NE5532 Headphones Preamplifier/Amplifier with EQ - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Headphone Systems

Headphone Systems Everything to do with Headphones

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 18th August 2011, 09:44 AM   #11
diyAudio Member
 
afternath's Avatar
 
Join Date: Dec 2010
Location: TOULOUSE
120Gohms for input impedance
  Reply With Quote
Old 22nd August 2011, 04:43 PM   #12
diyAudio Member
 
afternath's Avatar
 
Join Date: Dec 2010
Location: TOULOUSE
Quote:
Originally Posted by Anteaus View Post
D8, D9 are the wrong way. They need to be in the conducting direction. The way you have it, smoke instead of sound as the output pair will conduct hard.

Also, You may need to select the diodes to give the required quiescent current, as there is a fair tolerance on diode characteristics. Too little and you will have distortion at low sound levels, too much and the output stage will run hot.

As for the supply. I'd be inclined to either use a single-rail design, or if you have AC available, a proper dual rail design. Having the signal lines at non-ground potential could lead to all sorts of issues. Not to say it won't work, but he who ventures onto untried ground... finds out whether it works or not, and maybe saves others the trouble!

Carbon resistors are quite OK unless you are working at millivolt levels such as on a mic input. Metal film are preferable for audio circuits, though.

Finally, the standard and most important advice in amp design, watch how you return your grounds to common. If the load returns its current to the PSU via a wire shared with a signal ground, you will have instability. Keep them separated and you are OK. This is one of the things that can't be determined from a schematic, but where actual physical wiring matters.

HTH.
Yes, there is a mistake D8 & D9 are reversed.

What do you mean by single rail supply? I'm using 12VDC unregulated power outlet.

About OP07 I have several ones.

For the grounding, i see i'm disturbing some people with virtual ground, but i said i don't like manipulate main power, and IMO placing a transformer or using double 9V batteries for a little headphone amplifier is makes me sick.

I don't understand your advice when you say separate signal ground, can you show me an example?
  Reply With Quote
Old 22nd August 2011, 04:57 PM   #13
Mooly is online now Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
To me a single rail design implies an AC coupled amp... and there's nothing wrong in that

Virtual grounds are fine as any point or potential can be called "ground" and all signals etc referred to that one point. Where it gets interesting is whether the "virtual ground" has the ability to source and sink much current. In other words does the amp running from it behave as a DC coupled amp with the ability to supply and source DC into the load (which is a valid output from a DC coupled amp) or does the virtual ground rely on for example a couple of resistors with large electrolytics across them, in which case the DC coupled amp can not supply significant DC current to a load.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  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
FS: Dispre JFET line (headphones) preamplifier supernet Swap Meet 12 3rd October 2011 08:59 AM
Preamplifier with NE5532 for CAR Audio Szabadember Chip Amps 22 21st May 2011 12:14 AM
Best portable amplifier headphones Kashtan Headphone Systems 6 22nd January 2011 06:46 PM
Amplifier for headphones Sponkii Chip Amps 52 20th January 2009 06:07 PM
Simple Headphones Amplifier Chrisv1983 Solid State 7 22nd June 2004 10:02 AM


New To Site? Need Help?

All times are GMT. The time now is 08:31 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