Sansui QSD-2: Need help with parts list

QuadraphonicQuad

Help Support QuadraphonicQuad:

par4ken

2K Club - QQ Super Nova
QQ Supporter
Joined
May 28, 2011
Messages
2,598
Location
NW Ontario
Hehe yeah I only ment that one of those transistors possibly makes my SQ program pop and crackle, preventing me from listening to Mike comfortable in SQ. Other that that, the little SQ decoding i have actually heard between the crackle has been superb. They state a 12 db separation compared to much higher figures on QS, but to be honest I'm content and very impressed indeed.
Check the switches too. Deoxit works great. Dirty switch contacts are the biggest cause of crackle and pop.
 

kissklas

Member
Joined
Oct 27, 2022
Messages
31
Location
Norway
I have covid now....its brutal. 4 X Vaccinated, on the anti viral drug, type O blood and Dutch! I am the best case, I would hate to go through this unprotected.
Oh no... Had it previously... The sickness itself is bad enough, but the 3 weeks after for me was the worst part. Brain doesn't work, body doesn't work. Just a foggy mess and you're not even "sick" anymoreπŸ˜’
 

kissklas

Member
Joined
Oct 27, 2022
Messages
31
Location
Norway
Check the switches too. Deoxit works great. Dirty switch contacts are the biggest cause of crackle and pop.
First thing i did was the pot rowπŸ‘ initial thought when i heard the crackle was the pots, but no help, also it only crackles on SQ. They are really good pots though. Not a sign of scraping or anything after, what, 45 years? My Tandbergs needed a damn exorcism at age 50. Holy water and all.
 

par4ken

2K Club - QQ Super Nova
QQ Supporter
Joined
May 28, 2011
Messages
2,598
Location
NW Ontario
Well, where are you supposed to keep it otherwise? Gotta keep my Mastercard chilled.
A friend of mine kept his credit cards in the freezer, frozen in a block of ice. That way it had to be a real emergency, he would have to wait for them to thaw out giving him time to reconsider if the purchase was warranted or not!
 

kissklas

Member
Joined
Oct 27, 2022
Messages
31
Location
Norway
Thats OK, my brain is a foggy mess normally anyway
Haha yeah not gonna say I would be surprised to find my wallet in the fridge eitherπŸ€”
A friend of mine kept his credit cards in the freezer, frozen in a block of ice. That way it had to be a real emergency, he would have to wait for them to thaw out giving him time to reconsider if the purchase was warranted or not!
That is genious. I go for the approach of not having credit cards at all. Save up, and dump it all into 50 year old electronics and vinylπŸ˜‚
 

kissklas

Member
Joined
Oct 27, 2022
Messages
31
Location
Norway
Nah, the BC549 is pin compatible and available everywhere
Ordered a strip of these! Hopefully that sorts the SQ mode out. The sound has already improved dramatically after running the recapped boards for a few days. The clarity and detail is back to around where it was before I introduced the QSD-2 into the setup. I guess there may be more room for improvement in the noise department by replacing the power supply caps too.
 

kissklas

Member
Joined
Oct 27, 2022
Messages
31
Location
Norway
1669031555535.png
1669031799439.png

D'oh! Didn't notice this. Guess I'm crossing legs anyways:LOL:
At least its just the B and C, so It won't be a game of twister.
 

kissklas

Member
Joined
Oct 27, 2022
Messages
31
Location
Norway
When I had this problem, instead of crossing legs, I turned the transistor upside down and bent the legs around.
Good idea. I guess ot won't be a major problem anyways, since it looks like the holes are laid out in a triangle formation and not straight down. Some room to work with.
 

kissklas

Member
Joined
Oct 27, 2022
Messages
31
Location
Norway
Finally got around to replace the resistors in the AUX current divider of the amp today, and wow that made a huge change. There is actual headroom on the volume knobs now!
And I don't risk blowing my speakers, or ears, when changing over to the TV which is niceπŸ˜‚

If the winds keeps blowing from the south east and the moon is bright tonight, the mailman may make it alive over the mountains and into my fjord with the transistors tomorrow. The lady is out for a few hours as well so it sounds like a beer and soldering night☺️
 

kissklas

Member
Joined
Oct 27, 2022
Messages
31
Location
Norway
Well damn. Problem is still there. Any other SQ only part in here that could be an issue? I see there are some caps on the power board that seems to only be activated by the SQ mode. I guess it could be leakage or something.
 

kissklas

Member
Joined
Oct 27, 2022
Messages
31
Location
Norway
Ok thats every single electrolytic replaced, everything from 10uf and below with film! You couldn't fit any more in there without a hammerπŸ˜‚

It's now dead quiet, not a hint of anything but the signal. Like new I suppose is the term!

BUT...

the SQ mode still pops and crackles! I'm about to go mad. I'll go hide the hammer.

Could I have burnt one of the transistors during solder? It was only a second. Maybe it was a dud from the factory?

I see there are some diodes on the phase board that is switched on by the fifth position (SQ)... can they cause such noise?
Screenshot_20221126-222555.jpg
 
Top