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Signal Degradation Balanced Output

Has anyone developed a workaround that solves signal degradation when splitting. The problem that I have occurs even when the preamplifier has two balanced outputs.

Years ago I became aware of this problem when using my Sonic Frontiers Line 3, which has 2 pairs of balanced outputs, to drive a Theta Dreadnaught amp and a pair of Entec LF-20 subs. I thought the sound was excellent until oneday, I disconnected the cable to the sub and that’s when I heard what I had been missing from the Wilson Cub I, transparency and reverb that allows you to hear deep into the music.

Now, I’m running Focal Mini Utopia Be, Denafrips T+ DAC to Athena Pre, which has 2 pairs of balanced outputs driving a ARC VT-130 and a Focal Sub6. Same problem! I’ve tried inserting my Jeff Rowland Model 112, then tapping off the speaker terminals with a Jensen ISOMAX transformer which then goes to sub.. the problem persists.

The problem isn’t huge, it’s just that the higher the resolution of the components, the more noticable it is. My setup needs the lower fundamentals that a sub brings, but at a cost I’m not happy with.

Any ideas?




cathy062
russ69's avatar
russ69
3,523 posts
 
I'm totally confused at this point. When that happens, I break down my system to the bare essentials. Source, amplification, and speakers. Everything else sits in the corner for now. If you can't get your system sounding right with the bare minimum components, you'll be able to isolate the culprit. 
If the subs are the issue....are they forward firing and between your mains?  If not that is where I would start. My next step would be stereo woofer towers and a good crossover. That would be a big step up. 
cathy062 OP
15 posts
 
Thanks All! for your valuable input.  @russ69 
I definitely have broken the system(s) down too many times to always come up the same.  The culprit is always at the point of insertion of a splitter or in this case a dual preamp output.  The sound right now is awesome so long as only one amp is connected with no sub.  Additionally, the sound is awesome so long as I only use the balanced line out of my DAC, simply connecting my headphone amp to DAC's rca out diminishes the signal greatly, everything else being equal, meaning the DAC's balanced interface is connectes to the preamp. Looks like I will be doing a lot of connecting and disconnecting if I want to listen to the best sound, as needed.
cathy062 OP
15 posts
 
@cleeds ,
ARC tube amp specs  200K ohms balanced,
Jeff Rowland amp specs 20K ohms balanced
Sub6 specs 10K ohms input balanced
Athena preamp specs 400 ohms output balanced

Do you see a problem? What should I be looking for?
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cleeds
5,984 posts
 
cathy062
ARC tube amp specs 200K ohms balanced,
Jeff Rowland amp specs 20K ohms balanced
Sub6 specs 10K ohms input balanced
Athena preamp specs 400 ohms output balanced

Do you see a problem? What should I be looking for?
Typically @cathy062  -  the rule of thumb is the amplifier(s) input impedance should be 10x the preamp's output impedance.  (There's debate on that with some arguing it should be more and others arguing that it can be less.)

If I'm correctly recalling the formula for calculating combined impedance (Z) is (1/R1 + 1/R2 + 1/R3 ...), then you're around 6.4K for a combined input impedance. While that would seem to be ok, input impedance varies by frequency, so it's difficult to say for sure. Your results suggest it's an issue, especially because your sub has such a low input Z.
cathy062 OP
15 posts
 
@cleeds , Ok, I get it.  Hmmm, I guess it is what it is until I get some floorstanders.  I feel like I've tried just about everything and don't want to add more components in a feckless attempt to better the sound, when less sounds right.

Thanks everyone for all your help!
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