NAD- Marshall AVT50... and yep, I have a question about the fan

[thesamhill]

Hey all-

FIL found a Marshall AVT50 out for the trash at his condo. The speaker fabric was torn and the fan was making a really loud noise. So he spiffed it up- fixed the fabric and replaced the fan- and passed it along to me. Score!

IMO it sounds absolutely fantastic with the 335 copy plugged in. Clean and OD, bridge and neck, all of it sounds fantastic.

If anyone else has one, chime in and let me know what insights you have! So far I love it.


Just one small issue...

... yeah. The fan. It's still really loud. I'm not sure what they thought everyone was gonna do with these but apparently "hang a mic down in the front and record it" was not on the list because seriously, that's a loud fan noise.

I tried searching around and got a lot of results about how to fix a fan that was making noise because it was broken, but my question is... what are my options if the fan is working fine, but it's just too loud?

Did I just get a noisy new fan? Are there special quiet fans for these? Are there other cooling options?

Thanks for thoughts!

 

[naveed211]

I have an AVT150. I got it from my dad when he stopped playing in a church band, he warned me about the fan. At some point after a few months, the noise stopped and hasn’t come back since.

Maybe it broke...but it doesn’t seem to have a problem with overheating.

 

[edvard]

What kind of fan is it? Just a standard computer fan? If so, there are many manufacturers that make quietness their selling point, and many publish their noise figures in dbs. Marketers gonna market though, so take those with a grain of salt and read reviews.

If it's a different kind of fan, it depends. The fact that it needs a fan at all tells me maybe they scrimped on the heat sink, so get the best one you can find.

 

[Andy B]

Studio Sound Electronics has the fan you need.

 

[edvard]

Aha, I just looked up what's inside that amp, and it's the infamous TDA7293 chipamp, that claims 100W "peak musical power" but then farther down you see 50 watts at 70° C as the absolute maximum, and it's bolted to a piece of angle aluminum. NOT the best heatsink

Mind you, a fan can go a long way toward keeping an inadequate heatsink cool enough, but if it were my only amp that I had to depend on for gigs, I'd put in an actual heat sink, the biggest one that will fit with multiple fins, and I'd route a little bigger vent in the top too.

That'd probably cost more than the 2 cents I just gave, but that's the way I see it.

 

[thesamhill]

Thanks for the thoughts all-

Gonna play it for a week or two, try all the knobs and jacks and check for gremlins hiding in there.

If it seems fairly solid I'll open it up and see what I can do! It really sounds great with the 335-style so I'm hoping I can make it work.

Fun stuff! Thanks again, hopefully updates will come sometime soon.

 

[thesamhill]

Update: yeah, I like this amp! Enough to do some recording. Which means addressing the fan.

@Jakedog if you're around- you had a thread a few years ago about these and you commented:

I don't like that I can hear the internal fan at low volumes in a quiet room. You can't hear it at all in a stage situation. At home, it pretty noticeable. It's really old, though. I'm going to replace the fan and see if a new one isn't much quieter.

Did you ever do that? If so, how'd it go?

 

[Jakedog]

Update: yeah, I like this amp! Enough to do some recording. Which means addressing the fan.

@Jakedog if you're around- you had a thread a few years ago about these and you commented:



Did you ever do that? If so, how'd it go?

I did. It was much quieter. I no longer have the amp, though. I tend to switch things up a lot. I sold it when I got my DV Mark.