These monster receivers are heavy, the massive power transformer is the reason why. I have a Pioneer SX-D7000 on the bench right now and every time I need to flip it or reposition the thing, it feels like I'm going to blow out my spine
Hi Trevor, I've got a 747 on my bench and your video series is giving me tons of insight for working on it. I've got several of the same issues you fixed on yours. I've just started watching the third episode. I wanted to thank you for your very watchable videos and the professional work you do. I'm still in the check out mode right now. Keep up the great work and thanks again for your efforts.
I grew up in the sixties and seventies. The best and last cartridge made for quadraphonic was called Empire no longer made but made by the same manufacturer as Stanton cartridges also used for quad recordplay in the 80s.
Magnificent final conclusion to the QX. Quads, there will always be 1 speaker (usually rear) that does not get as loud. Wish I could have bought it from ya. Enjoyed your turn table fiasco, why........brought back memories of how much I dislike vinyl, had about 300 LP's and had enough with distortion in late 1970's to 1985. CD's and Tape only.
Hi Trevor, good job! I got the same unit on my bench. When biasing, where you placed the 5k1 resistor? Between input and ground of each power amp section? In series with the signal path?
Hi Trevor, Sorry if I missed it but where did you terminate the input terminals of the power amplifiers with 5.1k resistors for the amplifier adjustments?
I didn't. Generally, disconnected inputs is just fine. The Amplifiers already have a 100k termination to ground on the inputs, adding a 5.1k won't make any difference
Hi Trevor - thanks for the detailed videos. I happen to have a QX-747 on my bench right now. Recapped power supply first and all seemed to be working well except for a weak right phono channel (complex circuitry for phono on this one due to 4-channels I assume) Ended up being a bad cap on the Matrix Circuit Assembly board (not the first place I would look!) I have a question about the scope. My left rear lamp shows a very slight "dot" at all times and the right rear does not. As far as I can tell, the lamp is working, wondering if this Is this a bulb alignment issue? I'm not too excited about pulling that unit out if I don't have to. Any first steps to consider before major disassembly? Keep up the great work!
Hi Jeff. The lamps in the meter assembly need to be aligned with the holes or the light won't come through. It's easy to remove the lamp board then you can shine a flashlight through to see if it's working or not. It's not difficult to open it up, just one screw in the center and the back cover comes off and you will be able to inspect the shutters to see what's going on
Hola saludos desde Caracas Venezuela. Tengo un receiver Pioneer mod QX 747 y no se cómo conectar un ecualizador y un reververador Pioneer podrían decirme cómo lo puedo hacer? De antemano muchas gracias por su atención.
Nice job Trevor you could switch the l and r channel of the phono so you had the unbalance switched I bet the distortion came from the cardridge. And dusty adjust pots. Well there are only a view Quadro phonic recordings. But no phono 4 channel cardridges anymore. Over 100 caps replaced... Lol. Nice 3 videos
@@TrevorsBench I do a lot with vinyl and did setup a test record and did 4 test tones on the output of my mm phono stage (course messuring at the cardridge is deadly) and focused the signals with the antiscating settings on my rega planar 3-24 course the turntable arm has got two absolute tracking points there I set the balance 100% fixed. And with your table hhmm bit tatty use the left channel of the phono and adjust it in the left and right channel of your pioneer. Hope you get better results course 4 channel amps are very rare.
hi Trevor, thans for the great video's. I noticed the dailpointer emediatly. I have replaced my sx1010 dailpointer with a smd led, works good and bever burn! keep them video's comming. Peter.
Hi Trevor, I have been making great efforts to increase my knowladge about vintage equipment in the last two years. I enjoy watching your very useful videos that you have created by spending your time and effort on this subject. I am learning very good thinks. Thanks for all. I am also curious as to how is the quadrophonic soynd exprience. I have a Sansui model FR5080 TT. It is four channel TT. It has SV-40X (VM Type, dual coil or magnet) 4-channel cartridge and SN-40X diamond stylus. I think they call this 4-channel stylus a SHIBATA type. It has a special tip structure. I want to sharethşs information for a sincere contribution. Best regards, Murat
Hi Murat. Thanks for the info. Good to hear you're following your interests in vintage audio, there's so much to explore & learn. I hope you get your chance to hear 4 channel sound. Cheers
The finish line! Great job on this receiver; that was quite a project. It sounds really good as well, that CD4 alignment looks to be a bear that consumes a great deal of time. Is this one going into your personal system or on the market? Thanks for your time and for posting this series.
Hi Craig, I think I'll keep it for a while and keep my eyes open for a CD-4 record at the sales. I still want to experience full 4 channel sound. Maybe later I'll sell it
@@TrevorsBench Trevor, you'll need a phono cartridge that has a specific frequency range for the CD-4 record in order to adjust the alignment on the 747. I had a 949 way back when and I remember that specific thing for the CD 4 to work properly.
Yeah, tests are only as good as your test equipment. The cheap recordplayer might also have an antiskating not set properly, favoring one side of the stylus. I do believe with a better recordplayer, You'd get better results. BTW, that Harman Kardon ST7 does look pretty sexy, heh. I always wanted one with linear tracking. Getting that one fixed would make a really good video, i think. Thanks for this video. I love when i have the chance to watch interesting, epic length videos; epic in terms of youtube video lenth. Some coffee and relaxing watching *thumbs up*
Good to hear you're enjoying the edited down versions of my vids, lol. Now that i've looked at the HK ST-7, it seems pretty messed up, might be a epic length vid to get that all sorted It would make a good project for the cold winters we have here in Canada
Great video! very interesting and informative actually they all were.👍👍👍
Thanks, more to come
Hk looks cool!
Thanks, keep a eye out for the vid for this
Have ever repaired a Pioneer SX1980 the weight alone.
These monster receivers are heavy, the massive power transformer is the reason why. I have a Pioneer SX-D7000 on the bench right now and every time I need to flip it or reposition the thing, it feels like I'm going to blow out my spine
Hi Trevor, I've got a 747 on my bench and your video series is giving me tons of insight for working on it. I've got several of the same issues you fixed on yours. I've just started watching the third episode. I wanted to thank you for your very watchable videos and the professional work you do. I'm still in the check out mode right now. Keep up the great work and thanks again for your efforts.
I grew up in the sixties and seventies. The best and last cartridge made for quadraphonic was called Empire no longer made but made by the same manufacturer as Stanton cartridges also used for quad recordplay in the 80s.
Magnificent final conclusion to the QX. Quads, there will always be 1 speaker (usually rear) that does not get as loud. Wish I could have bought it from ya. Enjoyed your turn table fiasco, why........brought back memories of how much I dislike vinyl, had about 300 LP's and had enough with distortion in late 1970's to 1985. CD's and Tape only.
Top and methodic work! Congrats! That’s oursrtanding professional performance!
Hi Trevor, good job!
I got the same unit on my bench.
When biasing, where you placed the 5k1 resistor? Between input and ground of each power amp section? In series with the signal path?
TREVOR ALWAYS LIKE TO SEE TURNTABLES REPAIRED SINCE THEIR SO POPULAR TODAY AND ITS GOOD FOR MUSICIANS TO MAKE MONEY AGAIN OFF VINYL
Ok Tina, thanks for the feedback. I'll need to get to work then
Hi Trevor, Sorry if I missed it but where did you terminate the input terminals of the power amplifiers with 5.1k resistors for the amplifier adjustments?
I didn't. Generally, disconnected inputs is just fine. The Amplifiers already have a 100k termination to ground on the inputs, adding a 5.1k won't make any difference
Smoker's paradise. At least 2 packs a day right next to it for years. It's looking nice now though.
Thanks, yeah it was one of the worst I've seen
Excellent work.
Hi Trevor - thanks for the detailed videos. I happen to have a QX-747 on my bench right now. Recapped power supply first and all seemed to be working well except for a weak right phono channel (complex circuitry for phono on this one due to 4-channels I assume) Ended up being a bad cap on the Matrix Circuit Assembly board (not the first place I would look!)
I have a question about the scope. My left rear lamp shows a very slight "dot" at all times and the right rear does not. As far as I can tell, the lamp is working, wondering if this Is this a bulb alignment issue? I'm not too excited about pulling that unit out if I don't have to. Any first steps to consider before major disassembly? Keep up the great work!
Hi Jeff. The lamps in the meter assembly need to be aligned with the holes or the light won't come through. It's easy to remove the lamp board then you can shine a flashlight through to see if it's working or not. It's not difficult to open it up, just one screw in the center and the back cover comes off and you will be able to inspect the shutters to see what's going on
Hola saludos desde Caracas Venezuela. Tengo un receiver Pioneer mod QX 747 y no se cómo conectar un ecualizador y un reververador Pioneer podrían decirme cómo lo puedo hacer? De antemano muchas gracias por su atención.
Nice job Trevor you could switch the l and r channel of the phono so you had the unbalance switched I bet the distortion came from the cardridge. And dusty adjust pots.
Well there are only a view Quadro phonic recordings. But no phono 4 channel cardridges anymore.
Over 100 caps replaced... Lol.
Nice 3 videos
Hi digger, good idea about switching channels, why didn't I think of that. I was surprised it worked at all considering my turntable setup. Thanks!
@@TrevorsBench I do a lot with vinyl and did setup a test record and did 4 test tones on the output of my mm phono stage (course messuring at the cardridge is deadly) and focused the signals with the antiscating settings on my rega planar 3-24 course the turntable arm has got two absolute tracking points there I set the balance 100% fixed.
And with your table hhmm bit tatty use the left channel of the phono and adjust it in the left and right channel of your pioneer.
Hope you get better results course 4 channel amps are very rare.
hi Trevor, thans for the great video's. I noticed the dailpointer emediatly. I have replaced my sx1010 dailpointer with a smd led, works good and bever burn!
keep them video's comming.
Peter.
Hi Trevor,
I have been making great efforts to increase my knowladge about vintage equipment in the last two years. I enjoy watching your very useful videos that you have created by spending your time and effort on this subject. I am learning very good thinks. Thanks for all. I am also curious as to how is the quadrophonic soynd exprience. I have a Sansui model FR5080 TT. It is four channel TT. It has SV-40X (VM Type, dual coil or magnet) 4-channel cartridge and SN-40X diamond stylus. I think they call this 4-channel stylus a SHIBATA type. It has a special tip structure. I want to sharethşs information for a sincere contribution. Best regards, Murat
Hi Murat. Thanks for the info. Good to hear you're following your interests in vintage audio, there's so much to explore & learn. I hope you get your chance to hear 4 channel sound. Cheers
The finish line! Great job on this receiver; that was quite a project. It sounds really good as well, that CD4 alignment looks to be a bear that consumes a great deal of time. Is this one going into your personal system or on the market? Thanks for your time and for posting this series.
Hi Craig, I think I'll keep it for a while and keep my eyes open for a CD-4 record at the sales. I still want to experience full 4 channel sound. Maybe later I'll sell it
@@TrevorsBench Trevor, you'll need a phono cartridge that has a specific frequency range for the CD-4 record in order to adjust the alignment on the 747. I had a 949 way back when and I remember that specific thing for the CD 4 to work properly.
Yeah, tests are only as good as your test equipment. The cheap recordplayer might also have an antiskating not set properly, favoring one side of the stylus. I do believe with a better recordplayer, You'd get better results. BTW, that Harman Kardon ST7 does look pretty sexy, heh. I always wanted one with linear tracking. Getting that one fixed would make a really good video, i think. Thanks for this video. I love when i have the chance to watch interesting, epic length videos; epic in terms of youtube video lenth. Some coffee and relaxing watching *thumbs up*
Good to hear you're enjoying the edited down versions of my vids, lol. Now that i've looked at the HK ST-7, it seems pretty messed up, might be a epic length vid to get that all sorted
It would make a good project for the cold winters we have here in Canada
wrong video... sorrry....
I need someone smarter than me. ypu're too young.
Thank you very much for your video 73 kg4acg