qx949 sub channel board adjustment

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falcon123

New member
Joined
Apr 28, 2018
Messages
3
Location
angeles city rp
hi fellas greetings from the philippines. i rebuild pioneer stereos from the 70's as a hobby.currently im waiting for caps and transistors to rebuild a qx949. i owned one of these new in '74 and tho 4ch never really succeeded i have a soft spot in my heart for this receiver. the one i have was rather beat up but cosmetically it will regain its former beauty. the seller said it didnt work but after a deoxit treatment to all the switches it all still works without any snaps crackle's or pops. of course the thing is loaded with 2sa725's and 2sc1312's that will all need replacement during the recap for longevity. the fly in the oatmeal as it were,is the service manual only lists adjustment for vr1 and vr10 for the cd4. there are 8 other vr's that will all need adjustment after that board is rebuilt. do any of you fella's know what the procedure is for adjusting this board? or failing that, can you point me to someone who does? i am an active member in audio karma and have posted this question in the pioneer forum but havent yet received any useful replies any and all comments are welcome,regards JOHN
 
Unfortunately Jim passed away a few weeks ago. He was a great resource

As for adjusting the other pots in the cd4 circuit, take a look at the Akai 980 and the Akai 1080 service manuals. I’m not sure which chipset the QX949 uses but maybe the instructions in the Akai manuals will be helpful. I have a Sansui QRX 8001 which uses the CD392 chip and the Akai 1080 uses it also. I have not attempted the adjustment as yet but will try soon.
 
my set was built in march '74. as such it has 3 chips, a single m5109p and two m51361p chips. as i was reading about your business you prefer stacked film caps, so do i, whenever they physically fit. but it looks like the end of the line are up to wima 10mfd. your site seems to suggest that there are others or did i not read it thoroughly?
 
I’m sorry, I am not affiliated with QRXRestore. Just passing along some info. It looks as if the Akai 980 uses the CD 894 chip and the 1080 has the CD 392. Is the chips u mentioned Pioneer specific?
 
Different question about the same model.

When I push in the hi and low filters on my qx949 on of the speaker outputs dies.

Same speaker every time. Is this a d oxit fix or a whole new world?
 
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