Jump to content
The Klipsch Audio Community
Sign in to follow this  
ned

balanced interconnects....

Recommended Posts

Hi eveyone - 

 

After years of vintage hifi I just made a leap. I just bought a Parasound P6 and I am digging it. I may review it elsewhere. I am using its DAC via USB for streaming, its optical for my CD transport and its phono pre for a grado on a technics into a pair of 1979 KHorns. The KHorns remain the signature of my great sound whatever gear I run .

 

Here is my question: Using balanced outputs and inputs between a P6 and an A 23+ adds 6db according to the amp manual. I am curious if this has any effect on when the amp moves from "A" to "A/B". Does the increase in volume come from the circuitry of the pre or the amp? Do I get 6db for "free" from the pre?

 

I don't expect I'll use more than the first few of the 160 watts that the amp puts out. Should I even care about whether the amp is running in A or A/B? 

 

Thank you for any thoughts you have. I am enjoying the modern world.

 

Ned

 

 

Share this post


Link to post
Share on other sites

The volume knob on the preamp controls the signal going to the amplifier, so no concerns about overdriving the amp.

Share this post


Link to post
Share on other sites

Thanks Don,  I appreciate the response. You have a better sense of things than I do. 

 

My concern is almost exactly the opposite. I've never overdriven an amp with Klipsch. (I started with the RF line, then Cornwalls and now the stately corner horn)  The Parasound A23+ starts to engage A/B around 3 watts*. This is often more than I use with the KHorns. If my goal were to get 85dbs at 3 watts, would using balanced connections (and gaining 6db as a result) help me stay in class A? 

 

I guess my question is, will I get more volume and better sound at the same low wattage using balanced inputs? 

 

Should I care about A vs. A/B? 

 

Thanks again for the reply.

 

Ned

 

P.S. the A23+ produces 160 watts per channel into 8 ohms and so I have pleeeeeenty of headroom.

 

*I learned this number from Parasound who is very responsive to my OCD driven questions about the amp. I ordered one today from my local brick-and-mortar audio crack house.

Share this post


Link to post
Share on other sites
On 8/4/2019 at 11:02 AM, ned said:

Do I get 6db for "free" from the pre?

No, I'll bet you paid a pretty penny for the A23:) Seriously you get an extra 6db because the output is differential meaning there is a signal of equal but opposite polarity on the negative output pin.

Share this post


Link to post
Share on other sites

The manual for your Parasound A23+ seems to contradict itself.  The balanced input section mentions the 6 dB increase, yet the specifications page implies a 0 dB increase.

 

Total gain  29 dB

 

Input sensitivity for 28.28 Vout

    Unbalanced 1 V

    Balanced      1 V  per leg

 

This implies that once the non-inverted and inverted legs are subtracted from each other, the resulting single-ended voltage is then cut in half.

 

Confusing.

    

Share this post


Link to post
Share on other sites
On 8/5/2019 at 7:26 PM, ned said:

will I get more volume and better sound at the same low wattage using balanced inputs? 

 

It might affect the position of the volume knob, but it won't change the relationship between the amp and the speaker output. I have a preference for balanced cables when given the choice, but you are going to have a great sounding stereo either way. The Klipschorns will probably have your amp running in class A mode most of the time, so I wouldn't be very concerned about the numbers on the spec sheets.  

 

On 8/5/2019 at 7:26 PM, ned said:

Should I care about A vs. A/B?

 

That transition is automatic on your amp, at 3 watts you were told, correct?  Rather than A vs. A/B, it is A + A/B.  Most listeners would never know the switching is occurring. Please let us know if you are able to detect it. I would probably just say, "dang that is loud!"

 

 

Share this post


Link to post
Share on other sites

Thanks Khornukopia - Amp should arrive today and my dealer will lend me fancy RCAs and balanced ICs. They have no direct recommendation apart from asking me to use my ears in my room. I look forward to a lost weekend. I'll report back.

 

excellent!

 

 

Share this post


Link to post
Share on other sites
On 8/7/2019 at 12:14 PM, mboxler said:

The manual for your Parasound A23+ seems to contradict itself.  The balanced input section mentions the 6 dB increase, yet the specifications page implies a 0 dB increase.

 

Total gain  29 dB

 

Input sensitivity for 28.28 Vout

    Unbalanced 1 V

    Balanced      1 V  per leg

 

This implies that once the non-inverted and inverted legs are subtracted from each other, the resulting single-ended voltage is then cut in half.

 

Confusing.

    

Well that is confusing. There seems to be a general consensus - including the good people at Parasound by email, around the 6db number. I'll reply on what I hear when the needle hits the groove. 

 

N

 

 

Share this post


Link to post
Share on other sites

Took a closer look at Parasounds Documentation on these 2 pieces. What a mish mash. I'm sure some engineer knows what he wants to say but then the technical writers get a hold of it.

On 8/7/2019 at 8:31 AM, babadono said:

No, I'll bet you paid a pretty penny for the A23:) Seriously you get an extra 6db because the output is differential meaning there is a signal of equal but opposite polarity on the negative output pin.

Now I am not sure this is a true statement. Could be the minus output on pin 3 of the XLR on the P6 pre is just impedance balanced to signal return with no inverted signal on it. This kind of incongruity makes me want to get a scope on it.

Share this post


Link to post
Share on other sites

Phil Jackson at Parasound included the following in an email:

 

The +6dB gain is a result of the implementation of balanced circuitry given the hot/neutral/ground connections of the balanced cable.  There is no issue with the gain of either the preamp or the amp with respect to using the balanced cables.   With your sensitive corner horns you will want to use the gain control pots on the rear panel of the A23+ to turn DOWN the output of the amp so the volume control of the P 6 is smooth and consistent.   I would anticipate that, give you are using sensitive speakers, you will be doing most of your listening in Class A as the transition point is at the 2-3 watt mark.   :

 

Thank you babadono for your interest in research. At this point, I see creating a common ground between the pre and the amp as being the real benefit of the interconnects. 

 

N

 

 

 

Share this post


Link to post
Share on other sites

More confusion.  Hot/ neutral/ground ? What are we talking about the 115 VAC input mains?:) With balanced interconnects there is a +(call it hot if you want) that always has a signal on it. Then there is a -(some call it cold, neutral I have never heard it called before today). The - can have a signal on it but it does not have to. If it does have a signal it is the invert of the +. Or it can just be an impedance equal to the + side's impedance but to signal ground. You gain 6db of signal if the - has an inverted signal on it.

The purpose of balanced interconnects is to reject common mode noise and only pass the desired signal. Also in properly set up balanced systems the signal ground of each piece of equipment in the system is kept separated from the shield.i.e there is no signal return current flowing in the shield of the cables connecting the pieces of equipment. The shield is only tying the chassis of the equipment together.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...