VERY simple heaphone amplifier - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 April 2004, 09:53 PM   #1
diyAudio Member
 
sparkle's Avatar
 
Join Date: Oct 2003
Location: middle of nowhere...
Smile VERY simple heaphone amplifier

Hi!
This thread is for people that still don't have a nice little headphone amplifier and don't want to spend a lot of money to get one.
Amplifier below is VERY cheap and it works nice for me. I use it with my MBQuart QP450 Professional as a portable amplifier when I work on my computer or somewhere I don't need Hi End but good sound. They are 300 Ohms. My friend use this amplifier with his Grado SR80 with even better sound.
The circuit is very simple (the idea comes from my friend he use the same topology only a little bit bigger to drive his loudspeakers- thanks Darko).
He gets all the credits.
Regards
daniel
Attached Images
File Type: jpg sch.jpg (24.4 KB, 820 views)
  Reply With Quote
Old 20th April 2004, 09:57 PM   #2
diyAudio Member
 
sparkle's Avatar
 
Join Date: Oct 2003
Location: middle of nowhere...
some pictures:

The output cap's are Roe 2200uF/40V - nothing special. Cap's in power supply are 4700uF Matshushita- all of them. I have a little hum from the power supply so one should consider a better power supply
Attached Images
File Type: jpg p4200021_1.jpg (62.9 KB, 811 views)
  Reply With Quote
Old 20th April 2004, 09:59 PM   #3
diyAudio Member
 
sparkle's Avatar
 
Join Date: Oct 2003
Location: middle of nowhere...
some more:
Attached Images
File Type: jpg p4200026_1.jpg (36.2 KB, 659 views)
  Reply With Quote
Old 20th April 2004, 10:01 PM   #4
diyAudio Member
 
sparkle's Avatar
 
Join Date: Oct 2003
Location: middle of nowhere...
Potentiometer is blue burns and the wires are silver with teflon insulation......
regards
daniel


p.s. it is not an high end but it works very nice - so nice that no one could complain about it- it has everything what a nice little amp should have in a sound and it is CHEAP
  Reply With Quote
Old 20th April 2004, 10:10 PM   #5
diyAudio Member
 
Join Date: Jul 2001
Location: The Netherlands
Hi Sparkle,


250mA bias and 47K//47K resistor ... shouldn't that be 47R//47R?

greetz,
Thijs
  Reply With Quote
Old 20th April 2004, 10:13 PM   #6
Account Disabled
 
Join Date: Apr 2003
Location: US
one small suggestion to you: split the collector resistor into, and connect the pot to the junctionof the two resistors. This way, there is certain level of feedback to maintain very stable bias for the transistor.

the schematic is posted under "simple preamp". except that I used just one mosfet but you can try various medium power bjts with no ill effect.
  Reply With Quote
Old 20th April 2004, 10:57 PM   #7
azira is offline azira  United States
diyAudio Member
 
Join Date: Dec 2003
Location: Near Seattle
Nice simple CE amp...

1uF input capacitance seems kind of low. Using 2.5k impedance to gnd you would have a cutoff around 60Hz... I think you might want to raise that to 5uF or 10uF.

Do you hook up the headphone reversed polarity like on the zen amps?
  Reply With Quote
Old 21st April 2004, 02:02 AM   #8
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Thumbs up Interesting , i like it

Good looking machine..... wood made it full of "class"
very good!

Carlos
__________________
This Sunday assemble a toy amplifier....a good fun to your weekend; https://www.youtube.com/watch?v=yk0qvkwsAOY
  Reply With Quote
Old 21st April 2004, 05:04 AM   #9
diyAudio Member
 
sparkle's Avatar
 
Join Date: Oct 2003
Location: middle of nowhere...
OOOPPS!
Resistors are two 47R/5W in paralel
Millwood - thanks....
Azira- I have thought to add little more of the input cap. Thanks for the suggestion.


I have forgotten to say - my recitifier diodes are MR824 form motorola and input cap is wima 1uF (will change that to something bigger.
regards
daniel
  Reply With Quote
Old 4th September 2006, 01:50 PM   #10
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north

nice little project, sparkle!
Very!

for headphones amplifiers are many ways to go
from
- very advanced Op-amp based
- extremely complicated discrete amplifiers
to
- simple 1 OP-amp circuit
- a few transistors
- one single power transistor follower ( buffer )

I like this project.
You have built any other amplifiers?
Or new version of this one?

PICTURE of Circuit in box:
Click the image to open in full size.

regards
lineup
__________________
lineup
  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
Heaphone Amp rshep Solid State 4 23rd July 2009 02:50 AM
Heaphone Amplifier question olvrkrg Chip Amps 17 19th January 2007 11:19 AM
Beginner's heaphone amp? mr_push_pull Tubes / Valves 9 17th December 2004 02:19 AM


New To Site? Need Help?

All times are GMT. The time now is 10:25 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