Twisted Pear Audio Support
»
Product Support
»
Analog
»
Legato Discrete I/V Stage
»
[SOLVED] Help setting up Legato 3 no buffers / cannot adjust SE DC output voltage !!
Rank: Advanced Member
Groups: Member
Joined: 2/7/2009(UTC) Posts: 51 Location: Spain
|
[SOLVED] -> jumpers J5 and J6 missed, see below Hello everybody, I have just received my Legato 3 (no buffers) and finished soldering. Some parts have been upgraded: 180R resistors for 2V output, Silmic II caps (same specs as original ones), 1K and 100K resistors have been upgraded with PRP´s as well. Powering is done via 3 placids, the same ones that were powering my Legato 2. Output is set to 14.75 volts. Reading the manual, I was able to correctly set balanced outputs to 0 VDC with VR1 and VR2. Now I am trying to get 0 VDC as well for the SE outputs which measure almost 4 VDC. The problem is that VR3 and VR4 has little impact lowering the DC output so I reach the end of the pot when I am at 3.6 VDC. There is no way I can get 0 VDC at the moment ... anybody has an idea what I should check ?. I can only use the SE output and have no way to check whether the balanced output has any sound at all. Any help will be much appreciated. Here is a pic: Best regards, Pepe Edited by user Friday, July 8, 2011 1:06:14 AM(UTC)
| Reason: Not specified
|
|
|
|
Rank: Advanced Member
Groups: Member
Joined: 2/7/2009(UTC) Posts: 51 Location: Spain
|
Some measures I took, just in case : Opamp pin 4, V- : -14.36 VDC Opamp pin 8, V+ : 14.36 VDC Edited by user Thursday, July 7, 2011 6:45:44 AM(UTC)
| Reason: Not specified
|
|
|
|
Rank: Member
Groups: Member
Joined: 7/12/2010(UTC) Posts: 24 Location: Australia
|
Just two questions: 1. Did you install jumpers at J5 and J6? 2. Are resistors R25 and R26 required if the buffers aren't in use?
|
|
|
|
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)
|
Good question on J5 and J6. :)
R25 and R26 are fine. I would leave them.
|
|
|
|
Rank: Advanced Member
Groups: Member
Joined: 2/7/2009(UTC) Posts: 51 Location: Spain
|
YES !!!!
I had missed jumpers J5 and J6 !!!, they are soldered now and.... gorgeus music !! , super gorgeous music !! (what is the purpose or leaving those two jumpers unconnected?)
Thank you very much to Narla and of course Russ for your help guys, i love this community.
Special thanks as well for the team of Russ and Brian, your guys rock keeping the community enjoying and learning with your great products.
Cheers Pepe
|
|
|
|
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)
|
Glad you have it right now. :)
BTW that part is covered in the manual. The jumpers are only used when you are not using the SE buffers.
|
|
|
|
Twisted Pear Audio Support
»
Product Support
»
Analog
»
Legato Discrete I/V Stage
»
[SOLVED] Help setting up Legato 3 no buffers / cannot adjust SE DC output voltage !!
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.