Sansui Seven

[playittwice]

Im getting ready take on the task of restoring/re-capping my Seven. I did some research on this receiver trying to find a BOM list, and the only thing I found was a thread by gslikker. I read through it several times and some of the replacement parts don't make sense to me. So I'm asking for a little help from you folks here. I did download the manual from Hifi engine. I'll be the first to admit I'm not confident enough yet to know what to replace the original components with as far as upping values. I.e. capacitance and voltages on EC's. So if anyone could assist me with a list or help guide me with what to use for replacements, that would be great. I would like to use all high quality components in this receiver to bring it back to its glory!

The help I've received in the past has been nothing short of excellent! I've learned more than I ever thought I would or could have! Sorry to bother you folks, but I would rather ask for help than mess up a nice piece of equipment. I just struggle with replacement values and types of replacements, like where to use films and different types of caps. I.e. Nichicon Muse here and Nichicon KL there or whatever the case. Not enough experience yet, but Im trying to get it.

Thanks,
Loren.

 

[KingBubba]

I can't help you with your question, but the Seven is well worth the time and or money to get back to like new condition. There are not too many of them around and that is why you are having trouble getting info. Another thing is the inside of the seven is not an easy one to get around from what I have heard. I have the Eight and the Eight Deluxe and as soon as I opened them, I knew I wasn't going to stick my hands in there. I would take or ship it to one of our repair gurus, If it were me. Try to see if anyone is in your vicinity. If you handle it yourself, you are a better man than I. Enjoy one of the best Sansui had to offer.

 

[playittwice]

Thanks BK, I havent opened mine up yet to really assess the complexity of it. I did have the complete face off of it to clean the switches and buttons, yes there is lots of small components in that area as well. Regarding the rarity of this piece, Im not sure, but have noticed theres not much discussion about them other than having sound reproduction that resembles the Eight Deluxe. I'll figure something out trying to re-hab it, or just enjoy it in the state its in for now. It truly is a awesome unit.

 

[gslikker]

Note: my own part replacements were based on guessing and "thoughts" and parts I have available.
So indeed, not at all take it as a guideline to what "should" be the correct replacements (according or not to AK consensus ;-)

At my unit, after a few years now, the pushbutton switches start acting up again and if not having used the receiver for a month or so.
I have to "finger tap" one or two of them a little in and out for the signal to behave.

Anyway, this receiver is still the running piece in my hobby room.

If I ever open it up again, I will also change the lamp switching, because one reason to have it is the looks.
I want the lights on even if not selected to tuner position.

 

[stereofun]

The best is to make your own list, since Sansui often made revisions during a production run, meaning someone else's list might have different values here and there. Best way is to open up Hifiengine.com, then initially use the values given to make a list for each board. I assume you are only doing the amp section and only electrolytics for now, except those tantalums we talked about.

You will only have 4 different boards to deal with including phono. Then ofcourse some supply caps.

Once list made out from Hifi engine, you just check board by board against what you actually have in the amp and update list with whats actually there (of course you don't fill out part numbers until last)
My lists typically looks like this - here in the notes you write any changes from original values and its a good idea to write down the lead spacing of the incoming film caps, just to make sure they can fit. The (M) or (D) indicates if the part number is from Mouser or Digikey


F-1439 DRIVER x 2

POSITION TYPE/VALUE REPLACEMENT PARTNUMBER NOTES
VR801 Trim / 5K Bourne 5 turn 5K xxx-xxx-xxx (M) upgraded to 5 turn, check orientation !
VR802 Trim / 1K ------------------ 1K xxx-xxx-xxx (M) ---------------------------------------------------
C801 Cap / 1.5/25 Wima MKS4 1.5/40 505-MKS4C041503F00KS (M) Input orig. Tantalum 1.5/25 - spacing 10 mm
C806 BP Cap 100/10 Nichicon Muse 100/25 647-UES1E101MPM (M) Feedback, orig 100/10
-------------------------------------------
Hopefully this can get you started. As for upgrading components left and right, I'd go easy. Use Film caps in the C801's (see part number above) - other than that I'd just use Elna silmic II in the pre-amp / equalizer and Nichikon PW in the power supply board F-1441 - As for main supply's I'd upgrade the 2 x 4700uf to Nichicon KG - 6800/63 could be a good choice (647-LKG1J682MESCBK). I would also up the feedback C806 in voltage a bit, see above.

Good luck and let us know with pics please.

P.S the list is nicely spaced and organized, but it doesn't show to well here. You get the drift ...

 

[playittwice]

Thanks for the advice and ideas on this project. I will keep you updated on my progress. As of now this amp is functioning perfectly since I cleaned all switches twice two years ago. So I have that going for me.
Should be a fun and challenging unit.

 

[gslikker]

I looked back at the many pictures I made at the time.
I think the biggests challenge for recapping was the enormous wiring mess.

The power supply board sticks through the metal, so you have to desolder and take it out, otherwise you can not recap it.

The tone board has wire posts. You also have to take off the wires of this one for a good access for recapping.
These posts are not removable since they are anchored in the circuit card, so you have to desolder the wires from the posts.
Just cutting off may give another problem which is them getting too short, as some go to the tone rotary switches...

 

[playittwice]

Thanks for taking the time to research your restoration. I knew there was a reason to leave this one for last of the amps I wanted to restore. I knew it would ensue a challenge to navigate. Even though I am a tried and true determined German, I think I will let this one to the pros as was above mentioned. I wouldn’t be as intimidated by it if it wasn’t such a nice sounding machine. Therefore I don’t want to mess it up.

Thanks for the input and advice on how to handle this amp.

 

[dr*audio]

Do one board at a time, then test. Mark the polarity on the board before removing each cap, in case the silk screen is wrong or not there.
If you think you will do this to other units in the future, just order a supply of the most common values, they are cheap:
1uF/50V
2.2uF/50V
3.3uF/50V
3.3uF/50V Non Polarized
4.7uF/50V
10uF/50V
22uF/50V
33uF/50V
33uF/50V Non Polarized
47uF/50V
100uF/50V
220uF/50V
220uF/16V Non Polarized
330uF/50V
470uF/50V
1000uF/35V
1000uF/50V
The above values will take care of most of what you will encounter. No need to make lists, just replace the electrolytics one at a time.
Just order Panasonic or Nichicon caps, 105C rating in everything but the Non Polarized, those will be 85C.

 

[gslikker]

Thanks for taking the time to research your restoration. I knew there was a reason to leave this one for last of the amps I wanted to restore. I knew it would ensue a challenge to navigate. Even though I am a tried and true determined German, I think I will let this one to the pros as was above mentioned. I wouldn’t be as intimidated by it if it wasn’t such a nice sounding machine. Therefore I don’t want to mess it up.

Thanks for the input and advice on how to handle this amp.

I am not trying to discourage you!

Best advice is: take hires pictures before doing anything from all angles possible.
Mark any wire having same or alike color as other by putting dots on it using a marker, at any board to be desoldered.
Make a picture of any loosened wire together with where it came from.

(not to forget pictures for the AK audience )

Myself, I needed my pictures.
edit: if needed to discuss something, this is how the recap went.http://members.quicknet.nl/gerard.slikker/sansui-seven.htm
Maybe I would do it a little different today.

 

[playittwice]

I am not trying to discourage you!

Your'e not discouraging me at all. In fact quite the contrary. I would rather have that info up front instead of finding out later its more than i can handle. So thanks for that. Ive done 4 other amps, so I feel somewhat confidant, I think I'll open it up again and have a look and assess the challenge level.

@dr*audio, your list makes good sense. I'll heed that advice as well.

 

[buttahman]

You can do it. I have a six and I believe it is similarly laid out to the seven. In the six the two amp boards and the phono board are socketed, you just have to remove the one shield that covers both amp boards and the separate shield that covers the phono board. Each of the amp boards has a cylinder shaped diode that is attached to the individual heatsinks, be careful with those they slide out from the back of the housing.

I had the the same experience mentioned about with the preamp board, I had to desolder one wire to be able to flip the board over.

I did the power supply differently. The FM/MPX boards are mounted to the large middle section of the chassis. You can unscrew that and gently prop up that section to get to the power supply. You may also need to remove the metal shroud that encases the dial lights to get clearance. Good luck.

 

[playittwice]

Here’s my plan of attack as far as which boards I planned on doing.
F-1535
F-1536
F-1539 x2
F-1540
F-1541

New main caps.

If anyone has a different plan of attack or additional replacements,I’m open to suggestions.

Thanks.