noisy opamps - Page 2 - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, 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 20th August 2004, 03:51 PM   #11
sam9 is offline sam9  United States
diyAudio Member
 
sam9's Avatar
 
Join Date: Jun 2002
Location: Left Coast
Quote:
you can get 3nV/sqrtHZ instead of 18nV/sqrtHZ if you use opa227 instead of TL072
Yup. The OPAx227 and OPAx228 families are a possability as well. From the application, I suspect that in most cases the opamp is being used at unity gain, which means the OPA227 is preferred, but if the gain is >5, the data shgeets say OPAx228 is prefferred. **Check the datasheets as I might have that bassakwards!!** While you are looking at the datasheets, note that these families have some limits on the input currents that can be used without damaging the device - you are probably safe - but check. The data sheets app notes also contain info on how to get the best results from these devices so read them a couple of times.

It's not my intent to send the guy off to buy new equipment, but I think that kind of application is potentially better achieved with digital rather than analog technology. If I were interesting in something like this I would be looking for a digital version working at 24/96 or better.
  Reply With Quote
Old 20th August 2004, 06:31 PM   #12
djQUAN is offline djQUAN  Philippines
diyAudio Member
 
Join Date: May 2004
Location: manila
Send a message via MSN to djQUAN Send a message via Yahoo to djQUAN
well, if you have the extra money, you could just buy a gate. and set the threshold to cut off the noise when there is no music playing.
  Reply With Quote
Old 20th August 2004, 06:59 PM   #13
diyAudio Member
 
Join Date: Jul 2001
Location: The Netherlands
I see in the TL072 datasheet that below 400Hz the input noise rises... to 20 even 40nV/sqrtHz .. the opa227 has a far more flat noise curve.... that's I still think you could consider using opa227 opamps to try to improve S/N.


g'luck,
Thijs
  Reply With Quote
Old 20th August 2004, 07:05 PM   #14
p53 is offline p53  Germany
diyAudio Member
 
Join Date: Mar 2004
Location: Hamburg
@ sam

Quote:
Originally posted by sam9


It's not my intent to send the guy off to buy new equipment, but I think that kind of application is potentially better achieved with digital rather than analog technology. If I were interesting in something like this I would be looking for a digital version working at 24/96 or better.
The problem is, that there is nothing similar in the digital world! I know a lot of this hardware/software "Exciters" and "Spectralizers" but they do not the same thing. They all sound harsh. A Fletcher-Munson correction with digital equalizers (OK, Ive heared only the software solutions) also does sound "unnatural". And I can ensure you that Im not an analog freak.
  Reply With Quote
Old 20th August 2004, 07:13 PM   #15
p53 is offline p53  Germany
diyAudio Member
 
Join Date: Mar 2004
Location: Hamburg
Quote:
Originally posted by djQUAN
well, if you have the extra money, you could just buy a gate. and set the threshold to cut off the noise when there is no music playing.
well the noise is not that bad. I think 78 db S/N is a realistic value. I just wanted to have 86 db
  Reply With Quote
Old 21st August 2004, 06:02 AM   #16
dayvel is offline dayvel  United States
diyAudio Member
 
Join Date: Nov 2003
Location: Martinez CA
I'm pretty sure that the LM13700Ns *are* in the signal path being used as VCAs or VCFs. They are horrid little things. There is no drop-in upgrade.
  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
Help with noisy fan artcarmo Solid State 7 9th March 2009 07:34 AM
noisy noisy noisy noisy noisy tube dsavitsk Tubes / Valves 50 20th February 2006 05:07 PM
FS: Power Chip OpAmps and other OpAmps & D to A Converter dtm1962 Swap Meet 4 12th January 2006 11:07 PM
How can i use a noisy PSU ? Garbz Solid State 5 3rd January 2004 01:15 AM
ESP P3A amp, very noisy DaViruz Solid State 33 16th November 2002 07:07 PM


New To Site? Need Help?

All times are GMT. The time now is 03:45 AM.


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