vinylisfinyl
Member
Greetings, fellow AK'ers,
I have a Sansui 990DB that I have been slowly revitalizing over the past couple of years. Overall the unit is in great shape with clear, balanced sound out of both channels, but the bass leaves a lot to be desired. No matter what speakers I've connected it to, the bass is there but really lacks "punch". I've tried Electro-Voice Sentry III's, the 15inch woofers in a Magnavox console stereo, and Dayton Audio B452s, and all had the same results. Cranking up the Bass tone control adds some bass but nothing significant.
My research here suggests the main filter capacitors may be causing this. Using my Tenma 72-10465 LCR meter I found that both of them are at the bottom of the tolerance spec (~9,100 uF on both, they are 80V 12,000 UF) and dissipation factor was around 0.62-0.65 which is rather high. Seems these may be on their way out. I've gone through all the other capacitors on the driver, equalizer, power, and tone control boards and only found one that had drifted high (now replaced).
Before I order new main filter caps (which are NOT cheap!), I'm curious if others have experienced this with their Sansui's, and if the filter cap replacement fixed it. I can't think of anything else that would cause thin bass when all the other caps and controls are functioning as expected.
Thank you!
I have a Sansui 990DB that I have been slowly revitalizing over the past couple of years. Overall the unit is in great shape with clear, balanced sound out of both channels, but the bass leaves a lot to be desired. No matter what speakers I've connected it to, the bass is there but really lacks "punch". I've tried Electro-Voice Sentry III's, the 15inch woofers in a Magnavox console stereo, and Dayton Audio B452s, and all had the same results. Cranking up the Bass tone control adds some bass but nothing significant.
My research here suggests the main filter capacitors may be causing this. Using my Tenma 72-10465 LCR meter I found that both of them are at the bottom of the tolerance spec (~9,100 uF on both, they are 80V 12,000 UF) and dissipation factor was around 0.62-0.65 which is rather high. Seems these may be on their way out. I've gone through all the other capacitors on the driver, equalizer, power, and tone control boards and only found one that had drifted high (now replaced).
Before I order new main filter caps (which are NOT cheap!), I'm curious if others have experienced this with their Sansui's, and if the filter cap replacement fixed it. I can't think of anything else that would cause thin bass when all the other caps and controls are functioning as expected.
Thank you!
