Impedance between Pre to Amp SE to Balanced

So I generally knows that the higher the ratio the better.

My Amplifier has ONLY XLR inputs which rated at 300K ohm impedance(balanced)

now my question is this, what happens if my preamp has only SE outputs and I connect between the two with one of these options:

1. active direct box

2. RCA to XLR adaptors

3. ARC BL box

or if you guys know another or which way is the best to do it?

So my question is, what happens to the AMP input impedance in each way of the following above, and how it impacts the impedance, how much will it drop if it will(approximately) . I know fire sure I will have some volume loss so I guess the impedance ratio do drop to some degree.

this is what ARC said :”There should be no issues with using XLR to RCA cables. You will lose a bit of signal level using RCA outputs but it will not cause any damage or cause any issues.”

but I would like to hear your personal experience and how do you feel about that sonic wise? 
I did heard from some that it’s damaging the musicality and some claims it is perfectly fine.


Many thanks for the helpers !




To my understanding ARC amps sound a lot better when driven by a balanced line, since their input circuit lacks the Common Mode Rejection Ratio needed to have single-ended and balanced operation sound the same. IOW, distortion is higher driving single-ended.

You won't damage the amp but you won't hear what its capable of either.

@atmasphere I appreciate your comment.

So if for example I will feed it with a Jensen transformer/ ARC Balance Line 1(BL1)

it should be working as good as feeding it with Balanced pre?

@honeybadgertube Yes- probably better (depending on the balanced preamp), since transformers are so good at being balanced.


I do not believe you will hear a substantial difference in sound quality by simply using RCA to XLR cables. The quality of the interconnects, and definitely the power cord will make a larger difference. I would not get rid of such a great and prized amp on this issue. Someday I’m sure you’ll get a preamp that has balanced output or a newer Audio Research amp that have both RCA and XLR.