things; some desirable, some not.
If you can run balanced- do so. Balanced cables are more effective than their single-ended counterparts and the system will sound better for that reason alone- assuming that the amp is indeed balanced internally.

The original balanced standard was developed decades ago specifically to get around interconnect problems. If you think about it, all the best recordings of the 50s and 60s were done with balanced cables. If there was a problem with 150' long microphone interconnects (like the ones Mercury used to record at Northrup Auditorium in Minneapolis), you'd think you'd here it with today's equipment. But you don't and in fact many of those recordings are regarded as reference quality today.

I would think an audiophile would *jump* at the chance to eliminate the vulgarities that an interconnect cable can introduce! That's what balanced lines are *for*!!
Jumpers: some components recommend, some dont require it. Going to balanced usually increases the gain and allows a longer run of cable with less loss.
If everything is proper, no difference of sound quality.

Noise is cancelled when it gets on both hot and cold input of balanced system, and that was the main reason balanced input has been adopted for professional system where the input line can be long through noisy environment.
I can't hear a difference in my setup. My interconnects are only a meter though. For long runs over 6' I'd use balanced but it's usually not necessary.
You can't hear a difference, eh? Maybe it isn't properly implemented. A lot of SS gear is not. They seem like to use the garden variety circuit that comes out of some "cook book", and it leaves much to be desired.

The leads on our phono setup is less than 1 m, and there is a definite improvement.
Improvement vs. unbalanced when balanced input is used can be an indication of a poor CMRR (commom mode rejection ratio) of the amplifier. If the amplifier's front end differential stage is perfectly designed, there should be no difference.