Recapping Sansui 881 - 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 9th December 2009, 09:41 PM   #1
wicked1 is offline wicked1  United States
diyAudio Member
 
wicked1's Avatar
 
Join Date: Jan 2008
Location: Midwest
Default Recapping Sansui 881

I'm recapping an old sansui 881 for my dad. It was his first big stereo purchase. He gave it to me back in the 80's and I abused it through the 90's. It's been stored away in my basement for over 10 years now and my dad tells me he wants an amp to use w/ his MP3 player.. Perfect solution! He was unbelievebly excited when I mentioned it to him.

So, it's full of electrolytics. I definitely need to replace the power supply caps (buzz), and I think I'll probably just recap the entire thing so he can use it trouble free for the next 20 years...

I blew a fuse in it when I was a kid, and stuffed aluminum foil in its place. When I took the amp apart the other day I noticed some resistors on one channel on the driver board are completely burned up. Somehow the amp still works and both channels sound the same! Looks like I'll be replacing some resistors too.


I've got one question.. There are some low value electro's in here, 1uf and below, in the audio path. Any reason to put electro's back there, or should I use film in their place?
  Reply With Quote
Old 9th December 2009, 10:29 PM   #2
diyAudio Member
 
Join Date: May 2005
Location: toronto
Yes small caps below 1uf can be replaced with plastic film - polyester and even beter- The new small Wima polypropelenes
  Reply With Quote
Old 10th December 2009, 07:36 AM   #3
diyAudio Member
 
east electronics's Avatar
 
Join Date: Jan 2006
Location: Athens GREECE
often a wise choise is to use again good quality electrolytics but bypass them with filpm polyester polypropylene or even better smd styroflex which is hard to find but work very good and also are very easy to instal ....

then again there is a few other things you can do and some info may be found here ....

vintage amplifier repair/upgrade manual
__________________
SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr
  Reply With Quote
Old 10th December 2009, 05:43 PM   #4
wicked1 is offline wicked1  United States
diyAudio Member
 
wicked1's Avatar
 
Join Date: Jan 2008
Location: Midwest
I've got a question about the main power supply caps.. they are 500v 10kuf, 40mm. I want to replace them w/ 40mm caps, so they fit in the clamps.

I can't find anything of similar specs! (well, I was hoping to order everything from digikey, but I don't have to). All I can find at digikey in that size are 60 to 100v capacitors. The B+ (or whatever its called for solid state (im used to tubes)) is only 32 volts.

So, can I go with caps that much lower in voltage rating? Or, can someone suggest a place to purchase some large (about 1.5" wide x 4" tall) capacitors?

Thanks
  Reply With Quote
Old 10th December 2009, 08:26 PM   #5
wicked1 is offline wicked1  United States
diyAudio Member
 
wicked1's Avatar
 
Join Date: Jan 2008
Location: Midwest
So yeah, they're 50v caps.. the schematic im looking at has a typo....
  Reply With Quote
Old 10th December 2009, 09:01 PM   #6
wicked1 is offline wicked1  United States
diyAudio Member
 
wicked1's Avatar
 
Join Date: Jan 2008
Location: Midwest
Found some more! schematic labeled 4.7uf, and there's a 47uf on the pcb! (and this is the official sansui repair manual)
  Reply With Quote
Old 11th December 2009, 07:59 AM   #7
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
To be sure about the power supply rails, disconnect the transformer and measure the AC output of the secondary windings - from that, AC * 1.42 = rail voltages. The old capacitors could be sufficiently dried out that they are loading down the supply.

I had a quick Google for the 881 and noticed there seems to be a few different versions judging by the pictures I've seen. That could explain why your service manual doesn't match up.
  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
Recapping PS in a Hafler DH-101 gil1 Solid State 26 30th May 2012 08:45 PM
recapping Threshold SL-10 vendo81 Pass Labs 4 3rd November 2010 02:26 AM
recapping peace brainerd Everything Else 3 20th February 2006 07:26 PM
Recapping optimization? kyrochan Solid State 0 26th October 2005 03:16 PM
Recapping questions MikeA57 Solid State 1 24th March 2005 08:57 PM


New To Site? Need Help?

All times are GMT. The time now is 10:13 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