Preamps with balanced ins/outs and remote

Nagra PL-L although both balanced outputs are optional as is the remote so you'd have to find one so equipped. Balanced inputs are standard.

One reason for going with balanced operation is the effect that this has on the interconnects used, rather than just the fact that the amp might have a balanced input.

There is a standard for balanced operation that has been around for decades. It is there so that you can reliably and repeatably set up a system, with expectation for good results, regardless of the length or cost of the cables used.

IOW if the standard is used, the cables in the system cease to have significant effect on the sound of the system.

Here is the standard:
1) Pin 1 is ground. (pin 2 in the US is non-inverting, in Europe it is inverting)
2) The signal shall occur between pin 2 and pin 3 of the XLR. Ground is ignored!
3) The output impedance of the source shall be low enough that driving a low impedance can be done without change in frequency response or distortion. 'Low impedance' is typically less than 2Kohms.

If any of these rules are ignored (which is common-place in high end audio) the result is that the cable will express some artifact, and the length will be a problem. A common myth is that there is no advantage to short balanced runs; the truth is that balanced operation is lower noise even if the cable is only 6 inches long.

The take-away here is that if you can hear a difference with the cables in your system there is a problem. Its very likely that of two cables being compared, one might sound better than the other; the simple fact is that neither is entirely correct. It is the balanced standard that allowed the record labels to do the job that they did back in the late 50s (often known as the Golden Age of Stereo), when exotic high-buck cables did not exist.

The funny thing is that to drive the cable correctly such that its artifact is controlled and prevented is not difficult nor more expensive! The main thing seems to be education on the part of designers who very much seem to me to simply not know about the standard.

This is why I put up my prior post. Of all the preamps mentioned, how many can drive a 2000 ohm load without loss of bass or an audible increase in distortion or overall loss of volume? Its true that many amps have a high input impedance where this might seem to not come into play, but like I said earlier, if you ignore the standard then welcome to audible differences between cables, something the balanced line system is supposed to prevent. I am indeed saying that you need the low output impedance even if you are not driving a low impedance load.

... I am indeed saying that you need the low output impedance even if you are not driving a low impedance load...So true, you want the signal to drop across the load, not the preamplifiers output circuit. Its a simple voltage divider rule. The lower the amplifier's input impedance becomes, the more important the pre amplifiers output impedance becomes(need it to be LOW).

...It is the balanced standard that allowed the record labels to do the job that they did back in the late 50s (often known as the Golden Age of Stereo), when exotic high-buck cables did not exist... So true again. Listen to an old Peter Paul and Mary record, like the very first one, fantastic.

Atmasphere is 100% correct, except that most high buck cables are not really made right, just expensive.

I don't think you'll get true balanced circuits all the way through for 1K. Maybe a buffered input that is balanced, but it eventually goes unbalance into the overall gain strage. Why? It cost twice, or more, as much to be fully balanced all the way through. A cheater plug that uses just PIN 2 referenced to ground is common. This is done all the time to accommodate those with XLR's.

Something to look out for if not already mentioned is that you need to be careful with inexpensive preamp claiming to be balanced. As Rower mentioned, many companies will install an XLR connector on the back of their unit an say it has "Balanced Connections" when in fact, it is simply a single ended input through an XLR connector to accomodate those with balanced cables. It is no different than a single ended RCA connection.

If you find a preamp you are interested in that claims to have balanced connections (regardless of price), be sure to verify exactly what type of connections they are.

I also wanted to add to the discussion of output impedance. It is true that the lower the output impedance, the better a preamp will drive most solid state or low input impedance amplifiers. Our Purity Audio Design preamps have been paired with Audio Power Labs amplifiers at shows with an input of 600 ohms and MBL amps with 5k ohms.

Another thing to consider is the gain of the preamp. To high (or even to low) of an output gain and you will not be able to realize the full potential of your system.

In regard to the different sound of cables I think much of this has to do with their construction and material. All cable companies will make claims but in the end, it is your system and ears that will tell you what is best.