Transparent Interconnect Question....

Nsgarch...OK. I'll bite!

Balanced output provides twice the signal, but twice the circuit noise as well. Since signal/noise ratio is what matters you need to find another reason for balanced. A balanced interface avoids noise pickup in the wires, and only the noise picked up in the wires. For a 1.5 meter run this ought to be a non-issue.

FWIW, I do use some balanced lines, including 25 foot runs to my power amps. Why? Because the electronics have that kind of interface. Results are no different from single ended, in my case.

Actually, I was generalizing about "twice the signal". It does happen, but not always is it a factor of 2. And I already mentioned that noise cancellation is not the issue for 1.5m. What is really important is that (according to Eldartford) both the amp and preamp have truly balanced output and input circuit topology. Using them results in:

1.) Optimum signal transfer.
2.) No need to go through the unit's inversion circuits to convert to SE at the preamp and back to Bal at the amp. Thus eliminating two inversion steps for the signal.
3.) Better signal-to-noise ratio at the amplifier (since it doesn't have to work as hard to produce the same output.)

These (and there are other) reasons should be enough to produce audibly better results for the balanced hook-up, even if the cables themselves are one level down in quality from the single-ended ones.

N.

1.) Optimum signal transfer.

Optimum in what way? That's kind of generic, like "it's better because it is better."

2.) No need to go through the unit's inversion circuits to convert to SE at the preamp and back to Bal at the amp. Thus eliminating two inversion steps for the signal.

There is no conversion to SE at the output of a typical preamp. The non-inverting portion of the balanced signal is used for the SE output and the inverted signal simply remains unused. I agree with your point about converting to balanced at the input of the amp.

3.) Better signal-to-noise ratio at the amplifier (since it doesn't have to work as hard to produce the same output.)

If it is producing the same output then it is working just as hard no matter what you feed it.. Once the conversion is done at the input it acts just as if had been fed a balanced signal.

Herman,

If there were not a separate buffer circuit in the preamp to keep the SE output electrically separate from the balanced output, you could not use both outputs at the same time. With Krell, Levinson, ARC, and most other premium preamps, you can use the SE and the Bal at the same time because one (or both) are buffered. If the Krell is Bal circuit topology to begin with, then it's likely only the SE output is buffered.

Optimum signal transfer in Bal mode (compared to SE) occurs because the amp is receiving (from the preamp) a full strength push-pull signal around ground. A SE input (at the amp) must first go through an inverter circuit which takes the SE input signal, divides it into two SE signals, inverts the polarity of one of them, then recombines both parts as a balanced signal which the amp circuit has to see. But that "manufactured" balanced signal won't have either as low a noise floor or as high a signal strength as an actual balanced input signal coming straight from the preamp.

So with a (stronger) Bal signal at the input, the amp uses less (possibly half as much) gain to produce the same output voltage as when using a SE input. That results in greater headroom (less distortion at a given ouput to the speakers) than when using a SE input. So it's not just about less noise but better quality as well.

Checking the output specs for preamps that offer both types of outputs, you will notice the Bal outputs are usually rated at around twice the voltage as the SE outputs.

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i would call transparent, be specific about what you're connecting to what, and let them provide the answer. in my case, i have a rowland consumate preamp, and because jrdg strongly encourages the use of the balanced inputs due to the fully balanced circuit design, i got a pair of trsp bal.ref (w/mm tech) to connect my dac (m.lev 360s) to the preamp.
and it does sound very very good.
as for the (very) confusing trsp. model designations, it goes like this- 1.ultra 2.ref 3.ref xl 4. ref mm 5.opus.
simply state "current production" which implies all have "mm" technology. "old" trsp cable unfortunately is not as good as the new stuff imho. my wild guess/answer to your question- get ultra bal- current production.