NAD 3155 Relay replacement

[pwauk12]

The NAD 3155 uses the Fujitsu 323D024 relay for the speakers, which is long discontinued. It has 6 connections, four pins close together and 2 pins at about the mid point of the relay. The mid point ones are the speaker outputs, the next set along (not the set at the edge of the relay) are the coil (24v) and the set at the edge of the relay are the inputs from the power amp.

A good replacement is the OMRON G2R-2A-ASI-DC24 (mouser 653-G2R-2A-ASI-DC24), which can be mounted in the subframe of the NAD and secured with a cable tie. The connections to the OMRON are pins 1 and 8 are the coil (there is no coil polarity), pins 3&6 are input and 4&5 are output to the speakers.

I have attached a couple of photos of the installation for reference and to assist others, as when I searched I could not find this information.

Peter
www.quirkaudio.com

 

[jhjove]

I'll keep this bookmarked for my 3155.

But just wonder if it would be possible to keep the original relay, hack the base and attach the new relay?
Not sure if this would create a height restriction.

 

[pwauk12]

I though of drilling holes in the PCB, but when I looked it seemed more convenient to mount close by. I also considered putting hard wiring from the original relay holes, but the organization of the relay connections made me think this was not as practical as the solution I took. The footprint of the old relay is quite a bit small then the new one, and a different shape.

 

[leesonic]

I'll keep this bookmarked for my 3155.

But just wonder if it would be possible to keep the original relay, hack the base and attach the new relay?
Not sure if this would create a height restriction.

Maybe you can make an "adaptor", similar to what I did for a Sansui AU-D5?

https://www.audiokarma.org/forums/i...p-us-relay-drop-in-replacement-almost.505276/

Lee.

 

[regore]

It looks like a standard TV-5 relay found in many TV sets from the eighty's particularly Magnavox and Sylvania. They were available in 12 or 24 volt varieties. The cover will be stamped TV-5 12 or 24 volt.

 

[39cross]

A good replacement is the OMRON G2R-2A-ASI-DC24 (mouser 653-G2R-2A-ASI-DC24), which can be mounted in the subframe of the NAD and secured with a cable tie. The connections to the OMRON are pins 1 and 8 are the coil (there is no coil polarity), pins 3&4 are input and 4&5 are output to the speakers.

This is really great information, I have a 3155 and have been waiting to replace the relay. I realize this post is about 18 months ago, but I wonder if you meant to write that the OMRON input pins are 3 & 6. These look like the black and red wires.
Also I was wondering about the speaker output wires from pins 4&5. I see these wires are running off behind the relay. Were these originally soldered to the main board next to the relay?

 

[pwauk12]

Hi- yes 3 and 6 are input and 4 and 5 are output. The speaker wires were originally soldered to the PCB and have been desoldered and attached to the new relay. When you look at the PCB and compare to the circuit, the connections are obvious
original post now corrected

hope this helps

Peter

 

[39cross]

Thanks Peter! I'm glad you saw the post and were able to answer my questions. I'm going to get my order in this week and try it out. I have a DC pop at power off, just a split second before the relay kicks in. I tried everything else I can think of, I'm hoping maybe a new relay will fix that.

 

[kanurys]

Thanks for posting this! I'm doing the mod, now. The old relay is causing problems. While I'm in there I'll replaced the main power caps with https://www.mouser.com/ProductDetail/647-LLS1H103MELB which snap in and are slightly shorter than the originals. One could put a larger value cap in, but with this amp it seems 10000 uF is fine.

Excellent documentation, thank you, again.