Legato or IVY III outputs for Buffalo II? - Page 11 - diyAudio
Go Back   Home > Forums > Commercial Sector > Manufacturers > Twisted Pear

Twisted Pear Superior quality electronic kits

Reply
 
Thread Tools Search this Thread
Old 15th August 2010, 11:38 PM   #101
diyAudio Member
 
Russ White's Avatar
 
Join Date: Jan 2005
Location: Nashville, TN, USA
Send a message via Yahoo to Russ White
Quote:
Originally Posted by needsp View Post
Hi Russ

One other thing I don't understand. Your reply implies that Legato sounds better at 15V. If R20 etc is adequately rated as you say, why not recommend 15V operation in the manual, rather than 12V?

Thanks

Paul
The manual is clear why. There is no other reason than heat. If your case is adequately ventilated use 15V. I don't assume all people have adequately ventilated cases.

The manual does assume people will maybe use the buffer, which adds even more heat. So I decided to guide people toward moderation.

I am running and have always run 15V with no issues for more than a year. My legato is performing as well as ever.

Cheers!
Russ
__________________
Less pulp more juice Twisted Pear Audio.

Last edited by Russ White; 16th August 2010 at 12:20 AM.
  Reply With Quote
Old 16th August 2010, 03:21 AM   #102
ylingf is offline ylingf  United States
diyAudio Member
 
Join Date: Jun 2004
Location: New Jersey, US
Hi Russ,

I need a SE output, but really don't like to have an opamp in the path for balanced to SE conversion. Since I know my preamp's input impedance is 10K. Is it possible to load the negative output of the balanced output with a 10K resistor, and connect the positive output to the preamp?

Thanks,

Fred
  Reply With Quote
Old 16th August 2010, 10:47 AM   #103
diyAudio Member
 
Russ White's Avatar
 
Join Date: Jan 2005
Location: Nashville, TN, USA
Send a message via Yahoo to Russ White
Hi Fred, It is possible to do, but you likely to get some nasty turn on and turn off thump unless you employ some sort relay or something.

You would be better off just forgetting the opamp is there and enjoy the good music.

You could also use a transformer or some other external BAL/SE conversion.
__________________
Less pulp more juice Twisted Pear Audio.
  Reply With Quote
Old 16th August 2010, 03:07 PM   #104
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
I knew the opamp would cause some comments (as did you no doubt ) its not an issue for me, as i'm running BAL, but I did wonder a bit about the choice TBH. people buying legato are most often doing so in order to use a no global FB discrete circuit; seems a bit counterproductive (regardless of sound) to ruin that in the last stage with an opamp for SE conversion
  Reply With Quote
Old 16th August 2010, 03:23 PM   #105
diyAudio Member
 
Russ White's Avatar
 
Join Date: Jan 2005
Location: Nashville, TN, USA
Send a message via Yahoo to Russ White
Quote:
Originally Posted by qusp View Post
I knew the opamp would cause some comments (as did you no doubt ) its not an issue for me, as i'm running BAL, but I did wonder a bit about the choice TBH. people buying legato are most often doing so in order to use a no global FB discrete circuit; seems a bit counterproductive (regardless of sound) to ruin that in the last stage with an opamp for SE conversion
I don't see it that way at all. Here is why. There are two distinct processes involved here.

First we have a symmetrical I/V converter. It is fully discrete with no global NFB. It stands on its own.

Then we have an orthogonal but practical and extremely useful bal/se stage which you the builder can decide to use or not. It is completely optional. The DAC is a balanced DAC, not SE. This I/V stage is a balanced I/V stage.

All of that to say to do BAL/SE with discrete components right would take more space than I had on this PCB, and would not have yielded as good results as what is there right now.

Instead, I took the pragmatic approach and offered the builder options. Use the excellent on-board BAL/SE stage, or do something else with the balanced signal.

One great option would be the Ventus which is a discrete BAl/SE converter. But it is far too large and makes too much heat to put on something like the Legato PCB.

So I think the choice was the most logical I could make given the goals regarding form factor etc.

Cheers!
Russ
__________________
Less pulp more juice Twisted Pear Audio.

Last edited by Russ White; 16th August 2010 at 10:27 PM.
  Reply With Quote
Old 16th August 2010, 08:25 PM   #106
NicMac is offline NicMac  Italy
diyAudio Member
 
NicMac's Avatar
 
Join Date: Feb 2009
Quote:
Originally Posted by Russ White View Post
One excellent option would be the Ventus which is a discrete BAl/SE converter. But it is far too large and makes too much heat to put on something like the Legato PCB.
Hi Russ,

Would the Ventus used as a BAL/SE converter work better with or without the buffer stage on the Legato? Would the connection need decoupling caps? Can the output DC offset of the Ventus be set (very) close to zero?
I'm considering to use of the Ventus with a dual-mono BII/Legato connected to (balanced) Hypex modules with by-passed buffer stage (input impedance 1k8R, not very tolerant to DC offset).
Last but not least - will the Ventus be re-stocked?

Thanks,
Nic
  Reply With Quote
Old 16th August 2010, 08:41 PM   #107
diyAudio Member
 
BrianDonegan's Avatar
 
Join Date: Dec 2004
Location: TPA HQ
Quote:
Originally Posted by NicMac View Post
Would the Ventus used as a BAL/SE converter work better with or without the buffer stage on the Legato?
Either would be fine, without would be cooler and easier to power.

Quote:
Would the connection need decoupling caps?
No.

Quote:
Can the output DC offset of the Ventus be set (very) close to zero?
Yes.

Quote:
Last but not least - will the Ventus be re-stocked?
It is getting a little tweaking attention, but will be available again very soon.
__________________
Twisted Pear Audio
  Reply With Quote
Old 16th August 2010, 08:44 PM   #108
NicMac is offline NicMac  Italy
diyAudio Member
 
NicMac's Avatar
 
Join Date: Feb 2009
Quote:
Originally Posted by needsp View Post
It sounds absolutely superb! Stunningly good! Unbelievably good! I don't say this lightly- it sounds better than the I/V stage I was using (which used a CFT, with a CCS above and below), and I've recently invested a lot of time and effort in that. Believe me it was no slouch sound-wise either- Legato had to be damn good to get my attention!
Hi Paul,
What are you using for BAL/SE conversion? I seem to recall that you are using a single ended power amp.
Cheers,
Nic
  Reply With Quote
Old 16th August 2010, 08:59 PM   #109
NicMac is offline NicMac  Italy
diyAudio Member
 
NicMac's Avatar
 
Join Date: Feb 2009
Thanks Brian,
I will try this combination when the Ventus becomes available again.
I'm doing my best to understand why so many people hate op-amps
I seem to understand that the Ventus as added value can give me back a bit of the gain that I lost by bypassing the gain stage on the Hypex modules.
Cheers,
Nic
  Reply With Quote
Old 16th August 2010, 09:45 PM   #110
needsp is offline needsp  United Kingdom
diyAudio Member
 
Join Date: Jun 2006
Quote:
Originally Posted by NicMac View Post
Hi Paul,
What are you using for BAL/SE conversion? I seem to recall that you are using a single ended power amp.
Cheers,
Nic
Hi Nic

Just the op amp stage provided

Paul
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Buffalo DAC+IVY+OPUS+Dual PS for sale huskydawg9 Swap Meet 13 6th February 2010 02:33 AM
Buffalo DAC, IVY, LCBPS pdrie Swap Meet 2 24th July 2009 03:44 PM
Twisted Pear Buffalo/IVY/LCBPS/LCDPS Hacker Swap Meet 6 26th February 2009 04:57 PM
FS: TwistedPair Buffalo DAC+IVY+LCBPS VT67 Swap Meet 3 23rd February 2009 10:38 PM
Twisted Pear Buffalo Dac and Ivy modules - built - for sale phrarod Swap Meet 3 17th January 2009 02:25 AM


New To Site? Need Help?

All times are GMT. The time now is 09:11 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2