Spectron musician ii hybrid monoblock question


Greetings,
i was wondering if some question users can offer a bit of help. I am currently running a pair of spectron musician ii hybrids in monoblock with a Balanced Y splitter made by Jim Aud of PAD. One side of the splitter is reverse polarity as the older musicians do not have a phase switch on them.

I'm looking to add a new preamp that has two sets of balanced xlr outputs (possibly ARC LS17-SE). Would it be possible (or make sense) to use two seperate XLR cables for each amp, one in phase and the other out of phase, to remove the Y splitter? 

Thanks in advance
duckdownman
Yes, that will function ok. However I’m not sure that the resulting sonics would be optimal in the case of the LS17-SE and some other ARC line stages, due to impedance compatibility issues.

In the case of the LS17-SE (as well as many other ARC line stages) the recommended minimum load impedance spec is 20K. And although the specs I’ve seen don’t make it clear, I wouldn’t be surprised if that was for the unbalanced outputs only, and if the corresponding number for the balanced outputs is twice that amount, or 40K. And I also suspect that the two balanced output jacks of the LS17-SE (for each channel) are driven by the same output stage, which would mean it would be driving both inputs of the Spectron, and therefore seeing a load impedance corresponding to half of the input impedance of each of the Spectron’s inputs.

So if the input impedance of the Spectron Musician ii is spec’d at less than 80K the resulting sonics might not be optimal with the LS17-SE (and a number of other ARC line stages), especially in the bottom octave where the LS17-SE’s output impedance probably rises significantly relative to its specified nominal value.  And that concern would apply regardless of whether you connect to one output jack per channel using your present balanced splitter, or connect to the two jacks with separate cables.

Regards,
-- Al

For the ARC:
INPUT IMPEDANCE
120K ohms Balanced, 60K ohms SE. 

OUTPUT IMPEDANCE
600 ohms Balanced, 300 ohms SE Main (2). 20K ohms minimum load and 2000pF maximum capacitance. Outputs (3): 

spectron has an input of 50k ohms




Sorry I hit send too soon
i thought the thinking was the Amps input imp should be 10x higher than the preamps output (I could be wrong). Or maybe I am not considering the fact that I'm using the amps in mono? Would the amps input impedance be different in stereo vs mono? I couldn't find anything concrete but I'll see what I can research