How to repair Sansui AU-7700 Integrated amplifier Channel out or weak 

I bought an Sansui AU7900 with a couple of slightly bent heat sinks. I was able to get them back in shape and looks almost perfect. The Phono channels were doing exactly as you described. The fix was exactly the same, but to get to it was a lot simpler. Thanks for the video.

I have a Sansui AU-9500 from 1976 that has never had the cover off. Still is amazing amp.

So nice to see how well built these old Japanese amps were built. Friggin smashing job on troubleshooting and explaining the facts of customer amp repair. Keep on a rockin' Terry, and say "Hi" to Marsha for me, you're a lucky dude.

Well done, Terry!! Thank you for your service too!

Only got to this now--excuse my procrastination; I didn't choose wine and crackers; I poured a Stella, had a slice of cheese and some Hard Bite chips. These videos are one of the best things going anywhere ... only I'd like to see a video one or two hours, maybe even a three or four hours, with a possible intermission with some of that music you sometimes engratiate us fans with. An Academy Award might be in the offing.

Nice Terry! Following orders. Sansui made some outstanding amplifiers back in the day. B2300 sound quality still impresses me to this day. Servicing some of the high end Sansui's is complicated, reminds me of working on an old Jaguar.

LOL! Now I know why you rather work on Tube gear, rather than these S.S. nightmare(ish) printing boards and tiny soldering spots. Great methodology to eliminate possible sources of the problem! I have learn a lot from your videos Terry! Thanks for the inspiration and detailed tutoring.

You're a nice guy and a very competent and honest technician, thanks for sharing!

Great video! It fit to a T for my problem on my AU-5500. Same channel (Right), same mode (Aux 1), and same problem (intermittent). I watched this three times before I got into my amp ---- my first reflow of a PCB ever. But every works perfectly now. Thanks again!

great vids terry, thanks for your shares, not many people do this stuff anymore, you have a great utube voice easy to hear, easy to understand, hopefully your vids will help to keep this art alive

Yep, been doing electronics for over 25yrs and still enjoy a challenge of repairing or building audio equipment.. I would say us old techs have a valid skill set..

good job D lab watched alot of videos from you that got me inspired to fix eletronics 😊👍i finally acomplished my first repair

A trick to lessen stress on the jacks when plugging or unplugging cables: twist the RCA plugs in a rotary fashion as you push them on. Don't wiggle them side-to-side, that's how you stress the solder connections. The rotary motion also tends to wipe dust and oxidation off of the jack and plug..

Had the same problem on the same unit. Turned out to be those molex plugs where corroded and the solder joints on the RCA plugs . Changed all the caps while I was in there . This is an amazing sounding unit .

You are the man! Thanks for fixing another fine piece.....

Wow after all these years problem solved, I got the same one same problem. Thank you .

Great job Terry!

I friggin hate the Suits who told the engineers to put jacks, etc directly on to circuit boards to save money. There should never be an opportunity to put mechanical stress into a circuit board. Jacks should be mounted on a chassis!

Nice job.. wow not much for cooling / heatsinks there... but a NICE amp and great to have a look at how it's built. Great that you take a little time to reflow the rest. I'll take that advice and thanks !

I'm liking the Solid State Sinema nearly as much as the Tube Amp Theatre ... Cool beans Terry!

Ok, I have watched the whole video. I like this guy! 👍👏🏼

I love solid state cinema. Cracks me up!🐿️

Hello, I have an equal amplifier, inherited from my father, with great sentimental value. With the same problem, thanks, it was an excellent explanation about the problem and how to fix it. I only hope to find in my country someone with your experience so that they can fix it for me. I like your style. Continue following videos. I have a Dual 601 turntable that does not rotate, if you repair a similar one, share it

That's a nice piece. Would love to have a refurbished one. I've got a Carver 900 from the late 80s that could probably use a good recapping.

Terry. You have GOT to stop making this look so easy! :-) Thumbs up, and thanks again for the content.

Greetings Terry, I have this same amp and have owned it since 1978. Since this time I have been in there at least 3 times to fix the same repeat problem. I got in there by removing the output board underneath, guess there is more than one way to skin a cat. Resoldering won't fix it in the long term, it will fail again. I was thinking of some way to give more support to the jack and relieve the stress on the solder joint. JB weld came to mind, but seemed kind of tacky, excuse the pun. I did fix my son's Hafler 110 preamp by drilling and dremeling the board and putting stud mounted RCA jacks with bus wire jumpers to the board. Never use those monster turbine style interconnects on these amps! I need to get in there and solder it up again, Ughhhh!

My Sony STR-7045 (original owner, parents) from 1973 is awesome af - my daily runner for EVERYTHING (home studio, I am freak guitarist, and all else - since I was born) - just put DC offset to +/- 1 mV from about 30, each channel, yesterday! It screams I tell you, no joke. Part of the reason too is that my main speakers is Marshall cab that I rewired to stereo (try it!!!!!) too. B speakers are 3-way home stereo Sony SS-U 431 AV, modest but kickass nice nonetheless. Anyhow, the RCA connections are not soldered to the board. They are just mounted to the rear of the case, with leads coming off them to the board. I DID have to DeOxit them and get all up in them with Q-Tips to get them perfect but that is much much better design than having to resolder, however easy that may be. Nice video D-Lab!!! I want to somehow put 1/4" jacks for the Aux1 instead, as that would pair lovely with my MOTU Traveler interface - it is in my thoughts to do list. I probably won't do it because of keeping it original, but I want to hahaha.

love your videos

Mau contato e sujeira são um os piores problemas que a gente enfrenta......Bom trabalho !!!!!

This is what Walter white does after breaking bad..still skilled as ever!!! Salute boss.

I own the same one. Have the switches doing the same thing, some of the switches go in and out with one side or both but if I wiggle the switch then its works fine!

Good morning teacher I love your videos go my like always... Marcos from BRAZIL

Great fix Terry!!! I love the humor you put in it, or is that from drinking a little wine? No pro .................I love wine tooo....much???

10:00 Did you see that trace on the circuit board that is cut? The blue shielded wire connects to it. Looks like perhaps it is a factory revision. Will have to look at my AU-7700 when I get it apart again.

great video! I have one of these AU7700 and it sounds great but also need to solder the aux connections I think. On another note two of the spring type speaker connectors are are broken how hard to replace or fix these?

It’s me that sure looks easy. I’m Derk l Really appreciate you fixing this for me 😁😁😁👍👍

I like the older stereo systems they were built way better in my opinion.

You need to put together a small wine room and equip it with a small sound system. Wish I could have enjoyed a glass before hitting the bench with some of the equipment that used to come into the shop I worked at in the past. Abuse and DIY repairs. Made for a bad day.

another great video/ thanks! what track/artist is that at about 13:18? sounds cool.

Any chance you might do a service repair one of the great late 1970s Technics, like the SA-800 or SA-1000?

I have the same amplifier from my father.. loved the amp and it's sound .. problem is spkr relay engages seconds after amp has done warm up .. can't find schematics to repair..

At 7:50 is the point where my boss would be yelling at me to put some masking tape on the top edge of the front faceplate, and put a towel underneath that rear panel so it doesn't scratch the unit in a place that would be visible to the owner of the unit. It's true that often times I think it'll be a quick fix, and the back panel can sit where it's sitting for a minute, and then I'll be putting the thing back together, so I don't really have to worry about it; but I'm units this old, invariably there's something else wrong that you discover during the course of repairing the most obvious main issues, and therefore the unit stays in a disassembled state, with floppy metal parts tethered by wiring harnesses and laying all over the place, for rather a bit longer than you originally expected or intended.

I remember laughing at the Sansui joke, but you seemed to have a good point at the time, because that one had so much glue on the board components.

hi... i have sansui au d33 can you please make a video to repair ... my amp is problem is sound Tranjistar is fail reign to high voltage ... please help to fix this problem..

Great repair and video ! - I've got a Sansui Z-9000 receiver that's has an intermittent channel , wonder if it's a similar problem?

Nice repair of an all too common problem. The vertical position of the RCA plugs probably caused or exacerbated the condition. Also, I'm sure there's a reason for your deliberate misspelling of "cinema". Something to do with sine waves, perhaps?

hola tengo un amplificador sansui modelo su-9500 y el problema que suena como trueno en el audio ambos canales con volumen a cero,nose cual sera esa falla espero que me oriente un poco saludo desde chile

I notice the chrome like surfaces have that nicotine yellow cast. I clean a lot of cigarette smoke out of vintage electronics. I suspect that the units from the 1960s on have other smoke on them too. ;-) Toss all the knobs in an ultrasonic cleaner with some alcohol for a good soak while you soak up an extra glass of wine! (Ain't I a stinker?)

Was there actually a caareer in thir force that had you repairing amps or what? Did you repair anything else??

made me laugh when you said 10 million screws love watching the videos old school stuff

More sir!

Simply stupendous.... seriously...:-)

Trimakasih atas petunjuknya...saya.dari indonesia,jakarta timur.. Saya juga punya amply SANSUI AU-7700, yang saya mau pertanyakan sdh sekian lama ada 15 tahun,amply saya tdk.dihidupkan...masalahnya 1. begitu power ON,timbul distorsi,gresek2,pada out speaker (saya pasang speaker 8ohm x2 )..masalah ke 2 apakah out put speaker Sistem A-B (L &R) ada tegangan keluar 87.4VAC ...apakah ini ada masalah di amply sansui saya..mohon petunjuknya ..trimakasih pak

I have a 5000x that I traded an Ampeg bass amp for in 1972

Wow you were Air Force, so just my guess you were either PML, Ground Com or Avionics Com Nav troop? I was an in shop avionics Comp Repair manual test station troop for the F15's back in the 70's and 80's so thanks for serving, Great site you have! heres my question, I have two stereo units that are getting old LOL like me and both starting to have what seams like same type issues you have on this video, one is a Technics SU-V10X with 120 watt per channel I ought in Iceland in 1986 sometimes the output relays fail to switch on when powered on it will have no out power, then at other times when it dose power on and work and I increase the volume to say 1/3 volume or more ( but not all the time) they click off and I loose one and sometimes power to both speakers, so was thinking it may be same issues you just showed here with bad solder connection? the other unit i have is an old Carver 130 watt per channel Receiver, it is really bad very very intermittent, seems that this unit by what I've read is well known to have had a really bad solder joint issue! do you have any advice if maybe I myself should just take them apart and inspect and resolder all the joints to see if that fixes them before, I see about sending them off to be fixed by some unknown repair place, I live up in New England ( Ma) so not sure who up this way would be able to do any repairs on this old stuff, so any suggestions be appreciated. thanks Bob

You are the Man Terry! Do you have any fail video's? Is there anything you haven't been able to repair? I doubt it, but it would be funny to see! Take care, Tom

I have yamaha component system but no sound coming out from it it just stock and when i use it it doesnt work whats the problem sir?

I just discovered how good vintage gear can sound BUT I do hate those old fashioned connectors.

easy amp to fix

Nice!! Nice to "coast" through your vids... :-) (soon)

is that wine any good? we should all start sending you some great wines along with the gear

Check the interconnects first!

Looks like avionics from Mitsubishi zero, Japanese rainbow steel remembe rs wwII I am sure.

🙂

How long did it take to fix all that?

Well done ole man..I could not have done any better. It does seem however, that old electrolytic caps last longer than the newer design...maybe due to power supplies or composition ? I gave my old 1975 england version kenwood quad for similar problem..weak front channels and crackles.. but at 75watts per it played wonderfully. I still have the quad vinyl lp s.. keep up the super show. Cudabigfish in Michigan , USA

Drinking golden wine and talking about an AU something-or-other Sansui. Coincidence? I think not!

3:20

Like Jeffery, it sounds like any hardware problems with jacks connected directly to circuit boards are going to cause cracking on the PC boards! Bad designs

👍👍😎✌️🤟

What's your opinion on the 1985-1990 integria onkyos

I'm more used to Marantz, this model does not seem very tech friendly

How can a cap get pregnant? A leaky dielectric?

Fix Mine!!!! Pleeeez???

Oh D-lab you're such a kick in the head XD

Au v7000 sansui amp men transistor number please. (I am Sri Lanka )

Now that's a real Sansui, back when they were made in Japan and not China

ha ha.....sanssewage. anyone remember magnavox? maggotbox was its moniker.

I have an amp in need of repair - you interested?

why not replace all the 45 year old electrolytics?

My AU-6600 has a hum when in Phono, a tech I took it to said just use a an external preamp. Eventually I did that, and it does work fine with the Turntable preamp going into Aux-1. Disassembly on these is tough, but let's face it, the RCA input design is awful!

Those pregnant caps were probably in their third trimester

It's always fun to see what you can achieve with a botle of wine (lol):-), as always thumps upp.

yes I hate the google police big deal if you want play a song

Maybe not sewage but not a joy to work on either.

You really should have installed a new henway while you were in there!

Clink clink goes the wheelie bin

Never liked amplifiers where they have the audio input connection facing upwards. Stupidest design ever to collect dust. Fortunately on the Sansui amplifier I have, AU-20000, they are facing back, like they should!!

I really hope your not drinking alcohol before working with electricity and electronics. That would not be the smartest thing to do as the warning labels say it can impair your ability.

Replace that goofy 12AX7 in there.