Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 30th January 2011, 04:52 AM   #3621
diyAudio Member
 
Join Date: Jan 2006
Location: North East
Its coming from your squeezebox I believe. I had a similar problem. If you connect one or both (L or R) of the outputs with rca cables from your squeezebox to your preamp you will eliminate the problem (even though you will use the outputs of the dac not the squeezebox)
  Reply With Quote
Old 30th January 2011, 03:36 PM   #3622
Jim W is offline Jim W  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Brookfield, WI
Quote:
Originally Posted by Bill Fuss View Post
You don't see any windings grounded on their schematic, do you. You are shunting the output signal to ground. The output is plus and minus, not plus and ground. The shell of the RCA is referenced to ground at your preamp, it should not be grounded to the dac circuit.

Please remove those grounds and turn your output trafos in a different direction, or possibly turn your power trafo a different direction.
Make sure the yellow output lead is connected to your RCA connector shield, and the orange lead is connected to the RCA connector center. From the sound if it, I wonder if it's possible that you haven't done that and what you're actually listening to is the capacitive leakage across the transformers. The loud hum is what makes me wonder if you've got the transformer mis-connected.
Jim
  Reply With Quote
Old 30th January 2011, 04:59 PM   #3623
sendler is offline sendler  United States
diyAudio Member
 
Join Date: Aug 2004
Location: ny
Default absolute phase

Quote:
Originally Posted by Jim W View Post
Make sure the yellow output lead is connected to your RCA connector shield, and the orange lead is connected to the RCA connector center. From the sound if it, I wonder if it's possible that you haven't done that and what you're actually listening to is the capacitive leakage across the transformers. The loud hum is what makes me wonder if you've got the transformer mis-connected.
Jim
What difference does it make which leg of the tranformer output leads gets pulled to ground?
__________________
Scott
  Reply With Quote
Old 30th January 2011, 05:10 PM   #3624
diyAudio Member
 
Join Date: Sep 2004
The hum problem is already solved (post 3620)

Jenses is conected according to Jensen doc - brown on input is +, and red is -, on the output orange is + and yellow is -
  Reply With Quote
Old 31st January 2011, 01:12 AM   #3625
Jogi is offline Jogi  Germany
diyAudio Member
 
Join Date: Jan 2008
Hi,

accidently I have a gigawork dac on loan, and am mighty pleased by it, even with the stock configuration. It is a bit too tame then, but still good, regarding the electrolytics in the output...sacrilege...
Then of course the itch to fiddle or solder or both came up, and first I kicked out the Buffer opamp, sound opened up already. Then soldered 4 wires from the input of the 2,2 F caps close to the dac-board (they are not in the path now) directly to the RCAs, and from there to the Pass DCB1 I am using.
I pulled out the other opamp, and left everything else as it is. Measured zero DC at the output, so I gave it a try and I am thrilled now. Very transparent and musical
But my question is: am I doing anything wrong? No transformer, and no cap in this case, but I am wondering where the 2,5 VDC went. They are still over those 2,2 caps.
Is it possible that the B1 is doing what a transformer is doing?
Any comments?
Cheers,
Juergen
  Reply With Quote
Old 31st January 2011, 01:50 AM   #3626
Jim W is offline Jim W  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Brookfield, WI
Quote:
Originally Posted by sendler View Post
What difference does it make which leg of the tranformer output leads gets pulled to ground?
Nothing, except for inverting the phase if you're inconsisent from primary to secondary.

Jim
  Reply With Quote
Old 31st January 2011, 07:25 AM   #3627
diyAudio Member
 
Join Date: Dec 2003
Location: Sydney
Quote:
Originally Posted by Jogi View Post
Hi,

accidently I have a gigawork dac on loan, and am mighty pleased by it, even with the stock configuration. It is a bit too tame then, but still good, regarding the electrolytics in the output...sacrilege...
Then of course the itch to fiddle or solder or both came up, and first I kicked out the Buffer opamp, sound opened up already. Then soldered 4 wires from the input of the 2,2 F caps close to the dac-board (they are not in the path now) directly to the RCAs, and from there to the Pass DCB1 I am using.
I pulled out the other opamp, and left everything else as it is. Measured zero DC at the output, so I gave it a try and I am thrilled now. Very transparent and musical
But my question is: am I doing anything wrong? No transformer, and no cap in this case, but I am wondering where the 2,5 VDC went. They are still over those 2,2 caps.
Is it possible that the B1 is doing what a transformer is doing?
Any comments?
Cheers,
Juergen
you'll find the answer here...

Building a symmetrical psu B1 buffer

Boky
  Reply With Quote
Old 2nd February 2011, 11:38 AM   #3628
sendler is offline sendler  United States
diyAudio Member
 
Join Date: Aug 2004
Location: ny
Default Listening for the best attenuator load for direct out dacs

I listened to my AKM and CS direct out dacs to find the best load for a new stepped attenuator design. I like them into 15k the best. Read about it here.
.
Listening for the best attenuator load for direct out AKM and CS dac chips
.
__________________
Scott
  Reply With Quote
Old 5th February 2011, 03:21 AM   #3629
diyAudio Member
 
AdamThorne's Avatar
 
Join Date: Oct 2006
Location: Los Angeles, CA
Pardon me if this has already come up... but has the price jumped on the gigawork dac?

I had been saving my pennies for the dac, I think it was $90 or so, without the transformer. Now all I see in the ebay store is $120 (+ extra $10 for shipping).

Is this just a momentary quirk of the Gigawork store, or is that the way it is now? Is the transformer in the kit worth the extra price? It was mmm.... Jan 20 or so I last saw it w/o the trafo.
  Reply With Quote
Old 5th February 2011, 07:13 AM   #3630
tvicol is offline tvicol  Romania
vicol-audio.ro
diyAudio Member
 
tvicol's Avatar
 
Join Date: Jan 2005
Location: Bucharest
Send a message via Yahoo to tvicol Send a message via Skype™ to tvicol
Quote:
Originally Posted by sendler View Post
I listened to my AKM and CS direct out dacs to find the best load for a new stepped attenuator design. ...
.
An r-2r/shunt stepped atenuator project is also presented here Yet another Volume controlers and source selections

Regards,
Tibi
  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
A.O.S - Any experience? Keltern Multi-Way 16 26th April 2012 11:15 PM
my t-amp experience Eggzy Chip Amps 35 17th December 2005 06:29 PM


New To Site? Need Help?

All times are GMT. The time now is 02:25 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