|
Amp/Preamp Asylum Looking for a new Amp or Preamp? If you're after tubes, post over here. |
For Sale Ads |
Use this form to submit comments directly to the Asylum moderators for this forum. We're particularly interested in truly outstanding posts that might be added to our FAQs.You may also use this form to provide feedback or to call attention to messages that may be in violation of our content rules.
Original Message
RE: I don't think you need to do that
Posted by Ugly on June 3, 2017 at 09:30:52:
Thank you for your replies. They are very much appreciated. I had some ideas about things to try but it sure instills confidence to talk to someone who has tried some of this stuff.
The plan all along has been to make it easy to try either ground referenced or floating referenced servos via jumper setting.
My desire to leave the servos referenced to a floating , non ground node was triggered by these fully balanced/differential op amps, apparently targeted at the audio market, such as the OPA1632.
These parts have integrated servos to set output common mode voltage. The app notes suggest common usage being tying the Vocm pin to the ADC reference. To my mind this implies there are must be audio market ADC's out there using external non ground voltage references.
My concern is that if I wanted to use one of these ADC's and I had my front end servos referenced to ground I may exceed the common mode range of my of my output stage under certain large signal swing circumstances.
My thinking was that floating front end servo references or tying it to my own version of a Vocm reference pin and an output stage that allows setting output common mode voltage (similar to OPA1632 et al) gets me around that problem.