Low-distortion Audio-range Oscillator - Page 47 - diyAudio
Go Back   Home > Forums > Design & Build > Equipment & Tools

Equipment & Tools From test equipment to hand tools

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 24th September 2012, 02:58 PM   #461
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
I made some changes to improve DC balance and reduce DC offset. I added C3 to block the DC offset of U1, and I increased R4 and added R5. DC offset on the outputs of both U1 and U2 are now the same at about 12uV. The value of R3 is a function of the specific transformer used. Bass response can be extended by careful selection of this resistor's value. If it's too high, then a really big resonant peak appears at less than 1Hz, whereas reducing it progressively reduces the peak to eventually a flat extended response with what appears to be a second order roll off. In simulation I changed it to 18 ohms and bass response extends to 4Hz.
Attached Images
File Type: jpg mixed feedback v1.1.JPG (55.6 KB, 203 views)

Last edited by dirkwright; 24th September 2012 at 03:05 PM.
  Reply With Quote
Old 24th September 2012, 03:09 PM   #462
davada is offline davada  Canada
diyAudio Member
 
Join Date: Jul 2004
Location: Fort St John, BC Canada
I wonder if something like this would work for this application.
The transformer would take the place of the ADC in this schematic.


David.
Attached Images
File Type: png untitled.PNG (105.2 KB, 185 views)
__________________
David.
  Reply With Quote
Old 24th September 2012, 03:32 PM   #463
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
Quote:
Originally Posted by davada View Post
I wonder if something like this would work for this application.
The transformer would take the place of the ADC in this schematic.


David.
You can simulate it and find out, but I don't think the results will be better.

Speaking of the OPA1632, I I see that it can accept single ended or balanced inputs. I have the PCM4222EVM board from TI that uses this amplifier with XLR combi (accepts XLR or phone plugs) jacks on the board. Would you know how I would connect a single ended source to this board? Do I use a single ended phone plug? I'm lacking some information on this. Thanks.
  Reply With Quote
Old 24th September 2012, 07:03 PM   #464
davada is offline davada  Canada
diyAudio Member
 
Join Date: Jul 2004
Location: Fort St John, BC Canada
Quote:
Originally Posted by dirkwright View Post
You can simulate it and find out, but I don't think the results will be better.

Speaking of the OPA1632, I I see that it can accept single ended or balanced inputs. I have the PCM4222EVM board from TI that uses this amplifier with XLR combi (accepts XLR or phone plugs) jacks on the board. Would you know how I would connect a single ended source to this board? Do I use a single ended phone plug? I'm lacking some information on this. Thanks.
Short the pin that connects to the inverting input to ground and your good to go.

David.
__________________
David.
  Reply With Quote
Old 24th September 2012, 07:07 PM   #465
diyAudio Member
 
s3tup's Avatar
 
Join Date: Dec 2004
Location: Israel
Loosing a half (3dB) of ADC's potential... I've shorted the pin to ground at RCA-XLR adapter i've made, at RCA's end - so i've got a bit of wire compensation.
__________________
The missing link between lead and gold in alchemist's world was BS and commerce.
  Reply With Quote
Old 24th September 2012, 07:09 PM   #466
diyAudio Member
 
Join Date: Jun 2005
Location: Zürich
Quote:
Why do designers put 2x1.0 kOhm resistors in series when a perfectly good 2.0 kOhm resistor is available?
Perhaps lower voltage and power coefficient (i.e. less distortion contribution from the resistor).

Samuel
  Reply With Quote
Old 24th September 2012, 07:11 PM   #467
davada is offline davada  Canada
diyAudio Member
 
Join Date: Jul 2004
Location: Fort St John, BC Canada
Quote:
Originally Posted by dirkwright View Post
You can simulate it and find out, but I don't think the results will be better.

Speaking of the OPA1632, I I see that it can accept single ended or balanced inputs. I have the PCM4222EVM board from TI that uses this amplifier with XLR combi (accepts XLR or phone plugs) jacks on the board. Would you know how I would connect a single ended source to this board? Do I use a single ended phone plug? I'm lacking some information on this. Thanks.
I'm not looking for better just simpler. If one IC can do it then it's better than two.

The standard is a regular phone jack shorts the inverting pin if they set it up this way.

David.
__________________
David.

Last edited by davada; 24th September 2012 at 07:15 PM.
  Reply With Quote
Old 24th September 2012, 08:09 PM   #468
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
How do I control the gain of this oscillator from Linear Technology? I just ordered the parts. I want to try it out, but I don't need 20V output!
Attached Images
File Type: jpg LT oscillator.JPG (61.6 KB, 173 views)
  Reply With Quote
Old 24th September 2012, 08:11 PM   #469
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
Quote:
Originally Posted by s3tup View Post
Loosing a half (3dB) of ADC's potential... I've shorted the pin to ground at RCA-XLR adapter i've made, at RCA's end - so i've got a bit of wire compensation.
Ah, that's a good idea, thanks.
  Reply With Quote
Old 24th September 2012, 10:03 PM   #470
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
Quote:
Originally Posted by dirkwright View Post
How do I control the gain of this oscillator from Linear Technology? I just ordered the parts. I want to try it out, but I don't need 20V output!
Do I put an attenuator after the LT1029?
  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
Radford Low Distortion Oscillator Series 2 audiomik Equipment & Tools 21 19th February 2014 10:46 AM
ultra-low distortion audio oscillator geekysuavo Analog Line Level 16 26th March 2013 03:04 PM
Low distortion oscillator? rjm Equipment & Tools 30 4th May 2011 10:45 PM
Can we improve this low distortion sine oscillator ? gaetan8888 Solid State 22 29th March 2009 12:30 PM
Simple, low distortion 1kHz oscillator jackinnj Solid State 4 6th October 2003 03:58 AM


New To Site? Need Help?

All times are GMT. The time now is 06:19 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