Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Login
2 Pages12>
Running Legato balanced directly to amp?
Options
View
Go to last post Go to first unread
Previous Topic Next Topic
mjock3  
#1 Posted : Saturday, April 7, 2012 8:50:15 PM(UTC)
mjock3

Rank: Member

Groups: Member
Joined: 9/16/2011(UTC)
Posts: 85
Location: Wisconsin

Thanks: 1 times
Am I able to run the balanced outputs of the Legato directly into a balanced inputs of a amplifier? If so are there any precautions in doing so? I have never used balanced before so I am quite ignorant in these matters. Do I need to make any compensations to enable it to work?

Also could I still use the SE for a subwoofer using the volume control?

Thanks very much for making this setup. You have given me sound that I otherwise would not be able to afford.

Mark
Back to top
WWW

Wanna join the discussion?! Login to your Twisted Pear Audio Support forum accountor Register a new forum account.
Back to top  
LeonvB  
#2 Posted : Sunday, April 8, 2012 6:24:47 AM(UTC)
LeonvB

Rank: Member

Groups: Member
Joined: 5/23/2010(UTC)
Posts: 708
Location: Netherlands

Thanks: 2 times
Was thanked: 48 time(s) in 45 post(s)
No, not any amplifier. If the amp has coupling caps you could link to it directly. If it doesn't you could end up feeding DC to your speaker units, which can cause smoke.
Back to top
mjock3  
#3 Posted : Sunday, April 8, 2012 12:39:26 PM(UTC)
mjock3

Rank: Member

Groups: Member
Joined: 9/16/2011(UTC)
Posts: 85
Location: Wisconsin

Thanks: 1 times
Is there DC coming out of the balanced outputs?

And would I be able to run the SE as well as the balanced at the same time?

Thanks
Back to top
WWW
Russ White  
#4 Posted : Sunday, April 8, 2012 2:04:55 PM(UTC)
Russ White

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN

Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
The Legato can be trimmed to have no differential DC (measured between the balanced outputs) - but unless you add coupling caps it will have common mode DC (measured from either output to GND).

If you are unsure if a balanced amp can handle common mode DC (many can, some can't) then you should add the coupling cap to be safe. The size of the cap will depend on the input impedance of the amplifier.

Edited by user Monday, April 9, 2012 8:05:22 PM(UTC)  | Reason: Not specified
Back to top
WWW
mjock3  
#5 Posted : Monday, April 9, 2012 1:05:21 PM(UTC)
mjock3

Rank: Member

Groups: Member
Joined: 9/16/2011(UTC)
Posts: 85
Location: Wisconsin

Thanks: 1 times
Russ,

Would I be losing anything in the way of sound by doing the coupling caps? Or would I be just as well off converting SE to balanced?

Thank you
Back to top
WWW
Erlend Sæterdal  
#6 Posted : Monday, April 9, 2012 2:52:51 PM(UTC)
Erlend Sæterdal

Rank: Member

Groups: Member
Joined: 7/27/2008(UTC)
Posts: 158
LeonvB wrote:
No, not any amplifier. If the amp has coupling caps you could link to it directly. If it doesn't you could end up feeding DC to your speaker units, which can cause smoke.


8 v dc on the cables is a bad idee.

Electrolytic capacitors sound very good when there is some voltage on them , much better than Metallized polypropylene if you ask me.
Back to top
Russ White  
#7 Posted : Monday, April 9, 2012 8:06:38 PM(UTC)
Russ White

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN

Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
I wouldn't FRET over the coupling caps. There should have negligible impact on the final result.
Back to top
WWW
mjock3  
#8 Posted : Tuesday, April 10, 2012 7:22:26 AM(UTC)
mjock3

Rank: Member

Groups: Member
Joined: 9/16/2011(UTC)
Posts: 85
Location: Wisconsin

Thanks: 1 times
Thanks Russ. :d/
Back to top
WWW
mjock3  
#9 Posted : Thursday, April 12, 2012 5:36:17 PM(UTC)
mjock3

Rank: Member

Groups: Member
Joined: 9/16/2011(UTC)
Posts: 85
Location: Wisconsin

Thanks: 1 times
Is it possible to run a subwoofer on SE outputs while running the amp via balanced?

Thanks
Back to top
WWW
Russ White  
#10 Posted : Friday, April 13, 2012 6:35:15 AM(UTC)
Russ White

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN

Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
Absolutely.
Back to top
WWW
Erlend Sæterdal  
#11 Posted : Saturday, June 2, 2012 9:44:28 PM(UTC)
Erlend Sæterdal

Rank: Member

Groups: Member
Joined: 7/27/2008(UTC)
Posts: 158


I wonder why the discret Legato 3.1 sounds much better with minus ( 3 ) connected to ground ! Anybody else with that exsperience ?
Back to top
Russ White  
#12 Posted : Sunday, June 3, 2012 8:14:16 PM(UTC)
Russ White

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN

Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
NO - that's exactly opposite of my experience.

It could have to do with your amp.
Back to top
WWW
Russ White  
#13 Posted : Sunday, June 3, 2012 8:19:15 PM(UTC)
Russ White

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN

Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
Also you would never want to try that if you don't have output caps on the legato. You are basically just using one half the signal, which would not be good for many reasons.
Back to top
WWW
mjock3  
#14 Posted : Wednesday, June 13, 2012 1:26:35 AM(UTC)
mjock3

Rank: Member

Groups: Member
Joined: 9/16/2011(UTC)
Posts: 85
Location: Wisconsin

Thanks: 1 times
I am finally getting around to giving it a try. I just want to verify, the coupling caps go on pin 2 & 3. Is that right?

Thanks,

Mark
Back to top
WWW
Brian Donegan  
#15 Posted : Wednesday, June 13, 2012 3:03:38 AM(UTC)
Brian Donegan

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 2,868
Location: Massachusetts, USA

Thanks: 2 times
Was thanked: 141 time(s) in 134 post(s)
Yes.

Pin 1: Ground
Pin 2: +
Pin 3: -

What amp are you using? With many amplifiers (truly differential inputs), you can simply omit the Ground pin connection and no coupling caps are needed. A quick look at the schematic of the amp will tell the story...
Back to top
WWW
mjock3  
#16 Posted : Wednesday, June 13, 2012 5:58:38 AM(UTC)
mjock3

Rank: Member

Groups: Member
Joined: 9/16/2011(UTC)
Posts: 85
Location: Wisconsin

Thanks: 1 times
Ncore 400
Back to top
WWW
Erlend Sæterdal  
#17 Posted : Wednesday, June 13, 2012 11:17:49 PM(UTC)
Erlend Sæterdal

Rank: Member

Groups: Member
Joined: 7/27/2008(UTC)
Posts: 158
Originally Posted by: Russ White Go to Quoted Post
NO - that's exactly opposite of my experience.

It could have to do with your amp.


No it had something to do with the output on the Legato. At the minus output I had 22 uf. cap than 3,3 ohm Carbon Composite.
At the plus output I had 3,3 ohm and than 22 uf.

I changed that so the resistor was first for both. Also the new Trident V3 is just fantastic. Such a huge difference. Now I am running balanced sounds great.
Back to top
mjock3  
#18 Posted : Thursday, June 14, 2012 9:18:33 PM(UTC)
mjock3

Rank: Member

Groups: Member
Joined: 9/16/2011(UTC)
Posts: 85
Location: Wisconsin

Thanks: 1 times
Originally Posted by: Brian Donegan Go to Quoted Post
Yes.

Pin 1: Ground
Pin 2: +
Pin 3: -

What amp are you using? With many amplifiers (truly differential inputs), you can simply omit the Ground pin connection and no coupling caps are needed. A quick look at the schematic of the amp will tell the story...



Thanks Brian, I guess that is what I will do. I just want to make sure I understand, just don't wire the ground pin coming out of the Buffalo DAC right?
Back to top
WWW
mjock3  
#19 Posted : Thursday, June 28, 2012 8:24:13 PM(UTC)
mjock3

Rank: Member

Groups: Member
Joined: 9/16/2011(UTC)
Posts: 85
Location: Wisconsin

Thanks: 1 times
If I float the ground on the Legato to the amps without sub hooked up everything sounds fine. Once I hook the sub into SE I get a ground hum out of the sub. I had no ground hum when running everthing SE. Any suggestions on how to eliminate the ground hum?

Thanks
Back to top
WWW
Brian Donegan  
#20 Posted : Monday, July 2, 2012 3:44:29 PM(UTC)
Brian Donegan

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 2,868
Location: Massachusetts, USA

Thanks: 2 times
Was thanked: 141 time(s) in 134 post(s)
Off the top of my head, I cannot think of why this would cause a ground loop. If you disconnect the balanced connections to the amps, does the hum go away?
Back to top
WWW
Rss Feed  Atom Feed
Users browsing this topic
GuestUser (4)
2 Pages12>
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

Youtube
Copyright © Twisted Pear Audio