DS single and balanced connection use?

I know from other posts in the forum that it is not recommended to use both outputs of the DS at the same time; however, I’m thinking that for background music, I may want to go direct to amps (rather than burning the preamp tubes). So I’m considering the following:

  • leave the balanced connection to the preamp as is
  • make a SE connection to the “Cinema” input of the preamp

My assumption is that there is no load on the SE output when not using Cinema? So, besides the volume control setting risk when using cinema, is there any problem with this connection scheme?

You can’t hurt the DS either way. If it sounds good to you then it’s fine. If your system has hummmm (or other audible noise) with a single ended connection the balanced connection may help, but in most systems using both cables at the same time is no problem.

Thanks Ted,

There is a mild hum in Cinema mode (preamp off). It goes away when I turn on the preamp (Cinema disabled).

The Cinema connection is the only SE connection in the system, and it’s is a pass through. What’s interesting is that the preamp to amp connection is balanced. With the active circuitry off, how is the SE to balanced translation being accomplished? Is that the source of the hum (no inverted signal)?

I don’t quite understand the question. Which SE to balanced thranslation are you asking about? So if any of the following seems irrelevant just ignore it :slightly_smiling_face:
There’s no need to turn the receiver of one of the DS’s outputs off when using the other.
The outputs of the DS are always being driven by the output transformer: the balanced connection being the whole secondary winding of the transformer and the single ended being from the center tap to one side of the transformer.
If you are considering having two separate sources connected at the input of your amps, I’d reconsider. Without accurate circuit diagrams of the outputs in question you don’t know what they do when they are powered off (for example the DS shorts it’s outputs when powered off.)
FWIW I have a clean path from my DS to the preamp and then to the amps and my video’s audio processor output is simply another input to that preamp. Trying to have one side of my system bypassing the preamp wouldn’t work at all in my system.

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From the preamp user manual (edited for clarity):

“The special Cinema Bypass feature routes the balanced or unbalanced cinema outputs directly to the main preamp output, bypassing all the SLP 05 circuitry and turning over control to the user’s cinema processor. If the SLP 05 power switch is turned to the
off position, the SLP 05 automatically defaults to the cinema bypass mode“

What I’m doing is using the DS SE outputs as “cinema outputs”, which, when the Preamp is off, passes directly to the preamp’s main outputs, which are balanced.

The balanced output of the DS remains connected to a regular balanced input on the preamp. Sounds like this is not an issue for the DS. The low level hum that i get when connected to my amps through cinema is acceptable (to me any way) when in “background music” mode.

I have both connected. however the Unit on the SE does not “see” a signal when it is off. so it is the same as having it disconnected. This is per that units schematic. My DSS at 100 volume even with both connected is dead silent. I must be lucky. I have a good integrated amp. A ML 585.5. I can max the volume on it. Put my ear to one speakers tweeter and hear not a thing. I am speaking of with no source playing of course. I hear absolutely no difference between having just BAL connected and BAL+SE connected. So long as my headphone amp(the SE device) is off. That is not my GCHA but A Rudistor RP-030.

Nope, the cable itself is basically a capacitor even if the other end isn’t plugged in. Still for most reasonable cables that extra capacitance isn’t a problem.
Also a cable causes a ground loop even if the destination is powered off. Once again, not usually a problem.
Unless you hear a problem on listening when the balanced device when plugging and unplugging the unbalanced connection at the DAC end, don’t worry about it.

Correct. It could indeed be an issue. However I hear absolutely no difference whatsoever. So I do not worry about it :slight_smile: