Preamp with LM1036N and TDA7050 - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 3rd June 2013, 04:14 PM   #11
diyAudio Member
 
Join Date: Jan 2013
other than the hiss is the headphone circuit working?
Yes, the circuit works as it should
is it quiet hiss in the background?
Yep, the hiss remains constant whatever the position of the pot
what position on the volume is loud but comfortable listening?
I can open the pot completely without hearing distortion or ruining my ears (sound is not too loud I mean with that)
Is the outside of the POT earthed?
The outside of the pot is connected with the ground plane of the pcb. You can see this at the pic of the PCB I've posted earlier. However, my pcb is NOT connected to the ground in the test setup.
have you tried an earthed metal plate underneath the PCB?
No, I haven't. Could you explain this a bit more ? Is the earthed metal plate for shielding ?

Again, thanks for your help and quick reply

Greetings
Cedric
  Reply With Quote
Old 10th June 2013, 07:41 AM   #12
blu_glo is offline blu_glo  England
diyAudio Member
 
blu_glo's Avatar
 
Join Date: Aug 2005
Location: London, England
Quote:
Originally Posted by cedric88 View Post
other than the hiss is the headphone circuit working?
[LEFT]Yes, the circuit works as it should
Good. So fundamentally it's working!

is it quiet hiss in the background?
[LEFT]Yep, the hiss remains constant whatever the position of the pot
So that's going to be noise from the TDA7050 which is a high gain chip. Not necessarily the best option for a headphone amplifier.....

what position on the volume is loud but comfortable listening?
I can open the pot completely without hearing distortion or ruining my ears (sound is not too loud I mean with that)
Don't forget the LM1035 volume will also affect the signal and possibly noise passed on to this chip! try with LM1035 VOL pot set to max, then halfway and note differences (if any).

Is the outside of the POT earthed?
The outside of the pot is connected with the ground plane of the pcb. You can see this at the pic of the PCB I've posted earlier. However, my pcb is NOT connected to the ground in the test setup.
OK. What value is the POT? Couldn't see it in your schematic. I might suggest 10K and not much more. Also a 100pF from each chip input to earth.

have you tried an earthed metal plate underneath the PCB?
No, I haven't. Could you explain this a bit more ? Is the earthed metal plate for shielding ?
Yes, shielding does help a lot especially where high gains are involved.
Again, thanks for your help and quick reply
Not a problem glad to be of assistance.

Greetings
Cedric

Last edited by blu_glo; 10th June 2013 at 07:50 AM.
  Reply With Quote
Old 10th June 2013, 11:36 AM   #13
blu_glo is offline blu_glo  England
diyAudio Member
 
blu_glo's Avatar
 
Join Date: Aug 2005
Location: London, England
Me: - OK. What value is the POT? Couldn't see it in your schematic. I might suggest 10K and not much more. Also a 100pF from each chip input to earth.

Sorry picked it out of the original, I assume you left it 22K which is not bad at all.... use ~100pf caps as previously mentioned on input pins.....
  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
LM1036N Potentiometer Type Hengy Analog Line Level 4 14th January 2013 08:20 PM
Tube Preamp Popping on Source Input Change (?) / 6DJ8 Preamp On Chip Amps MartyM Tubes / Valves 3 16th October 2008 04:52 AM
Guitar Preamp = MIC Preamp = other preamp ,,are they all same? Paswa Solid State 1 12th March 2008 05:16 PM
twisted pear Preamp/other suggestions for Preamp kit LukeDuke Chip Amps 1 1st February 2008 09:57 PM
Lm1036n Leolabs Solid State 1 4th April 2005 02:17 AM


New To Site? Need Help?

All times are GMT. The time now is 05:03 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