Bridge mode activated (Nac C370)

[Liberty Prime]

Hi there. A few months ago I sent my Nad C370 to a shop since a channel had stopped working. I finally have it home, after some hours of listening I noticed the “Bridge Mode” led indicator was on. I disconnected and checked everything, but the switch in the back panel was in the correct position. It doesn’t matter what I do, after a few minutes of listening, the indicator turns on and keeps active. There is no audible sonic effects, both channels sound fine, no clipping, noise etc., just the led on. Should I have it checked again?

Thanks

PS: Sorry for the pictures

 

[pjug]

View attachment 169402View attachment 169401


Hi there. A few months ago I sent my Nad C370 to a shop since a channel had stopped working. I finally have it home, after some hours of listening I noticed the “Bridge Mode” led indicator was on. I disconnected and checked everything, but the switch in the back panel was in the correct position. It doesn’t matter what I do, after a few minutes of listening, the indicator turns on and keeps active. There is no audible sonic effects, both channels sound fine, no clipping, noise etc., just the led on. Should I have it checked again?

Thanks

PS: Sorry for the pictures

Did you try connecting a speaker in bridged (use two + speaker A terminals on the amp), to see if you get much sound playing a mono track? I think that should tell you whether it is in bridge mode or not. If it is bridged and you want stereo, you can run one speaker with wires connected in opposite polarity to make it proper stereo (at least I think that would be OK, and you can do further checks if you care about absolute polarity).

No matter what you still have the issue of wondering why the bridge light is on when the switch is set to stereo. So I guess you need to have it checked if that bothers you, which maybe it should. Maybe start by just calling the shop to tell them about it.

 

[pjug]

Did you figure out what is going on with the amp? I have a C370 so I'm curious about what happened.

 

[Liberty Prime]

Did you figure out what is going on with the amp? I have a C370 so I'm curious about what happened.

Hi. Unfortunately I haven’t had time to talk to the technician, I’m planning to take it to the shop next week if possible. I’ve tested it with many songs I know (sounds that should be played in each channel) and everything seems fine, I mean the stereo image. In case bridge mode was indeed activated, would the stereo sound still be fine?

 

[pjug]

It might not be too obvious if one channel has the wrong polarity. You can check by playing a tone and measuring SPL at the listening position, and then connecting +/- opposite way in one speaker and measuring again. It will measure louder when the speakers both have the same polarity. Since the measurement is relative you can just use the laptop microphone to measure (can use SPL meter in REW) since the measurement is relative. Or a phone SPL app.