25W almost finished - 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 6th September 2003, 03:53 PM   #1
iceman is offline iceman  Sweden
diyAudio Member
 
Join Date: Jun 2003
Location: Gothenburg
Send a message via MSN to iceman
Talking 25W almost finished

I'm almost finished with my amp now. I should put the headphone amp in the case to, then I'm finished.
What I wonder is:
Should I use the transformer i use to the 25W Amp (18-0-18 before rectifie) and regulate the power to headphone-amp(-+ 5-15 V) withex:lm7812 & lm7912 or should i use a seperate PS to the headphone ?
__________________
"Quis custodiet ipsos custodes?"
  Reply With Quote
Old 6th September 2003, 04:49 PM   #2
diyAudio Member
 
JOE DIRT®'s Avatar
 
Join Date: Apr 2003
Location: Brantford, ON
I would leave the headphone amp separate to avoid crosstalk in the enclosure especially if its compact

DIRT®
  Reply With Quote
Old 6th September 2003, 05:24 PM   #3
sam9 is offline sam9  United States
diyAudio Member
 
sam9's Avatar
 
Join Date: Jun 2002
Location: Left Coast
If the headpone amp is based on high performance opamp(s) or another Self based design, the curcuit itself should be pretty much resistant to cross talk via the PS. I would take care that that amp input signal wiring and both in and out signal wiring for the headphone amp be shielded.

Using the same transformer makes sense with the following provisos. I've read that to get good results the power rails should be at least 3V higher than the regulator output. The next ios unlikely to be an issue but . . . . Are you going to use the headphones and power amp at the same time? If so, be sure the VA rating is just a smidgen greater than needed. Not much headphones don't draw that much current, just be sure you aren't already "at the edge".
  Reply With Quote
Old 6th September 2003, 05:30 PM   #4
diyAudio Member
 
Jan Dupont's Avatar
 
Join Date: Apr 2003
Location: Copenhagen, Denmark
Send a message via MSN to Jan Dupont
I will go with sam9

Use the sam transformer with seperate bridge and caps for each amp. No need to make space for yet another toroid/transformer.
__________________
Free Schematic and Service Manual downloads www.audio-circuit.dk, Company: www.dupont-audio.com, Joint venture: www.DupontMantra.com
  Reply With Quote
Old 6th September 2003, 06:33 PM   #5
iceman is offline iceman  Sweden
diyAudio Member
 
Join Date: Jun 2003
Location: Gothenburg
Send a message via MSN to iceman
Smile Thanks

Thanks for the answer/reply

I go for the same transformer for both amp's.

Joe Dirt:No it's not compact. the case is width=19" and height=2UH deep=10". Lot of space

Sam9: The headphone amp is based on OPA2134, and it's not my design. I think people call it "cmoy"
And no, i dont use the headphone and amp at the same time.
I gonna put a switch to select speaker/headphone
__________________
"Quis custodiet ipsos custodes?"
  Reply With Quote
Old 7th September 2003, 12:26 AM   #6
sam9 is offline sam9  United States
diyAudio Member
 
sam9's Avatar
 
Join Date: Jun 2002
Location: Left Coast
The OPA134 has pretty good power supply rejection. So long off PCB wiring keep input signals away from the power supply and other signal sources you are not likely to have a problem.
  Reply With Quote
Old 8th September 2003, 03:57 PM   #7
iceman is offline iceman  Sweden
diyAudio Member
 
Join Date: Jun 2003
Location: Gothenburg
Send a message via MSN to iceman
Default picture

Joe Dirt:
Here's a picture of the amp inside.
I draw a line where i want to put the headphone-amp.
As you can see there is lot of space in the case.
Attached Images
File Type: jpg inside_2.jpg (37.2 KB, 400 views)
__________________
"Quis custodiet ipsos custodes?"
  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
finished sub chainenoble Subwoofers 2 20th September 2007 08:11 PM
Finished Sub eag Subwoofers 5 19th April 2006 11:09 PM
Finished my GC! drfrink24 Chip Amps 19 17th March 2005 02:58 PM
Here's my finished DIY (yet another one...) ChesterFuzzin' Multi-Way 2 22nd April 2003 06:02 PM


New To Site? Need Help?

All times are GMT. The time now is 04:15 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