NAD 7080 Volume Drops

[Nick2k]

I recently bought a NAD 7080, but it has an issue.

When first powered up, the volume level seems to be fine, but after a few seconds it drops significantly, maybe around 50%. If I power it off and back on, it does the same thing.

I can't find any resources to see what may be happening, anyone familiar with this issue?

Thanks!

-Nick

 

[Binkman]

G'day.. if ya never got one.. Welcome to A.K
Didn't want to see your post go off page.. @leesonic might chime in? if others don't.
Got any experience in repairs?
Any owner history on it? orig. condition?
service manual here
https://www.hifiengine.com/manual_library/nad/7080.shtml

Any owner history on it? orig. condition?

 

[Nick2k]

G'day.. if ya never got one.. Welcome to A.K
Didn't want to see your post go off page.. @leesonic might chime in? if others don't.
Got any experience in repairs?
Any owner history on it? orig. condition?
service manual here
https://www.hifiengine.com/manual_library/nad/7080.shtml

Any owner history on it? orig. condition?

I don't know any history on it, I was able to pick it up off Facebook Marketplace for $100, so I figured it was worth the gamble.

I haven't opened it up yet, but it looks to be in all original condition, other than missing a couple of buttons. I do simple repairs, but I'm no artist with a soldering iron. Anything too complicated, and it will go to a repair shop. If it comes to that, I definitely want to give them some insight for a running start.

Thank you for the link to the service manual!

 

[Binkman]

Good that it does work. I recommend not playing anymore long term... could check inputs tuner etc.. eliminate or all functions?
I would pop the cover and take pics... more than one as close as possible, missing buttons. they're worth a thou. words; people here can see a lot right off. Generally the Nads need recaps As Nads are hens teeth in NC (love to get my hands on one) can't really comment on the low Vol. issue or if any mods required, but the the pcb's are roomy to work on.
Perhaps best to post your location if you don't have a good tech.
keep us posted us posted....as. responses might be slow with all the crap going on...

 

[Nick2k]

Good that it does work. I recommend not playing anymore long term... could check inputs tuner etc.. eliminate or all functions?
I would pop the cover and take pics... more than one as close as possible, missing buttons. they're worth a thou. words; people here can see a lot right off. Generally the Nads need recaps As Nads are hens teeth in NC (love to get my hands on one) can't really comment on the low Vol. issue or if any mods required, but the the pcb's are roomy to work on.
Perhaps best to post your location if you don't have a good tech.
keep us posted us posted....as. responses might be slow with all the crap going on...

Will do! I'm in Spokane, WA

 

[dr*audio]

Do both channels drop, or just one channel? Walk up to the speakers to be sure. I would start by cleaning all the controls. Buy Deoxit, open the unit, with power disconnected, and inject the D5 into any opening you can see in each control, then work the control back and forth 30 times.

 

[Nick2k]

Here are photos, I have de-ox’d all the knobs and switches:

 

[Nick2k]

More photos:

 

[dr*audio]

Do both channels drop, or just one channel?

 

[Binkman]

QUOTE="dr*audio, post: 14250258, member: 365"]Do both channels drop, or just one channel?[/QUOTE]

When first powered up, the volume level seems to be fine, but after a few seconds it drops significantly, maybe around 50%

I read that as speakers okay just a volume loss.
Pics...I see more than a few shrunken cap sleeves.. pcb's clean.. What cha think Doc? P.s. not holding up enough juice? cap job?

 

[notdigital]

Try this: Power it up, wait for the dropped volume condition; when it occurs, tickle the loudness button. Don't depress it fully, just depress/tap it slightly and see if volume changes. If so, it needs a real good cleaning. If not, do same with all buttons that would cut out volume , e.g. tape control, mute, etc. If this exercise does not reveal the cause, then go directly to the volume control and aggressively clean it. Since it is buried in the corner, you really have to stick your straw in there to access the 2 holes in the control for the R&L channels. And like the Dr. said: work the controll a good # of times across its full range.

And yeah, if you just picked it up, and you want to use it regularly, a re-cap is in order. That model was NAD's top of the line when released and is worthy of proper restoration.

Good luck!

 

[dr*audio]

QUOTE="dr*audio, post: 14250258, member: 365"]Do both channels drop, or just one channel?

I read that as speakers okay just a volume loss.
Pics...I see more than a few shrunken cap sleeves.. pcb's clean.. What cha think Doc? P.s. not holding up enough juice? cap job?[/QUOTE]
Power supply defect would cause distortion or early clipping, not volume loss. I am waiting for him to answer my question.

 

[Nick2k]

I read that as speakers okay just a volume loss.
Pics...I see more than a few shrunken cap sleeves.. pcb's clean.. What cha think Doc? P.s. not holding up enough juice? cap job?

Power supply defect would cause distortion or early clipping, not volume loss. I am waiting for him to answer my question.[/QUOTE]

Sorry for the slow response; Volume drops on both channels.

Also, as you suspected, audio becomes distorted at half volume, very “crackly”.

The volume drop happens when I switch the “Infrasonic” switch to “Out”. Volume jumps when I flip it to OUT, or if it is already on OUT upon power up. You will have to enlighten me to what this switch does, I am unfamiliar with it.

 

[dr*audio]

Does it work correctly with the infrasonic switch in?

 

[Nick2k]

Does it work correctly with the infrasonic switch in?

With the switch in the “In” position, the volume stays consistent (but maybe lower than it should be? I don’t have any reference to tell what the output should be)

When I flip it to “OUT” the volume jumps to almost double, then drops to the same level it was when the switch was in the “in” position.

Any thoughts on what the cost would be to have this unit refurbished? The Signal and Tuning meters also do not seem to be functioning.

Levels do the same thing if it is external speakers or headphones, for what that is worth.

Apologies in advance for repeating myself, just trying to give complete information.

 

[dr*audio]

The infrasonic switch puts a cap in series with the input to the amp, to block DC voltage and rumble from a turntable.. A DC voltage would affect the operation of the amp. There could be a problem in the preamp that causes DC to be present on the preamp output.
If you tell us your location we may be able to refer you to a tech.

 

[Nick2k]

Makes sense. I'm in Spokane, WA.

 

[Binkman]

f you tell us your location we may be able to refer you to a tech.

Perhaps best to post your location if you don't have a good tech.
keep us posted us posted....as. responses might be slow with all the crap going on...

He did.... Only caught that because I read a lot of yout posts regardless of brand.

(If we only had a data base of techs of reliable repute nationwide.... in my dreams).