Go Back   Home > Forums > Amplifiers > Chip Amps
Home Forums Rules Articles Store Gallery Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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 30th March 2005, 08:16 PM   #1
diyAudio Member
 
costiss's Avatar
 
Join Date: Dec 2002
Location: greece
Cool my view on a 549 amplifier (photos)

thats my readily finished opa 549 amp, built quite differently from the gainclone trend. .that is: 200VA +IXYS screw terminal bridges (320A peak) + 44000uF for each channel in a dual mono config.. sounds really good.. and features considerable bass extension and volume.. imaging is really beyond critic, with acurate represantation of depth, heidth, and width.. detail to the most.. really satisfactory result..
Click the image to open in full size.
__________________
i am currently using 60,000 uF of capacitance in my preamplifier..
  Reply With Quote
Old 30th March 2005, 08:24 PM   #2
diyAudio Member
 
costiss's Avatar
 
Join Date: Dec 2002
Location: greece
heres another one
Click the image to open in full size.
__________________
i am currently using 60,000 uF of capacitance in my preamplifier..
  Reply With Quote
Old 30th March 2005, 08:26 PM   #3
diyAudio Member
 
costiss's Avatar
 
Join Date: Dec 2002
Location: greece
and yet another..
Click the image to open in full size.
__________________
i am currently using 60,000 uF of capacitance in my preamplifier..
  Reply With Quote
Old 30th March 2005, 11:19 PM   #4
diyAudio Member
 
uvodee's Avatar
 
Join Date: Aug 2002
Location: Washington
Default euh euh

schematics or link to them please....


thank You

J-P
  Reply With Quote
Old 31st March 2005, 12:48 AM   #5
diyAudio Member
 
I_Forgot's Avatar
 
Join Date: Jan 2005
Location: Phoenix, Az.
Hooray! Let's hear it for good engineering sense in amp construction!

My LM3886 amp has 108,000 uF (4x 27,000) in the power supply and it sounds fantastic. At these voltages capacitors are cheap. If you want decent bass, you need a stiff power supply.

You might want to go to PCBs as they will prevent things from moving around and possibly shorting with disastrous results. Otherwise, keep up the good work! I recently replaced my hay-wired LM3886 stuff with PCBs and now I rest a little easier...

I commend you!

I_F
  Reply With Quote
Old 31st March 2005, 11:39 AM   #6
diyAudio Member
 
costiss's Avatar
 
Join Date: Dec 2002
Location: greece
theres no schematic.. its simply a 549 in non inverting topology with a gain of 4,9, set with 1k & 3k9 resistors.. no input cap - you see, its not needed, with 5 mV of offset - bypassed with 470u elna starget at the crimped juction at the supply pins, with a bus ground topology on the chip, connected with an ample gauge to the star ground.. i prefer hard wired on those easy circuits, coz its easier to make contacts really heavy duty.. im happy to see people are using some SERIOUS capacitance at the psu.. and i ve tried it with 1000u, and its not worth the fuss.. in contradiction, this setup, (with heavy duty psu and cabling) sounds much more serious and real - accurate to me... im using 2x22000uF 63v per channel (nippon chemicon u32d), and dont think theres a better at the range for this one (was also using rifa and it just didnt sound right - bit too dry), except maybe for the nice elna for audio caps, that are in the same league, maybe a bit more laid back and warm...
__________________
i am currently using 60,000 uF of capacitance in my preamplifier..
  Reply With Quote
Old 1st April 2005, 08:06 AM   #7
getafix is offline getafix  Philippines
diyAudio Member
 
getafix's Avatar
 
Join Date: Jun 2003
Location: somewhere in Mandaluyong
Quote:
Originally posted by costiss
theres no schematic.. its simply a 549 in non inverting topology with a gain of 4,9, set with 1k & 3k9 resistors.. no input cap - you see, its not needed, with 5 mV of offset - bypassed with 470u elna starget at the crimped juction at the supply pins, with a bus ground topology on the chip, connected with an ample gauge to the star ground.. i prefer hard wired on those easy circuits, coz its easier to make contacts really heavy duty.. im happy to see people are using some SERIOUS capacitance at the psu.. and i ve tried it with 1000u, and its not worth the fuss.. in contradiction, this setup, (with heavy duty psu and cabling) sounds much more serious and real - accurate to me... im using 2x22000uF 63v per channel (nippon chemicon u32d), and dont think theres a better at the range for this one (was also using rifa and it just didnt sound right - bit too dry), except maybe for the nice elna for audio caps, that are in the same league, maybe a bit more laid back and warm...
a schematic would really help for us non-elecrical engineering types
__________________
forever dreaming of a better set-up...
  Reply With Quote
Old 1st April 2005, 09:32 AM   #8
diyAudio Member
 
Join Date: Aug 2003
Location: Prague,Czech Republic
And whatabout fuses, Costiss ? " 320 A " can also go to load . Is for you problem to make some simply PCB for this amp ? And whatabout some repairing ?
  Reply With Quote
Old 1st April 2005, 11:16 AM   #9
diyAudio Member
 
costiss's Avatar
 
Join Date: Dec 2002
Location: greece
heres the schematic...
i dont use fuses, coz the best contact is no contact.. that is, i didnt mean to havent even more series resistance on my supply rails.. 320A is the rectifiers peak current capacity.. the psus peak current capacity is about 30A.. i dont worry about speaker protection.. i dont use a pcb, coz i think its a better solution (and more pure) for such circuits... i have a series resistance, on the supply rails from the bridge to the chip, less than 20mOhms..
Attached Images
File Type: jpg opa.jpg (22.6 KB, 749 views)
__________________
i am currently using 60,000 uF of capacitance in my preamplifier..
  Reply With Quote
Old 1st April 2005, 11:30 AM   #10
diyAudio Member
 
Join Date: Aug 2003
Location: Prague,Czech Republic
Yes, you have compromisless rails, which ended in very compromis integrated amp . Nothing evil , but stand by both foots on ground .
  Reply With Quote

Reply


Hide this!Advertise here!

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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
A Sneak Pre-View of NX400NL Sub-Woofer Amplifier The Saint Vendor's Bazaar 5 1st October 2007 07:31 PM
Photos of almost finished amplifier. vynuhl.addict Solid State 18 11th May 2007 08:57 AM
Need help to view images...Please rcavictim Everything Else 10 22nd March 2005 09:33 AM


New To Site? Need Help?

All times are GMT. The time now is 09:35 AM.

Page generated in 0.12407 seconds (76.04% PHP - 23.96% MySQL) with 11 queries

Copyright ©1999-2012 diyAudio