All animals are equal, but some animals are more equal than others (From Animal Farm by George Orwell)

There are many XLR-XLR in-line isolation units on the market. They pretty much look the same, so what is the difference, and why should you pay substantially more for a Lundahl unit compared to units of other brands?
When audio input transformers are used inside pro audio equipment, they are normally specified to handle 10 – 20 dB higher signal levels than normal “line level”. The reason is to guarantee that in all possible situations, the input transformers will never saturate and thus ruin the signal quality.
The ONLY XLR-XLR inline units on the market that give you similar signal level margins are our LL1584 (and LL156X ) units. Most units on the market will break up ground loops, which is the most common problem in live sound situations. But only a few units on the market will provide the same signal integrity normally found in standard input transformers.
Next time you are using an XLR inline unit, make sure it is a unit more equal than others.