Sansui AU-317 Recap

h3ll0

Active Member
This is my first recap of an amp and I'll be doing it in pieces or segments of parts as I don't have enough to buy all the parts right away.

I thought I would start off with the parts that have the most problems first.

Which are the 150 ohm fusistors and 470uf caps on the poweramp board. I used Gemcon capacitors which specs and measurements wise are comparable to the Panasonic caps everyone else uses.
20150625_2217071_zpspqoztq2m.jpg

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Unfortunately I couldn't get the glue off the PCB, I tried using nail polish remover (acetone) and a guitar pick to scrap it off, but 37 year old glue is strong. I also found what looked like blood is actually burnt or corroded glue, I managed to get that off at least. :D

If anyone has any idea what to use to take the glue off, please tell me.

Does anyone also know of a drop in Cap replacement for the two large 4 pin caps? Because the Panasonic model everyone recommends no longer exists.

I've just ordered Nichicon KZ Muse series caps for the 220uF,100uf, 100uF bipolar, and 330uF caps on the power amp board, turned out to be cheaper than buying the Gemcon caps locally.

I'd also like to endorse the Weller SP25 soldering iron for working on electronics. After trying multiple third party brands from princess auto and a few mastercraft irons, I found the tips to be disintegrating after only a few uses. I've used this Weller one for this amp and two turntables and the tip hasn't worn at all also the rubber handle and really useful LED's are a nice touch. Not to mention the plethora of tips available for $6-$8.
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Looks like your having a good time. I like the leds on your iron. Is that a pencil tip your using?


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Looks like your having a good time. I like the leds on your iron. Is that a pencil tip your using?


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I am having a good time! I thought soldering would be hard but this amp is so easy to work on and soldering right is SUPER easy.

I am using a pencil tip, although I prefer chisel tips, I'd rather spend that $6 on caps. :D
 
I understand...caps although mostly inexpensive can add up over time. I tallied up all of my mouser orders I placed this year and the total was kind of high lol. But I'm also enjoying the hobby so I don't mind, my wife on the other hand... I'll be following along your progress.


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* When a check or money order accompanies your order, Digi-Key pays all shipping and insurance (our choice for method of shipping) to all addresses in the U.S. and Canada."
Thanks for that Roger!

I just ordered some Nichicon MUSE KZ series for 5% more for than local Chinese caps at Partsconnexion with free shipping. I'll probably buy Nichicon KZ caps for all the signal caps from PcX because they are cheaper than Digikey or Mouser. People seem to like MUSE series caps for audio.

I think I'll get the big PSU caps at Digikey though as I can't find them on Mouser or Partsconnextion.
 
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Thanks for that Roger!

I just ordered some Nichicon MUSE KZ series for 5% more for than local Chinese caps at Partsconnexion with free shipping. I'll probably buy Nichicon KZ caps for all the signal caps from PcX because they are cheaper than Digikey or Mouser. People seem to like MUSE series caps for audio.

I think I'll get the big PSU caps at Digikey though as I can't find them on Mouser or Partsconnextion.


One thing: hope you got the bipolar MUSE green caps, not KZ for the bipolar caps. And if I read the filter caps right, are t these what you're looking for?
http://www.mouser.com/Search/m_Prod...=sGAEpiMZZMtZ1n0r9vR22UlxzFezKzzdRDVPRSXfwxs=
I have used these exact ones in the past.
Maybe you need 30mm diameter caps?
 
One thing: hope you got the bipolar MUSE green caps, not KZ for the bipolar caps. And if I read the filter caps right, are t these what you're looking for?
http://www.mouser.com/Search/m_Prod...=sGAEpiMZZMtZ1n0r9vR22UlxzFezKzzdRDVPRSXfwxs=
I have used these exact ones in the past.
Maybe you need 30mm diameter caps?
Yes I ordered the green MUSE ES series Cap for the bipolar 100uF.

http://www.digikey.ca/product-detail/en/ECE-T1JA123EA/P10636-ND/272776

That is the cap everyone uses for their AU-317 PS caps yet Panasonic doent make them anymore. Also they are unique because they have 4 leads not 2. Can I use the 2 lead ones in my amp?
 
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I didn't end up orderingl the MUSE caps because the shipping quote at checkout said $0 but when I got the sales quote via email it said $11.50 in s&h.:thumbsdn:

How do I connect two 1N4148 transistors in series to replace the VD1212 transistors? Do I just put two of them side by side in one hole?

roger2, how do I get the free shipping at Digikey? Do I get a forum and send a paper order via mail with a cheque?
 
You put the diodes in the same direction, one after another.

Good eyes and worthy of a bump. They look orig. to me with the isolation over the lead? but then some restorers do that. (pretty rare though)

Just bumping it as the pic shows that fact and type of diodes. Q? I'm wondering if I see these should I replace? as in reliable certainty in the p.s.
 
Good eyes and worthy of a bump. They look orig. to me with the isolation over the lead? but then some restorers do that. (pretty rare though)

Just bumping it as the pic shows that fact and type of diodes. Q? I'm wondering if I see these should I replace? as in reliable certainty in the p.s.
If you are talking about the pic at the top of the thread those are the original VD1212's I'm going to replace those tonight.

I have seen other posters in various AU-317 threads 95% of the time recommend to replace VD1212 transistors with two 1N4148 in series.
 
So I replaced every electrolytic Cap other than the two huge PS one and the bi polars, because my local electronics store didn't have them in stock.

I replace the VD 1212 diodes with two 1N4148 in series. Couldn't any other rectifiers or zener diodes locally.

I will get all remaining parts on Digikey thanks to Roger.:tresbon:

Replaced all fusistors.

Cleaned the old thermal past off the heatsink and applied new silicon goop.

The soldering went well except for 3 pulled pads so I had to bridge them to the next component in the trace.


Turned it on.

and...... two sparks on the power amp board.... the 125V 7A fuses blew.

So I checked everything and realised I put the san-kai transistors in the wrong places on the heatsink. So I put them in the right place.

I will get new fuses tommorow and try again. If it blows again I need some help.
 
...2) The best way, IMHO, to search AK is to go to Google Advanced Search and type "audiokarma.org" into the box labeled "site or domain". Of course you also have to type in your search term. Here is a screen shot, what I typed in is circled in red. This search will give you lots of AK hits for DBT (or anything else you need to find on AK).

You can do this without going to Advanced. In the Google search bar, put this: DBT site:audiokarma.org

h3ll0, looking forward to seeing your progress on this amp. I'm still trying to find the gumption (and time) to start practicing.
 
DBT is the acronym for Dim Bulb Tester. It is a DIY device that places a typical incandescent light bulb in series with the AC power to an amp. It is used for testing purposes with an unknown amp or after work has been done. The purpose of a DBT is to protect output transistors (and other components).

A couple quick thoughts, if I may...

1) It is not wise to do large amounts of work without testing. Too many things can go wrong, and when they do it makes troubleshooting much more difficult if it is necessary to backtrack over lots of changes. Just do small amounts of work, change only a few components, then test.

2) The best way, IMHO, to search AK is to go to Google Advanced Search and type "audiokarma.org" into the box labeled "site or domain". Of course you also have to type in your search term. Here is a screen shot, what I typed in is circled in red. This search will give you lots of AK hits for DBT (or anything else you need to find on AK).

I tried the amp with just the power amp board recapped and it worked fine, however after I recapped the head amp board and tone control board and cleaned up the power transistors then the fuses blew, so I'm guessing it was because I had the transistors in the wrong spots. Hope the transistors are OK.:sigh:

I checked all caps, diodes, and resistors replaced and made sure the polarity was correct and it all checked out. I will replace the fuses and get a dim bulb tester. Hopefully it will all work out.

Thanks for everyone's help.
 
So the only fuses I can get locally are 7A 250V. Will this work for the 7A 125V slots?
 
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