Biwiring Parasound C2 to Parasound A23

[MichiganMike]

Someone posted on Audiogon.com that they experienced improved sound when connecting both balanced and unbalanced cables to input a Parasound A21 amp. I have a Parasound C2 preamp processor normally connected to a Parasound A23 amp using balanced cables in a 2 channel system. Since I had a spare set of unbalanced cables available, I decided to try connecting both unbalanced and balanced cables between my Parasound C2 and A23 not expecting to hear any significant difference. To my surprise the sound seemed fuller and more detailed through my Salk SongTower Speakers with both balanced and unbalanced cables connected between the C2 and the A23 whether the amp was switched to the balanced or unbalanced cable position. The unbalanced position of the switch sounded slightly better to me when the sound level was matched (i.e., volume control was increased for the unbalanced position).
I have noted that even when the switch on the A23 amp is in the wrong position for the type of cables used (that is unbalanced if only balanced cables are used or balanced if only unbalanced cables are used) there is some sound output albeit at an attenuated level. It may be that the amp is being input by both sets of cables although one at a much lower level that for reasons unknown to me gives a richer sound at the same volume. Then again this may be a placebo effect. In any case it was worth trying as I had spare unbalanced cables available. YMMV.
I have been careful to only switch the A23 between balanced and unbalanced cable positions with the system off.

[Kal Rubinson]

Have you measured to determine if, in fact, using both is simply giving you more signal voltage which easily fools most ears, including mine? An increase by a fraction of a dB is usually interpreted as the same level but "fuller."

[MichiganMike]

Kal, fair point on the importance of matching the signal voltage. I have not taken the time to confirm signal voltage or output dB levels are matched. However, even when the balanced cables alone are used to produce what I think is a clearly louder volume by ear, the dual cables sounded more appealing in some way that is difficult for me to describe. I do not have the ability to do rapid A and B comparisons of these cables which is another problem in my methodology. There may also be differences in the balanced and unbalanced cables that would be apparent if used separately, but I had tried this sometime ago and did not hear a significant difference.
I admit that my assessment is highly subjective and therefore suspect.

[Kal Rubinson]

Kal, fair point on the importance of matching the signal voltage. I have not taken the time to confirm signal voltage or output dB levels are matched. However, even when the balanced cables alone are used to produce what I think is a clearly louder volume by ear, the dual cables sounded more appealing in some way that is difficult for me to describe. I do not have the ability to do rapid A and B comparisons of these cables which is another problem in my methodology. There may also be differences in the balanced and unbalanced cables that would be apparent if used separately, but I had tried this sometime ago and did not hear a significant difference.
I admit that my assessment is highly subjective and therefore suspect.

Join the club. :W Little things, like small level differences, can confuse anyone focusing attention on the finer grain details.

[Chris D]

Huh... I don't get it. I thought the whole point of the balanced/unbalanced switch was to get only one source at a time. I don't know why hooking up both would add any more signal.

[duketbrd88]

i could be wrong, but i had an A21 & P3 preamp before my classe and i don't think the parasound is a fully balanced amp.I mean internally they are connected and just give you the option to use balanced or unbalanced. I could be dead wrong so please correct me if i am. I do love the halo stuff. There classic stuff is great also.

[Kal Rubinson]

Huh... I don't get it. I thought the whole point of the balanced/unbalanced switch was to get only one source at a time. I don't know why hooking up both would add any more signal.

The switch is probably not simply selecting between inputs. It is probably switching the ground connection and/or shunting the (-) input on the BAL input. Both are physically connected all the time and this is, excuse the expression, common.

[Peter Nielsen]

i could be wrong, but i had an A21 & P3 preamp before my classe and i don't think the parasound is a fully balanced amp.I mean internally they are connected and just give you the option to use balanced or unbalanced. I could be dead wrong so please correct me if i am. I do love the halo stuff. There classic stuff is great also.

What you may be referring to is electronically balanced vs. using a balancing transformer. I'm not sure, but I believe that Parasound might be using electronic balancing in favor of the old-fashioned traditional transformer. However, Halo *is* FULLY balanced for sure!

Peter

[Chris D]

Well, Parasound talks about their components being "partially balanced", which refers to the XLR balanced componentry going from plug on the processor back panel (i.e. P3) to plug on the amp rear panel (i.e. A21). It does not extend inside the unit into the "guts".

... I just searched for where I previously found this information, and can't find it anywhere. I'm sure I saw it in a Parasound manual or brochure before.

[duketbrd88]

Chris, thanks! That is what i was trying to say.

[Peter Nielsen]

Well, Parasound talks about their components being "partially balanced", which refers to the XLR balanced componentry going from plug on the processor back panel (i.e. P3) to plug on the amp rear panel (i.e. A21). It does not extend inside the unit into the "guts".

Ah, so in other words they're not internally balanced. Makes perfect sense for the C1/C2 that is based on the Titan platform (3rd party) which probably is not balanced.

However, I'm pretty sure that the amps that are designed from the ground up by Parasound, for instance the JC1 and JC2 are fully balanced. (Probably the A21/A23 too).

Peter

[Peter Nielsen]

Yep. That's it. The JC-1 and JC-2 are fully balanced.

However, it appears the rest of the Halo gear is not internally balanced.

For sure, the C1/C2 is not internally balanced. Section 3 of the FAQ confirms this: http://www.htguide.com/forum/showthread.php4?t=6995