What interconnects are you guys using for bi-wiring speakers? I need a Y XLR based cable.


I'm using 802 D3s and krell amps.  I want to use two amp channels per speaker.  Just wanted to know what you guys were using for this and where to get a good cable that sounds good.

Thanks in advance.

mgould
Cleeds, note that he said more than one "active" XLR output. I interpret that to mean he was referring to the two output connectors on each channel each being driven by its own dedicated output stage, which appears to be the case for the Classe CP-800. But based on schematics I’ve seen at arcdb.ws most or all ARC line stages and preamps which provide two XLR outputs drive both of them from the same output stage, and simply jumper the two connectors together internally. I believe that the same holds true for the great majority of preamps and line stages from other manufacturers which provide two pairs of XLR outputs, and for RCA outputs as well.

In those cases the preamp’s output stage will have to drive the input impedances of both of the power amp inputs to which it is connected, just as if a splitter were used.

And the results could actually be worse than using a splitter, because if a short splitter is placed near the two amp inputs the cable capacitance seen by the preamp’s output stage would essentially be just the capacitance of one cable rather than two. The splitter approach being most likely to provide better results if the preamp’s output impedance is high at high frequencies, and if cable length is long (cable capacitance is proportional to length), and if the cables do not have low capacitance per unit length. In that situation some degree of rolloff and/or undesirable phase shifts may occur in the upper treble region if two long cables are used, which could be avoided or minimized if a short splitter is used in combination with a single long cable.

Regards,
-- Al

I don't know much about tube preamps because most of what I have dealt with are solid-state preamps and processors.  I had seen some DACs and preamps that do have separate actual output circuits for XLR and RCA, however, they are all opamp-based and it's really easy and cheap to just plop in another opamp to drive RCA outputs (and just chain them from the same input stage).  In the case of discrete circuits or tube preamps, the manufacturer will have to design and allocate space for an entirely separate tube output stage (in the case of discrete, this could mean another 5" x 5" section of the board or more).  This is definitely expensive for the manufacturers to support a situation that might happen 5% of the time.  Al may be correct in his statement.  That being said, you're right in the sense that ARC (and BAT now that I look) do have multiple XLR outputs.
You are spinning your wheels....  Your amp is not differentially balanced and therefore you will hear no improvement.  Balanced connections actually have 2 separate circuits ...one for the plus and one for the minus signal.   What you have is XLR connections that are there for bragging rights.  ..that's not denigrating your amp...it probably sounds fine.  If it were to have true balanced connections, the unit would cost twice as much.
Your amp is not differentially balanced and therefore you will hear no improvement. Balanced connections actually have 2 separate circuits ...one for the plus and one for the minus signal. What you have is XLR connections that are there for bragging rights. ..that’s not denigrating your amp...it probably sounds fine. If it were to have true balanced connections, the unit would cost twice as much.
Stringreen, I suspect that you meant to refer to the OPs Marantz 8802A, which is a "network audio/video surround processor/pre-amp/tuner," not to the amp. The model of the OP’s Krell amps has not been stated, and some Krell power amps are fully balanced.

Also, it can be inferred from the specs of the Marantz 8802A that it does in fact provide true balanced **connections**, since the specs indicate a "rated output" that is twice as great for the XLR outputs as for the RCA outputs. What it presumably does not have is a balanced internal signal path, which IMO has no relevance to the questions that are being discussed. And as we’ve discussed in past threads balanced connections between components having unbalanced internal signal paths (and, again, the Krell amps might very well be fully balanced) IMO may sound either better than, worse than, or similar to unbalanced connections, depending on the specific designs.

Regards,
-- Al

When I was researching the 8802a a while back, I could not absolutely determine if the internal circuits were fully "differential balanced".  A piece of equipment could have a true balanced output that is not differential - it depends on how the circuit is implemented.

That being said, looking at a detailed pic of the 8802A fully discrete HDAM module (below), I could definitely believe that each module has 2 analog circuits (which would make a truly balanced differential circuit).  The HDAM module looks to have a 9-pin connector to the main board, so there are enough pins to support 2 circuits.  The 8802A has 13 of these modules, so 2 of the XLR outputs are lacking these circuits (maybe the subwoofer output?).  Each module has a couple of 220uf caps along with smaller 22uf caps to power the circuit -- Marantz did an excellent job of designing this 8802 and I would think it's an excellent piece (until you start comparing it to stuff like the Krell).

http://www.schwartzpr.de/de/newsroom/Marantz/MarantzAV8802HDAMBoards.jpg