• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

AU 717 Protection Relay are there better choices?

Hyperion said:
These are obsolete, and the contact current rating is poor at only 2A.

Nice try though. ;)
Click to expand...
Ugh! Thanks for the clarification Hyperion. There are so many things to consider in these substitutions. I did the math on 85W and realized just how much current these amps can drive. Seeing all the challenges finding replacements, I'm never going to throw one of these away, just in case I need it some day.

To further the discussion from Tom B for cleaning the contacts, I like to use the white drafting erasers (https://www.amazon.com/STAEDTLER-Plastic-Latex-free-Age-resistant-Crumbling/dp/B00006IFAN?th=1). I cut a thin slice that will just fit between the contacts, spray it with a little contact cleaner and run it between the contacts. It's easy to see the grime on the white. I've never tried it on a new relay, but may start cleaning them before installation as a precaution.
 
For giggles I re-flowed the solder pads for the relay. Played for 3 min and right channel went out. Tap on relay comes back.
Next, will try to remove relay cover and clean contacts.
The Omron relay seems to be the best, contacts rated @ 5A.
 
Checked resistance at terminals 28/30 on F2663, with amp on resistance was 15 ohms. Tap on relay and it was all over the place Checked opposite channel (27/29) and this was 1.5 ohms steady.
Removed relay and with finger pressure on relay arm it would sometimes go open. Tried running paper under contacts,and noticed hardly any drag on the bad set of contacts. Bent the non moving contact arm slightly for more pressure, and cleaned contacts with deoxit and paper. Finally got the resistance on both sets to read 1.2, which is the resistance of the test leads.
Installed relay and double checked at terminals, all good.
So it was the relay the whole time.
Next project the relay will be checked before install!

spk relay.jpg
 
If I'm reading this thread correctly, and others that I have found in the Sansui forum, the Omron MY4-02-DC24 is a direct replacement for the speaker relay in AU-717. It's even stated above that it is a drop in replacement.
So I just received a new Omron MY4-02-DC24 relay from Mouser and it is not a drop in replacement.

Did I order the wrong relay?

From above, if this was going in a AU-517 it is stated that I would have to trim contact pins 2 & 3. But what I have in my hands right now, I would have to trim those pins to make it fit in the 717.

Do I need to order the MY2-02-DC24? What gives. I already have problems with this amp from another thread, I don't need to add to my issues by installing the wrong relay and having to modify it as well.
The original relay that I removed was a Tairo RABK-4B.

DJ
 
Can you answer your question by opening the datasheets? If I wasn’t on my phone I’d take a look myself, but in my experience it’s often better to verify yourself than try to build consensus from a forum (unless you it’s leestereo or another guru).

Edit: I checked my records and I used MY2-02-DC24 on all three of my AU-717 projects with no pin cutting required. But I believe the one you ordered may have been recommended in the past because of part shortages. Again, if you look at the datasheets it should be possible to verify that the part you have (with two pins removed) is functionally equivalent to the ‘drop in’ replacement.
 
I used the MY2-02-dc24 without cutting any pins.
I have cut pins on other amps when the correct relay was not available. Just compare data sheets.
 
A MY2-02 type relay can be installed on the F-2663 board without modification; to install a MY4-02 type relay on the F-2663 board, 2 pins in the center of the front row need to be trimmed since the board is not drilled to accommodate them.

F-2663 relay.jpg

F-2663 relay solder side restored.jpg
 
Thanks for the quick reply's.

I guess my question now, does it make any difference which relay I go with other than trimming the MY4-02 to make it fit?
 
The MY4 relay has 2 pairs of contacts for each channel (much better) instead of one pair. ;) (the MY2 relay has 1 pair of contacts per channel).

The AU-717 board is drilled for 2 pairs of contacts - whereas the AU-517 can use either MYx relay providing the appropriate pins are cut off - thus the AU-517 is only using one pair of contacts per channel.

BTW: Regarding cutting pins off a relay - measure twice - cut once.

This post has been edited to remove any incorrect or confusing information.
 
Last edited:
Hyperion said:
If you don't cut the pins off (and drill the board instead?), you will have 2 pairs of contacts (much better) for each channel instead of one pair. ;)...
Click to expand...

This would defeat the purpose of a relay since the amplifier output would be available through the center pins whether the relay is closed or open!

Hyperion said:
Actually, I was under the impression that the AU-717 board was drilled for 2 pairs of contacts...
Click to expand...
This is correct, there are 2 relay contacts per channel on the AU-717's F-2663 board.
 
Leestereo said:
This would defeat the purpose of a relay since the amplifier output would be available through the center pins whether the relay is closed or open!
Click to expand...
Maybe I was getting slightly confused about which contacts were to be cut off, or not - obviously it is the two inner NC (normally closed) contacts - as you say.
 
Last edited:
Hyperion said:
The MY4 relay has 2 pairs of contacts for each channel (much better) instead of one pair. ;) (the MY2 relay has 1 pair of contacts per channel).

The AU-717 board is drilled for 2 pairs of contacts - whereas the AU-517 can use either MYx relay providing the appropriate pins are cut off - thus the AU-517 is only using one pair of contacts per channel.

BTW: Regarding cutting pins off a relay - measure twice - cut once.

This post has been edited to remove any incorrect or confusing information.
Click to expand...

i have sansui au 517,, i want put back relay to board ,, what kind type relay for this amp ?
 
The relay terminal pins on the MY2-GS-24VDC are not for direct PCB board installation; they are used with "plug-in" relay sockets.
 
Leestereo said:
The relay terminal pins on the MY2-GS-24VDC are not for direct PCB board installation; they are used with "plug-in" relay sockets.
Click to expand...
Specifications
Transparent case
With mechanical indicator
Mounting method With plug-in socket
Usage General purpose
Poles 2
Rated carry current 7 A
Coil voltage 24 V
Operation voltage DC
Contact material Ag
Contact description DPDT
Terminal Plug-in, Solder

I read the above bolded description as either/or - but looking further into the data sheet, it does seem like you are correct.

 
You must log in or register to reply here.
Back
Top Bottom