Left channel on amp occasionally cuts out.

[seanyc5]

Hi all,

I have a NAD 3130 - Had it about 8 years at a guess. £60 from eBay love it.

Its got to be 30 years old I would imagine.

Any ideas what would cause this? It's not very often and normally comes back after a couple of seconds.

Also hard to try and rule out cables/source/speaker as it is very intermittent and I have a broken leg haha so can not be messing around like that.

Speakers and cables are about 4 years old Dali Zensor 1 and decent cables so doubt they are at fault.

 

[MissChief]

Change the wires over from left to right for a short while. If right channel starts cutting out, it's the amp. If the left still cuts out it's the cable/speaker. Easy, no?

 

[Kei]

The most common problem on these seems to be dirty contacts on switches and potentiometers. They would require cleaning with a suitable contact cleaner like kontakt 60, servisol super 10, deoxit D5 or electrolube eml. These are just aerosols that get sprayed into the switch or pot. There are plenty of video guides on how to do this, mainly on guitar amps. The usual giveaway is some slight noise from the speaker when using any of the controls. There are also controls on the back to check.

It’s also not unknown to see dodgy solder joints on these too, but the switches/pots are the more likely candidate.

 

[seanyc5]

Change the wires over from left to right for a short while. If right channel starts cutting out, it's the amp. If the left still cuts out it's the cable/speaker. Easy, no?

Yeah, when you have 4 working limbs! Not so easy to do get to the speaker wires to swap with a broken leg!

The most common problem on these seems to be dirty contacts on switches and potentiometers. They would require cleaning with a suitable contact cleaner like kontakt 60, servisol super 10, deoxit D5 or electrolube eml. These are just aerosols that get sprayed into the switch or pot. There are plenty of video guides on how to do this, mainly on guitar amps. The usual giveaway is some slight noise from the speaker when using any of the controls. There are also controls on the back to check.

It’s also not unknown to see dodgy solder joints on these too, but the switches/pots are the more likely candidate.

Thanks, I shall watch a few videos and get a can. The tone controls are all at zero. I can't really look because of my leg but do not recall have controls on the rear?

 

[Kei]

Thanks, I shall watch a few videos and get a can. The tone controls are all at zero. I can't really look because of my leg but do not recall have controls on the rear?

There are three switches on the rear panel. 4/8 ohm selector switch, soft clipping switch and the phono MM/MC selector.

In principal, giving the pots and switches a tap/wiggle may help pin point which one, if any, it is. If none of them seem to trigger it, it could well be a different issue.

 

[seanyc5]

There are three switches on the rear panel. 4/8 ohm selector switch, soft clipping switch and the phono MM/MC selector.

In principal, giving the pots and switches a tap/wiggle may help pin point which one, if any, it is. If none of them seem to trigger it, it could well be a different issue.

Ah yeah forgot about those! Although I have never touched them since having it. I just about managed to play with the from pots/switches. I got a bit of crackle in the left side when messing the balance - so I shall defo get a can of contact cleaner and clean it all out. Avoid those nasty caps!

I assume you have had one in the past or worked on one? What are you general thoughts? Would a modern day amp say around £400 blow it out of the water?

I would never sell it just curious. From my knowledge its the speakers that make all the difference as long as the amp is decent and can drive them.

 

[Kei]

I've never had or worked on a NAD amp. They are certainly well regarded and well designed. I mostly have vintage British kit which is where the maintenance knowledge has come from. Plus I love doing a bit of DIY electronics. (Building my own valve based power amps during the lockdown)

Difficult to say if a modern amp would better the NAD. In good working order, I reckon the NAD is still a fine bit of kit.

 

[C64]

check for leaky / bulged capacitors

 

[seanyc5]

Well, my cast comes of tomorrow so I should be able to give it a clean/ check the caps etc. I shall have to order to some contact cleaner - that deoxit d5 seems to be the best but is also £30 a can! That's half of what I paid for the amp haha.

I'm sure the cheaper ones will do me just fine - anything is better than nothing. I have not touched it since I have had it.

Never even entered my head to clean it out. I wonder if it has ever been done since new?!?! It looks mint from the outside still.

Thanks

 

[seanyc5]

The most common problem on these seems to be dirty contacts on switches and potentiometers. They would require cleaning with a suitable contact cleaner like kontakt 60, servisol super 10, deoxit D5 or electrolube eml. These are just aerosols that get sprayed into the switch or pot. There are plenty of video guides on how to do this, mainly on guitar amps. The usual giveaway is some slight noise from the speaker when using any of the controls. There are also controls on the back to check.

It’s also not unknown to see dodgy solder joints on these too, but the switches/pots are the more likely candidate.

Hi Kei,

I ordered a can of Serisol Super 10. Was going to go for the de-oxit but I only paid £60 for amp and that was £30 a can lol.

Anyway, sprayed a **** load in all the pots/switches and cleaned all the PCBs down. All the caps look decent as far as I could see.

Bit of surface rust on the top of the power supply but only a bit.

Had it plugged back in for a hours and its been mint, not dropped or crackle once. It was probs ever 15mins or so before. So seems to have sorted it.

Thanks a lot,
Sean

 

[C64]

leaky or burst capacitors is normally what goes first and they need to be replaced luckily it's very easy as the boards tend to be big