Sony saw40 sub problem - 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 November 2006, 10:53 AM   #1
diyAudio Member
 
Join Date: Aug 2006
Default Sony saw40 sub problem

Hi

I just brought a second hand Sony saw40 subwoofer. at low volumes the sub sounds alrite, (unsure of how it should sound). But as the volume is increased it seems to make a strange noise, as if the sub is bottoming out or clipping. ( Im sure its not bottoming out) This seems to only occur at some frequencies am thinking of replacing the filter capacitors and rectifying diodes incase something is faulty in this area. I may also replace the two power Transistors ( mn2488 & mp1620) with replacement type ( 2sd2488 & 2sb1620 )

Does anyone know what this noise could be? Is it a good idea to replace the 6800mF with 8000mF. Or would it be best to put the new caps in paralel with the old ones for more capacitance.

Thanks in advance for any input.

Scott Drake
  Reply With Quote
Old 14th November 2006, 11:33 AM   #2
diyAudio Member
 
Join Date: Aug 2006
Hi

I have now replaced the output transistors and the power rectification diodes. I started the sub up and YES there is much less of this "clipping noise" at high volumes. But im still not fully satisfied with the performance. As this is quite an old sub would it be best to also replace the filter caps with ones i previously talked about?

Would i put these caps in paralel with the old ones for more capacitace or just simply replace them?

Please help


Scott Drake
  Reply With Quote
Old 16th November 2006, 10:12 PM   #3
gni is offline gni  United States
diyAudio Member
 
gni's Avatar
 
Join Date: Sep 2006
Default Replacement Caps

If you are going to take the time to work on the Caps. . .replace them!

If they are in the Power Supply, it will clean up ripple and give a
better, stable DC voltage for the amplifier to amplify.

I would check for mechanical issues. . .especially in a sub.

Chris
  Reply With Quote
Old 17th November 2006, 02:17 AM   #4
diyAudio Member
 
Join Date: Aug 2006
Hi - Thanks for the reply, what do you mean by mechanical issues? what should i be looking for?
  Reply With Quote
Old 17th November 2006, 02:29 AM   #5
gni is offline gni  United States
diyAudio Member
 
gni's Avatar
 
Join Date: Sep 2006
Default Mechanical Issues

A subwoofer by nature must move a large volume of air
in order to produce sound at low frequencies. The bolts that hold
the woofer in place can come loose. The driver itself can "ring."
Parts on the driver (solder plates) can buzz and rattle. The box
itself may be old and the glue is failing. The electronic parts may
be vibrating and adding noise to the output.

All can be solved. . . gentle pressure to various part while operating
can usually detect the mechanical vibration. . . gunk the bad areas
with something to deaden the vibration.. . sheetrock screws work
well for glued cabinets that are coming apart.

That about does it. Had "noise" problems with a pair of JBLs a few
years ago. . .did all the above. . .and gave another 6 years of life to a
pair of loudspeaker.

Chris
  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
Sony DTC-790 dat problem dukasound Digital Source 2 3rd October 2008 05:33 PM
Sony V-Fet Amp TA-N7B problem Bernhard Solid State 62 2nd March 2005 12:28 PM
Problem on SONY CD Player CDP-203 DeeGee Analogue Source 1 26th December 2003 08:23 PM
sony amp problem supes Solid State 3 1st February 2003 08:09 PM


New To Site? Need Help?

All times are GMT. The time now is 08:26 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